Working machine

Abstract

A working machine includes a machine body, a device mount to replaceably attach a working device thereto, the working device including a transmitter to transmit a unique identifying signal and being operable to perform a function corresponding to work, and a controller configured or programmed to control the machine body. The machine body includes receivers to receive the identifying signal from the transmitter. The receivers are located at respective at least two positions separated from the device mount by different distances. The controller is configured or programmed to recognize the working device attached to or to be attached to the device mount based on a received signal strength of the identifying signal received by at least one of the receivers that is located at at least one of the at least two positions.

Description

BACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to working machines each including a device mount to replaceably attach thereto a working device to perform predetermined work.2. Description of the Related Art

[0002] Working machines such as compact track loaders, skid-steer loaders, and agricultural tractors each include a device mount to replaceably (detachably) attach thereto a working device to perform a function corresponding to work. Such a working machine is configured to be able to control the working device attached to the device mount, and replacing the working devices allows work corresponding to the purpose to be performed. That is, such a working machine includes a manual operator to be operated by a user, and a controller to control the working device based on how the manual operator is operated.

[0003] Since the working device performs the function corresponding to work, the operation (action) of the working device varies depending on the type of the working device. Accordingly, the working machine needs to recognize the working device that the controller controls. That is, in order to perform control corresponding to the type of working device, the working machine needs to recognize the working device attached to the device mount.

[0004] In view of this, there is provided a working machine in which a controller communicates with a working device in a wired manner to recognize the working device attached to the device mount (see, for example, Japanese Unexamined Patent Application Publication No. 2021-182887).SUMMARY OF THE INVENTION

[0005] The working machine which communicates with working device(s) in a wired manner needs to be connected to the working device by a cable (signal wire), and therefore there has recently been an increasing number of working machines to communicate with a transmitter (tag) attached to the working device in a wireless manner to automatically recognize the working device attached to the device mount. Such a working machine receives a unique identifying signal which is specific to each type of working device and which is transmitted from a transmitter, and recognizes the working device based on the identifying signal.

[0006] However, such working machines recognize the working device based only on the content of the received identifying signal, and therefore the reliability of the recognition of the working device is low, that is, the recognized working device may differ from the working device actually attached to the device mount. That is, such working machines may receive all identifying signals transmitted from the working devices (transmitters) present in the covered area (range) and recognizes that the working device corresponding to the content of the identifying signals is the working device attached to the device mount, and therefore the working machine may accidentally recognize that a working device other than the working device actually attached to the device mount is the working device attached to the device mount.

[0007] Example embodiments of the present invention provide working machines each of which is able to appropriately recognize a working device to be attached to the device mount.

[0008] A working machine according to an example embodiment of the present invention includes a machine body, a device mount to replaceably attach a working device thereto, the working device including a transmitter to transmit a unique identifying signal and being operable to perform a function corresponding to work, and a controller configured or programmed to control the machine body, wherein the machine body includes receivers to receive the identifying signal from the transmitter, the receivers are located at respective at least two positions separated from the device mount by different distances, and the controller is configured or programmed to recognize the working device attached to or to be attached to the device mount based on a received signal strength of the identifying signal received by at least one of the receivers that is located at at least one of the at least two positions.

[0009] The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at the at least two positions at increasing distances from the device mount in the front-rear direction of the machine body.

[0010] The receivers may be located at respective at least three different positions which include the at least two positions separated from the device mount by different distances. The controller may be configured or programmed to determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least three positions, based on a combination of levels of received signal strengths at the receivers at the at least three positions.

[0011] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions one of which is in an area between the device mount and the cabin in the front-rear direction and the other of which is within the cabin. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength of the identifying signal received by one of the receivers that is in the area between the device mount and the cabin is equal to or greater than a preset threshold and a received signal strength at the other of the receivers that is within the cabin is within a predetermined range.

[0012] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions one of which is forward of a center of the cabin in the front-rear direction and the other of which is rearward of the center. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

[0013] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at at least four positions including positions at a front and a rear of the cabin in the front-rear direction and on opposite sides of the cabin in a lateral direction perpendicular to the front-rear direction. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the cabin is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0014] The machine body may include a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions forward of and rearward of the seat in the front-rear direction. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

[0015] The machine body may include a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at at least four positions including positions forward of and rearward of the seat in the front-rear direction and on opposite sides of the seat in a lateral direction perpendicular to the front-rear direction. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located forward of and / or rearward of the seat is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0016] The receivers may be located at at least four positions including positions at a front and a rear of the machine body in a front-rear direction and on opposite sides of the machine body in a lateral direction perpendicular to the front-rear direction. The device mount may be located at at least one of (i) in front of one of the receivers that is at the front of the machine body or (ii) rearward of another of the receivers that is at the rear of the machine body. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the machine body is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0017] The receivers at the at least two positions may include respective directional antennas to receive identifying signals from a particular direction, and are each positioned such that an orientation in which the receiver receives the identifying signals is directed toward the device mount.

[0018] The receivers at the at least two positions may include respective directional antennas to receive identifying signals from a particular direction. A first receiver of the receivers at the at least two positions that is closest to the device mount may be positioned such that an orientation in which the first receiver receives the identifying signals is directed toward the device mount. One or more second receivers of the receivers that are distant from the device mount may each be positioned such that the orientation in which the second receiver receives the identifying signal is directed in a different direction from a direction toward a side where the device mount is present.

[0019] The one or more second receivers that are distant from the device mount may each be positioned such that the orientation in which the second receiver receives the identifying signals is directed in a direction away from the device mount.

[0020] The working machine may further include a cover to cover each of one or more of the receivers at the at least two positions that are farther from the device mount than the other one or more of the receivers, the cover being positioned to block the identifying signal. The cover may include an opening which faces in a direction different from a direction toward a side where the device mount is present.

[0021] The opening may face away from the device mount.

[0022] The controller may be configured or programmed to, after recognizing the working device to be attached to the device mount based on one or more received signal strengths of the identifying signal received by the receivers at the at least two positions, when the receivers at the at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device is attached to the device mount.

[0023] The working machine may further include a support structure supported by the machine body to support the device mount to allow the device mount to move along a predetermined path, and an actuator to cause the device mount to move along the path. The controller may be configured or programmed to directly or indirectly recognize a load on the actuator and determine whether the working device is attached to or detached from the device mount.

[0024] The device mount may include a linkage to connect the working device thereto. The linkage may include an engagement portion movable between an engaging position in which the engagement portion engages with the working device to connect the working device thereto and a disengaging position in which the engagement portion disengages from the working device to disconnect the working device therefrom. The controller may be configured or programmed to determine that the working device is attached to the device mount when the engagement portion is in the engaging position.

[0025] The working machine may further include receivers each including an assembly of an antenna which is one of the receivers and a receiver main body to receive the identifying signal from the antenna. The receivers may be located at the respective at least two positions, and connected to the controller such that the identifying signal is transmittable to the controller.

[0026] The receivers may include antennas. The working machine may include a receiver including a receiver main body to receive the identifying signal from the antennas, input interfaces to connect thereto the antennas at the at least two positions, and an output interface to output to the controller the identifying signal inputted into the input interfaces.

[0027] The working machine may further include a monitor. The controller may be configured or programmed to determine a location of the working device which includes the transmitter transmitting the identifying signal based on the identifying signal received by one or more of the receivers and based on one or more received signal strengths of the identifying signal, and cause the monitor to display the determined location of the working device.

[0028] In such a case, the monitor may be operable to display pieces of device information corresponding to a plurality of the working devices and to allow a selection of one of the pieces of device information. The controller may be configured or programmed to, based on the identifying signal from the transmitter of a corresponding one of the plurality of working devices that corresponds to the selected piece of device information selected on the monitor and based on the one or more received signal strengths of the identifying signal, determine a location of the corresponding one of the plurality of working devices that includes the transmitter transmitting the identifying signal.

[0029] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete appreciation of example embodiments of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings described below.

[0031] FIG. 1 is a perspective view of a working machine (compact track loader) according to a first example embodiment of the present invention.

[0032] FIG. 2 is a perspective view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a working device is detached from a device mount.

[0033] FIG. 3 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0034] FIG. 4 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a pallet fork as a working device is attached to a device mount.

[0035] FIG. 5 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a snow pusher as a working device is attached to a device mount.

[0036] FIG. 6 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a grapple as a working device is attached to a device mount.

[0037] FIG. 7 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a sweeper as a working device is attached to a device mount.

[0038] FIG. 8 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which an angle broom as a working device is attached to a device mount.

[0039] FIG. 9 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a snow blower as a working device is attached to a device mount.

[0040] FIG. 10 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a trencher as a working device is attached to a device mount.

[0041] FIG. 11 is a back view schematically illustrating a linkage of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0042] FIG. 12 is a side view schematically illustrating a linkage of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0043] FIG. 13 is a block diagram schematically illustrating a controller of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0044] FIG. 14 schematically illustrates a device list to be displayed on a monitor, stored in a controller (storing unit) of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0045] FIG. 15 is a conceptual view of information relating to working devices stored in a controller (storing unit) of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0046] FIG. 16 is a flowchart of a process performed when a working device is attached to a device mount of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0047] FIG. 17 is a perspective view of a working machine (compact track loader) according to a second example embodiment of the present invention, in which a working device is detached from a device mount.

[0048] FIG. 18 is a left side view of a working machine (compact track loader) according to the second example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0049] FIG. 19 is a flowchart of a process performed when a working device is attached to a device mount of a working machine (compact track loader) according to the second example embodiment of the present invention.

[0050] FIG. 20 is a perspective view of a working machine (compact track loader) according to a third example embodiment of the present invention, in which a working device is detached from a device mount.

[0051] FIG. 21 is a right side view of a working machine (compact track loader) according to the third example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0052] FIG. 22 is a perspective view of a working machine (agricultural tractor) according to a fourth example embodiment of the present invention.

[0053] FIG. 23 is a left side view of a working machine (agricultural tractor) according to the fourth example embodiment of the present invention.

[0054] FIG. 24 is a plan view of a working machine (agricultural tractor without cabin) according to a fifth example embodiment of the present invention.

[0055] FIG. 25 is a left side view of a working machine (agricultural tractor without cabin) according to the fifth example embodiment of the present invention.

[0056] FIG. 26 is a left side view of a working machine (compact track loader) according to another example embodiment of the present invention.

[0057] FIG. 27 is a left side view of a working machine (agricultural tractor) according to another example embodiment of the present invention.

[0058] FIG. 28 is a perspective view of a working machine (compact track loader) according to a further example embodiment of the present invention, in which a working device is detached from a device mount.

[0059] FIG. 29 is a perspective view of a working machine (compact track loader) according to a further example embodiment of the present invention, in which a working device is detached from a device mount.

[0060] FIG. 30 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0061] FIG. 31 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0062] FIG. 32 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0063] FIG. 33 is a plan view schematically illustrating a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0064] FIG. 34 is a plan view schematically illustrating a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0065] FIG. 35 is a block diagram illustrating a receiver of a working machine according to a further example embodiment of the present invention.

[0066] FIG. 36 is an enlarged view of a main portion including a receiver of a working machine according to a further example embodiment of the present invention.

[0067] FIG. 37 is a cross-sectional view taken along line A-A in FIG. 36.

[0068] FIG. 38 is a left side view of a variation of a working machine (compact track loader) according to the third example embodiment of the present invention.

[0069] FIG. 39 is a left side view of a variation of a working machine (agricultural tractor) according to a fifth example embodiment of the present invention.

[0070] FIG. 40 is a left side view of another variation of a working machine (agricultural tractor) according to the fifth example embodiment of the present invention.

[0071] FIG. 41 illustrates content displayed on a monitor of a working machine according to a further example embodiment of the present invention.

[0072] FIG. 42 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0073] FIG. 43 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 42.

[0074] FIG. 44 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0075] FIG. 45 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 44.

[0076] FIG. 46 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0077] FIG. 47 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 46.

[0078] FIG. 48 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0079] FIG. 49 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 48.

[0080] FIG. 50 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0081] FIG. 51 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 50, which is another way of displaying content when the working machine and the working device are in a particular positional relationship.

[0082] FIG. 52 illustrates another way in which the monitor displays content when the working machine and the working device are in a particular positional relationship.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0083] Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.First Example Embodiment

[0084] The following description discusses a working machine according to a first example embodiment of the present invention with reference to drawings. Note that, assuming that the working machine is able to travel, the direction of straight travel (direction of forward travel or rearward travel) is hereinafter referred to as a front-rear direction, a direction perpendicular to the front-rear direction and an up-down direction is hereinafter referred to as a lateral direction. One of such lateral directions that is on the right side when the user faces forward is hereinafter referred to as a rightward direction (right), and the other of the lateral directions that is on the left side when the user faces forward is hereinafter referred to as a leftward direction (left).

[0085] A working machine 1 according to the first example embodiment is a compact track loader for use in construction work, civil engineering work or the like, as illustrated in FIGS. 1 to 10. The working machine 1 includes a machine body 2. The working machine 1 includes traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes a device mount 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work (see FIGS. 1 and 2). That is, the working machine 1 includes a device mount 40 to attach thereto each of a plurality of types of working devices 9 independently.

[0086] In the first example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61, 62 (operational actuator(s) 61, 62) to cause the device mount 40 to move along the path (see FIGS. 3 to 10). The working machine 1 includes an actuator 60 (travel actuator 60) to drive the traveling devices 3. The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0087] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a manual operator 11 to be operated by the user to perform operations relating to travel of the traveling devices 3 (which may be hereinafter referred to as a first manual operator). The working machine 1 includes a manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path (which may be hereinafter referred to as a second manual operator).

[0088] The first manual operator 11 includes a pivotable operating lever. The direction of pivoting of the operating lever corresponds to the direction of travel of the traveling devices 3, and the degree to which the operating lever is pivoted corresponds to the travel speed of the traveling devices 3. The second manual operator 12 includes a pivotable operating lever. Changing the direction of pivoting of the operating lever controls the upward / downward movement of arms 43 and the pivoting (rotation) of the device mount 40 (working device 9), and changing the degree to which the operating lever is pivoted controls the speed of the upward / downward movement of the arms 43, i.e., the speed at which the device mount 40 is raised or lowered and the speed of pivoting of the device mount 40 (working device 9).

[0089] The machine body 2 include a frame chassis 20, a seat 21 provided on the frame chassis 20, and a seat protection structure 22 to protect the seat 21. The machine body 2 includes a first receiver 150a and a second receiver 150b to receive identifying signals from transmitters T (described later).

[0090] The frame chassis 20 is made of sheet metal, has in a three-dimensional shape corresponding the shape and size of the working machine 1, and defines, at a rear portion in the front-rear direction, a prime mover room MR to house a prime mover 10 to directly or indirectly drive the actuators 60, 61, 62. Note that, in the first example embodiment, the actuators 60, 61, 62 each include a hydraulic actuator. Accordingly, the working machine 1 includes a hydraulic system 6 including hydraulic pump(s) to deliver hydraulic fluid to the actuators 60, 61, 62, and control valve(s) to control the flow of hydraulic fluid. The hydraulic system 6 (hydraulic pump(s)) is driven by the prime mover 10, and the hydraulic system 6 (control valve(s)) is controlled by the controller. Accordingly, the hydraulic system 6 and the prime mover 10 are housed in the prime mover room MR. The prime mover 10 in the first example embodiment is an internal combustion engine (diesel engine), but may be an electric motor.

[0091] The seat 21 is located forward of the prime mover room MR (prime mover 10) and is fixed to the frame chassis 20. In the first example embodiment, the seat protection structure 22 is a cabin to surround the seat 21. Since the seat 21 is located forward of the prime mover room MR as described above, the cabin 22 (seat protection structure 22) is also located forward of the prime mover room MR. That is, the cabin 22 defines, at a location forward of the prime mover room MR, an operator cab OR in which the user seated in the seat 21 stays. Note that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12), and the like are provided within the cabin 22 (operator cab OR) such that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12) and the like can be operated by the user.

[0092] The cabin 22 includes front, rear, left and right windows. With regard to this type of working machine 1, the front window of the cabin 22 is openable and closable. This allows the user to enter and exit the operator cab OR through the front portion of the cabin 22. The left and right windows each have a protective lattice attached thereto. Note that, in FIGS. 1 and 3 to 10, a portion of the lattice is not illustrated for illustration of a portion of the interior of the operator cab OR.

[0093] The first manual operator 11 and the second manual operator 12 are located such that the user seated in the seat 21 can operate the first manual operator 11 and the second manual operator 12. In the first example embodiment, the first manual operator 11 and the second manual operator 12 are located forward of the seat 21.

[0094] The receivers 150a and 150b at two positions are located at two positions separated from the device mount 40 by different distances. Specifically, the receivers 150a and 150b at two positions are located at two positions at increasing distances from the device mount 40. Note that, in the following description, one (receiver 150a) of the receivers 150a and 150b at the two positions that is closest to the device mount 40 is referred to as a first receiver 150a, and the other (receiver 150b) of the receivers 150a and 150b that is farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 150b.

[0095] More specifically, as illustrated in FIG. 3, the first receiver 150a and the second receiver 150b are located such that the first receiver 150a and the second receiver 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40.

[0096] The first receiver 150a and the second receiver 150b may be arranged on a single imaginary straight line that extends from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and may be located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40. The latter case is used in the first example embodiment. That is, the first receiver 150a and the second receiver 150b in the first example embodiment are located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40.

[0097] More specifically, in the first example embodiment, the first receiver 150a and the second receiver 150b are located at the following two positions: a position in an area SA between the device mount 40 (the rotation shaft S2 of the device mount 40) and the cabin 22 in the front-rear direction, and a position within the cabin 22.

[0098] The device mount 40 is located forward of the machine body 2 in the front-rear direction. More specifically, the device mount 40 is located forward of the cabin 22, and is raised and lowered at a position forward of the cabin 22. Accordingly, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the first example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22. With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0099] In contrast, the second receiver 150b is located at a position farther from the device mount 40 than the other receiver 150a (i.e., the second receiver 150b is located on the imaginary concentric circle VC2 having a larger radius r2) and within the cabin 22. In the first example embodiment, the second receiver 150b located within the cabin 22 is located rearward of the seat 21 in the operator cab OR. In the present example embodiment, the first receiver 150a and the second receiver 150b are displaced from each other in the front-rear direction, but are each located at a central portion of the cabin 22 in the lateral direction.

[0100] The first receiver 150a and the second receiver 150b receive identifying signals transmitted from transmitters T. Specifically, the first receiver 150a and the second receiver 150b receive unique identification information relating to a working device 9 from a tag T which is a transmitter attached to the working device 9.

[0101] In the first example embodiment, the first receiver 150a and the second receiver 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna.

[0102] Note that the receiver 15a which includes the first receiver 150a that is the closest, of the receivers, to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b which includes the second receiver 150b farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 15b. That is, the receiver 15a located closest, of the receivers, to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b located farther from the device mount 40 than the first receiver 15a is referred to as a second receiver 15b. Note that, although the first receiver 15a and the second receiver 15b are named differently based on the locations for convenience of the following description, the first receiver 15a and the second receiver 15b include the same configuration.

[0103] Specifically, the first receiver 150a and the second receiver 150b are each an antenna, and receive, as identification information, a wireless signal (beacon signal) compliant with Bluetooth (registered trademark) Low Energy which is a near field communication standard. That is, the receivers 15a and 15b are beacon scanners to receive beacon signals. The receiver main bodies 151a and 151b of the receivers 15a and 15b (beacon scanners 15) each measure the received signal strength (Received Signal Strength Indicator, RSSI) of the accepted wireless signal.

[0104] In the first example embodiment, the receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b each have a signal converting function to convert a Bluetooth signal into a control area network (CAN) signal. Accordingly, the receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b are connected to the controller 5 via a CAN bus.

[0105] The first receiver 150a and the second receiver 150b at two positions are each a directional antenna to receive identifying signals from a particular direction. The first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). In the first example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the first receiver 15a and the second receiver 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the second receiver 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0106] That is, the first receiver 15a is fixed to the cabin 22 such that the first receiver 150a is located within the area SA between the device mount 40 and the cabin 22 in the front-rear direction, and the second receiver 15b is fixed to the cabin 22 such that the second receiver 150b is located within the cabin 22 (rearward of the seat 21). The receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b each transmit, to the controller 5 via a signal wire (CAN bus), an identifying signal received by the first receiver 150a or the second receiver 150b.

[0107] The traveling devices 3 are operable to achieve straight travel in which the machine body 2 travels straight, and achieve pivot turn travel. The traveling devices 3 are operable to also achieve spin turn travel.

[0108] Specifically, the traveling devices 3 are provided on the left and right sides of the machine body 2. That is, the working machine 1 includes a pair of the traveling devices 3 to support opposite portions in the width direction (left and right portions) of the machine body 2 (the frame chassis 20 in the first example embodiment). In the first example embodiment, the pair of traveling devices 3 are respective crawler traveling devices 3. That is, the working machine 1 according to the first example embodiment is a crawler compact track loader.

[0109] The device mount 40 is supported directly or indirectly by the machine body 2. In the first example embodiment, the device mount 40 is supported by the machine body 2 via a support structure 4 (arms 43, described later). The device mount 40 is, as described earlier, operable to attach thereto each of a plurality of types of working devices 9 independently. That is, the device mount 40 is operable to replaceably attach thereto each of a plurality of types of working device 9 that performs a function corresponding to work.

[0110] Specifically, as illustrated in FIGS. 11 and 12, the device mount 40 includes a linkage 41 to connect a working device 9 thereto. The linkage 41 includes an engagement portion 412 switchable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 to connect the working device 9 thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 to disconnect the working device 9 therefrom.

[0111] Specifically, as illustrated in FIG. 12, the device mount 40 includes a frame 42 to be connected to distal portions of the arms 43, and a linkage 41 attached to the frame 42.

[0112] The frame 42 includes a frame body 420 in the form of a plate. The working device 9 includes a mount base 91 (described later) which includes a pawl 910 for engagement. In the first example embodiment, the pawl 910 engages with the upper edge of the frame body 420.

[0113] The linkage 41 includes a so-called quick hitch (hitch) to connect (attach) and disconnect (detach) the working device 9 thereto and therefrom, and is also called “quick changer”. The linkage 41 engages with the mount base 91 such that the pawl 910 engages with the upper edge of the frame body 420, so that the linkage 41 maintains the working device 9 (mount base 91) in the connected state.

[0114] Specifically, the linkage 41 is located within the area of the frame body 420 of the frame 42. That is, the linkage 41 is located between the upper edge and the lower edge of the frame body 420 and is fixed to the frame body 420.

[0115] The linkage (quick hitch) 41 includes latching mechanism(s) 410 and a latch cylinder 411 to actuate the latching mechanism(s) 410 (see FIGS. 11 and 12).

[0116] Each latching mechanism 410 includes a latch pin 412 (which is the engagement portion 412) which is movable in the axial direction and which is switchable between (i) the engaging position PE1 in which the latch pin 412 engages with an engagement section 92a (which is a peripheral portion around an engagement hole 92a in the first example embodiment) of the mount base 91 of the working device 9, and (ii) the disengaging position PE2 in which the latch pin 412 is disengaged from the working device 9 of the mount base 91. In the first example embodiment, the latching mechanism 410 includes a lever body 413 which is rotatable about a predetermined axis and which, by rotating about the axis, changes the position of (moves) the latch pin 412 between the engaging position PE1 and the disengaging position PE2.

[0117] With this, the latching mechanism 410 is able to switch between (i) a latching state (engaging state) in which the latch pin (engagement portion) 412 is in the engaging position PE1 to secure the working device 9 and (ii) an unlatching state (disengaging state) in which the latch pin (engagement portion) 412 is in the disengaging position PE2 to allow the working device 9 to be detached.

[0118] The latch cylinder 411 actuates the latching mechanisms 410. In the first example embodiment, each latching mechanism 410 includes a spring 414 to cause the latch pin 412 to return from the disengaging position PE2 to the engaging position PE1. Accordingly, in the first example embodiment, the springs 414 keep the latching mechanisms 410 in the latching state, and the latch cylinder 411 switches the latching mechanisms 410 from the latching state to the unlatching state.

[0119] In the first example embodiment, the linkage 41 includes a plurality of the latch pins 412, and the latch pins 412 engage with the mount base 91 of the working device 9 at a plurality of positions to hold the working device 9. That is, the linkage 41 includes a plurality of the latching mechanisms 410 each including a latch pin 412. In the first example embodiment, the linkage 41 includes a pair of the latching mechanisms 410. The pair of latching mechanisms 410 are arranged symmetrically with respect to the widthwise center of the frame 42.

[0120] In the first example embodiment, the latch cylinder 411 includes a hydraulic cylinder. Accordingly, the latch cylinder 411 is connected to the hydraulic system 6, and extends and retracts by receiving and discharging hydraulic fluid from and to the hydraulic system 6. The latch cylinder 411 is connected to the lever bodies 413 (first lever portions 413a, described later) of the latching mechanisms 410, and the extension or retraction of the latch cylinder 411 rotates each lever body 413 about a predetermined axis. In the first example embodiment, since the pair of latching mechanisms 410 are arranged symmetrically, the latch cylinder 411 is arranged to connect the lever bodies 413 of the pair of latching mechanisms 410. With this, with a single latch cylinder 411, a pair of latching mechanisms 410 are actuated in a synchronized manner. That is, the latch cylinder 411 rotates each of the lever bodies 413 of the pair of latching mechanisms 410 to move each of the latch pins 412 of the pair of latching mechanisms 410 between the engaging position PE1 and the disengaging position PE2 in a synchronized manner.

[0121] In the first example embodiment, each lever body 413 includes a first lever portion 413a extending from the center of rotation, and a second lever portion 413b extending from the center of rotation in a different direction from the first lever portion 413a. The first lever portion 413a is connected to the latch pin 412 (which is the engagement portion) via the spring 414, and to the latch cylinder 411. The second lever portion 413b of the lever body 413 overlaps (is hidden behind) the frame 42 when viewed in the front-rear direction when the latch pin 412 is in the engaging position PE1, and protrudes from the upper edge of the frame 42 when the latch pin 412 is in the disengaging position PE2. Thus, the device mount 40 of the first example embodiment is configured such that whether the device mount 40 is in the latching state or the unlatching state can be visually recognized (checked) by checking, from the outside (from the operator cab OR), whether or not the second lever portions 413b are protruding from the frame 42.

[0122] As illustrated in FIGS. 3 to 10, the device mount 40 is connected to the support structure 4 (arms 43, described later) rotatably about the second shaft S2 extending in the lateral direction. Specifically, the frame 42 of the device mount 40 is rotatably connected to the distal portions of the arms 43 via the second shaft S2 having an axis (central axis) extending in the lateral direction. With this, the device mount 40 is movable along a path (second path) in the shape of an arc centered on the second shaft S2. Accordingly, the working device 9 attached (connected) to the device mount 40 is also movable along a path in the form of an arc centered on the second shaft S2 similarly to the device mount 40. That is, the working device 9 is movable along a path in the shape of an arc which is concentric and similar to the second path for the device mount 40.

[0123] The support structure 4 is supported by the machine body 2, and includes arms 43 which are supported rotatably about a first shaft S1 extending in the lateral direction perpendicular to the up-down direction and which have the device mount 40 connected thereto.

[0124] Each arm 43 extends in a direction (hereinafter may be referred to as an arm extension direction) perpendicular to the up-down direction and the lateral direction, and includes a proximal portion and a distal portion at the opposite ends in the arm extension direction. The proximal portion of the arm 43 is connected to the machine body 2 rotatably about the first shaft S1 having an axis (center of rotation) extending in the lateral direction. In the first example embodiment, the arm 43 is connected to the machine body 2 via a linking body 44 connected to the machine body 2. In contrast, the distal portion of the arm 43 has the device mount 40 connected thereto.

[0125] With this, the device mount 40 is movable along a path (first path) in the shape of an arc centered on the first shafts S1 by the rotation of the arms 43. The proximal portions of the arms 43 are connected to a rear portion of the machine body 2. When the arms 43 are in a position in which the arms 43 extend from the rear portion of the machine body 2 toward the space in front of the machine body 2 (when the arms 43 are oriented such that the arms 43 extend in a rear-to-front direction of the machine body 2), the distal portions of the arms 43 (the connected device mount 40) are located forward of the machine body 2. The device mount 40 is, by the arms 43 rotating about the first shafts S1 to move along the first path, movable between a low position in the vicinity of the ground and a high position higher than the low position. The high position and the low position are determined by the range of rotation of the arms 43.

[0126] In the first example embodiment, the arms 43 are provided at the left and right sides of the cabin 22. That is, the working machine 1 includes a pair of the arms 43 provided with the cabin 22 therebetween. The shapes and locations of the pair of arms 43 are symmetrical with respect to the widthwise center (center in the lateral direction) of the cabin 22. Accordingly, also a pair of the left and right linking bodies 44, to which the arms 43 are connected, are provided. FIGS. 3 to 10 each illustrate the left side of the working machine 1, and therefore only the left one of the arms 43 and the left one of the linking bodies 44 are illustrated in FIGS. 3 to 10 similarly to the traveling devices 3.

[0127] In the first example embodiment, the operational actuators 61 and 62 include first actuator(s) 61 to cause the arms 43 to rotate about the first shafts S1 and to raise and lower the device mount 40 in the up-down direction. In the first example embodiment, the operational actuators 61 and 62 include second actuator(s) 62 to cause the device mount 40 to rotate about the second shaft S2 to pivot. That is, the working machine 1 of the first example embodiment includes the operational actuators 61 and 62, one of which is the first actuator 61 to cause the device mount 40 to move along a predetermined path (first path), and the other of which is the second actuator 62 to cause the device mount 40 to move along another predetermined path (second path) different from the first path.

[0128] In the first example embodiment, the first actuator 61 and the second actuator 62 each include a hydraulic cylinder. That is, the first actuator 61 and the second actuator 62 each include a hydraulic cylinder to extend and retract in the axial direction by receiving and discharging hydraulic fluid. Accordingly, the first actuator 61 is hereinafter referred to as a first hydraulic cylinder 61, and the second actuator 62 is hereinafter referred to as a second hydraulic cylinder 62.

[0129] In the first example embodiment, the first hydraulic cylinder 61 extends or retracts by receiving and discharging hydraulic fluid to cause the corresponding arm 43 to rotate about the first shaft S1. That is, the extent to which the first hydraulic cylinder 61 extends or retracts determines the range of rotation of the arm 43. The first hydraulic cylinder 61 and the second hydraulic cylinder 62 each include a tubular cylinder 610, 620 and a piston rod 611, 621 inserted in the tubular cylinder 610, 620 such that the piston rod 611, 621 is extendable and retractable.

[0130] The first hydraulic cylinder 61 and the second hydraulic cylinder 62 each include a first port Pa1, Pb1 to allow hydraulic fluid to flow into the tubular cylinder 610, 620 for the piston rod 611, 621 to extend out of the tubular cylinder 610, 620, and a second port Pa2, Pb2 to allow hydraulic fluid to flow into the tubular cylinder 610, 620 for the piston rod 611, 621 to retract into the tubular cylinder 610, 620. That is, the first hydraulic cylinder 61 and the second hydraulic cylinder 62 are each a double-acting hydraulic cylinder.

[0131] Such a first hydraulic cylinder 61 is provided for each arm 34. That is, the working machine 1 includes a pair of the first hydraulic cylinders 61 provided at the opposite sides of the cabin 22. The pair of first hydraulic cylinders 61 are located symmetrically with respect to the widthwise center (center in the lateral direction) of the cabin 22 to correspond to the pair of arms 43.

[0132] Each of the pair of first hydraulic cylinders 61 connects the corresponding arm 43 and the frame chassis 20. That is, the distal end of the piston rod 611 of the first hydraulic cylinder 61 is connected to the arm 43 rotatably about an axis perpendicular to the up-down direction, and the bottom of the tubular cylinder 610 of the first hydraulic cylinder 61 is connected to the frame chassis 20 rotatably about an axis perpendicular to the up-down direction.

[0133] In the first example embodiment, a pair of the second hydraulic cylinders 62 are arranged in the width direction with a space therebetween. The pair of second hydraulic cylinders 62 are symmetrical with respect to the widthwise center (center in the lateral direction) of the cabin 22. Each of the pair of second hydraulic cylinders 62 connects the corresponding arm 43 and the frame 902 of the device mount 40. That is, the distal portion of the piston rod 621 of the second hydraulic cylinder 62 is connected to the frame 42 of the device mount 40 rotatably about an axis perpendicular to the up-down direction, and the bottom of the tubular cylinder 620 of the second hydraulic cylinder 62 is connected to the corresponding arm 43 rotatably about an axis perpendicular to the up-down direction.

[0134] With this, the arms 43 rotate about the first shafts S1 and the distal portions of the arms 43 are raised or lowered by the first hydraulic cylinders 61 extending or retracting. The device mount 40 rotates about the second shaft S2 and swings in the up-down direction by the second hydraulic cylinders 62 extending and retracting. With this, the device mount 40 is movable along the first path and along the second path. Note that as the first hydraulic cylinders 61 and the second hydraulic cylinders 62 are actuated concurrently, the device mount 40 moves along the first path while moving along the second path, i.e., the device mount 40 moves along a combination of the first and second paths. Since the working device 9 is attached (connected) to the device mount 40, the working device 9 behaves similarly to the device mount 40.

[0135] As illustrated in FIG. 13, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50 to store information for use in processes performed by the arithmetic controller 51, an input interface 52 electrically connected to the arithmetic controller 51 to input, into the arithmetic controller 51, an electric signal which is input information from an external electric device, and an output interface 53 electrically connected to the arithmetic controller 51 to output, to an external electric device, a command signal (electric signal) which is output information from the arithmetic controller 51.

[0136] The arithmetic controller 51 may be a so-called CPU, and may include a calculator 510 and a controller 511. In the controller 5 of the first example embodiment, the storing unit 50 includes a first storing unit 500 to store, temporarily or for a short period of time, information for use in processes performed by the arithmetic controller 51 (the calculator 510 and the controller 511), and a second storing unit 501 to store, for a long period of time, information for use in processes performed by the arithmetic controller 51 (the calculator 510 and the controller 511). The first storing unit 500 is a so-called memory, and the second storing unit 501 is a storage such as a hard disc or solid state drive (SSD).

[0137] In the first example embodiment, the storing unit 50 stores a device list which is a list of a plurality of working devices 9 (9A to 9T) and which is to be displayed on the monitor 55 (see FIG. 14). The device list has embedded therein images of the working devices 9 (pictograms shown in FIG. 15), and is associated with operation conditions of the working devices 9 (9A to 9T) shown in FIG. 15. The device list is configured such that one of the working devices 9 (9A to 9T) displayed on the monitor 55 can be selected.

[0138] The storing unit 50 stores (has registered therein) information relating to a plurality of types of working devices 9 (9A to 9T) attachable to the device mount 40 (see FIG. 15). Note that the plurality of types of working devices 9 include a bucket 9A, a pallet fork 9B, a ripper 9C, a snow pusher 9D, a dozer blade 9E, a crusher 9F, a grapple 9G, a skid grader 9H, a spreader 9I, a sweeper 9J, a skid cutter 9K, a breaker 9L, an earth auger 9M, a rotary tiller 9N, a broom (angle broom) 9O, a cold planer 9P, a stump grinder 9Q, a snow blower 9R, a trencher 9S, a mower 9T, and / or the like. FIG. 15 illustrates pieces of graphics (pictograms) schematically representing such working devices 9 as examples of the working devices 9.

[0139] The storing unit 50 stores the names of the plurality of types of working devices 9 and pieces of identification information 9A to 9T allocated to the respective plurality of types of working devices 9, which are associated with each other. The storing unit 50 stores the names of plurality of types of working devices 9 (9A to 9T) and pieces of graphics (pictograms, in the first example embodiment) of the working devices 9 (9A to 9T) to be displayed on the monitor 55, which are associated with each other. The storing unit 50 stores the names of the plurality of types of working devices 9 (9A to 9T) and the operation conditions D1 to D20 (control conditions D1 to D20) for the working devices 9 (9A to 9T), which are associated with each other. Note that, in the first example embodiment, the names of the working devices 9 (9A to 9T), the pieces of identification information 9A to 9T, the working devices 9 (9A to 9T), and the pieces of graphics of the working device 9 (i.e., pieces of information arranged horizontally in the table in FIG. 15) are stored such that they are associated with each other.

[0140] The storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the second receiver 150b (the receivers 150a and 150b at two positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the second receiver 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at the second receiver 150b.

[0141] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0142] With regard to the combination pattern of received signal strengths in the first example embodiment, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a and for the received signal strength at the second receiver 150b. The range of the received signal strength for the first receiver 150a and the range of the received signal strength for the second receiver 150b are defined such that they do not overlap each other. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for the second receiver 150b is 55 dBm to 64 dBm.

[0143] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the second receiver 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the first example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0144] Referring back to FIG. 13, the input interface 52 and the output interface 53 are each a so-called interface. The input interface 52 is operable to connect thereto electric device(s) which outputs an electric signal (i.e., information). In contrast, the output interface 53 is operable to connect thereto electric device(s) which receives input of an electric signal (i.e., information).

[0145] Specifically, the input interface 52 is operable to connect thereto the manual operators 11 and 12 (first manual operator 11, second manual operator 12), the receivers 15a and 15b, and / or the hydraulic system 6 (in practice, control valve(s), pressure sensor(s), and / or the like contained in the hydraulic system 6 (circuit)). In contrast, the output interface 53 is operable to connect thereto the hydraulic system 6 (in practice, control valve(s), pressure sensor(s), and / or the like contained in the hydraulic system 6 (circuit)).

[0146] The monitor 55 according to the first example embodiment includes a touchscreen monitor, which is operable to receive input of information. Accordingly, the monitor 55 is connected to the input interface 52 and the output interface 53 to transmit and receive information to and from the controller 5 (arithmetic controller 51).

[0147] The monitor 55 displays a device list read from the storing unit 50. As described above, the monitor 55 includes a touchscreen monitor, and therefore, upon the user selecting (touching) the icon of the working device 9 to be used from the device list displayed on the monitor 55, the controller 5 (arithmetic controller 51) recognizes the type of the working device 9 to be used (the selected working device 9). The controller 5 (arithmetic controller 51) is configured or programmed to, in the case where the recognized type is a working device 9 configured for work-during-travel, retrieve (read) control condition(s) (e.g., travel condition(s)) for the working device 9 that corresponds to the selected icon from the storing unit 50 (second storing unit 501).

[0148] Accordingly, the controller 5 (arithmetic controller 51) recognizes (the type of) the working device 9 to be used (the selected working device 9), based on the identification information received by the first receiver 150a and the second receiver 150b.

[0149] The controller 5 retrieves operation conditions (control conditions) for the working device 9 corresponding to the selected icon (pictogram) selected via the monitor 55 (reads the operation conditions (control conditions) from the storing unit 50). Note that the controller 5 is configured or programmed to, if a working device 9 is selected from the device list displayed on the monitor 55, recognize the selected working device 9 as the working device 9 intended by the user, and prioritize this recognition over the recognition of the working device 9 based on reading the identification information received by the receivers 15a and 15b (the first receiver 150a and the second receiver 150b).

[0150] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information. The unique identification information here is used to identify the working device 9, and includes, for example, unique ID, model name, model number, and / or the like. In the first example embodiment, the tag T is a beacon tag to transmit unique identification information as a wireless signal (advertisement signal Q1) compliant with Bluetooth (registered trademark) Low Energy.

[0151] The following discusses the working devices 9. Each of the plurality of types of working devices 9 includes, as illustrated in FIGS. 3 to 10, (i) a mount base 91 attachable to the device mount 40 and (ii) a functioning portion 93 connected to the mount base 91 and operable to perform a function corresponding to work.

[0152] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mount 40 of the working machine 1. As illustrated in FIG. 12, the mount base 91 includes the pawl 910 which can be engaged to the upper edge of the frame body 420, as described earlier. The mount base 91 includes, at a position lower than the upper edge, the engagement holes 92a for engagement with the engagement portions 412 (latch pins 412) of the device mount 40. Specifically, the mount base 91 includes the engagement holes 92a at positions that correspond to the locations of the engagement portions 412 (latch pins 412) of the device mount 40.

[0153] With this, while the mount base 91 is in an attaching position relative to the device mount 40 (while the pawl 910 is engaged with frame body 420), when the latch pins (engagement portions) 412 of the linkage 41 are in the engaging position PE1, the latch pins (engagement portions) 412 are engaged with the mount base 91 (fitted in the engagement holes 92a) to achieve a connected state, whereas, when the latch pins (engagement portions) 412 of the linkage 41 are in the disengaging position PE2, the latch pins (engagement portions) 412 are disengaged from the mount base 91 (from the engagement hole 92a) to allow the mount base 91 to be detached.

[0154] A plurality of types of working devices 9 are attachable to the working machine 1 of the first example embodiment. More specifically, examples of the working devices 9 attachable to the working machine 1 of the first example embodiment (working devices 9 recorded (registered) in the storing unit 50) include, as described earlier, a bucket 9A, a pallet fork 9B, a ripper 9C, a snow pusher 9D, a dozer blade 9E, a crusher 9F, a grapple 9G, a skid grader 9H, a spreader 9I, a sweeper 9J, a skid cutter 9K, a breaker 9L, an earth auger 9M, a rotary tiller 9N, a broom (angle broom) 90, a cold planer 9P, a stump grinder 9Q, a snow blower 9R, a trencher 9S, and a mower 9T. Note that, for illustration of such examples, FIGS. 1 and 3 illustrate the working machine 1 having the bucket 9A attached thereto, FIG. 4 illustrates the working machine 1 having the pallet fork 9B attached thereto, FIG. 5 illustrates the working machine 1 having the snow pusher 9D attached thereto, FIG. 6 illustrates the working machine 1 having the grapple 9G attached thereto, FIG. 7 illustrates the working machine 1 having the sweeper 9J attached thereto, FIG. 8 illustrates the working machine 1 having the angle broom 90 attached thereto, FIG. 9 illustrates the working machine 1 having the snow blower 9R attached thereto, and FIG. 10 illustrates the working machine 1 having the trencher 9S attached thereto.

[0155] The working machine 1 of the first example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0156] Specifically, as shown in FIG. 16, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S1). Meanwhile, the first receiver 150a and the second receiver 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S2). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the second receiver 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S2).

[0157] The received signal strength of identification information increases as the distance to the tag T that is the source of the identification information decreases. Therefore, in the case where the first receiver 150a and the second receiver 150b receive a plurality of pieces of identification information, the controller 5 recognizes that the piece of identification information with the highest received signal strength, of the pieces of identification information received by the first receiver 150a and the second receiver 150b, is the piece of information of the closest working device 9 (9A to 9T).

[0158] Under such circumstances, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S3), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0159] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and the first receiver 150a and the second receiver 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes.

[0160] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0161] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the second receiver 150b, is located nearest the first receiver 150a and the second receiver 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the second receiver 150b with the highest received signal strength changes to another identifying signal.

[0162] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S3), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0163] In the first example embodiment, the orientation in which the first receiver 150a receives identifying signals is directed forward along the front-rear direction (toward the device mount 40), and the first receiver 150a receives pieces of identification information (wireless signals) coming from a wide area in front of the first receiver 150a. On the contrary, pieces of identification information (wireless signals) coming from locations on opposite sides of the cabin 22 or locations diagonally forward of the cabin 22 are blocked by the cabin 22 (lattice). The orientation in which the second receiver 150b receives identifying signals is directed forward (toward the side where the device mount 40 is present). Therefore, the second receiver 150b does not receive identifying signal from sides, diagonally from front, or from rear and receives only identifying signals (wireless signal) coming from the front side in the front-rear direction (coming from the side where the device mount 40 is present) within the range of the cabin 22 in the lateral direction. Thus, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b, to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward (S3).

[0164] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the second receiver 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the second receiver150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the second receiver 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b (S3), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0165] Under such circumstances, the controller 5 compares information stored in the storing unit 50 with the actual received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b, and determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the receiver 150b in the cabin 22 is within a predetermined range (S4).

[0166] Specifically, in the case where the received signal strength at the first receiver 150a and the second receiver 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S4), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) which can be attached (S3).

[0167] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b increases and matches a condition stored in the storing unit 50, the controller 5 recognizes the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (YES at S4).

[0168] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the receiver 150b in the cabin 22 is within a predetermined range (YES at S4), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0169] In the first example embodiment, the controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0170] The controller 5 then, upon recognizing the working device 9 (9A to 9T) to be attached to the device mount 40 (YES at S6), if the engagement portion 412 of the linkage 41 is in the engaging position PE1, determines that the working device 9 (9A to 9T) is attached to the device mount 40 (S7). That is, in the first example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is attached to the device mount 40 via the linkage 41.

[0171] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40, reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S9). This allows the user to operate the working device 9 under appropriate conditions.Second Example Embodiment

[0172] The following description discusses a working machine according to a second example embodiment of the present invention. Note that the working machine according to the second example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine of the first example embodiment except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the second example embodiment only discusses the differences from the first example embodiment, and the description for the same configurations as the first example embodiment is not repeated here but the description in the first example embodiment is applied as that for the second example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment are assigned the same names and reference signs as in the first example embodiment.

[0173] As illustrated in FIGS. 17 and 18, similar to the first example embodiment, the working machine 1 of the second example embodiment includes a machine body 2, a traveling device 3, a device mount 40, a support structure 4, a controller 5, manual operators 11 and 12 (first manual operator 11, second manual operator 12), and a monitor 55. The machine body 2 includes a seat 21 and a cabin 22. These features are the same as those of the working machine 1 of the first example embodiment. In the working machine 1 of the present example embodiment, the machine body 2 includes first receiver(s) 150a and second receiver(s) 150b to receive identifying signals from transmitters T.

[0174] In the second example embodiment, the first receiver(s) 150a and the second receiver(s) 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances.

[0175] Specifically, in the second example embodiment, the machine body 2 includes a first receiver 150a and a pair of second receivers 150b. As illustrated in FIG. 18, the first receiver 150a and the pair of second receivers 150b are located such that the first receiver 150a and the pair of second receivers 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40.

[0176] Specifically, of the three receivers (i.e., the first receiver 150a and the pair of second receivers 150b), the first receiver 150a is on (located at) one of the two imaginary concentric circles VC1 and VC2 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40 that has a smaller radius r1, and the pair of pair of second receivers 150b are on (located at) the other of the two imaginary concentric circles VC1 and VC2 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40 that has a larger radius r1. Thus, the pair of second receivers 150b are arranged with a space therebetween in the lateral direction.

[0177] That is, in the second example embodiment, the first receiver 150a is located, in a side view, on a first imaginary straight line VL1 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and the pair of second receivers 150b are arranged, in a side view, on a second imaginary straight line VL2 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40.

[0178] More specifically, also in the second example embodiment, the device mount 40 is located forward of the machine body 2 along the front-rear direction. Accordingly, of the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions), the first receiver 150a is in an area SA located between the device mount 40 and the cabin 22 in the front-rear direction, and the pair of second receivers 150b are located rearward of the first receiver 150a in the front-rear direction.

[0179] The first receiver 150a is located closest to the device mount 40, of the first receiver 150a and the pair of second receivers 150b (of the receivers 150a and 150b at three positions). In the present example embodiment, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the second example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0180] With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0181] In contrast, the pair of second receivers 150b are located at positions farther from the device mount 40 than the other receiver 150a (i.e., the pair of second receivers 150b are located on the imaginary concentric circle VC2 having a larger radius r2) and outside the cabin 22. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the cabin 22 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a and the pair of second receivers 150b are located at vertices of an isosceles triangle centered on an imaginary straight line passing through the center of the cabin 22 in the lateral direction, in plan view (see FIG. 17).

[0182] The first receiver 150a and the pair of second receivers 150b each receive identifying signals transmitted from tags T (transmitters T). Specifically, the first receiver 150a and the pair of second receivers 150b each receive unique identification information relating to a working device 9 from a tag T which is a transmitter attached to the working device 9. In the second example embodiment, the first receiver 150a and the pair of second receivers 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b (a first receiver 15a and a pair of second receivers 15b) each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna. Note that the first receiver 15a and the pair of second receivers 15b have the same configuration. The first receiver 15a and the pair of second receivers 15b are the same as the first receiver 15a and the second receiver 15b of the first example embodiment. Thus, the description of the first example embodiment is used as the description of the second example embodiment, and the description of the first receiver 15a and the second receivers 15b is omitted here.

[0183] The first receiver 150a and the pair of second receivers 150b are each a directional antenna to receive identifying signals from a particular direction. Accordingly, the first receiver 150a and the pair of second receivers 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). Also in the second example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a and the pair of second receivers 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the receivers 15a and 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the pair of second receivers 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0184] That is, the first receiver 15a is fixed to the cabin 22 such that the first receiver 150a is located within the area SA between the device mount 40 and the cabin 22 in the front-rear direction, and the second receivers 15b are fixed to the cabin 22 such that the second receivers 150b are located at a rear portion of the cabin 22 at the outer surfaces of the cabin 22. The receiver main bodies 151a and 151b of the respective first receiver 15a and the pair of second receivers 15b each transmit, to the controller 5 via a signal wire (CAN bus), an identifying signal received by the first receiver 150a or the second receiver 150b.

[0185] Similar to the first example embodiment, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50, an input interface 52, and an output interface 53. The input interface 52 is connected to the manual operators 11 and 12 (the first manual operator 11, the second manual operator 12), the first receiver 15a (the first receiver 150a), and the pair of second receivers 15b (the second receivers 150b).

[0186] In the second example embodiment, the controller 5 receives identifying signal(s) (wireless signal(s)) from three positions, i.e., from the first receiver 15a (first receiver 150a) and the pair of second receivers 15b (second receivers 150b), and performs control based on such signal(s).

[0187] Accordingly, the storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the pair of second receivers 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at each of the pair of second receivers 150b.

[0188] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the pair of second receivers 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strengths at the second receivers 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0189] With regard to the combination pattern of received signal strengths in the second example embodiment, assuming that the first receiver 150a and the pair of second receivers 150b each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a and for the received signal strengths at the second receivers 150b. The range of the received signal strength for the first receiver 150a and the ranges of the received signal strengths for the second receivers 150b are defined such that they do not overlap each other. The ranges of the received signal strengths for the pair of second receivers 150b are defined to be the same. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for each of the second receivers 150b is 55 dBm to 64 dBm.

[0190] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the pair of second receivers 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the second example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0191] Note that, similar to the first example embodiment, the storing unit 50 stores a device list (see FIG. 14) and information relating to a plurality of types of working devices 9 (9A to 9T) (see FIG. 15).

[0192] The working machine 1 of the second example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0193] Specifically, as shown in FIG. 19, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S10). Meanwhile, the first receiver 150a and the pair of second receivers 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S11). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the pair of second receivers 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S11).

[0194] Accordingly, similar to the first example embodiment, the controller 5 causes the monitor 55 to display information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about working device(s) 9 (9A to 9T) relating to the piece(s) of identification information received by the first receiver 150a (S12), to provide the user with a notification of the working device(s) 9 (9A to 9T) approached by the working machine 1 (device mount 40). In the present example embodiment, the controller 5 causes the monitor 55 to also display the position(s) of (approximate direction(s) to) the working device(s) 9 (9A to 9T) together with the information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about the working device(s) 9 (9A to 9T) (S12).

[0195] Specifically, in the present example embodiment, the pair of second receivers 150b are located rearward of the first receiver 150a (which is located at the center of the cabin 22 in the lateral direction) and at the left and right sides of the cabin 22 (left-right symmetrical with respect to the center of the cabin 22 in the lateral direction). With such an arrangement, in the case where a tag T of a working device 9 (9A to 9T) is located right in front of the working machine 1, the shortest linear distance from the tag T to the first receiver 150a in plan view is achieved, and the linear distances from the tag T to the pair of second receivers 150b in plan view are the same and longer (greater) than the distance from the tag T to the first receiver 150a. With this, the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strengths at the pair of second receivers 150b, and the received signal strengths at the pair of second receivers 150b are the same.

[0196] In the case where the tag T of the working device 9 (9A to 9T) is located on one of opposite sides (right side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T is shorter than the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the one of the opposite sides (right side) of the center of the cabin 22 in the lateral direction, the received signal strength at the one of the second receivers 150b is higher (greater) than the received signal strength at the other of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the one of opposite sides (right side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the one of the second receivers 150b is high.

[0197] On the contrary, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T is shorter than the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the received signal strength at the other of the second receivers 150b is higher (greater) than the received signal strength at the one of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the other of the opposite sides (left side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the other of the second receivers 150b is high.

[0198] Thus, there is a correlation between the combination of levels of received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions) and the position of the tag T of the working device 9 (9A to 9T). Therefore, the controller 5 recognizes the position of the working device 9 (9A to 9T) (the direction to the working device 9) based on the received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions), and causes the monitor 55 to display the result of the recognition (S12).

[0199] Note that, in the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the first receiver 150a and the pair of second receivers 150b receive identifying signals (a plurality of different identifying signals) form the respective tags T of the working devices 9 (9A to 9T). Therefore, pieces of information relating to the working devices 9 (9A to 9T) corresponding to the actually received identifying signals and the positions of (directions to) the working devices 9 (9A to 9T) are both displayed (S12). Note that, in the case where the first receiver 150a and the pair of second receivers 150b receive a plurality of identifying signals (receive a plurality of (a plurality of types of) identifying signals from the tags T of a plurality of working devices 9 (9A to 9T)), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the plurality of identifying signals, is the closest. Therefore, the controller 5 recognizes that the closest working device 9 (9A to 9T) is being approached, and causes the monitor 55 to display such.

[0200] In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, upon switching (changing) of identifying signals with the highest received signal strength due to travel of the working machine 1, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S12).

[0201] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and each of the first receiver 150a and the pair of second receivers 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b changes.

[0202] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0203] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the pair of second receivers 150b, is located nearest the first receiver 150a and the pair of second receivers 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the pair of second receivers 150b with the highest received signal strength changes to another identifying signal.

[0204] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S12), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0205] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the pair of second receivers 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the pair of second receivers 150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the pair of second receivers 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by the first receiver 150a and the pair of second receivers 150b (S12), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0206] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at each of the receivers 150b outside the cabin 22 is within a predetermined range (S13).

[0207] Specifically, in the case where the received signal strength at the first receiver 150a and the pair of second receivers 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the pair of second receivers 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S13), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receivers 150b is the working device 9 (9A to 9T) which can be attached (S12).

[0208] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the pair of second receivers 150b increases and matches a condition stored in the storing unit 50 (YES at S13), the controller 5 recognizes the working device 9 (9A to 9T) to be (planned to be) attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the pair of second receivers 150b (S14).

[0209] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at each of the receivers 150b outside the cabin 22 is within a predetermined range (YES at S13), recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receivers 150b (S14).

[0210] The controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receivers 150b matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receivers 150b (S14).

[0211] The controller 5 then, upon recognizing that the working device 9 (9A to 9T) is to be attached to the device mount 40 (S14), if the engagement portion 412 of the linkage 41 is in the engaging position PE1 (YES at S15), determines (recognizes) that the working device 9 (9A to 9T) is attached to the device mount 40 (S16). That is, in the second example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is connected to the device mount 40 via the linkage 41 (YES at S15, S16).

[0212] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40 (S16), reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T) (S17). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S18). This allows the user to operate the working device 9 under appropriate conditions.Third Example Embodiment

[0213] The following description discusses a working machine according to a third example embodiment of the present invention. Note that the working machine according to the third example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine 1 of the first example embodiment and the working machine 1 of the second example embodiment, except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the third example embodiment only discusses the differences from the first example embodiment and the second example embodiment, and the description for the same configurations as the first example embodiment and the second example embodiment is not repeated here but the description in the first example embodiment and the second example embodiment is applied as that for the third example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment and the second example embodiment are assigned the same names and reference signs as in the first example embodiment and the second example embodiment.

[0214] As illustrated in FIGS. 20 and 21, similar to the first example embodiment, the working machine 1 of the third example embodiment includes a machine body 2, a traveling device 3, a device mount 40, a support structure 4, a controller 5, manual operators 11 and 12 (first manual operator 11, second manual operator 12), and a monitor 55. The machine body 2 includes a seat 21 and a cabin 22. These features are the same as those of the working machine 1 of the first example embodiment and the second example embodiment. In the working machine 1 of the present example embodiment, the machine body 2 includes receivers 150a and 150b, 150b, 150c to receive identifying signals from transmitters T.

[0215] In the present example embodiment, the receivers 150a, 150b and 150c are located at the following four positions: positions at the front and rear of the cabin 22 (forward of and rearward of the seat 21) in the front-rear direction, and positions on the opposite sides of the cabin 22 (seat 21) in the lateral direction. Specifically, the receivers 150a, 150b and 150c of the machine body 2 include a first receiver 150a located at the front of the cabin 22, a pair of second receivers 150b located at the opposite sides of the cabin 22 in the lateral direction, and a third receiver 150c located at the rear of the cabin 22.

[0216] More specifically, as illustrated in FIG. 21, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are on (located at) three imaginary concentric circles VC1, VC2 and VC3 having different radii r1, r2 and r3 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40. Specifically, the first receiver 150a is on (located at) the imaginary concentric circle VC1 having the smallest radius r1 of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40. The pair of second receivers 150b are on (located at) the imaginary concentric circle VC2 having the radius r2 (which is between the imaginary concentric circle VC1 having the smallest radius r1 and the imaginary concentric circle VC3 having the largest radius r3) of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction) of the device mount 40. The third receiver 150c is on (located at) the imaginary concentric circle VC3 having the largest radius r3 of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction) of the device mount 40.

[0217] The pair of second receivers 150b are on the same imaginary concentric circle VC2, and are arranged with a space therebetween in the lateral direction in plan view (see FIG. 20).

[0218] That is, in the third example embodiment, the first receiver 150a is located, in a side view, on a first imaginary straight line VL1 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and the pair of second receivers 150b are arranged, in a side view, on a second imaginary straight line VL2 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction that is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 and that differs from the direction of the first imaginary straight line VL1. The third receiver 150c is located, in a side view, on a third imaginary straight line VL3 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction that is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 and that differs from the directions of the first imaginary straight line VL1 and the second imaginary straight line VL2.

[0219] More specifically, also in the third example embodiment, the device mount 40 is located forward of the machine body 2 along the front-rear direction. Accordingly, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a to 150c at four positions), the first receiver 150a is in an area SA located between the device mount 40 and the cabin 22 in the front-rear direction, the pair of second receivers 150b are located rearward of the first receiver 150a in the front-rear direction, and the third receiver 150c is located rearward of the first receiver 150a and the pair of second receivers 150b in the front-rear direction.

[0220] The first receiver 150a is located closest to the device mount 40, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (of the receivers 150a, 150b and 150c at four positions). In the present example embodiment, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the third example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0221] With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (on the imaginary concentric circle VC1 having the smallest radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0222] The third receiver 150c is located farthest from the device mount 40, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (of the receivers 150a, 150b and 150c at four positions). In the present example embodiment, the third receiver 150c is located outward of a rear portion of the upper surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0223] With this, the third receiver 150c is located at a position farthest from the device mount 40 (on the third imaginary concentric circle VC3 having the largest radius r3) and located on the cabin 22.

[0224] In contrast, the pair of second receivers 150b are located between the first receiver 150a and the third receiver 150c (on the second imaginary concentric circle VC2 having the radius r2 which is larger than the radius r1 of the first imaginary concentric circle VC1 and larger than the radius r3 of the third imaginary concentric circle VC3), and are located outside the cabin 22. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the cabin 22 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are located at four vertices of a quadrangle (lozenge) in plan view.

[0225] The first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive identifying signals transmitted from transmitters T. Specifically, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive unique identification information relating to a working device 9 from a tag T which is a transmitter T attached to the working device 9. Similar to the first example embodiment and the second example embodiment, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are combined with respective receiver main bodies 151a, 151b and 151c to accept identifying signals. That is, in the machine body 2, the first receiver 150a, the second receivers 150b, and the third receiver 150c (which are antennas) are combined with respective receiver main bodies 151a, 151b and 151c to accept identifying signals from the antennas. That is, the working machine 1 of the third example embodiment includes a first receiver 15a which is a receiver 15a located closest to the device mount 40, a third receiver 15c which is a receiver 15c located farthest from the device mount 40, and second receivers 15b which are receivers 15b located between the first receiver 15a and the third receiver 15c. Note that, also in the present example embodiment, the receivers 15a, 15b, and 15c (first receiver 15a, second receiver 15b, third receiver 15c) are the same as the receivers 15a and 15b (first receiver 15a, second receiver 15b) of the first example embodiment and the second example embodiment. Thus, the description of the first example embodiment and the second example embodiment is used as the description of the present example embodiment, and the description of the first receiver 15a, the second receivers 15b and the third receiver 15c is omitted here.

[0226] The first receiver 150a, the pair of second receivers 150b and the third receiver 150c are each a directional antenna to receive identifying signals from a particular direction. Accordingly, each receiver is positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). In the present example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the receivers 15a to 15c (first receiver 15a, second receiver 15b, third receiver 15c) are fixed to the cabin 22 such that the orientation in which the receivers 150a, 150b and 150c (first receiver 150a, pair of second receivers 150b and third receiver 150c) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0227] Specifically, the first receiver 15a is fixed to the front surface of the cabin 22 such that the first receiver 150a is located in the area SA between the device mount 40 and the cabin 22 in the front-rear direction. The pair of second receivers 15b are each fixed to the cabin 22 such that the second receiver 150b or 150b is located at the center of an outer side surface of the cabin 22 in the front-rear direction. The third receiver 15c is fixed to an upper surface of a rear portion of the cabin 22 such that the third receiver 150c is located at the rear portion of the cabin 22.

[0228] Similar to the first example embodiment, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50, an input interface 52, and an output interface 53. The input interface 52 is connected to the manual operators 11 and 12 (the first manual operator 11, the second manual operator 12), the first receiver 15a (the first receiver 150a), the pair of second receivers 15b (the second receivers 150b), and the third receiver 15c (third receiver 150c).

[0229] Accordingly, in the third example embodiment, the controller 5 receives identifying signal(s) (wireless signal(s)) from four positions, i.e., from the first receiver 15a (first receiver 150a), the pair of second receivers 15b (second receivers 150b), and the third receiver 15c (third receiver 150c), and performs control based on such signal(s).

[0230] Accordingly, the storing unit 50 of the controller 5 of the present example embodiment stores combination pattern(s) of received signal strengths at the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c. The combination pattern of received signal strengths is defined such that the received signal strength at the first receiver 150a is greater than the received signal strength at each of the pair of second receivers 150b.

[0231] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a, the received signal strengths at the second receivers 150b, and the received signal strength at the third receiver 150c are respective predetermined values (respective single values) or respective predetermined ranges.

[0232] With regard to the combination pattern of received signal strengths in the third example embodiment, assuming that the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a, for the received signal strengths at the second receivers 150b, and for the received signal strength at the third receiver 150c. The range of the received signal strength for the first receiver 150a and the ranges of the received signal strengths for the pair of second receivers 150b are defined such that they do not overlap each other. The range of the received signal strength for the third receiver 150c and the ranges of the received signal strengths for the pair of second receivers 150b are defined such that they do not overlap each other. In the present example embodiment, the ranges of the received signal strengths for the pair of second receivers 150b are defined to be the same. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for each of the pair of second receivers 150b is 55 dBm to 64 dBm and the range of the received signal strength for the third receiver 150c is 45 dBm to 54 dBm.

[0233] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the pair of second receivers 150b and the third receiver 150c, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the third example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0234] Note that the storing unit 50 stores a device list (see FIG. 14) and information relating to a plurality of types of working devices 9 (9A to 9T) (see FIG. 15) in addition to the combination pattern of the received signal strengths at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c, similar to the first example embodiment and the second example embodiment.

[0235] The working machine 1 of the third example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0236] The action of attaching (connecting) a working device 9 at the working machine 1 of the present example embodiment (control performed by the controller 5) is the same as that of the second example embodiment. Accordingly, referring to FIG. 19, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S10). Meanwhile, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S11). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S11).

[0237] Accordingly, similar to the first example embodiment and the second example embodiment, the controller 5 causes the monitor 55 to display information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about working device(s) 9 (9A to 9T) relating to the piece(s) of identification information received by the first receiver 150a (S12), to provide the user with a notification of the working device(s) 9 (9A to 9T) approached by the working machine 1 (device mount 40). In the present example embodiment, the controller 5 causes the monitor 55 to also display the position(s) of (approximate direction(s) to) the working device(s) 9 (9A to 9T) together with the information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about the working device(s) 9 (9A to9T) (S12).

[0238] Specifically, in the present example embodiment, the pair of second receivers 150b are located rearward of the first receiver 150a (which is located at the center of the cabin 22 in the lateral direction) and at the left and right sides of the cabin 22 (left-right symmetrical with respect to the center of the cabin 22 in the lateral direction). With such an arrangement, in the case where a tag T of a working device 9 (9A to 9T) is located right in front of the working machine 1, the shortest linear distance from the tag T to the first receiver 150a in plan view is achieved, and the linear distances from the tag T to the pair of second receivers 150b in plan view are the same and longer (greater) than the distance from the tag T to the first receiver 150a. With this, the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strengths at the pair of second receivers 150b, and the received signal strengths at the pair of second receivers 150b are the same.

[0239] In the case where the tag T of the working device 9 (9A to 9T) is located on one of opposite sides (right side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T is shorter than the distance from the second receiver 150 at the other of the opposite sides (left side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the one of the opposite sides (right side) of the center of the cabin 22 in the lateral direction, the received signal strength at the one of the second receivers 150b is higher (greater) than the received signal strength at the other of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the one of opposite sides (right side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the one of the second receivers 150b is high.

[0240] On the contrary, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T is shorter than the distance from the second receiver 150 at the one of the opposite sides (right side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the received signal strength at the other of the second receivers 150b is higher (greater) than the received signal strength at the one of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the other of the opposite sides (left side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the other of the second receivers 150b is high.

[0241] When the tag T of the working device 9 (9A to 9T) is located at one side of the cabin 22 such that the position of the tag T corresponds to the center of the cabin 22 in the front-rear direction, the linear distance from one of the second receiver 150b that is located on the same side of the cabin 22 as the working device 9 (9A to 9T) to the tag T is the shortest, whereas the linear distance from the other second receiver 150b to the tag T is the longest. In the case where the tag T of the working device 9 (9A to 9T) is located at one side of the cabin 22 such that the position of the tag T corresponds to the center of the cabin 22 in the front-rear direction, the linear distance from the first receiver 150a to the tag T is the same or substantially the same as the linear distance from the third receiver 150c to the tag T. Thus, in such a case, the received signal strength at the one of the second receivers 150b is the highest, the received signal strength at the other second receiver 150b is the lowest, and the received signal strength at the first receiver 150a is the same or substantially the same as the received signal strength at the third receiver 150c.

[0242] Under such conditions, when the tag T of the working device 9 (9A to 9T) moves rearward along the front-rear direction of the cabin 22 or when the tag T of the working device 9 (9A to 9T) is located rearward of the cabin 22, the distance from the third receiver 150c to the tag T becomes shorter than the distance from the first receiver 150a to the tag T. When the tag T of the working device 9 (9A to 9T) moves forward along the front-rear direction or when the tag T of the working device 9 (9A to 9T) is located forward of the cabin 22, the distance from the third receiver 150c to the tag T becomes longer than the distance from the first receiver 150a to the tag T. Thus, in the case where the tag T of the working device 9 (9A to 9T) is located rearward of the cabin 22, the received signal strength at the third receiver 150c is higher (greater) than the received signal strength at the first receiver 150a, whereas, in the case where the tag T of the working device 9 (9A to 9T) is located forward of the cabin 22, the received signal strength at the third receiver 150c is lower (less) than the received signal strength at the first receiver 150a.

[0243] Thus, there is a correlation between the combination of levels of received signal strengths at the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions) and the position of the tag T of the working device 9 (9A to 9T). Therefore, the controller 5 recognizes the position of the working device 9 (9A to 9T) (the direction to the working device 9) based on the received signal strengths at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), and causes the monitor 55 to display the result of the recognition (S12).

[0244] Note that, in the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c receive identifying signals (a plurality of different identifying signals) form the respective tags T of the working devices 9 (9A to 9T). Therefore, pieces of information relating to the working devices 9 (9A to 9T) corresponding to the currently receiving identifying signals and the positions of (directions to) the working devices 9 (9A to 9T) are both displayed (S12).

[0245] Note that, in the case where the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c receive a plurality of identifying signals (receive a plurality of (a plurality of types of) identifying signals from the tags T of a plurality of working devices 9 (9A to 9T)), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the plurality of identifying signals, is the closest. Therefore, the controller 5 recognizes that the closest working device 9 (9A to 9T) is being approached, and causes the monitor 55 to display such (S12).

[0246] In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, upon switching (changing) of identifying signals with the highest received signal strength due to travel of the working machine 1, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S12).

[0247] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and each of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c changes.

[0248] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c changes, e.g., the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0249] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c, is located nearest the first receiver 150a, the pair of second receivers 150b and the third receiver 150c. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c with the highest received signal strength changes to another identifying signal.

[0250] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S12), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0251] Note that, also in the present example embodiment, when the working machine 1 changes the direction of travel, in some cases, not all the first receiver 150a, the pair of second receivers 150b and the third receiver 150c can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.)

[0252] Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a, the pair of second receivers 150b and the third receiver 150c all start receiving an identifying signal or the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by all the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S12), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0253] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a, the second receivers 150b and the third receiver 150c matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a is equal to or greater than a preset threshold and the received signal strength at each of the pair of second receivers 150b and the third receiver 150c is within a predetermined range (S13).

[0254] Specifically, in the case where the received signal strength at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S13), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a, the second receivers 150b and the third receiver 150c is the working device 9 (9A to 9T) which can be attached (S12).

[0255] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c increases and matches a condition stored in the storing unit 50, the controller 5 recognizes the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (YES at S13).

[0256] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a is equal to or greater than a preset threshold and the received signal strength at each of the pair of receivers 150b and the third receiver 150c is within a predetermined range (YES at S13), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S14).

[0257] The controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S14).

[0258] The controller 5 then, upon recognizing that the working device 9 (9A to 9T) is to be attached to the device mount 40 (S14), if the engagement portion 412 of the linkage 41 is in the engaging position PE1 (YES at S15), determines (recognizes) that the working device 9 (9A to 9T) is attached to the device mount 40 (S15). That is, also in the third example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is connected to the device mount 40 via the linkage 41 (YES at S15, S16).

[0259] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40 (S16), reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T) (S17). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S18). This allows the user to operate the working device 9 under appropriate conditions.Fourth Example Embodiment

[0260] The following description discusses a working machine according to a fourth example embodiment of the present invention. Note that the working machine according to the fourth example embodiment is an agricultural tractor different from the first to third example embodiments, but includes features to achieve the same functions as the working machine 1 of the first to third example embodiments. Accordingly, in the fourth example embodiment, the features to achieve the same functions as those of the first to third example embodiments are regarded as the feature corresponding to those of the first to third example embodiments, and assigned the same names and reference signs as in the first to third example embodiments. The description of the features corresponding to those of the first to third example embodiments or features to achieve the same functions (processes) as the first to third example embodiments is omitted here, and the corresponding description in the first to third example embodiments is applied mutatis mutandis to the fourth example embodiment.

[0261] As illustrated in FIGS. 22 and 23, the working machine 1 according to the fourth example embodiment includes a machine body 2. The working machine 1 includes traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes device mount(s) 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work (see FIG. 23). That is, the working machine 1 includes a device mount 40 to attach thereto each of a plurality of types of working devices 9 independently.

[0262] In the fourth example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61 to cause the device mount 40 to move along the path (see FIG. 23). The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0263] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a manual operator 11 to be operated by the user to perform operations relating to travel of the traveling device 3 (which may be hereinafter referred to as a first manual operator). The working machine 1 includes a manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path (which may be hereinafter referred to as a second manual operator).

[0264] In the present example embodiment, the first manual operator 11 includes a steering operator, which is rotated to pivotally control the direction of travel of the traveling device 3. The second manual operator 12 includes a group of switches, which are configured such that when a predetermined switch is turned ON or OFF, the working device 9 attached to the support structure 4 and the device mount 40 is caused to perform a predetermined action.

[0265] The machine body 2 include a frame chassis 20, a seat 21 provided on the frame chassis 20, and a seat protection structure 22 to protect the seat 21. The machine body 2 includes receivers 150a and 150b to receive identifying signals from transmitters T.

[0266] In the present example embodiment, the frame chassis 20 supports the prime mover 10 to drive the traveling device 3. In the present example embodiment, the prime mover 10 is located at a front portion of the frame chassis 20. The working machine 1 of the present example embodiment is an agricultural tractor, and therefore includes a PTO shaft (not illustrated) to transmit power to the working device 9 (9A or the like) attached to the device mount 40. The actuators 61 in the present example embodiment each include a hydraulic cylinder.

[0267] Thus, the working machine 1 includes a hydraulic system 6 including a hydraulic pump to supply hydraulic fluid to actuators 61 and a control valve to control the flow of hydraulic fluid. Accordingly, the prime mover 10 functions as a drive source to drive (rotate) the PTO shaft and as a drive source to drive (rotate) the hydraulic pump included in the hydraulic system 6. Note that the hydraulic system 6 (hydraulic pump) is driven by the prime mover 10, and the hydraulic system 6 (control valve) is controlled by the controller 5.

[0268] In the present example embodiment, the machine body 2 includes a hood 25 to cover apparatuses (such as the prime mover 10 and the hydraulic system 6, in the present example embodiment) supported on the frame chassis 20. The hood 25 covers a substantially front-half portion of the frame chassis 20 in the front-rear direction, and defines a prime mover room MR to hose the hydraulic system 6 and the prime mover 10. Note that, in the present example embodiment, the prime mover 10 includes an internal combustion engine (diesel engine). The prime mover 10 may include an electric motor.

[0269] The seat 21 is located rearward of the prime mover room MR (prime mover 10) and is fixed to the frame chassis 20. In the present example embodiment, the seat protection structure 22 is a cabin to surround the seat 21. Since the seat 21 is located rearward of the prime mover room MR as described above, the cabin 22 (seat protection structure 22) is also located rearward of the prime mover room MR. That is, the cabin 22 defines, at a location rearward of the prime mover room MR, an operator cab OR in which the user seated in the seat 21 stays. Note that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12), and the like are provided within the cabin 22 (operator cab OR) such that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12) and the like can be operated by the user.

[0270] The cabin 22 includes front, rear, left and right windows, and one or both of the opposite side windows in the lateral direction is / are door(s) openable and closable. This allows the user to enter and exit the operator cab OR via a side of the cabin 22.

[0271] The receivers 150a and 150b are located at two positions at the front and rear of the center of the cabin 22 in the front-rear direction. In the present example embodiment, the device mount 40 (hook 40) is located rearward of the machine body 2 (cabin 22) along the front-rear direction. Accordingly, the receivers 150a and 150b are located at two positions at different distances from the device mount 40. Specifically, the receivers 150a and 150b at two positions are at increasing distances from the device mount 40. In the present example embodiment, the receivers 150a and 150b are located at two positions at increasing distance from the device mount 40 in the forward direction. Note that the device mount 40 is located rearward of the machine body 2 (cabin 22) along the front-rear direction. as described earlier. In the following description, one (receiver 150a) of the receivers 150a and 150b at the two positions that is closest to the device mount 40 is referred to as a first receiver 150a, and the other (receiver 150b) of the receivers 150a and 150b that is farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 150b, as with the case of the first example embodiment.

[0272] More specifically, the first receiver 150a and the second receiver 150b are located such that the first receiver 150a and the second receiver 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 which is the rotational axis of the working device 9 (9A or the like) supported by the device mount 40 (centered on the axis of the shaft S2 that is engaged with the hook 40 which is the device mount 40 attached to an upper link (described later) and that extends in the lateral direction, in the present example embodiment).

[0273] The first receiver 150a and the second receiver 150b may be arranged on a single imaginary straight line that extends from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40, and may be located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40. The latter case is used in the present example embodiment. That is, the first receiver 150a and the second receiver 150b in the present example embodiment are located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40.

[0274] More specifically, in the present example embodiment, the first receiver 150a and the second receiver 150b are located at the following two positions: a position in an area SA between the device mount 40 and the cabin 22 in the front-rear direction, and a position at a front portion of the cabin 22.

[0275] The device mount 40 is located rearward of the machine body 2 in the front-rear direction, as described earlier. More specifically, the device mount 40 is located rearward of the cabin 22, and is raised and lowered at a position rearward of the cabin 22. Accordingly, the first receiver 150a is located outward of (rearward of) the rear surface (back surface) of the cabin 22. In the fourth example embodiment, the first receiver 150a is located outward of (rearward of) an upper portion of the cabin 22. With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0276] In contrast, the second receiver 150b is located at a position farther from the device mount 40 than the other receiver 150a (i.e., the second receiver 150b is located on the imaginary concentric circle VC2 having a larger radius r2) and outside the cabin 22. In the present example embodiment, the second receiver 150b is located at an upper surface (roof) of a front portion of the cabin 22. In the present example embodiment, the first receiver 150a and the second receiver 150b are displaced from each other in the front-rear direction, but are each located at a central portion of the cabin 22 in the lateral direction.

[0277] The first receiver 150a and the second receiver 150b receive unique identification information relating to a working device 9 from a tag T which is a transmitter T attached to the working device 9, as with the first example embodiment. The first receiver 150a and the second receiver 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna. Note that, also in the present example embodiment, the receiver 15a including the first receiver 150a which is located closest to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b including the second receiver 150b located farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 15b. The first receiver 15a and the second receiver 15b are the same as the receivers 15a, 15b and 15c of the first to third example embodiments. Accordingly, the description of the configuration of the receivers 15a and 15b and the relationship between the receivers 15a and 15b and the controller 5 is not repeated here, and the description in the first example embodiment is also used in the present example embodiment.

[0278] In the present example embodiment, since the device mount 40 is located rearward of the machine body 2 (cabin 22), the first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed rearward in the front-rear direction. Accordingly, the first receiver 15a and the second receiver 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the second receiver 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed rearward).

[0279] In the present example embodiment, the traveling device 3 is a tire traveling device, which includes front wheels and rear wheels at opposite sides of the machine body 2 in the lateral direction (at left and right sides of the machine body 2). In the present example embodiment, the front wheels are steered wheels, and the angle of steering of a pair of left and right front wheels is changed by operation of the first manual operator 11 (steering operator). In the present example embodiment, the traveling device 3 can switch between two-wheel drive and four-wheel drive. In the case of the two-wheel drive, the drive force is transmitted from the prime mover 10 to the rear wheels, and, in the case of the four-wheel drive, the drive force is transmitted from the prime mover 10 to all the four wheels including the front wheels and the rear wheels.

[0280] The device mount 40 is supported on the machine body 2 via the support structure 4. In the present example embodiment, the device mount 40 is a structure including hooks configured to engage with the shafts S2 extending in the lateral direction.

[0281] More specifically, the support structure 4 of the present example embodiment is a three-point linkage, which includes an upper link and a pair of lower links connected to a rear portion of the machine body 2 via shafts extending in the lateral direction. The pair of lower links are arranged with a space therebetween in the lateral direction, and the upper link is located higher than the pair of lower links such that the upper link is located between the pair of lower links. The device mount 40 is joined to the distal portions of the upper link and of the pair of lower links.

[0282] With this, a working device 9 is connected such that the working device 9 is engaged with a hook 40 (which is included in the device mount 40) joined to the distal portion of the upper link and engaged with a set of hooks 40 (which are included in the device mount 40) joined to the distal portions of the pair of lower links, i.e., such that the working device 9 is supported at three points. Note that the actuator(s) 61 is / are hydraulic cylinder(s), which extend or retract to swing the pair of lower links. With this, the working device 9 is raised or lowered in the up-down direction by the swinging movement of the pair of lower links.

[0283] The controller 5 is the same as that of the first example embodiment. Accordingly, referring to FIG. 13, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50 to store information for use in processes performed by the arithmetic controller 51, an input interface 52 electrically connected to the arithmetic controller 51 to input, into the arithmetic controller 51, an electric signal which is input information from an external electric device, and an output interface 53 electrically connected to the arithmetic controller 51 to output, to an external electric device, a command signal (electric signal) which is output information from the arithmetic controller 51.

[0284] The arithmetic controller 51 may be a so-called CPU, and may include a calculator 510 and a controller 511. In the controller 5 of the present example embodiment, the storing unit 50 includes a first storing unit 500 and a second storing unit 501. The first storing unit 500 is a so-called memory, and the second storing unit 501 is a storage such as a hard disc or solid state drive (SSD).

[0285] The storing unit 50 stores a device list which is a list of a plurality of working devices 9 (9A to 9T) and which is to be displayed on the monitor 55. Note that, since the working machine 1 of the present example embodiment is an agricultural tractor different from the first example embodiment, working devices 9 attached to the device mount 40 are different from those in the first example embodiment. However, the device list includes a plurality of devices also in the present example embodiment. That is, the pictographs illustrated in the device list in FIG. 14 are replaced by pieces of graphics representing agricultural working devices 9. Furthermore, the pieces of information relating to the plurality of types of working devices 9 (9A to 9T) attachable to the device mount 40 in FIG. 15 are replaced by pieces of information about agricultural working devices 9. Thus, the storing unit 50 stores information similar to that in the first example embodiment.

[0286] Examples of the plurality of types of working devices 9 (9A to 9T) recorded in the storing unit 50 include a rotary, a plow, a harrow, a broadcaster, a manure spreader, a planter, a rice transplanter, a lister, a mulcher, a speed sprayer, a boom sprayer, a trailer, a front loader, and a roll baler. The pieces of information (pieces of graphics) in FIGS. 14 and 15 are replaced by pieces of information about these devices. Also in such a case, the names of the working devices 9 (9A to 9T), the pieces of identification information 9A to 9T, the working devices 9 (9A to 9T), and the pieces of graphics of the working devices 9 (i.e., pieces of information arranged horizontally in FIG. 15) are stored such that they are associated with each other, similar to the first example embodiment.

[0287] The storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the second receiver 150b (the receivers 150a and 150b at two positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the second receiver 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at the second receiver 150b.

[0288] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0289] With regard to the combination pattern of received signal strengths in the fourth example embodiment, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), similar to the second example embodiment, respective predetermined ranges are defined for the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b. The range of the received signal strength for the first receiver 150a and the range of the received signal strength for the second receiver 150b are defined such that they do not overlap each other. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for the second receiver 150b is 55 dBm to 64 dBm.

[0290] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the second receiver 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the fourth example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0291] The monitor 55 includes a touchscreen monitor, which is operable to receive input of information. The monitor 55 displays a device list read from the storing unit 50. As described above, the monitor 55 includes a touchscreen monitor, and therefore, upon the user selecting (touching) the icon of the working device 9 to be used from the device list displayed on the monitor 55, the controller 5 (arithmetic controller 51) recognizes the type of the working device 9 to be used (the selected working device 9).

[0292] Accordingly, the controller 5 (arithmetic controller 51) recognizes (the type of) the working device 9 to be used (the selected working device 9), based on the identification information received by the first receiver 150a and the second receiver 150b.

[0293] The controller 5 retrieves operation conditions (control conditions) for the working device 9 corresponding the selected icon selected via the monitor 55 (reads the operation conditions (control conditions) from the storing unit 50). Note that the controller 5 is configured or programmed to, if a working device 9 is selected from the device list displayed on the monitor 55, recognize the selected working device 9 as the working device 9 intended by the user, and prioritize this recognition over the recognition of the working device 9 based on reading the identification information received by the receivers 15a and 15b (the first receiver 150a and the second receiver 150b).

[0294] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information. The unique identification information here is used to identify the working device 9, and includes, for example, unique ID, model name, model number, and / or the like. Also in the fourth example embodiment, the tag T is a beacon tag to transmit unique identification information as a wireless signal (advertisement signal Q1) compliant with Bluetooth (registered trademark) Low Energy.

[0295] The following discusses the working devices 9. Each of the plurality of types of working devices 9 includes (i) a mount base 91 attachable to the device mount 40 and (ii) a functioning portion 93 connected to the mount base 91 and operable to perform a function corresponding to work.

[0296] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mount 40 of the working machine 1. In the present example embodiment, the device mount 40 of the working machine 1 includes hooks 40, and therefore the mount base 91 of each working device 9 includes shafts S2 (rotation shafts S2) to be engaged with the hooks 40 (of the device mount 40). Since this is a well-known configuration, a detailed description thereof is omitted here.

[0297] The working machine 1 of the fourth example embodiment has been described. While no working devices 9 are attached to the device mounts 40, the action of attaching (connecting) a desired working device 9 is performed. The processes performed by the controller 5 to perform the action of connecting are similar to those of the first example embodiment. Accordingly, referring to FIG. 16, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S1). Meanwhile, the first receiver 150a and the second receiver 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S2). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the second receiver 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S2).

[0298] The received signal strength of identification information increases as the distance to the tag T that is the source of the identification information decreases. Therefore, in the case where the first receiver 150a and the second receiver 150b receive a plurality of pieces of identification information, the controller 5 recognizes that the piece of identification information with the highest received signal strength, of the pieces of identification information received by the first receiver 150a and the second receiver 150b, is the piece of information of the closest working device 9 (9A to 9T).

[0299] Under such circumstances, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S3).

[0300] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and the first receiver 150a and the second receiver 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes.

[0301] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0302] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the second receiver 150b, is located nearest the first receiver 150a and the second receiver 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the second receiver 150b with the highest received signal strength changes to another identifying signal.

[0303] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S3).

[0304] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the second receiver 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the second receiver 150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the second receiver 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b, to provide the user with a notification of the working device 9 (9A to 9T) located rearward of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is located rearward of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling rearward. Thus, the working machine 1 is configured to, based on the orientation thereof, provide the user with a notification of the working device 9 located rearward thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling rearward).

[0305] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the first receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the second receiver 150b outside the cabin 22 is within a predetermined range (S4).

[0306] Specifically, in the case where the received signal strength at the first receiver 150a and the second receiver 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S4), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) which can be attached (S3).

[0307] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b increases and matches a condition stored in the storing unit 50 (YES at S4), the controller 5 recognizes the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0308] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the first receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the second receiver 150b outside the cabin 22 is within a predetermined range (YES at S4), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0309] In the fourth example embodiment, the controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b matches a condition stored in the storing unit 50 (YES at S4), recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0310] The controller 5 then recognizes that the working device 9 (9A to 9T) is to be attached to the device mount 40 (YES at S6), and determines (recognizes) that the working devices 9 (9A to 9T) has been connected (attached) to the device mounts 40 (S7). In the present example embodiment, the device mounts 40 are hooks 40 and include no actuators to be driven to achieve connection such as the linkage 41 of the first to third example embodiments. Therefore, the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) (S5), when the receivers 150a and 150b at two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined period of time, determine that the position of the working device 9 (9A or the like) has been identified (determined) and recognizes that the working device 9 is now attached to the device mount 40 as well as recognizing the attached working device 9 (9A to 9T).

[0311] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40, reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S9). This allows the user to operate the working device 9 under appropriate conditions.Fifth Example Embodiment

[0312] The following description discusses a working machine according to a fifth example embodiment of the present invention. Note that the working machine according to the fifth example embodiment is an agricultural tractor similar to the fourth example embodiment, but is an agricultural tractor without a cabin, i.e., including no cabins 22. The fifth example embodiment is the same as the fourth example embodiment except for the above, and therefore, as with the fourth example embodiment, the features corresponding to those of the first to fourth example embodiments are assigned the identical names and reference sings as those in the first to fourth example embodiments. The description of the features corresponding to those of the first to fourth example embodiments or features to achieve the same functions (processes) as the first to fourth example embodiments is omitted here, and the corresponding description in the first to fourth example embodiments is applied mutatis mutandis to the fifth example embodiment.

[0313] As illustrated in FIGS. 24 and 25, the working machine 1 according to the fifth example embodiment includes a machine body 2 and traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes a device mount 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work.

[0314] In the fifth example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61 to cause the device mount 40 to move along the path. The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0315] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a first manual operator 11 to be operated by the user to perform operations relating to travel of the traveling device 3, and a second manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path. The first manual operator 11 in the present example embodiment includes a steering operator, as with the fourth example embodiment, whereas the second manual operator 12 includes an operating lever. Accordingly, when the operating lever is operated, the second manual operator 12 causes the working device 9 attached to the support structure 4 and the device mount 40 to perform a predetermined action.

[0316] The machine body 2 includes a frame chassis 20, and a seat 21 provided on the frame chassis 20. The machine body 2 includes receivers 150a and 150b to receive identifying signals from transmitters T. The seat 21 is located rearward of the prime mover room MR (prime mover 10), and fixed to the frame chassis 20. As mentioned earlier, the present example embodiment does not include a cabin 22, and the other features are the same as those of the agricultural tractor of the fourth example embodiment. Specifically, the working machine 1 includes a PTO shaft, a hood 25 is provided at a substantially front-half of the frame chassis 20 in the front-rear direction to define a machine room MR, and the prime mover 10 and the hydraulic system 6 are provided in the machine room MR. Note that a detailed description of these features is omitted here, and the description in the fourth example embodiment is applied to the present example embodiment.

[0317] In the present example embodiment, the receivers 150a, 150b and 150c are located at the following four positions: positions forward of and rearward of the seat 21 in the front-rear direction, and positions on the opposite sides of the seat 21 in the lateral direction. Specifically, the receivers 150a, 150b and 150c of the machine body 2 include a first receiver 150a located rearward of the seat 21 and closest to the device mount 40, a pair of second receivers 150b located farther from the device mount 40 than the first receiver 150a, and a third receiver 150c located farther from the device mount 40 than the first receiver 150a and the pair of second receivers 150b.

[0318] Specifically, in the present example embodiment, the device mount 40 is located rearward of the machine body 2 along the front-rear direction, and the first receiver 150a is located within an area SA between the device mount 40 and the seat 21. Such a first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are arranged in the order named in a rear-to-front direction. The pair of second receivers 150b are located at the midpoint or substantially at the midpoint between the first receiver 150a and the third receiver 150c in the front-rear direction.

[0319] The first receiver 150a, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), is located forward of the device mount 40 but rearward of the seat 21, and is closest to the device mount 40. In the present example embodiment, the first receiver 150a is located rearward of the seat 21 at the center of the machine body 2 in the lateral direction.

[0320] The third receiver 150c, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), is located farthest to the device mount 40. In the present example embodiment, the third receiver 150c is located forward of the seat 21. In the present example embodiment, the third receiver 150c is located at the center, in the lateral direction, of a dashboard located in front of the seat 21 (located between the seat 21 and the hood 25). With this, the first receiver 150a and the third receiver 150c are arranged along a centerline of the machine body 2 that extends in the front-rear direction.

[0321] In contrast, the pair of second receivers 150b are located between the first receiver 150a and the third receiver 150c, and are located on opposite sides of the seat 21. Specifically, the pair of second receivers 150b are arranged in the lateral direction with the seat 21 between them. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the machine body 2 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are located at four vertices of a quadrangle (lozenge) in plan view.

[0322] The controller 5 is the same as the controller 5 of the first to fourth example embodiments, and information stored in the storing unit 50 can be estimated based on similar information stored in the storing unit 50 of the third example embodiment, as with the case of the fourth example embodiment, and therefore the description of the controller 5 and the description of the information stored in the storing unit 50 are omitted here, and the descriptions in the first example embodiment and the third example embodiment are applied to the present example embodiment. Note that, similar to the fourth example embodiment, also in the working machine 1 of the present example embodiment, the device mounts 40 are located rearward of the machine body 2 differently from the first to third example embodiments. The locations of the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are defined based on this location of the device mounts 40. That is, in the present example embodiment, the locations of the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are described such that front and rear are opposite to those in the first to third example embodiments. Therefore, there is no inconsistency between the description in the present example embodiment and the first and third example embodiments.

[0323] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information, similar to the first to fourth example embodiments.

[0324] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mounts 40 of the working machine 1. In the present example embodiment, similar to the fourth example embodiment, the device mounts 40 of the working machine 1 are hooks 40, and therefore the mount base 91 of each working device 9 includes a shaft S2 (rotation shaft S2) to be engaged with the hooks 40 (device mounts 40). Since this is a well-known configuration, a detailed description thereof is omitted here.

[0325] The working machine 1 of the fifth example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed. In the present example embodiment, the action of attaching (connecting) a working device 9 (i.e., processes performed by the controller 5) is the same as that in the third example embodiment of the working machine 1 including the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (receivers 150a, 150b, and 150c at four positions), and the same effects as the third example embodiment are achieved.

[0326] Note that the present invention is not limited to the above-described example embodiments, and can be modified without departing from the gist of the present invention.

[0327] In the above-described example embodiments, a working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 is recognized based on the received signal strengths of identifying signal(s) received by two or more receivers located at two or more positions. Note, however, that this does not imply any limitation. For example, a working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 may be recognized based on the received signal strengths of identifying signal(s) received by one of the receivers 150a, 150b and 150c located at two or more positions (a plurality of positions). Specifically, since the received signal strength of the identifying signal received by the receivers 150a, 150b and 150c increases as the distance between the tag T (transmitter T) and the receivers 150a, 150b and 150c decreases, the controller 5 is able to recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 by checking the peak (the highest value) of the received signal strength at a single receiver (a receiver at a single position).

[0328] In the above-described example embodiments, the receivers (first receiver 150a, second receiver 150b, third receiver 150c) are directional antennas, and the orientations in which the receivers (first receiver 150a, second receiver 150b, third receiver 150c) receive identifying signals are all directed toward the side where the device mount 40 is present. Note, however, that this does not imply any limitation. For example, in another example embodiment of the present invention, as illustrated in FIGS. 26 to 29, the orientation of the first receiver 150a (which is closest to the device mount 40) in which the first receiver 150a receives identifying signals may be directed toward the side where the device mount 40 is present, whereas the orientation of the receiver(s) 150b, 150c (second receiver(s) 150b, third receiver 150c) (which is farther from the device mount 40 than the first receiver 150a) in which the receiver receives identifying signals may be directed in a direction different from the direction toward the side where the device mount 40 is present. More specifically, the orientation of the receiver(s) 150b, 150c (second receiver 150b, third receiver 150c) (which is farther from the device mount 40 than the first receiver 150a) in which the receiver receives identifying signals may be directed away from the device mount 40.

[0329] With this, the receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) which are farther from the device mount 40 than the first receiver 150a have low sensitivity to receive identifying signals coming from the side where the device mount 40 is present.

[0330] Specifically, the first receiver 150a has high sensitivity to receive an identifying signal from the tag T of a working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength increases), whereas the other receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) have low sensitivity to receive the identifying signal from the tag T of the working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength decreases). Thus, under the conditions in which the other receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) receive identifying signals coming from the side where the device mount 40 is present, when the first receiver 150a and the receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40.

[0331] In the agricultural tractor 1 (working machine 1) of the above-described fourth example embodiment, the device mount 40 (support structure 4) is located rearward of the machine body 2, but this does not imply any limitation. In another example embodiment of the present invention, in the case where the working machine 1 is an agricultural tractor, the agricultural tractor may be a working machine 1 (agricultural tractor 1) which includes a device mount 40 (a three-point linkage which is a support structure 4) in front of the machine body 2, as illustrated in FIG. 30.

[0332] In such a case, since the device mount 40 is located in front of the machine body 2 similar to the working machine 1 (compact track loader 1) of the first example embodiment, the receivers 150a, 150b, and / or 150c may be located at two to four positions and processes (control) corresponding to the number of the receivers may be performed, similar to the first to third example embodiments. Specifically, in the case where the receivers 150a and 150b are located at two positions arranged in the front-rear direction, the same processes as in the first or second example embodiment may be performed. In the case where the receivers 150a and 150b are located at four positions arranged in the front-rear direction, the same processes as in the third example embodiment may be performed. In the case where the receivers 150a and 150b are located at three positions arranged in the front-rear direction, the same processes as in the fourth example embodiment or the fifth example embodiment may be performed.

[0333] In the case where the working machine 1 is an agricultural tractor, the agricultural tractor may be a working machine 1 (agricultural tractor 1) including device mounts 40 (three-point linkages 4 which are support structures 4) both in front of and rearward of the machine body 2 (see FIG. 31). The receivers 150a and 150b are located with a space therebetween in the front-rear direction, similar to the foregoing example embodiments. Specifically, the receivers 150a and 150b are located within an area SA between the front device mount 40 and the cabin 22 (seat 21), and within an area SA between the rear device mount 40 and the cabin 22 (seat 21), respectively.

[0334] With this, the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the front device mount 40, and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a second receiver 150b located farther from the front device mount 40 than the first receiver 150a. On the other hand, the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the rear device mount 40, and the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a second receiver 150b located farther from the rear device mount 40 than the first receiver 150a.

[0335] Thus, in the case of a working machine 1 including the front and rear device mounts 40, the working machine 1 is configured such that, depending on which of the front and rear device mounts 40 has attached thereto a working device 9 (9A or the like), a switch or the like allows switching between (i) a state in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a and (ii) a state in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a. In such a case in which one of the receivers at two positions is regarded as a first receiver 150a (in the case where the states are switchable), the other receiver is defined as a second receiver 150b.

[0336] With this, when a working device 9 (9A or the like) is attached to one of the front and rear device mounts 40, it is possible to perform the same processes as in the second example embodiment using the smallest number of receivers 150a and 150b possible. Note that, although the receivers 150a and 150b are located at two positions at the front and rear of the cabin 22 in FIG. 31, receivers 150a, 150b, and 150c (first receiver 150a, a pair of second receivers 150b, third receiver 150c) may be located at four positions at the front and rear and on opposite sides of the cabin 22, as with the fourth example embodiment (see FIG. 32).

[0337] In such a case, the receiver located within the area SA1 between the front device mounts 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the front device mount 40, and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a third receiver 150c located farther from the front device mount 40 than the first receiver 150a. On the other hand, the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the rear device mount 40, and the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a third receiver 150c located farther from the rear device mount 40 than the first receiver 150a.

[0338] Thus, in the case of a working machine 1 including the front and rear device mounts 40, the working machine 1 is configured such that, depending on which of the front and rear device mounts 40 has attached thereto a working device 9 (9A or the like), a switch or the like allows switching between (i) a state in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a and (ii) a state in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a. In such a case in which one of the receivers at two positions is regarded as a first receiver 150a (in the case where the states are switchable), the other receiver is defined as a second receiver 150b. Note that, because the pair of second receivers 150b are located between the front and rear receivers in the front-rear direction, the pair of second receivers 150b are regarded as second receivers 150b regardless of which of the front and rear device mounts 40 has a working device 9 (9A or the like) attached thereto. With this, when a working device 9 (9A or the like) is attached to one of the front and rear device mounts 40, it is possible to perform the same processes as in the fourth example embodiment using the smallest number of receivers 150a, 150b and 150c possible.

[0339] In each of such cases, in a case that the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) are both directional antennas and that the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) are directional in the orientation in which the receiver receives identifying signals, the orientation in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) receives identifying signals is directed toward the side where the front device mount 40 is present, whereas the orientation in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) receives identifying signals is directed toward the side where rear device mount 40 is present. With this, the receiver 150c (third receiver 150c) located farther from the device mount 40 than the first receiver 150a has low sensitivity to receive identifying signals coming from the side where the device mount 40 is present, as described earlier.

[0340] Specifically, the first receiver 150a has high sensitivity to receive an identifying signal from the tag T of a working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength increases), whereas the other receivers 150b, 150c have low sensitivity to receive the identifying signal from the tag T of the working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength decreases). Thus, when the first receiver 150a and the other receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40. Note that, in such a case, when the pair of second receivers 150b are omnidirectional antennas, the receivers have the same or substantially the same sensitivity to receive identifying signals from the front and from the rear, making it possible to cause one of the front and rear receivers in the front-rear direction to function as a first receiver 150a and the other to function as a second receiver 150b.

[0341] In the fifth example embodiment, the receivers 150a, 150b and 150c are located at three positions on the agricultural tractor without cabin, but this does not imply any limitation. For example, the receivers 150a and 150b may be located at two positions forward of and rearward of the seat 21, based on the position of the device mount 40 (see FIG. 33), and the receivers 150a and 150b may be located at the following three positions: a position rearward of the seat 21, and two positions forward of the seat 21 or on opposite sides of the seat 21 in the lateral direction, based on the position of the device mount 40 (see FIG. 34). Also in such cases, the same effects as in the first example embodiment and the second example embodiment can be achieved by performing the same processes as in the first example embodiment and the second example embodiment.

[0342] In the above-described example embodiments, the receivers 150a, 150b, and 150c (first receiver 150a, second receivers 150b, third receiver 150c), which are antennas, and the receiver main bodies 151a and 151b are combined to define receivers 15a, 15b, and 15c (first receiver 15a, second receivers 15b, third receiver 15c), and the receivers 15a, 15b, and 15c are arranged such that the receivers 150a, 150b, and 150c (first receiver 150a, second receivers 150b, third receiver 150c) are located at appropriate positions. Note, however, that this does not imply any limitation.

[0343] For example, in another example embodiment of the present invention, as illustrated in FIG. 35, the receivers 150a, 150b and 150c may be antennas 150a, 150b and 150c, the working machine 1 may include receiver(s) 15a, 15b, 15c including receiver main body(bodies) 151a, 151b and 151c to accept identifying signals from the antennas 150a, 150b and 150c, and the receiver(s) 15a, 15b, 15c may include a plurality of input interfaces 153a, 153b, and 153c connected to the antennas 150a, 150b, and 150c and an output interface 154 to output, to the controller 5, identifying signals inputted into the input interfaces 153a, 153b, and 153c. That is, the receivers 150a, 150b and 150c (first receiver 150a, second receiver 150b, third receiver 150c) and the receiver main bodies 151a, 151b and 151c (first receiver main body 151a, second receiver main body 151b, third receiver main body 151c) may be provided independently of each other.

[0344] In such a case, since the receiver 15a, 15b, 15c (receiver main body 151a, 151b, 151c) is a multi-channel receiver and includes a plurality of input interfaces 153a, 153b and 153c, a plurality of coaxial cables are connected to the plurality of receivers 150a, 150b and 150c (first receiver 150a, second receiver(s) 150b, third receiver 150c). This allows the receivers 150a, 150b and 150c and the receiver 15a, 15b, 15c (receiver main body 151a, 151b and 151c) to be located at different positions. Also in such a case, the receiver main body 151a, 151b, 151c (first receiver main body 151a, second receiver main body 151b, third receiver main body 151c) is connected to the controller 5 via a signal wire (CAN bus).

[0345] In the above-described example embodiments, the receivers 150a, 150b and 150c are directional antennas to receive identifying signals from a particular direction. Note, however, that this does not imply any limitation. For example, in another example embodiment of the present invention, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c may be omnidirectional antennas. In such a case, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c are capable of receiving signals from particular directions (signals coming from the side where the device mount 40 is present), making it possible to also receive signals not necessary to recognize a working device 9.

[0346] In view of the above, as illustrated in FIGS. 36 and 37, the machine body 2 preferably includes a cover 16 which covers the first receiver 150a, the second receiver 150b, or the third receiver 150c, which blocks identifying signals, and which includes an opening 160. In such a case, the cover 16 is positioned such that the opening 160 faces toward the side where the device mount 40 is present. With this, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c each only receive identifying signals that have passed through the opening 160. Thus, even in the case where the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c are omnidirectional antennas, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c do not receive signals unnecessary to recognize a working device 9, improving the accuracy of identification of the working device 9. Even in the case where the first receiver 150a, the second receivers 150b, and the third receiver 150c are directional antennas, the first receiver 150a, the second receivers 150b, and the third receiver 150c may be covered by such covers 16.

[0347] In such a case, at least the cover 16 that covers the first receiver 150a is positioned such that the opening 160 faces toward the side where the device mount 40 is present. The covers 16 that cover the receivers 150b, 150c which are distant from the device mount 40 are positioned such that the opening 160 faces in a direction different from a direction toward the side where the device mount 40 is present, making it possible to lower (reduce) the sensitivity of the receivers 150b, 150c to receive identifying signals from the side where the device mount 40 is present.

[0348] Thus, when the first receiver 150a and the other receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40. Note that, when the receivers 150b, 150c distant from the device mount 40 are positioned such that the opening 160 (the orientation in which the receiver receives identifying signals) is directed away from the device mount 40, the sensitivity of the receivers 150b, 150c to receive identifying signals from the side where the device mount 40 is present can be reduced, making it possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40.

[0349] In the foregoing first to third example embodiments, the device mount 40 includes a linkage 41 to connect a working device 9 (9A or the like) thereto, the linkage 41 includes an engagement portion 412 movable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 (9A or the like) to connect the working device 9 (9A or the like) thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 (9A or the like) to disconnect the working device 9 (9A or the like) therefrom, and the controller 5 is configured or programmed to determine that the working device 9 (9A or the like) is attached to the device mount 40 when the engagement portion 412 is in the engaging position PE1. Note, however, that this does not imply any limitation.

[0350] For example, in another example embodiment of the present invention, similar to the fourth and fifth example embodiments, the controller 5 may be configured or programmed to, after recognizing the working device 9 (9A or the like), when the receivers 150a, 150b and / or 150c (first receiver 150a, second receiver 150b, third receiver 150c) at at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device (9A or the like) is attached to the device mount 40.

[0351] Specifically, the level of the received signal strength of an identifying signal received by each of the receivers 150a, 150b and 150c is correlated with the distance between the tag T and the receiver 150a, 150b or 150c. That is, the received signal strength of an identifying signal received by each receiver 150a, 150b or 150c increases as the distance between the tag T and the receiver 150a, 150b or 150c decreases, whereas the received signal strength of an identifying signal received by each receiver 150a, 150b or 150c decreases as the distance between the tag T and the receiver 150a, 150b or 150c increases.

[0352] Thus, in the case where the received signal strength of an identifying signal received by the receiver(s) 150a, 150b, 150c is a predetermined received signal strength (high received signal strength) and does not change even after a predetermined time period, it is possible to estimate that the working device 9 (9A or the like) is now attached to the device mount 40. Note that the relative distance between the tag T and each receiver 150a, 150b or 150c with the working device 9 (9A or the like) attached to the device mount 40 is fixed. Therefore, it is possible to improve reliability by measuring received signal strength with the working device 9 (9A or the like) connected to the device mount 40 in advance and setting the measured value as the predetermined received signal strength.

[0353] As another example, the controller 5 may be configured or programmed to directly or indirectly recognize a load on the actuator 61 (which causes the device mount 40 to move along a path) and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40 (whether the working device 9 (9A or the like) is attached to the device mount 40).

[0354] Specifically, when a working device 9 (9A or the like) is attached to the device mount 40, the weight of the working device 9 (9A or the like) is applied as a load to the actuator 61 via the support structure 4, so that a change occurs in pressure in a pipe which is included in the hydraulic system 6 and via which hydraulic fluid is supplied to and discharged from the actuator 61.

[0355] Therefore, when a pressure sensor provided in the pipe connected to the actuator 61 is connected to the controller 5 (input interface 52) and the controller 5 receive the detection from the pressure sensor, the controller 5 is able to recognize the load on the actuator 61, and, based on the recognition, determine whether the working device 9 (9A or the like) is attached to or detached from (whether the working device 9 (9A or the like) is attached to) the device mount 40. Note that the working machine 1 (agricultural tractor 1) of the fourth and fifth example embodiments also includes an actuator 61 to actuate the support structure 4, and therefore the above-described configuration (manner) can also be applied to the fourth and fifth example embodiments.

[0356] In the first to fourth example embodiments, the receivers 150a, 150b and 150c are arranged with reference to the cabin 22, and, in the fifth example embodiment, the receivers 150a, 150b and 150c are arranged with reference to the seat 21. Note, however, that this does not imply any limitation. For example, assuming that the device mount 40 is provided at at least one of the positions forward and rearward of the machine body 2, the receivers 150a, 150b and / or 150c may be located at increasing distances from the device mount 40, e.g., (i) located at two positions at the front and rear of the machine body 2 in the front-rear direction, (ii) located at vertices of a triangle in plan view (at three positions) as in the second example embodiment, or (iii) located at vertices of a quadrangle (lozenge) in plan view (at four positions) as in the third example embodiment. That is, the receiver 150a (first receiver 150a), which is closest to the device mount 40, may be located at one of the positions at the front and rear of the machine body 2, and the receiver 150b, 150c (second receiver 150b or third receiver 150c) farthest from the device mount 40 may be located at the other of the positions at the front and rear of the machine body 2. In the case where receivers 150b are provided between the receiver 150a (first receiver 150a) closest to the device mount 40 and the receiver 150c (third receiver 150c) farthest from the device mount 40, the receivers 150b may be located on opposite sides of the machine body 2 in the lateral direction. With this, the reference based on which the receivers 150a, 150b and 150c are arranged merely changes from the cabin 22 or the seat 21 to the machine body 2, making it possible to achieve similar effects to the foregoing example embodiments.

[0357] In the third example embodiment and the fifth example embodiment, a pair of second receivers 150b provided on opposite sides of the cabin 22 or the seat 21 in the lateral direction are oriented forward in the front-rear direction. Note, however, that this does not imply any limitation. For example, as illustrated in FIGS. 38 and 39, the pair of second receivers 150b provided on opposite sides of the cabin 22 or the seat 21 in the lateral direction may be oriented sideward (outward in the lateral direction). Specifically, one of the pair of second receivers 150b arranged with a space therebetween in the lateral direction that is located at one of opposite sides in the lateral direction (that is located at the right side) may be oriented rightward, and the other of the pair of second receivers 150b that is located at the other of the opposite sides in the lateral direction (that is located at the left side) may be oriented leftward. With this, the one of the second receivers 150b receives identifying signals coming from the right with high received signal strength, and receives identifying signals coming from the front and left with low received signal strength. On the other hand, the other of the second receivers 150b receives identifying signals coming from the left with high received signal strength, and receives identifying signals coming from the front and right with low received signal strength. With this, in the case where the working device 9 (9A or the like) is located at a side (right side or left side) of the machine body, the second receiver 150b on the same side of the machine body as the working device 9 (9A or the like) receives identifying signals with high received signal strength, so that the accuracy of determining the position (location) of the working device 9 (9A or the like) increases.

[0358] The third receiver 150c may be oriented in a direction opposite to the direction in which the first receiver 150a is oriented. Specifically, in the case where the third receiver 150c is provided at the rear of the machine body 2 (the cabin 22 or the seat 21), the third receiver 150c may be oriented rearward in the front-rear direction, whereas in the case where the third receiver 150c is provided forward of (or at a front portion of) the machine body 2 (forward of the cabin 22 or the seat 21), the third receiver 150c may be oriented forward of the machine body 2 (the cabin 22 or the seat 21). With this, when a working device 9 (9A or the like) is present on the same side of the machine body 2 (the cabin 22 or the seat 21) as the third receiver 150c, the third receiver 150c receives an identifying signal with a higher received signal strength than the first receiver 150a, making it possible to accurately determine whether the working device 9 (9A or the like) is present forward of or rearward of the machine body 2 (the cabin 22 or the seat 21). It is also possible to determine whether the working device 9 (9A or the like) is present diagonally forward or diagonally rearward of the machine body 2 using the combination of (the ratio between) the received signal strengths of the identifying signals received by the first receiver 150a and the second receiver 150b or using the combination of (the ratio between) the received signal strengths of the identifying signals received by the second receiver 150b and the third receiver 150c.

[0359] As illustrated in FIG. 40, in the case where a working device 9 (9A or the like) is attached at a position rearward of the machine body 2 and a hood 25 is provided forward of the seat 21, by providing the third receiver 150c at a position farthest from the first receiver 150a (at the front end of the hood 25 in the case of FIG. 40), it is possible to reduce the received signal strength of identifying signals received by the third receiver 150c when the working device 9 (9A or the like) is present on the same side of the machine body 2 as the first receiver 150a, and possible to increase the received signal strength of identifying signals received by the third receiver 150c when the working device 9 (9A or the like) is present on the same side of the machine body 2 as the third receiver 150c. With this, it is possible to accurately determine whether the working device 9 (9A or the like) is present forward of or rearward of the machine body 2 (the cabin 22 or the seat 21).

[0360] The controller 5 may be configured or programmed to, based on an identifying signal received by the receivers 150a, 150b and / or 150c and based on the received signal strength(s) (the level(s) of the received signal strength(s)) of the identifying signal, determine the location of the working device 9 (9A or the like) including the transmitter T which transmits the identifying signal and cause the monitor 33 to display the determined location (position) of the working device 9 (9A or the like).

[0361] As illustrated in FIG. 41, the monitor 55 may be operable to display pieces of device information 9A and the like corresponding to respective working devices 9 (9A and the like) and allow selection of one of the pieces of device information 9A (selection of a working device 9 (9A or the like) for which the user wishes to know the location). In the example illustrated in FIG. 41, similar to the foregoing example embodiments, the monitor 55 is a touchscreen, the pieces of device information 9A and the like are icons of the working devices 9 (9A or the like), and touching (selecting) an icon allows selection of a working device for which the user wishes to know the location. The pieces of device information 9A and the like may be displayed in text form (names of devices) in a table form. In such a case, the controller 5 may be configured or programmed to, based on an identifying signal from the transmitter T of the working device 9 (9A or the like) corresponding to the piece of device information 9A or the like selected via the monitor 55 and based on the received signal strength(s) of the identifying signal, determine the location of the working device 9 (9A or the like) including the transmitter T which transmits the identifying signal and cause the monitor 33 to display the determined information (location of the working device 9 (9A or the like)).

[0362] Specifically, when the user selects a working device 9 (9A or the like) for which the user wishes to know the location on the monitor 55, the controller 5 determines whether or not an identifying signal is received from the transmitter T of the selected working device 9 (9A or the like). Next, when the receivers 150a, 150b and / or 150c receive that identifying signal, the controller 5 determines the location of the working device 9 (9A or the like) based on that identifying signal and the received signal strength(s) of the identifying signal. For example, in the case where the receivers 150a, 150b and 150c are provided at front, rear, left and right, as illustrated in FIG. 42, when the working device 9 (9A or the like) is located at a side of the machine body 2 (the right side in the example illustrated in FIG. 42), the working device 9 (9A or the like) is closest to the right second receiver 150b, so that the right second receiver 150b receives the identifying signal with the highest received signal strength. The controller 5 is configured or programmed to, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal, cause the monitor 55 to display, as illustrated in FIG. 43, the direction toward the location of the working device 9 (9A or the like) (the rightward direction, which is one of opposite lateral directions in FIG. 43). The direction is represented by arrow AR in the present example embodiment.

[0363] When, as illustrated in FIG. 44, the working device 9 (9A or the like) is present diagonally forward of the machine body 2 (diagonally forward and rightward in the case of FIG. 44), the working device 9 (9A or the like) is closest to at least one of (i) the first receiver 150a or (ii) one of the second receivers 150b, so that the at least one of (i) the first receiver 150a or (ii) one of the second receivers 150b receives the identifying signal with the highest received signal strength. Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal, as illustrated in FIG. 45, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (diagonally rightward and forward in FIG. 45). The direction is represented by arrow AR in the present example embodiment.

[0364] Thus, with the use of the combination of the levels of the received signal strengths of the identifying signal received by the receivers 150a, 150b and 150c located at four positions at front, rear, left and right, it is possible to accurately determine the location (position) of the working device 9 (9A or the like) and allow the user to recognize the position of the working device 9 (9A or the like) (the direction toward the working device 9 (9A or the like)) via the indication (arrow AR) on the monitor 55.

[0365] In another example embodiment, in the case where the working machine 1 includes receivers 150a and 150b located at three positions at front and rear, i.e., a first receiver 150a and a left and right pair of second receivers 150b, for example, as illustrated in FIG. 46, when the working device 9 (9A or the like) is present at a side of (just beside) the machine body 2 (the cabin 22 or the seat 21) in the lateral direction, one of the second receivers 150b that is on the same side of the machine body 2 as the working device 9 (9A or the like) receives the identifying signal with the highest received signal strength, and the received signal strength of the identifying signal decreases in the order of the first receiver 150a and the other second receiver 150b. Specifically, as illustrated in FIG. 46, when the working device 9 (9A or the like) is located at the right side of the machine body 2 (the cabin 22 or the seat 21), the one of the second receivers 150b that is located at the right side of the machine body 2 receives the identifying signal with the highest received signal strength, and the received signal strength of the identifying signal decreases in the order of the first receiver 150a closest to the device mount 40 and the other second receiver 150b at the left side of the machine body 2.

[0366] Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the location of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 47, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (rightward direction in FIG. 47). The direction is represented by arrow AR in the present example embodiment.

[0367] As illustrated in FIG. 48, in the case where the working device 9 (9A or the like) is present diagonally forward of the machine body 2 (the cabin 22 or the seat 21), at least one of (i) one of the pair of second receivers 150b or (ii) the first receiver 150a located forward of (or at a front portion of) the machine body 2 receives the identifying signal with the highest received signal strength, and the other second receiver 150b receives the identifying signal with the lowest received signal strength.

[0368] For example, as illustrated in FIG. 48, when the working device 9 (9A or the like) is present diagonally rightward and forward of the machine body 2 (the cabin 22 or the seat 21), at least one of the right second receiver 150b or the first receiver 150a receives the identifying signal with the highest received signal strength. Specifically, in the case where the strengths of the identifying signal at the first receiver 150a and the right second receiver 150b are equal or substantially equal, the working device 9 (9A or the like) is present at a position diagonally forward of the machine body 2 at equal distances from the first receiver 150a and the right second receiver 150b. In the case where the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strength of the identifying signal at the right second receiver 150b, the working device 9 (9A or the like) is located at a position diagonally forward of the machine body 2 but closer to the position directly in front of the machine body 2 than to the position rightward of the machine body 2. On the contrary, in the case where the received signal strength of the identifying signal at the right second receiver 150b is higher than the received signal strength of the identifying signal at the first receiver 150a, the working device 9 (9A or the like) is located at a position diagonally forward of the machine body 2 but closer to the position sideward of (directly beside) the machine body 2 than to the position directly in front of the machine body 2. Note that, in the case where the working device 9 (9A or the like) is present diagonally leftward and forward of the machine body 2 (the cabin 22 or the seat 21), at least one of (i) the left second receiver 150b instead of the right second receiver 150b or (ii) the first receiver 150a receives the identifying signal with the highest received signal strength. Thus, the relationship between the level of the received signal strength of the identifying signal at the left second receiver 150b and the level of the received signal strength of the identifying signal at the first receiver 150a is the same as in the case where the working device 9 (9A or the like) is present diagonally rightward and forward of the machine body 2. Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the position of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 49, causes the monitor 55 to display the direction to the working device 9 (9A or the like) (diagonally rightward and forward direction in the example illustrated in FIG. 49). The direction is represented by arrow AR in the present example embodiment.

[0369] As illustrated in FIG. 50, in the case where the working device 9 (9A or the like) is present rearward of the machine body 2 (the cabin 22 or the seat 21), at least one of the pair of second receivers 150b receives the identifying signal with the highest received signal strength, and the first receiver 150a receives the identifying signal with the lowest received signal strength. That is, the pair of second receivers 150b receive the signal with the same or substantially the same strength, and the first receiver 150a receives the identifying signal with a received signal strength lower than those at the pair of second receivers 150b. For example, as illustrated in FIG. 50, in the case where the working device 9 (9A or the like) is present directly rearward of the machine body 2 (the cabin 22 or the seat 21), the pair of second receivers 150b receive the identifying signal with the same or substantially the same strength. On the contrary, in the case where the working device 9 (9A or the like) is present rearward of the machine body 2 (the cabin 22 or the seat 21) and is offset in one of the first and second lateral directions, one of the second receivers 150b that is on the same side as the working device 9 (or the like 9A) receives the identifying signal with a higher received signal strength than the other second receiver 150b.

[0370] Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the location of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 51, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (directly rearward in FIG. 51). The direction is represented by arrow AR in the present example embodiment.

[0371] Since the controller 5 determines the location of the working device 9 (9A or the like) corresponding to the selected one of the pieces of device information 9A and the like displayed on the monitor 55 and causes the monitor 55 to display the determined location of the working device 9 (9A or the like) in such a manner, the user can quickly know the location of the intended working device 9 (9A or the like). With this, even in the case where a plurality of working devices 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0372] In the case where the monitor 55 displays the position of (direction to) the working device 9 (9A or the like), the screen displayed on the monitor 55 may be a dedicated screen. Note, however, that as illustrated in FIGS. 43, 45, 47, 49, and 51, the position of (direction to) the working device 9 (9A or the like) may be displayed on a screen to display other items. Note that, in FIGS. 43, 45, 47, 49, and 51, the monitor 55 displays the arrow AR representing the position of (direction to) the working device 9 (9A or the like), and also displays the type of the attached working device 9 (9A or the like) attached to the device mount 40 (text “Sweeper” and the icon in FIGS. 43, 45, 47, 49, and 51) as well as an indication that the position of (direction to) the working device 9 (9A or the like) is currently displayed (the text “Displaying direction to 9B Pallet fork” in FIGS. 43, 45, 47, 49, and 51). The monitor 55 also displays a fuel meter, a water temperature meter, an oil temperature meter, and the like, in digital form.

[0373] In FIGS. 43, 45, 47, and 49, the arrow AR representing the direction toward the location of the working device 9 (9A or the like) is displayed at a certain position or a fixed position of the screen displayed on the monitor 55 (right corner in FIGS. 43, 45, 47, and 49). Note, however, that the position of (direction to) the working device 9 (9A or the like) and the arrow AR may be displayed in a manner that is more easily visually recognizable. for example, as illustrated in FIGS. 51 and 52, the monitor 55 may display a circular or substantially circular area or a boundary line that defines a circular or substantially circular area, and display the arrow AR such that the arrow AR rotates around the center of the circular or substantially circular area according to the position of (direction to) the working device 9 (9A or the like), i.e., such that the arrow AR moves along the boundary line defining the circular or substantially circular area according to the position of (direction to) the working device 9 (9A or the like). That is, the monitor 55 may display the arrow AR such that the arrow AR indicates the direction to the location of the working device 9 (9A or the like) in a manner similar to the needle of a compass indicating a direction. Note that FIG. 51 shows that the working device 9 (9A or the like) is present rearward of the machine body 2, and FIG. 52 shows that the working device 9 (9A or the like) is present rightward of the machine body 2. In the above-described example embodiments, although the monitor 55 displays the direction to the location of the working device 9 (9A or the like) using the arrow AR, this does not imply any limitation. For example, the monitor 55 may display a map and display a symbol representing the location of the working device 9 (9A or the like) on the map.

[0374] Example embodiments of the present invention have been described so far. Example embodiments of the present invention provide working machines described in the following items.

[0375] (Item 1) A working machine 1 including a machine body 2, a device mount 40 to replaceably attach a working device 9 (9A or the like) thereto, the working device 9 (9A or the like) including a transmitter T to transmit a unique identifying signal and being operable to perform a function corresponding to work, and a controller 5 configured or programmed to control the machine body 2, wherein the machine body 2 includes receivers 150a, 150b, 150c to receive the identifying signal from the transmitter T, the receivers 150a, 150b, 150c are located at respective at least two positions separated from the device mount 40 by different distances, and the controller 5 is configured or programmed to recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on a received signal strength of the identifying signal received by at least one of the receivers 150a, 150b, 150c that is located at at least one of the at least two positions.

[0376] With the working machine 1 described in item 1, since the receivers 150a, 150b and / or 150c located at respective at least two positions receive an identifying signal transmitted from a single transmitter T, it is possible to eliminate or reduce the likelihood that the working device 9 (9A or the like) will be difficult to identify because, for example, the identifying signal from the transmitter T is not received sufficiently. Furthermore, since the controller 5 recognizes the received signal strengths in addition to the information included in the identifying signal received by at least one of the receivers 150a, 150b and 150c located at least one of the two positions, the controller 5 recognizes the relative distance between the machine body 2 and the working device 9 (9A or the like) (recognizes the position of the working device 9 (9A or the like)). That is, the controller 5 is able to appropriately determine whether the working device 9 (9A or the like) is located at a position at which the working device 9 (9A or the like) can be attached to the device mount 40. Thus, it is possible to eliminate or reduce the likelihood that the working device 9 (9A or the like) will be recognized in a wrong manner and also possible to appropriately determine whether or not the working device 9 (9A or the like) is located at a position at which the working device 9 (9A or the like) can be attached to the device mount 40. Therefore, with the working machine 1 of item 1, it is possible to accurately recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40. That is, the working machine 1 of item 1 is able to accurately recognize the working device 9 (9A or the like) to be attached to the device mount 40.

[0377] (Item 2) The working machine 1 according to item 1, wherein the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, and the receivers 150a, 150b, 150c are located at the at least two positions at increasing distances from the device mount 40 in the front-rear direction of the machine body 2.

[0378] With the working machine 1 according to item 2, since the receivers 150a, 150b and / or 150c are located at at least two positions at increasing distances from the device mount 40 in the front-rear direction of the machine body 2, the receivers 150a, 150b and / or 150c receive an identical identifying signal but the received signal strength of the identifying signal received by each of them differs depending on the distance from the device mount 40. Specifically, in order to attach a working device 9 (9A or the like) to the device mount 40, the working machine 1 moves the device mount 40 such that the device mount 40 approaches the working device 9 (9A or the like). Under such conditions, the receivers 150a, 150b and / or 150c are located at increasing distances also from the working device 9 (9A or the like). Thus, since the distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a, 150b and / or 150c is different, the received signal strength of the identifying signal received by each of the receivers 150a, 150b and / or 150c differs depending on the distance. Specifically, the received signal strength at the receiver 150a, 150b or 150c increases as the distance to the device mount 40 decreases. Therefore, it is possible to appropriately recognize the position of the working device 9 (9A or the like) relative to the working machine 1 (the direction from the working machine 1 to the working device 9 (9A or the like)) and the distance to the working device 9 (9A or the like) based on the received signal strengths at the receivers 150a, 150b and / or 150c located at least two positions.

[0379] (Item 3) The working machine 1 according to item 1, wherein the receivers 150a, 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances, and the controller 5 is configured or programmed to determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b at the at least three positions, based on a combination of levels of received signal strengths at the receivers 150a, 150b at the at least three positions.

[0380] With the working machine 1 according to item 3, since the receivers 150a and 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances, the receivers 150a and 150b are located at vertices of a triangle. Thus, the received signal strength of the identifying signal at each of the receivers 150a and 150b at the vertices of the triangle depends on the length of a corresponding one of three imaginary straight lines that connects the receiver 150a, 150b and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b and the transmitter T). It is therefore possible to appropriately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0381] (Item 4) The working machine 1 according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions one of which is in an area SA between the device mount 40 and the cabin 22 in the front-rear direction and the other of which is within the cabin 22, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength of the identifying signal received by one of the receivers (receiver 150a) that is in the area SA between the more device mount 40 and the cabin 22 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) that is within the cabin 22 is within a predetermined range.

[0382] With the working machine 1 according to item 4, the receiver 150a that is located at a position within the area SA between the device mount 40 and the cabin 22 in the front-rear direction is closest to the device mount 40 of the two receivers 150a and 150b. With this, the received signal strength of the identifying signal from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 is higher (greater) at the receiver 150a than at the other receiver 150b. In contrast, the receiver 150b located within the cabin 22 is at a position distant from the device mount 40, and the received signal strength of the identifying signal from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 is lower (less) at the receiver 150b than at the other receiver 150a which is closest to the device mount 40. Furthermore, since the cabin 22 reduces the rate of the identifying signal entering the cabin22, the received signal strength at the receiver 150b within the cabin 22 decreases further. With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with greatly different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0383] (Item 5) The working machine 1 according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions one of which is forward of a center of the cabin 22 in the front-rear direction and the other of which is rearward of the center, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers (receiver 150a) that is closest to the device mount 40 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) is within a predetermined range.

[0384] With the working machine 1 according to item 5, the receivers 150a and 150b are located at two positions one of which is forward of a center of the cabin 22 in the front-rear direction and the other of which is rearward of the center. That is, one (receiver 150a) of the two receivers 150a and 150b is located closest to the device mount 40 of the two receivers 150a and 150b, and the other receiver 150b is located farther from the device mount 40 than the one receiver 150a is from the device mount 40. With this, the received signal strength of the identifying signal transmitted from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 and received by the one receiver 150a is higher (greater) than that of the other receiver 150b, whereas the received signal strength at the other receiver 150b is lower (less) than the received signal strength at the one receiver 150a.

[0385] With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0386] (Item 6) The working machine according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b, 150c are located at at least four positions including positions at a front and a rear of the cabin 22 in the front-rear direction and on opposite sides of the cabin 22 in a lateral direction perpendicular to the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b, 150c at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four receivers, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the cabin 22 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0387] With the working machine 1 according to item 6, the receivers 150a, 150b, and 150c are located at at least four positions including positions at the front and rear of the cabin 22 in the front-rear direction and on opposite sides of the cabin 22 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver 150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more accurately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0388] With this, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0389] (Item 7) The working machine 1 according to item 1, wherein the machine body 2 includes a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions forward of and rearward of the seat 21 in the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers (receiver 150a) that is closest to the device mount 40 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) is within a predetermined range.

[0390] With the working machine 1 according to item 7, the receivers 150a and 150b are located at two positions forward of and rearward of the seat 21 in the front-rear direction. That is, one (receiver 150a) of the two receivers 150a and 150b is located closest to the device mount 40 of the two receivers 150a and 150b, and the other receiver 150b is located farther from the device mount 40 than the one receiver 150a is from the device mount 40. With this, the received signal strength of the identifying signal transmitted from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 and received by the one receiver 150a is higher (greater) than that of the other receiver 150b, whereas the received signal strength at the other receiver 150b is lower (less) than the received signal strength at the one receiver 150a.

[0391] With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strength, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0392] (Item 8) The working machine 1 according to item 1, wherein the machine body 2 includes a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b, 150c are located at at least four positions including positions forward of and rearward of the seat 21 in the front-rear direction and on opposite sides of the seat 21 in a lateral direction perpendicular to the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b, 150c at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four positions, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located forward of and / or rearward of the seat 21 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0393] With the working machine 1 according to item 8, the receivers 150a, 150b, and 150c are located at at least four positions including positions forward of and rearward of the seat 21 in the front-rear direction and on opposite sides of the seat 21 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver 150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more appropriately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0394] With this, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strength, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0395] (Item 9) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c are located at at least four positions including positions at a front and a rear of the machine body 2 in a front-rear direction and on opposite sides of the machine body 2 in a lateral direction perpendicular to the front-rear direction, the device mount 40 is located at at least one of (i) in front of one of the receivers that is at the front of the machine body 2 or (ii) rearward of another of the receivers that is at the rear of the machine body 2, and the controller 5 is configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four positions, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the machine body 2 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0396] With the working machine 1 according to item 9, the receivers 150a, 150b, and 150c are located at at least four positions including positions at the front and rear of the machine body 2 in the front-rear direction and on opposite sides of the machine body 2 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more accurately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0397] Furthermore, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0398] (Item 10) The working machine according to item 1, wherein the receivers 150a, 150b at the at least two positions include respective directional antennas to receive identifying signals from a particular direction, and are each positioned such that an orientation in which the receiver 150a, 150b receives the identifying signals is directed toward the device mount 40.

[0399] With the working machine 1 according to item 10, the receivers 150a and 150b include respective directional antennas, and are each positioned such that the orientation in which the receiver receives the identifying signal is directed toward the device mount 40. Therefore, when the working device 9 (9A or the like), the device mount 40, and the receivers 150a and 150b are arranged in a line, the shortest linear distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a and 150b is achieved, and the highest received signal strength of the identifying signal at each of the receivers 150a and 150b is achieved. Thus, by determining the position of the working device 9 (9A or the like) based on the highest received signal strength, it is possible to accurately recognize the position of the working device 9 (9A or the like).

[0400] (Item 11) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c at the at least two positions include respective directional antennas to receive identifying signals from a particular direction, a first receiver of the receivers 150a, 150b, 150c at the at least two positions that is closest to the device mount 40 (receiver 150a) is positioned such that an orientation in which the first receiver 150a receives the identifying signals is directed toward the device mount 40, and one or more second receivers of the receivers 150a, 150b, 150c that are distant from the device mount (receivers 150b, 150c) are each positioned such that the orientation in which the second receiver 150b, 150c receives the identifying signal is directed in a different direction from a direction toward a side where the device mount 40 is present.

[0401] With the working machine 1 according to item 11, when the working device 9 (9A or the like), the device mount 40, and the receivers 150a and 150b are arranged in a line, the shortest linear distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a and 150b is achieved, and therefore the highest received signal strength of the identifying signal is achieved at the first receiver 150a closest to the device mount 40. On the contrary, with regard to the second receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is directed in a direction differing from the direction toward the side where the device mount 40 is present, and the sensitivity of the second receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is lower than the first receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0402] (Item 12) The working machine 1 according to item 11, wherein the one or more second receivers 150b, 150c that are distant from the device mount 40 are each positioned such that the orientation in which the second receiver 150b, 150c receives the identifying signals is directed in a direction away from the device mount 40.

[0403] With the working machine 1 according to item 12, with regard to the second receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is spaced away from the device mount 40, and the sensitivity of the second receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is even lower than the first receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with greatly different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0404] (Item 13) The working machine 1 according to item 1, further including a cover 16 to cover each of one or more of the receivers 150a, 150b, 150c at the at least two positions that are farther from the device mount 40 than the other one or more of the receivers (cover the receivers 150b, 150c), the cover 16 being positioned to block the identifying signal, and the cover 16 includes an opening 160 which faces in a direction different from a direction toward a side where the device mount 40 is present.

[0405] With the working machine 1 according to item 13, with regard to the receivers 150b, 150c each covered by the cover 16, identifying signals that reach the portion of the cover 16 that is other than the opening 160 are blocked by the cover 16, and the receivers 150b, 150c each only receive identifying signals that have passed through the opening 160. Thus, the cover 16 increases the directivity of the receiver 150b, 150b in receiving identifying signals.

[0406] (Item 14) The working machine 1 according to item 13, wherein the opening 160 faces away from the device mount 40.

[0407] With the working machine 1 according to item 14, with regard to the receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is spaced away from the side where the device mount 40 is present, and the sensitivity of the receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is even lower than the receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with greatly different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0408] (Item 15) The working machine 1 according to item 1, wherein the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) to be attached to the device mount 40 based on one or more received signal strengths of the identifying signal received by the receivers 150a, 150b, 150c at the at least two positions, when the receivers 150a, 150b, 150c at the at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device 9 (9A or the like) is attached to the device mount 40.

[0409] With the working machine 1 according to item 15, the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) to be attached to the device mount 40, when the receivers 150a, 150b, 150c at the at least two positions have received an identical identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device 9 (9A or the like) is attached to the device mount 40. Therefore, using a series of processes relating to the receivers 150a, 150b and 150c receiving an identifying signal, it is possible to recognize the working device 9 (9A or the like) and appropriately recognize that the working device 9 (9A or the like) is attached to the device mount 40.

[0410] (Item 16) The working machine 1 according to item 1, further including a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and an actuator 61 to cause the device mount 40 to move along the path, wherein the controller 5 is configured or programmed to directly or indirectly recognize a load on the actuator 61 and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40.

[0411] With the working machine 1 according to item 16, the controller 5 is configured or programmed to directly or indirectly recognize a load on the actuator 61 and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40. Thus, whether the working device 9 (9A or the like) is attached to or detached from the device mount 40 is determined based on the actual conditions. Specifically, when a working device 9 (9A or the like) is attached to the device mount 40, the load (weight) of the working device 9 (9A or the like) is applied to the actuator 61 via the support structure 4. The load of the working device 9 (9A or the like) is the load on the actuator 61, and therefore, when the load on the actuator 61 is directly or indirectly recognized to determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40, the result of determination that matches the actual conditions is obtained.

[0412] (Item 17) The working machine 1 according to item 1, wherein the device mount 40 includes a linkage 41 to connect the working device 9 (9A or the like) thereto, and the linkage 41 includes an engagement portion 412 movable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 (9A or the like) to connect the working device 9 (9A or the like) thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 (9A or the like) to disconnect the working device 9 (9A or the like) therefrom, and the controller 5 is configured or programmed to determine that the working device 9 (9A or the like) is attached to the device mount 40 when the engagement portion 412 is in the engaging position PE1.

[0413] With the working machine 1 according to item 17, the controller 5 determines whether the working device 9 (9A or the like) is attached to the device mount 40 based on the state of the linkage 41 which connects the working device 9 (9A or the like). Therefore, the result of determination that matches the actual conditions is obtained.

[0414] (Item 18) The working machine 1 according to item 1, further including receivers 15a, 15b, 15c each including an assembly of an antenna 150a, 150b, 150c which is one of the receivers 150a, 150b, 150c and a receiver main body 151a, 151b, 151c to receive the identifying signal from the antenna 150a, 150b, 150c, and the receivers 15a, 15b, 15c are located at the respective at least two positions, and connected to the controller 5 such that the identifying signal is transmittable to the controller 5.

[0415] With the working machine 1 according to item 18, since the receivers 15a, 15b and 15c are independent units, even in case of trouble in any of the receivers 15a, 15b and 15c, the other(s) of the receivers 15a, 15b and 15c can still receive the identifying signal from the transmitter T of the working device 9 (9A or the like) and transmit the identifying signal to the controller 5.

[0416] (Item 19) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c include antennas 150a, 150b, 150c, the working machine 1 includes a receiver 15a, 15b, 15c including: a receiver main body 151a, 151b, 151c to receive the identifying signal from the antennas 150a, 150b, 150c, input interfaces 153a, 153b, 153c to connect thereto the antennas 150a, 150b, 150c at the at least two positions, and an output interface 154 to output, to the controller 5, the identifying signal inputted into the input interfaces 153a, 153b, 153c.

[0417] With the working machine 1 according to item 19, the receiver 15a, 15b, 15c includes input interfaces 153a, 153b, 153c to connect thereto the antennas 150a, 150b, 150c at the at least two positions, and includes an output interface 154 to output, to the controller 5, the identifying signals inputted into the input interfaces 153a, 153b, 153c. With this, the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) can be connected to the input interfaces 153a, 153b, 153c (to the receiver 15a, 15b, 15c)) via coaxial cables. This makes it possible to provide the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) and the receiver main body 151a, 151b, 151b (receiver 15a, 15b, 15c), independently of each other, at different positions. With this, even if there are only limited spaces for the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) (even if there is no space for the receivers 15a, 15b and 15c (receiver main bodies 151a, 151b and 151c), it is still possible to provide the receivers 150a, 150b and 150c at appropriate positions.

[0418] (Item 20) The working machine 1 according to item 1, further including a monitor 55, wherein the controller 5 is configured or programmed to determine a location of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal based on the identifying signal received by one or more of the receivers 150a, 150b, 150c and based on one or more received signal strengths of the identifying signal, and cause the monitor 55 to display the determined location of the working device 9 (9A or the like).

[0419] With the working machine 1 according to item 20, the display on the monitor 55 allows the user to know the location of the working device 9 (9A or the like) to be attached to the device mount 40. With this, even in the case where a plurality of working device 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0420] (Item 21) The working machine 1 according to item 20, wherein the monitor 55 is operable to display pieces of device information 9A and the like corresponding to a plurality of the working devices 9 (9A and the like) and to allow a selection of one of the pieces of device information 9A and the like, and the controller 5 is configured or programmed to, based on the identifying signal from the transmitter T of a corresponding one of the plurality of working devices 9 (9A and the like) that corresponds to the selected piece of device information 9A and the like selected on the monitor 55 and based on the one or more received signal strengths of the identifying signal, determine a location of the corresponding one of the plurality of working devices 9 (9A and the like) that includes the transmitter T transmitting the identifying signal.

[0421] With the working machine 1 according to item 21, the location of the working device 9 (9A or the like) corresponding to the selected one of the pieces of device information 9A and the like displayed on the monitor 55 is determined, and the determined location of the working device 9 (9A or the like) is displayed on the monitor 55, allowing the user to quickly know the location of the intended working device 9 (9A or the like). With this, even in the case where a plurality of working device 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0422] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

first example embodiment

[0084]The following description discusses a working machine according to a first example embodiment of the present invention with reference to drawings. Note that, assuming that the working machine is able to travel, the direction of straight travel (direction of forward travel or rearward travel) is hereinafter referred to as a front-rear direction, a direction perpendicular to the front-rear direction and an up-down direction is hereinafter referred to as a lateral direction. One of such lateral directions that is on the right side when the user faces forward is hereinafter referred to as a rightward direction (right), and the other of the lateral directions that is on the left side when the user faces forward is hereinafter referred to as a leftward direction (left).

[0085]A working machine 1 according to the first example embodiment is a compact track loader for use in construction work, civil engineering work or the like, as illustrated in FIGS. 1 to 10. The working machine 1 in...

second example embodiment

[0172]The following description discusses a working machine according to a second example embodiment of the present invention. Note that the working machine according to the second example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine of the first example embodiment except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the second example embodiment only discusses the differences from the first example embodiment, and the description for the same configurations as the first example embodiment is not repeated here but the description in the first example embodiment is applied as that for the second example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment are assigned the same names and reference signs as in the first example embodimen...

third example embodiment

[0213]The following description discusses a working machine according to a third example embodiment of the present invention. Note that the working machine according to the third example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine 1 of the first example embodiment and the working machine 1 of the second example embodiment, except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the third example embodiment only discusses the differences from the first example embodiment and the second example embodiment, and the description for the same configurations as the first example embodiment and the second example embodiment is not repeated here but the description in the first example embodiment and the second example embodiment is applied as that for the third example embodiment. Furthermore, the f...

BACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to working machines each including a device mount to replaceably attach thereto a working device to perform predetermined work.2. Description of the Related Art

[0002] Working machines such as compact track loaders, skid-steer loaders, and agricultural tractors each include a device mount to replaceably (detachably) attach thereto a working device to perform a function corresponding to work. Such a working machine is configured to be able to control the working device attached to the device mount, and replacing the working devices allows work corresponding to the purpose to be performed. That is, such a working machine includes a manual operator to be operated by a user, and a controller to control the working device based on how the manual operator is operated.

[0003] Since the working device performs the function corresponding to work, the operation (action) of the working device varies depending on the type of the working device. Accordingly, the working machine needs to recognize the working device that the controller controls. That is, in order to perform control corresponding to the type of working device, the working machine needs to recognize the working device attached to the device mount.

[0004] In view of this, there is provided a working machine in which a controller communicates with a working device in a wired manner to recognize the working device attached to the device mount (see, for example, Japanese Unexamined Patent Application Publication No. 2021-182887).SUMMARY OF THE INVENTION

[0005] The working machine which communicates with working device(s) in a wired manner needs to be connected to the working device by a cable (signal wire), and therefore there has recently been an increasing number of working machines to communicate with a transmitter (tag) attached to the working device in a wireless manner to automatically recognize the working device attached to the device mount. Such a working machine receives a unique identifying signal which is specific to each type of working device and which is transmitted from a transmitter, and recognizes the working device based on the identifying signal.

[0006] However, such working machines recognize the working device based only on the content of the received identifying signal, and therefore the reliability of the recognition of the working device is low, that is, the recognized working device may differ from the working device actually attached to the device mount. That is, such working machines may receive all identifying signals transmitted from the working devices (transmitters) present in the covered area (range) and recognizes that the working device corresponding to the content of the identifying signals is the working device attached to the device mount, and therefore the working machine may accidentally recognize that a working device other than the working device actually attached to the device mount is the working device attached to the device mount.

[0007] Example embodiments of the present invention provide working machines each of which is able to appropriately recognize a working device to be attached to the device mount.

[0008] A working machine according to an example embodiment of the present invention includes a machine body, a device mount to replaceably attach a working device thereto, the working device including a transmitter to transmit a unique identifying signal and being operable to perform a function corresponding to work, and a controller configured or programmed to control the machine body, wherein the machine body includes receivers to receive the identifying signal from the transmitter, the receivers are located at respective at least two positions separated from the device mount by different distances, and the controller is configured or programmed to recognize the working device attached to or to be attached to the device mount based on a received signal strength of the identifying signal received by at least one of the receivers that is located at at least one of the at least two positions.

[0009] The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at the at least two positions at increasing distances from the device mount in the front-rear direction of the machine body.

[0010] The receivers may be located at respective at least three different positions which include the at least two positions separated from the device mount by different distances. The controller may be configured or programmed to determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least three positions, based on a combination of levels of received signal strengths at the receivers at the at least three positions.

[0011] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions one of which is in an area between the device mount and the cabin in the front-rear direction and the other of which is within the cabin. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength of the identifying signal received by one of the receivers that is in the area between the device mount and the cabin is equal to or greater than a preset threshold and a received signal strength at the other of the receivers that is within the cabin is within a predetermined range.

[0012] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions one of which is forward of a center of the cabin in the front-rear direction and the other of which is rearward of the center. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

[0013] The machine body may include a cabin to surround a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at at least four positions including positions at a front and a rear of the cabin in the front-rear direction and on opposite sides of the cabin in a lateral direction perpendicular to the front-rear direction. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the cabin is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0014] The machine body may include a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at two positions forward of and rearward of the seat in the front-rear direction. The controller may be configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

[0015] The machine body may include a seat for a user. The device mount may be located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body. The receivers may be located at at least four positions including positions forward of and rearward of the seat in the front-rear direction and on opposite sides of the seat in a lateral direction perpendicular to the front-rear direction. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located forward of and / or rearward of the seat is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0016] The receivers may be located at at least four positions including positions at a front and a rear of the machine body in a front-rear direction and on opposite sides of the machine body in a lateral direction perpendicular to the front-rear direction. The device mount may be located at at least one of (i) in front of one of the receivers that is at the front of the machine body or (ii) rearward of another of the receivers that is at the rear of the machine body. The controller may be configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions, and recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the machine body is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

[0017] The receivers at the at least two positions may include respective directional antennas to receive identifying signals from a particular direction, and are each positioned such that an orientation in which the receiver receives the identifying signals is directed toward the device mount.

[0018] The receivers at the at least two positions may include respective directional antennas to receive identifying signals from a particular direction. A first receiver of the receivers at the at least two positions that is closest to the device mount may be positioned such that an orientation in which the first receiver receives the identifying signals is directed toward the device mount. One or more second receivers of the receivers that are distant from the device mount may each be positioned such that the orientation in which the second receiver receives the identifying signal is directed in a different direction from a direction toward a side where the device mount is present.

[0019] The one or more second receivers that are distant from the device mount may each be positioned such that the orientation in which the second receiver receives the identifying signals is directed in a direction away from the device mount.

[0020] The working machine may further include a cover to cover each of one or more of the receivers at the at least two positions that are farther from the device mount than the other one or more of the receivers, the cover being positioned to block the identifying signal. The cover may include an opening which faces in a direction different from a direction toward a side where the device mount is present.

[0021] The opening may face away from the device mount.

[0022] The controller may be configured or programmed to, after recognizing the working device to be attached to the device mount based on one or more received signal strengths of the identifying signal received by the receivers at the at least two positions, when the receivers at the at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device is attached to the device mount.

[0023] The working machine may further include a support structure supported by the machine body to support the device mount to allow the device mount to move along a predetermined path, and an actuator to cause the device mount to move along the path. The controller may be configured or programmed to directly or indirectly recognize a load on the actuator and determine whether the working device is attached to or detached from the device mount.

[0024] The device mount may include a linkage to connect the working device thereto. The linkage may include an engagement portion movable between an engaging position in which the engagement portion engages with the working device to connect the working device thereto and a disengaging position in which the engagement portion disengages from the working device to disconnect the working device therefrom. The controller may be configured or programmed to determine that the working device is attached to the device mount when the engagement portion is in the engaging position.

[0025] The working machine may further include receivers each including an assembly of an antenna which is one of the receivers and a receiver main body to receive the identifying signal from the antenna. The receivers may be located at the respective at least two positions, and connected to the controller such that the identifying signal is transmittable to the controller.

[0026] The receivers may include antennas. The working machine may include a receiver including a receiver main body to receive the identifying signal from the antennas, input interfaces to connect thereto the antennas at the at least two positions, and an output interface to output to the controller the identifying signal inputted into the input interfaces.

[0027] The working machine may further include a monitor. The controller may be configured or programmed to determine a location of the working device which includes the transmitter transmitting the identifying signal based on the identifying signal received by one or more of the receivers and based on one or more received signal strengths of the identifying signal, and cause the monitor to display the determined location of the working device.

[0028] In such a case, the monitor may be operable to display pieces of device information corresponding to a plurality of the working devices and to allow a selection of one of the pieces of device information. The controller may be configured or programmed to, based on the identifying signal from the transmitter of a corresponding one of the plurality of working devices that corresponds to the selected piece of device information selected on the monitor and based on the one or more received signal strengths of the identifying signal, determine a location of the corresponding one of the plurality of working devices that includes the transmitter transmitting the identifying signal.

[0029] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete appreciation of example embodiments of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings described below.

[0031] FIG. 1 is a perspective view of a working machine (compact track loader) according to a first example embodiment of the present invention.

[0032] FIG. 2 is a perspective view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a working device is detached from a device mount.

[0033] FIG. 3 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0034] FIG. 4 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a pallet fork as a working device is attached to a device mount.

[0035] FIG. 5 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a snow pusher as a working device is attached to a device mount.

[0036] FIG. 6 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a grapple as a working device is attached to a device mount.

[0037] FIG. 7 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a sweeper as a working device is attached to a device mount.

[0038] FIG. 8 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which an angle broom as a working device is attached to a device mount.

[0039] FIG. 9 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a snow blower as a working device is attached to a device mount.

[0040] FIG. 10 is a left side view of a working machine (compact track loader) according to the first example embodiment of the present invention, in which a trencher as a working device is attached to a device mount.

[0041] FIG. 11 is a back view schematically illustrating a linkage of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0042] FIG. 12 is a side view schematically illustrating a linkage of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0043] FIG. 13 is a block diagram schematically illustrating a controller of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0044] FIG. 14 schematically illustrates a device list to be displayed on a monitor, stored in a controller (storing unit) of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0045] FIG. 15 is a conceptual view of information relating to working devices stored in a controller (storing unit) of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0046] FIG. 16 is a flowchart of a process performed when a working device is attached to a device mount of a working machine (compact track loader) according to the first example embodiment of the present invention.

[0047] FIG. 17 is a perspective view of a working machine (compact track loader) according to a second example embodiment of the present invention, in which a working device is detached from a device mount.

[0048] FIG. 18 is a left side view of a working machine (compact track loader) according to the second example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0049] FIG. 19 is a flowchart of a process performed when a working device is attached to a device mount of a working machine (compact track loader) according to the second example embodiment of the present invention.

[0050] FIG. 20 is a perspective view of a working machine (compact track loader) according to a third example embodiment of the present invention, in which a working device is detached from a device mount.

[0051] FIG. 21 is a right side view of a working machine (compact track loader) according to the third example embodiment of the present invention, in which a bucket as a working device is attached to a device mount.

[0052] FIG. 22 is a perspective view of a working machine (agricultural tractor) according to a fourth example embodiment of the present invention.

[0053] FIG. 23 is a left side view of a working machine (agricultural tractor) according to the fourth example embodiment of the present invention.

[0054] FIG. 24 is a plan view of a working machine (agricultural tractor without cabin) according to a fifth example embodiment of the present invention.

[0055] FIG. 25 is a left side view of a working machine (agricultural tractor without cabin) according to the fifth example embodiment of the present invention.

[0056] FIG. 26 is a left side view of a working machine (compact track loader) according to another example embodiment of the present invention.

[0057] FIG. 27 is a left side view of a working machine (agricultural tractor) according to another example embodiment of the present invention.

[0058] FIG. 28 is a perspective view of a working machine (compact track loader) according to a further example embodiment of the present invention, in which a working device is detached from a device mount.

[0059] FIG. 29 is a perspective view of a working machine (compact track loader) according to a further example embodiment of the present invention, in which a working device is detached from a device mount.

[0060] FIG. 30 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0061] FIG. 31 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0062] FIG. 32 is a left side view of a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0063] FIG. 33 is a plan view schematically illustrating a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0064] FIG. 34 is a plan view schematically illustrating a working machine (agricultural tractor) according to a further example embodiment of the present invention.

[0065] FIG. 35 is a block diagram illustrating a receiver of a working machine according to a further example embodiment of the present invention.

[0066] FIG. 36 is an enlarged view of a main portion including a receiver of a working machine according to a further example embodiment of the present invention.

[0067] FIG. 37 is a cross-sectional view taken along line A-A in FIG. 36.

[0068] FIG. 38 is a left side view of a variation of a working machine (compact track loader) according to the third example embodiment of the present invention.

[0069] FIG. 39 is a left side view of a variation of a working machine (agricultural tractor) according to a fifth example embodiment of the present invention.

[0070] FIG. 40 is a left side view of another variation of a working machine (agricultural tractor) according to the fifth example embodiment of the present invention.

[0071] FIG. 41 illustrates content displayed on a monitor of a working machine according to a further example embodiment of the present invention.

[0072] FIG. 42 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0073] FIG. 43 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 42.

[0074] FIG. 44 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0075] FIG. 45 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 44.

[0076] FIG. 46 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0077] FIG. 47 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 46.

[0078] FIG. 48 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0079] FIG. 49 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 48.

[0080] FIG. 50 schematically illustrates an example of, when a working device selected on the monitor illustrated in FIG. 41 is attached to a working machine, the positional relationship between the working machine and the working device.

[0081] FIG. 51 illustrates content displayed on a monitor when the working machine and the working device are in the positional relationship as illustrated in FIG. 50, which is another way of displaying content when the working machine and the working device are in a particular positional relationship.

[0082] FIG. 52 illustrates another way in which the monitor displays content when the working machine and the working device are in a particular positional relationship.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0083] Example embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements throughout the various drawings. The drawings are to be viewed in an orientation in which the reference numerals are viewed correctly.First Example Embodiment

[0084] The following description discusses a working machine according to a first example embodiment of the present invention with reference to drawings. Note that, assuming that the working machine is able to travel, the direction of straight travel (direction of forward travel or rearward travel) is hereinafter referred to as a front-rear direction, a direction perpendicular to the front-rear direction and an up-down direction is hereinafter referred to as a lateral direction. One of such lateral directions that is on the right side when the user faces forward is hereinafter referred to as a rightward direction (right), and the other of the lateral directions that is on the left side when the user faces forward is hereinafter referred to as a leftward direction (left).

[0085] A working machine 1 according to the first example embodiment is a compact track loader for use in construction work, civil engineering work or the like, as illustrated in FIGS. 1 to 10. The working machine 1 includes a machine body 2. The working machine 1 includes traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes a device mount 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work (see FIGS. 1 and 2). That is, the working machine 1 includes a device mount 40 to attach thereto each of a plurality of types of working devices 9 independently.

[0086] In the first example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61, 62 (operational actuator(s) 61, 62) to cause the device mount 40 to move along the path (see FIGS. 3 to 10). The working machine 1 includes an actuator 60 (travel actuator 60) to drive the traveling devices 3. The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0087] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a manual operator 11 to be operated by the user to perform operations relating to travel of the traveling devices 3 (which may be hereinafter referred to as a first manual operator). The working machine 1 includes a manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path (which may be hereinafter referred to as a second manual operator).

[0088] The first manual operator 11 includes a pivotable operating lever. The direction of pivoting of the operating lever corresponds to the direction of travel of the traveling devices 3, and the degree to which the operating lever is pivoted corresponds to the travel speed of the traveling devices 3. The second manual operator 12 includes a pivotable operating lever. Changing the direction of pivoting of the operating lever controls the upward / downward movement of arms 43 and the pivoting (rotation) of the device mount 40 (working device 9), and changing the degree to which the operating lever is pivoted controls the speed of the upward / downward movement of the arms 43, i.e., the speed at which the device mount 40 is raised or lowered and the speed of pivoting of the device mount 40 (working device 9).

[0089] The machine body 2 include a frame chassis 20, a seat 21 provided on the frame chassis 20, and a seat protection structure 22 to protect the seat 21. The machine body 2 includes a first receiver 150a and a second receiver 150b to receive identifying signals from transmitters T (described later).

[0090] The frame chassis 20 is made of sheet metal, has in a three-dimensional shape corresponding the shape and size of the working machine 1, and defines, at a rear portion in the front-rear direction, a prime mover room MR to house a prime mover 10 to directly or indirectly drive the actuators 60, 61, 62. Note that, in the first example embodiment, the actuators 60, 61, 62 each include a hydraulic actuator. Accordingly, the working machine 1 includes a hydraulic system 6 including hydraulic pump(s) to deliver hydraulic fluid to the actuators 60, 61, 62, and control valve(s) to control the flow of hydraulic fluid. The hydraulic system 6 (hydraulic pump(s)) is driven by the prime mover 10, and the hydraulic system 6 (control valve(s)) is controlled by the controller. Accordingly, the hydraulic system 6 and the prime mover 10 are housed in the prime mover room MR. The prime mover 10 in the first example embodiment is an internal combustion engine (diesel engine), but may be an electric motor.

[0091] The seat 21 is located forward of the prime mover room MR (prime mover 10) and is fixed to the frame chassis 20. In the first example embodiment, the seat protection structure 22 is a cabin to surround the seat 21. Since the seat 21 is located forward of the prime mover room MR as described above, the cabin 22 (seat protection structure 22) is also located forward of the prime mover room MR. That is, the cabin 22 defines, at a location forward of the prime mover room MR, an operator cab OR in which the user seated in the seat 21 stays. Note that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12), and the like are provided within the cabin 22 (operator cab OR) such that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12) and the like can be operated by the user.

[0092] The cabin 22 includes front, rear, left and right windows. With regard to this type of working machine 1, the front window of the cabin 22 is openable and closable. This allows the user to enter and exit the operator cab OR through the front portion of the cabin 22. The left and right windows each have a protective lattice attached thereto. Note that, in FIGS. 1 and 3 to 10, a portion of the lattice is not illustrated for illustration of a portion of the interior of the operator cab OR.

[0093] The first manual operator 11 and the second manual operator 12 are located such that the user seated in the seat 21 can operate the first manual operator 11 and the second manual operator 12. In the first example embodiment, the first manual operator 11 and the second manual operator 12 are located forward of the seat 21.

[0094] The receivers 150a and 150b at two positions are located at two positions separated from the device mount 40 by different distances. Specifically, the receivers 150a and 150b at two positions are located at two positions at increasing distances from the device mount 40. Note that, in the following description, one (receiver 150a) of the receivers 150a and 150b at the two positions that is closest to the device mount 40 is referred to as a first receiver 150a, and the other (receiver 150b) of the receivers 150a and 150b that is farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 150b.

[0095] More specifically, as illustrated in FIG. 3, the first receiver 150a and the second receiver 150b are located such that the first receiver 150a and the second receiver 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40.

[0096] The first receiver 150a and the second receiver 150b may be arranged on a single imaginary straight line that extends from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and may be located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40. The latter case is used in the first example embodiment. That is, the first receiver 150a and the second receiver 150b in the first example embodiment are located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40.

[0097] More specifically, in the first example embodiment, the first receiver 150a and the second receiver 150b are located at the following two positions: a position in an area SA between the device mount 40 (the rotation shaft S2 of the device mount 40) and the cabin 22 in the front-rear direction, and a position within the cabin 22.

[0098] The device mount 40 is located forward of the machine body 2 in the front-rear direction. More specifically, the device mount 40 is located forward of the cabin 22, and is raised and lowered at a position forward of the cabin 22. Accordingly, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the first example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22. With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0099] In contrast, the second receiver 150b is located at a position farther from the device mount 40 than the other receiver 150a (i.e., the second receiver 150b is located on the imaginary concentric circle VC2 having a larger radius r2) and within the cabin 22. In the first example embodiment, the second receiver 150b located within the cabin 22 is located rearward of the seat 21 in the operator cab OR. In the present example embodiment, the first receiver 150a and the second receiver 150b are displaced from each other in the front-rear direction, but are each located at a central portion of the cabin 22 in the lateral direction.

[0100] The first receiver 150a and the second receiver 150b receive identifying signals transmitted from transmitters T. Specifically, the first receiver 150a and the second receiver 150b receive unique identification information relating to a working device 9 from a tag T which is a transmitter attached to the working device 9.

[0101] In the first example embodiment, the first receiver 150a and the second receiver 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna.

[0102] Note that the receiver 15a which includes the first receiver 150a that is the closest, of the receivers, to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b which includes the second receiver 150b farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 15b. That is, the receiver 15a located closest, of the receivers, to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b located farther from the device mount 40 than the first receiver 15a is referred to as a second receiver 15b. Note that, although the first receiver 15a and the second receiver 15b are named differently based on the locations for convenience of the following description, the first receiver 15a and the second receiver 15b include the same configuration.

[0103] Specifically, the first receiver 150a and the second receiver 150b are each an antenna, and receive, as identification information, a wireless signal (beacon signal) compliant with Bluetooth (registered trademark) Low Energy which is a near field communication standard. That is, the receivers 15a and 15b are beacon scanners to receive beacon signals. The receiver main bodies 151a and 151b of the receivers 15a and 15b (beacon scanners 15) each measure the received signal strength (Received Signal Strength Indicator, RSSI) of the accepted wireless signal.

[0104] In the first example embodiment, the receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b each have a signal converting function to convert a Bluetooth signal into a control area network (CAN) signal. Accordingly, the receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b are connected to the controller 5 via a CAN bus.

[0105] The first receiver 150a and the second receiver 150b at two positions are each a directional antenna to receive identifying signals from a particular direction. The first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). In the first example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the first receiver 15a and the second receiver 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the second receiver 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0106] That is, the first receiver 15a is fixed to the cabin 22 such that the first receiver 150a is located within the area SA between the device mount 40 and the cabin 22 in the front-rear direction, and the second receiver 15b is fixed to the cabin 22 such that the second receiver 150b is located within the cabin 22 (rearward of the seat 21). The receiver main bodies 151a and 151b of the respective first and second receivers 15a and 15b each transmit, to the controller 5 via a signal wire (CAN bus), an identifying signal received by the first receiver 150a or the second receiver 150b.

[0107] The traveling devices 3 are operable to achieve straight travel in which the machine body 2 travels straight, and achieve pivot turn travel. The traveling devices 3 are operable to also achieve spin turn travel.

[0108] Specifically, the traveling devices 3 are provided on the left and right sides of the machine body 2. That is, the working machine 1 includes a pair of the traveling devices 3 to support opposite portions in the width direction (left and right portions) of the machine body 2 (the frame chassis 20 in the first example embodiment). In the first example embodiment, the pair of traveling devices 3 are respective crawler traveling devices 3. That is, the working machine 1 according to the first example embodiment is a crawler compact track loader.

[0109] The device mount 40 is supported directly or indirectly by the machine body 2. In the first example embodiment, the device mount 40 is supported by the machine body 2 via a support structure 4 (arms 43, described later). The device mount 40 is, as described earlier, operable to attach thereto each of a plurality of types of working devices 9 independently. That is, the device mount 40 is operable to replaceably attach thereto each of a plurality of types of working device 9 that performs a function corresponding to work.

[0110] Specifically, as illustrated in FIGS. 11 and 12, the device mount 40 includes a linkage 41 to connect a working device 9 thereto. The linkage 41 includes an engagement portion 412 switchable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 to connect the working device 9 thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 to disconnect the working device 9 therefrom.

[0111] Specifically, as illustrated in FIG. 12, the device mount 40 includes a frame 42 to be connected to distal portions of the arms 43, and a linkage 41 attached to the frame 42.

[0112] The frame 42 includes a frame body 420 in the form of a plate. The working device 9 includes a mount base 91 (described later) which includes a pawl 910 for engagement. In the first example embodiment, the pawl 910 engages with the upper edge of the frame body 420.

[0113] The linkage 41 includes a so-called quick hitch (hitch) to connect (attach) and disconnect (detach) the working device 9 thereto and therefrom, and is also called “quick changer”. The linkage 41 engages with the mount base 91 such that the pawl 910 engages with the upper edge of the frame body 420, so that the linkage 41 maintains the working device 9 (mount base 91) in the connected state.

[0114] Specifically, the linkage 41 is located within the area of the frame body 420 of the frame 42. That is, the linkage 41 is located between the upper edge and the lower edge of the frame body 420 and is fixed to the frame body 420.

[0115] The linkage (quick hitch) 41 includes latching mechanism(s) 410 and a latch cylinder 411 to actuate the latching mechanism(s) 410 (see FIGS. 11 and 12).

[0116] Each latching mechanism 410 includes a latch pin 412 (which is the engagement portion 412) which is movable in the axial direction and which is switchable between (i) the engaging position PE1 in which the latch pin 412 engages with an engagement section 92a (which is a peripheral portion around an engagement hole 92a in the first example embodiment) of the mount base 91 of the working device 9, and (ii) the disengaging position PE2 in which the latch pin 412 is disengaged from the working device 9 of the mount base 91. In the first example embodiment, the latching mechanism 410 includes a lever body 413 which is rotatable about a predetermined axis and which, by rotating about the axis, changes the position of (moves) the latch pin 412 between the engaging position PE1 and the disengaging position PE2.

[0117] With this, the latching mechanism 410 is able to switch between (i) a latching state (engaging state) in which the latch pin (engagement portion) 412 is in the engaging position PE1 to secure the working device 9 and (ii) an unlatching state (disengaging state) in which the latch pin (engagement portion) 412 is in the disengaging position PE2 to allow the working device 9 to be detached.

[0118] The latch cylinder 411 actuates the latching mechanisms 410. In the first example embodiment, each latching mechanism 410 includes a spring 414 to cause the latch pin 412 to return from the disengaging position PE2 to the engaging position PE1. Accordingly, in the first example embodiment, the springs 414 keep the latching mechanisms 410 in the latching state, and the latch cylinder 411 switches the latching mechanisms 410 from the latching state to the unlatching state.

[0119] In the first example embodiment, the linkage 41 includes a plurality of the latch pins 412, and the latch pins 412 engage with the mount base 91 of the working device 9 at a plurality of positions to hold the working device 9. That is, the linkage 41 includes a plurality of the latching mechanisms 410 each including a latch pin 412. In the first example embodiment, the linkage 41 includes a pair of the latching mechanisms 410. The pair of latching mechanisms 410 are arranged symmetrically with respect to the widthwise center of the frame 42.

[0120] In the first example embodiment, the latch cylinder 411 includes a hydraulic cylinder. Accordingly, the latch cylinder 411 is connected to the hydraulic system 6, and extends and retracts by receiving and discharging hydraulic fluid from and to the hydraulic system 6. The latch cylinder 411 is connected to the lever bodies 413 (first lever portions 413a, described later) of the latching mechanisms 410, and the extension or retraction of the latch cylinder 411 rotates each lever body 413 about a predetermined axis. In the first example embodiment, since the pair of latching mechanisms 410 are arranged symmetrically, the latch cylinder 411 is arranged to connect the lever bodies 413 of the pair of latching mechanisms 410. With this, with a single latch cylinder 411, a pair of latching mechanisms 410 are actuated in a synchronized manner. That is, the latch cylinder 411 rotates each of the lever bodies 413 of the pair of latching mechanisms 410 to move each of the latch pins 412 of the pair of latching mechanisms 410 between the engaging position PE1 and the disengaging position PE2 in a synchronized manner.

[0121] In the first example embodiment, each lever body 413 includes a first lever portion 413a extending from the center of rotation, and a second lever portion 413b extending from the center of rotation in a different direction from the first lever portion 413a. The first lever portion 413a is connected to the latch pin 412 (which is the engagement portion) via the spring 414, and to the latch cylinder 411. The second lever portion 413b of the lever body 413 overlaps (is hidden behind) the frame 42 when viewed in the front-rear direction when the latch pin 412 is in the engaging position PE1, and protrudes from the upper edge of the frame 42 when the latch pin 412 is in the disengaging position PE2. Thus, the device mount 40 of the first example embodiment is configured such that whether the device mount 40 is in the latching state or the unlatching state can be visually recognized (checked) by checking, from the outside (from the operator cab OR), whether or not the second lever portions 413b are protruding from the frame 42.

[0122] As illustrated in FIGS. 3 to 10, the device mount 40 is connected to the support structure 4 (arms 43, described later) rotatably about the second shaft S2 extending in the lateral direction. Specifically, the frame 42 of the device mount 40 is rotatably connected to the distal portions of the arms 43 via the second shaft S2 having an axis (central axis) extending in the lateral direction. With this, the device mount 40 is movable along a path (second path) in the shape of an arc centered on the second shaft S2. Accordingly, the working device 9 attached (connected) to the device mount 40 is also movable along a path in the form of an arc centered on the second shaft S2 similarly to the device mount 40. That is, the working device 9 is movable along a path in the shape of an arc which is concentric and similar to the second path for the device mount 40.

[0123] The support structure 4 is supported by the machine body 2, and includes arms 43 which are supported rotatably about a first shaft S1 extending in the lateral direction perpendicular to the up-down direction and which have the device mount 40 connected thereto.

[0124] Each arm 43 extends in a direction (hereinafter may be referred to as an arm extension direction) perpendicular to the up-down direction and the lateral direction, and includes a proximal portion and a distal portion at the opposite ends in the arm extension direction. The proximal portion of the arm 43 is connected to the machine body 2 rotatably about the first shaft S1 having an axis (center of rotation) extending in the lateral direction. In the first example embodiment, the arm 43 is connected to the machine body 2 via a linking body 44 connected to the machine body 2. In contrast, the distal portion of the arm 43 has the device mount 40 connected thereto.

[0125] With this, the device mount 40 is movable along a path (first path) in the shape of an arc centered on the first shafts S1 by the rotation of the arms 43. The proximal portions of the arms 43 are connected to a rear portion of the machine body 2. When the arms 43 are in a position in which the arms 43 extend from the rear portion of the machine body 2 toward the space in front of the machine body 2 (when the arms 43 are oriented such that the arms 43 extend in a rear-to-front direction of the machine body 2), the distal portions of the arms 43 (the connected device mount 40) are located forward of the machine body 2. The device mount 40 is, by the arms 43 rotating about the first shafts S1 to move along the first path, movable between a low position in the vicinity of the ground and a high position higher than the low position. The high position and the low position are determined by the range of rotation of the arms 43.

[0126] In the first example embodiment, the arms 43 are provided at the left and right sides of the cabin 22. That is, the working machine 1 includes a pair of the arms 43 provided with the cabin 22 therebetween. The shapes and locations of the pair of arms 43 are symmetrical with respect to the widthwise center (center in the lateral direction) of the cabin 22. Accordingly, also a pair of the left and right linking bodies 44, to which the arms 43 are connected, are provided. FIGS. 3 to 10 each illustrate the left side of the working machine 1, and therefore only the left one of the arms 43 and the left one of the linking bodies 44 are illustrated in FIGS. 3 to 10 similarly to the traveling devices 3.

[0127] In the first example embodiment, the operational actuators 61 and 62 include first actuator(s) 61 to cause the arms 43 to rotate about the first shafts S1 and to raise and lower the device mount 40 in the up-down direction. In the first example embodiment, the operational actuators 61 and 62 include second actuator(s) 62 to cause the device mount 40 to rotate about the second shaft S2 to pivot. That is, the working machine 1 of the first example embodiment includes the operational actuators 61 and 62, one of which is the first actuator 61 to cause the device mount 40 to move along a predetermined path (first path), and the other of which is the second actuator 62 to cause the device mount 40 to move along another predetermined path (second path) different from the first path.

[0128] In the first example embodiment, the first actuator 61 and the second actuator 62 each include a hydraulic cylinder. That is, the first actuator 61 and the second actuator 62 each include a hydraulic cylinder to extend and retract in the axial direction by receiving and discharging hydraulic fluid. Accordingly, the first actuator 61 is hereinafter referred to as a first hydraulic cylinder 61, and the second actuator 62 is hereinafter referred to as a second hydraulic cylinder 62.

[0129] In the first example embodiment, the first hydraulic cylinder 61 extends or retracts by receiving and discharging hydraulic fluid to cause the corresponding arm 43 to rotate about the first shaft S1. That is, the extent to which the first hydraulic cylinder 61 extends or retracts determines the range of rotation of the arm 43. The first hydraulic cylinder 61 and the second hydraulic cylinder 62 each include a tubular cylinder 610, 620 and a piston rod 611, 621 inserted in the tubular cylinder 610, 620 such that the piston rod 611, 621 is extendable and retractable.

[0130] The first hydraulic cylinder 61 and the second hydraulic cylinder 62 each include a first port Pa1, Pb1 to allow hydraulic fluid to flow into the tubular cylinder 610, 620 for the piston rod 611, 621 to extend out of the tubular cylinder 610, 620, and a second port Pa2, Pb2 to allow hydraulic fluid to flow into the tubular cylinder 610, 620 for the piston rod 611, 621 to retract into the tubular cylinder 610, 620. That is, the first hydraulic cylinder 61 and the second hydraulic cylinder 62 are each a double-acting hydraulic cylinder.

[0131] Such a first hydraulic cylinder 61 is provided for each arm 34. That is, the working machine 1 includes a pair of the first hydraulic cylinders 61 provided at the opposite sides of the cabin 22. The pair of first hydraulic cylinders 61 are located symmetrically with respect to the widthwise center (center in the lateral direction) of the cabin 22 to correspond to the pair of arms 43.

[0132] Each of the pair of first hydraulic cylinders 61 connects the corresponding arm 43 and the frame chassis 20. That is, the distal end of the piston rod 611 of the first hydraulic cylinder 61 is connected to the arm 43 rotatably about an axis perpendicular to the up-down direction, and the bottom of the tubular cylinder 610 of the first hydraulic cylinder 61 is connected to the frame chassis 20 rotatably about an axis perpendicular to the up-down direction.

[0133] In the first example embodiment, a pair of the second hydraulic cylinders 62 are arranged in the width direction with a space therebetween. The pair of second hydraulic cylinders 62 are symmetrical with respect to the widthwise center (center in the lateral direction) of the cabin 22. Each of the pair of second hydraulic cylinders 62 connects the corresponding arm 43 and the frame 902 of the device mount 40. That is, the distal portion of the piston rod 621 of the second hydraulic cylinder 62 is connected to the frame 42 of the device mount 40 rotatably about an axis perpendicular to the up-down direction, and the bottom of the tubular cylinder 620 of the second hydraulic cylinder 62 is connected to the corresponding arm 43 rotatably about an axis perpendicular to the up-down direction.

[0134] With this, the arms 43 rotate about the first shafts S1 and the distal portions of the arms 43 are raised or lowered by the first hydraulic cylinders 61 extending or retracting. The device mount 40 rotates about the second shaft S2 and swings in the up-down direction by the second hydraulic cylinders 62 extending and retracting. With this, the device mount 40 is movable along the first path and along the second path. Note that as the first hydraulic cylinders 61 and the second hydraulic cylinders 62 are actuated concurrently, the device mount 40 moves along the first path while moving along the second path, i.e., the device mount 40 moves along a combination of the first and second paths. Since the working device 9 is attached (connected) to the device mount 40, the working device 9 behaves similarly to the device mount 40.

[0135] As illustrated in FIG. 13, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50 to store information for use in processes performed by the arithmetic controller 51, an input interface 52 electrically connected to the arithmetic controller 51 to input, into the arithmetic controller 51, an electric signal which is input information from an external electric device, and an output interface 53 electrically connected to the arithmetic controller 51 to output, to an external electric device, a command signal (electric signal) which is output information from the arithmetic controller 51.

[0136] The arithmetic controller 51 may be a so-called CPU, and may include a calculator 510 and a controller 511. In the controller 5 of the first example embodiment, the storing unit 50 includes a first storing unit 500 to store, temporarily or for a short period of time, information for use in processes performed by the arithmetic controller 51 (the calculator 510 and the controller 511), and a second storing unit 501 to store, for a long period of time, information for use in processes performed by the arithmetic controller 51 (the calculator 510 and the controller 511). The first storing unit 500 is a so-called memory, and the second storing unit 501 is a storage such as a hard disc or solid state drive (SSD).

[0137] In the first example embodiment, the storing unit 50 stores a device list which is a list of a plurality of working devices 9 (9A to 9T) and which is to be displayed on the monitor 55 (see FIG. 14). The device list has embedded therein images of the working devices 9 (pictograms shown in FIG. 15), and is associated with operation conditions of the working devices 9 (9A to 9T) shown in FIG. 15. The device list is configured such that one of the working devices 9 (9A to 9T) displayed on the monitor 55 can be selected.

[0138] The storing unit 50 stores (has registered therein) information relating to a plurality of types of working devices 9 (9A to 9T) attachable to the device mount 40 (see FIG. 15). Note that the plurality of types of working devices 9 include a bucket 9A, a pallet fork 9B, a ripper 9C, a snow pusher 9D, a dozer blade 9E, a crusher 9F, a grapple 9G, a skid grader 9H, a spreader 9I, a sweeper 9J, a skid cutter 9K, a breaker 9L, an earth auger 9M, a rotary tiller 9N, a broom (angle broom) 9O, a cold planer 9P, a stump grinder 9Q, a snow blower 9R, a trencher 9S, a mower 9T, and / or the like. FIG. 15 illustrates pieces of graphics (pictograms) schematically representing such working devices 9 as examples of the working devices 9.

[0139] The storing unit 50 stores the names of the plurality of types of working devices 9 and pieces of identification information 9A to 9T allocated to the respective plurality of types of working devices 9, which are associated with each other. The storing unit 50 stores the names of plurality of types of working devices 9 (9A to 9T) and pieces of graphics (pictograms, in the first example embodiment) of the working devices 9 (9A to 9T) to be displayed on the monitor 55, which are associated with each other. The storing unit 50 stores the names of the plurality of types of working devices 9 (9A to 9T) and the operation conditions D1 to D20 (control conditions D1 to D20) for the working devices 9 (9A to 9T), which are associated with each other. Note that, in the first example embodiment, the names of the working devices 9 (9A to 9T), the pieces of identification information 9A to 9T, the working devices 9 (9A to 9T), and the pieces of graphics of the working device 9 (i.e., pieces of information arranged horizontally in the table in FIG. 15) are stored such that they are associated with each other.

[0140] The storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the second receiver 150b (the receivers 150a and 150b at two positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the second receiver 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at the second receiver 150b.

[0141] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0142] With regard to the combination pattern of received signal strengths in the first example embodiment, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a and for the received signal strength at the second receiver 150b. The range of the received signal strength for the first receiver 150a and the range of the received signal strength for the second receiver 150b are defined such that they do not overlap each other. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for the second receiver 150b is 55 dBm to 64 dBm.

[0143] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the second receiver 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the first example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0144] Referring back to FIG. 13, the input interface 52 and the output interface 53 are each a so-called interface. The input interface 52 is operable to connect thereto electric device(s) which outputs an electric signal (i.e., information). In contrast, the output interface 53 is operable to connect thereto electric device(s) which receives input of an electric signal (i.e., information).

[0145] Specifically, the input interface 52 is operable to connect thereto the manual operators 11 and 12 (first manual operator 11, second manual operator 12), the receivers 15a and 15b, and / or the hydraulic system 6 (in practice, control valve(s), pressure sensor(s), and / or the like contained in the hydraulic system 6 (circuit)). In contrast, the output interface 53 is operable to connect thereto the hydraulic system 6 (in practice, control valve(s), pressure sensor(s), and / or the like contained in the hydraulic system 6 (circuit)).

[0146] The monitor 55 according to the first example embodiment includes a touchscreen monitor, which is operable to receive input of information. Accordingly, the monitor 55 is connected to the input interface 52 and the output interface 53 to transmit and receive information to and from the controller 5 (arithmetic controller 51).

[0147] The monitor 55 displays a device list read from the storing unit 50. As described above, the monitor 55 includes a touchscreen monitor, and therefore, upon the user selecting (touching) the icon of the working device 9 to be used from the device list displayed on the monitor 55, the controller 5 (arithmetic controller 51) recognizes the type of the working device 9 to be used (the selected working device 9). The controller 5 (arithmetic controller 51) is configured or programmed to, in the case where the recognized type is a working device 9 configured for work-during-travel, retrieve (read) control condition(s) (e.g., travel condition(s)) for the working device 9 that corresponds to the selected icon from the storing unit 50 (second storing unit 501).

[0148] Accordingly, the controller 5 (arithmetic controller 51) recognizes (the type of) the working device 9 to be used (the selected working device 9), based on the identification information received by the first receiver 150a and the second receiver 150b.

[0149] The controller 5 retrieves operation conditions (control conditions) for the working device 9 corresponding to the selected icon (pictogram) selected via the monitor 55 (reads the operation conditions (control conditions) from the storing unit 50). Note that the controller 5 is configured or programmed to, if a working device 9 is selected from the device list displayed on the monitor 55, recognize the selected working device 9 as the working device 9 intended by the user, and prioritize this recognition over the recognition of the working device 9 based on reading the identification information received by the receivers 15a and 15b (the first receiver 150a and the second receiver 150b).

[0150] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information. The unique identification information here is used to identify the working device 9, and includes, for example, unique ID, model name, model number, and / or the like. In the first example embodiment, the tag T is a beacon tag to transmit unique identification information as a wireless signal (advertisement signal Q1) compliant with Bluetooth (registered trademark) Low Energy.

[0151] The following discusses the working devices 9. Each of the plurality of types of working devices 9 includes, as illustrated in FIGS. 3 to 10, (i) a mount base 91 attachable to the device mount 40 and (ii) a functioning portion 93 connected to the mount base 91 and operable to perform a function corresponding to work.

[0152] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mount 40 of the working machine 1. As illustrated in FIG. 12, the mount base 91 includes the pawl 910 which can be engaged to the upper edge of the frame body 420, as described earlier. The mount base 91 includes, at a position lower than the upper edge, the engagement holes 92a for engagement with the engagement portions 412 (latch pins 412) of the device mount 40. Specifically, the mount base 91 includes the engagement holes 92a at positions that correspond to the locations of the engagement portions 412 (latch pins 412) of the device mount 40.

[0153] With this, while the mount base 91 is in an attaching position relative to the device mount 40 (while the pawl 910 is engaged with frame body 420), when the latch pins (engagement portions) 412 of the linkage 41 are in the engaging position PE1, the latch pins (engagement portions) 412 are engaged with the mount base 91 (fitted in the engagement holes 92a) to achieve a connected state, whereas, when the latch pins (engagement portions) 412 of the linkage 41 are in the disengaging position PE2, the latch pins (engagement portions) 412 are disengaged from the mount base 91 (from the engagement hole 92a) to allow the mount base 91 to be detached.

[0154] A plurality of types of working devices 9 are attachable to the working machine 1 of the first example embodiment. More specifically, examples of the working devices 9 attachable to the working machine 1 of the first example embodiment (working devices 9 recorded (registered) in the storing unit 50) include, as described earlier, a bucket 9A, a pallet fork 9B, a ripper 9C, a snow pusher 9D, a dozer blade 9E, a crusher 9F, a grapple 9G, a skid grader 9H, a spreader 9I, a sweeper 9J, a skid cutter 9K, a breaker 9L, an earth auger 9M, a rotary tiller 9N, a broom (angle broom) 90, a cold planer 9P, a stump grinder 9Q, a snow blower 9R, a trencher 9S, and a mower 9T. Note that, for illustration of such examples, FIGS. 1 and 3 illustrate the working machine 1 having the bucket 9A attached thereto, FIG. 4 illustrates the working machine 1 having the pallet fork 9B attached thereto, FIG. 5 illustrates the working machine 1 having the snow pusher 9D attached thereto, FIG. 6 illustrates the working machine 1 having the grapple 9G attached thereto, FIG. 7 illustrates the working machine 1 having the sweeper 9J attached thereto, FIG. 8 illustrates the working machine 1 having the angle broom 90 attached thereto, FIG. 9 illustrates the working machine 1 having the snow blower 9R attached thereto, and FIG. 10 illustrates the working machine 1 having the trencher 9S attached thereto.

[0155] The working machine 1 of the first example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0156] Specifically, as shown in FIG. 16, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S1). Meanwhile, the first receiver 150a and the second receiver 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S2). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the second receiver 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S2).

[0157] The received signal strength of identification information increases as the distance to the tag T that is the source of the identification information decreases. Therefore, in the case where the first receiver 150a and the second receiver 150b receive a plurality of pieces of identification information, the controller 5 recognizes that the piece of identification information with the highest received signal strength, of the pieces of identification information received by the first receiver 150a and the second receiver 150b, is the piece of information of the closest working device 9 (9A to 9T).

[0158] Under such circumstances, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S3), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0159] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and the first receiver 150a and the second receiver 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes.

[0160] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0161] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the second receiver 150b, is located nearest the first receiver 150a and the second receiver 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the second receiver 150b with the highest received signal strength changes to another identifying signal.

[0162] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S3), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0163] In the first example embodiment, the orientation in which the first receiver 150a receives identifying signals is directed forward along the front-rear direction (toward the device mount 40), and the first receiver 150a receives pieces of identification information (wireless signals) coming from a wide area in front of the first receiver 150a. On the contrary, pieces of identification information (wireless signals) coming from locations on opposite sides of the cabin 22 or locations diagonally forward of the cabin 22 are blocked by the cabin 22 (lattice). The orientation in which the second receiver 150b receives identifying signals is directed forward (toward the side where the device mount 40 is present). Therefore, the second receiver 150b does not receive identifying signal from sides, diagonally from front, or from rear and receives only identifying signals (wireless signal) coming from the front side in the front-rear direction (coming from the side where the device mount 40 is present) within the range of the cabin 22 in the lateral direction. Thus, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b, to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward (S3).

[0164] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the second receiver 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the second receiver150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the second receiver 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b (S3), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0165] Under such circumstances, the controller 5 compares information stored in the storing unit 50 with the actual received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b, and determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the receiver 150b in the cabin 22 is within a predetermined range (S4).

[0166] Specifically, in the case where the received signal strength at the first receiver 150a and the second receiver 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S4), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) which can be attached (S3).

[0167] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b increases and matches a condition stored in the storing unit 50, the controller 5 recognizes the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (YES at S4).

[0168] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the receiver 150b in the cabin 22 is within a predetermined range (YES at S4), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0169] In the first example embodiment, the controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0170] The controller 5 then, upon recognizing the working device 9 (9A to 9T) to be attached to the device mount 40 (YES at S6), if the engagement portion 412 of the linkage 41 is in the engaging position PE1, determines that the working device 9 (9A to 9T) is attached to the device mount 40 (S7). That is, in the first example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is attached to the device mount 40 via the linkage 41.

[0171] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40, reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S9). This allows the user to operate the working device 9 under appropriate conditions.Second Example Embodiment

[0172] The following description discusses a working machine according to a second example embodiment of the present invention. Note that the working machine according to the second example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine of the first example embodiment except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the second example embodiment only discusses the differences from the first example embodiment, and the description for the same configurations as the first example embodiment is not repeated here but the description in the first example embodiment is applied as that for the second example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment are assigned the same names and reference signs as in the first example embodiment.

[0173] As illustrated in FIGS. 17 and 18, similar to the first example embodiment, the working machine 1 of the second example embodiment includes a machine body 2, a traveling device 3, a device mount 40, a support structure 4, a controller 5, manual operators 11 and 12 (first manual operator 11, second manual operator 12), and a monitor 55. The machine body 2 includes a seat 21 and a cabin 22. These features are the same as those of the working machine 1 of the first example embodiment. In the working machine 1 of the present example embodiment, the machine body 2 includes first receiver(s) 150a and second receiver(s) 150b to receive identifying signals from transmitters T.

[0174] In the second example embodiment, the first receiver(s) 150a and the second receiver(s) 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances.

[0175] Specifically, in the second example embodiment, the machine body 2 includes a first receiver 150a and a pair of second receivers 150b. As illustrated in FIG. 18, the first receiver 150a and the pair of second receivers 150b are located such that the first receiver 150a and the pair of second receivers 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40.

[0176] Specifically, of the three receivers (i.e., the first receiver 150a and the pair of second receivers 150b), the first receiver 150a is on (located at) one of the two imaginary concentric circles VC1 and VC2 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40 that has a smaller radius r1, and the pair of pair of second receivers 150b are on (located at) the other of the two imaginary concentric circles VC1 and VC2 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40 that has a larger radius r1. Thus, the pair of second receivers 150b are arranged with a space therebetween in the lateral direction.

[0177] That is, in the second example embodiment, the first receiver 150a is located, in a side view, on a first imaginary straight line VL1 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and the pair of second receivers 150b are arranged, in a side view, on a second imaginary straight line VL2 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40.

[0178] More specifically, also in the second example embodiment, the device mount 40 is located forward of the machine body 2 along the front-rear direction. Accordingly, of the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions), the first receiver 150a is in an area SA located between the device mount 40 and the cabin 22 in the front-rear direction, and the pair of second receivers 150b are located rearward of the first receiver 150a in the front-rear direction.

[0179] The first receiver 150a is located closest to the device mount 40, of the first receiver 150a and the pair of second receivers 150b (of the receivers 150a and 150b at three positions). In the present example embodiment, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the second example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0180] With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0181] In contrast, the pair of second receivers 150b are located at positions farther from the device mount 40 than the other receiver 150a (i.e., the pair of second receivers 150b are located on the imaginary concentric circle VC2 having a larger radius r2) and outside the cabin 22. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the cabin 22 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a and the pair of second receivers 150b are located at vertices of an isosceles triangle centered on an imaginary straight line passing through the center of the cabin 22 in the lateral direction, in plan view (see FIG. 17).

[0182] The first receiver 150a and the pair of second receivers 150b each receive identifying signals transmitted from tags T (transmitters T). Specifically, the first receiver 150a and the pair of second receivers 150b each receive unique identification information relating to a working device 9 from a tag T which is a transmitter attached to the working device 9. In the second example embodiment, the first receiver 150a and the pair of second receivers 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b (a first receiver 15a and a pair of second receivers 15b) each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna. Note that the first receiver 15a and the pair of second receivers 15b have the same configuration. The first receiver 15a and the pair of second receivers 15b are the same as the first receiver 15a and the second receiver 15b of the first example embodiment. Thus, the description of the first example embodiment is used as the description of the second example embodiment, and the description of the first receiver 15a and the second receivers 15b is omitted here.

[0183] The first receiver 150a and the pair of second receivers 150b are each a directional antenna to receive identifying signals from a particular direction. Accordingly, the first receiver 150a and the pair of second receivers 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). Also in the second example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a and the pair of second receivers 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the receivers 15a and 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the pair of second receivers 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0184] That is, the first receiver 15a is fixed to the cabin 22 such that the first receiver 150a is located within the area SA between the device mount 40 and the cabin 22 in the front-rear direction, and the second receivers 15b are fixed to the cabin 22 such that the second receivers 150b are located at a rear portion of the cabin 22 at the outer surfaces of the cabin 22. The receiver main bodies 151a and 151b of the respective first receiver 15a and the pair of second receivers 15b each transmit, to the controller 5 via a signal wire (CAN bus), an identifying signal received by the first receiver 150a or the second receiver 150b.

[0185] Similar to the first example embodiment, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50, an input interface 52, and an output interface 53. The input interface 52 is connected to the manual operators 11 and 12 (the first manual operator 11, the second manual operator 12), the first receiver 15a (the first receiver 150a), and the pair of second receivers 15b (the second receivers 150b).

[0186] In the second example embodiment, the controller 5 receives identifying signal(s) (wireless signal(s)) from three positions, i.e., from the first receiver 15a (first receiver 150a) and the pair of second receivers 15b (second receivers 150b), and performs control based on such signal(s).

[0187] Accordingly, the storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the pair of second receivers 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at each of the pair of second receivers 150b.

[0188] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the pair of second receivers 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strengths at the second receivers 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0189] With regard to the combination pattern of received signal strengths in the second example embodiment, assuming that the first receiver 150a and the pair of second receivers 150b each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a and for the received signal strengths at the second receivers 150b. The range of the received signal strength for the first receiver 150a and the ranges of the received signal strengths for the second receivers 150b are defined such that they do not overlap each other. The ranges of the received signal strengths for the pair of second receivers 150b are defined to be the same. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for each of the second receivers 150b is 55 dBm to 64 dBm.

[0190] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the pair of second receivers 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the second example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0191] Note that, similar to the first example embodiment, the storing unit 50 stores a device list (see FIG. 14) and information relating to a plurality of types of working devices 9 (9A to 9T) (see FIG. 15).

[0192] The working machine 1 of the second example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0193] Specifically, as shown in FIG. 19, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S10). Meanwhile, the first receiver 150a and the pair of second receivers 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S11). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the pair of second receivers 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S11).

[0194] Accordingly, similar to the first example embodiment, the controller 5 causes the monitor 55 to display information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about working device(s) 9 (9A to 9T) relating to the piece(s) of identification information received by the first receiver 150a (S12), to provide the user with a notification of the working device(s) 9 (9A to 9T) approached by the working machine 1 (device mount 40). In the present example embodiment, the controller 5 causes the monitor 55 to also display the position(s) of (approximate direction(s) to) the working device(s) 9 (9A to 9T) together with the information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about the working device(s) 9 (9A to 9T) (S12).

[0195] Specifically, in the present example embodiment, the pair of second receivers 150b are located rearward of the first receiver 150a (which is located at the center of the cabin 22 in the lateral direction) and at the left and right sides of the cabin 22 (left-right symmetrical with respect to the center of the cabin 22 in the lateral direction). With such an arrangement, in the case where a tag T of a working device 9 (9A to 9T) is located right in front of the working machine 1, the shortest linear distance from the tag T to the first receiver 150a in plan view is achieved, and the linear distances from the tag T to the pair of second receivers 150b in plan view are the same and longer (greater) than the distance from the tag T to the first receiver 150a. With this, the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strengths at the pair of second receivers 150b, and the received signal strengths at the pair of second receivers 150b are the same.

[0196] In the case where the tag T of the working device 9 (9A to 9T) is located on one of opposite sides (right side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T is shorter than the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the one of the opposite sides (right side) of the center of the cabin 22 in the lateral direction, the received signal strength at the one of the second receivers 150b is higher (greater) than the received signal strength at the other of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the one of opposite sides (right side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the one of the second receivers 150b is high.

[0197] On the contrary, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T is shorter than the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the received signal strength at the other of the second receivers 150b is higher (greater) than the received signal strength at the one of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the other of the opposite sides (left side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the other of the second receivers 150b is high.

[0198] Thus, there is a correlation between the combination of levels of received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions) and the position of the tag T of the working device 9 (9A to 9T). Therefore, the controller 5 recognizes the position of the working device 9 (9A to 9T) (the direction to the working device 9) based on the received signal strengths at the first receiver 150a and the pair of second receivers 150b (the receivers 150a and 150b at three positions), and causes the monitor 55 to display the result of the recognition (S12).

[0199] Note that, in the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the first receiver 150a and the pair of second receivers 150b receive identifying signals (a plurality of different identifying signals) form the respective tags T of the working devices 9 (9A to 9T). Therefore, pieces of information relating to the working devices 9 (9A to 9T) corresponding to the actually received identifying signals and the positions of (directions to) the working devices 9 (9A to 9T) are both displayed (S12). Note that, in the case where the first receiver 150a and the pair of second receivers 150b receive a plurality of identifying signals (receive a plurality of (a plurality of types of) identifying signals from the tags T of a plurality of working devices 9 (9A to 9T)), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the plurality of identifying signals, is the closest. Therefore, the controller 5 recognizes that the closest working device 9 (9A to 9T) is being approached, and causes the monitor 55 to display such.

[0200] In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, upon switching (changing) of identifying signals with the highest received signal strength due to travel of the working machine 1, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S12).

[0201] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and each of the first receiver 150a and the pair of second receivers 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b changes.

[0202] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the pair of second receivers 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0203] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the pair of second receivers 150b, is located nearest the first receiver 150a and the pair of second receivers 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the pair of second receivers 150b with the highest received signal strength changes to another identifying signal.

[0204] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S12), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0205] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the pair of second receivers 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the pair of second receivers 150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the pair of second receivers 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by the first receiver 150a and the pair of second receivers 150b (S12), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0206] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at each of the receivers 150b outside the cabin 22 is within a predetermined range (S13).

[0207] Specifically, in the case where the received signal strength at the first receiver 150a and the pair of second receivers 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the pair of second receivers 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S13), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receivers 150b is the working device 9 (9A to 9T) which can be attached (S12).

[0208] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the pair of second receivers 150b increases and matches a condition stored in the storing unit 50 (YES at S13), the controller 5 recognizes the working device 9 (9A to 9T) to be (planned to be) attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the pair of second receivers 150b (S14).

[0209] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at each of the receivers 150b outside the cabin 22 is within a predetermined range (YES at S13), recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receivers 150b (S14).

[0210] The controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receivers 150b matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receivers 150b (S14).

[0211] The controller 5 then, upon recognizing that the working device 9 (9A to 9T) is to be attached to the device mount 40 (S14), if the engagement portion 412 of the linkage 41 is in the engaging position PE1 (YES at S15), determines (recognizes) that the working device 9 (9A to 9T) is attached to the device mount 40 (S16). That is, in the second example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is connected to the device mount 40 via the linkage 41 (YES at S15, S16).

[0212] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40 (S16), reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T) (S17). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S18). This allows the user to operate the working device 9 under appropriate conditions.Third Example Embodiment

[0213] The following description discusses a working machine according to a third example embodiment of the present invention. Note that the working machine according to the third example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine 1 of the first example embodiment and the working machine 1 of the second example embodiment, except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the third example embodiment only discusses the differences from the first example embodiment and the second example embodiment, and the description for the same configurations as the first example embodiment and the second example embodiment is not repeated here but the description in the first example embodiment and the second example embodiment is applied as that for the third example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment and the second example embodiment are assigned the same names and reference signs as in the first example embodiment and the second example embodiment.

[0214] As illustrated in FIGS. 20 and 21, similar to the first example embodiment, the working machine 1 of the third example embodiment includes a machine body 2, a traveling device 3, a device mount 40, a support structure 4, a controller 5, manual operators 11 and 12 (first manual operator 11, second manual operator 12), and a monitor 55. The machine body 2 includes a seat 21 and a cabin 22. These features are the same as those of the working machine 1 of the first example embodiment and the second example embodiment. In the working machine 1 of the present example embodiment, the machine body 2 includes receivers 150a and 150b, 150b, 150c to receive identifying signals from transmitters T.

[0215] In the present example embodiment, the receivers 150a, 150b and 150c are located at the following four positions: positions at the front and rear of the cabin 22 (forward of and rearward of the seat 21) in the front-rear direction, and positions on the opposite sides of the cabin 22 (seat 21) in the lateral direction. Specifically, the receivers 150a, 150b and 150c of the machine body 2 include a first receiver 150a located at the front of the cabin 22, a pair of second receivers 150b located at the opposite sides of the cabin 22 in the lateral direction, and a third receiver 150c located at the rear of the cabin 22.

[0216] More specifically, as illustrated in FIG. 21, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are on (located at) three imaginary concentric circles VC1, VC2 and VC3 having different radii r1, r2 and r3 and centered on a rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40. Specifically, the first receiver 150a is on (located at) the imaginary concentric circle VC1 having the smallest radius r1 of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction, described later) of the device mount 40. The pair of second receivers 150b are on (located at) the imaginary concentric circle VC2 having the radius r2 (which is between the imaginary concentric circle VC1 having the smallest radius r1 and the imaginary concentric circle VC3 having the largest radius r3) of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction) of the device mount 40. The third receiver 150c is on (located at) the imaginary concentric circle VC3 having the largest radius r3 of the three imaginary concentric circles VC1, VC2 and VC3 centered on the rotation shaft S2 (the axis of the second shaft S2 that extends in the lateral direction) of the device mount 40.

[0217] The pair of second receivers 150b are on the same imaginary concentric circle VC2, and are arranged with a space therebetween in the lateral direction in plan view (see FIG. 20).

[0218] That is, in the third example embodiment, the first receiver 150a is located, in a side view, on a first imaginary straight line VL1 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40, and the pair of second receivers 150b are arranged, in a side view, on a second imaginary straight line VL2 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction that is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 and that differs from the direction of the first imaginary straight line VL1. The third receiver 150c is located, in a side view, on a third imaginary straight line VL3 that extends from a point on the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 in a direction that is perpendicular to the rotation shaft S2 (the axis of the second shaft S2) of the device mount 40 and that differs from the directions of the first imaginary straight line VL1 and the second imaginary straight line VL2.

[0219] More specifically, also in the third example embodiment, the device mount 40 is located forward of the machine body 2 along the front-rear direction. Accordingly, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a to 150c at four positions), the first receiver 150a is in an area SA located between the device mount 40 and the cabin 22 in the front-rear direction, the pair of second receivers 150b are located rearward of the first receiver 150a in the front-rear direction, and the third receiver 150c is located rearward of the first receiver 150a and the pair of second receivers 150b in the front-rear direction.

[0220] The first receiver 150a is located closest to the device mount 40, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (of the receivers 150a, 150b and 150c at four positions). In the present example embodiment, the first receiver 150a is located outward of (forward of) the front surface of the cabin 22. In the third example embodiment, the first receiver 150a is located outward of (forward of) an upper portion of the front surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0221] With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (on the imaginary concentric circle VC1 having the smallest radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0222] The third receiver 150c is located farthest from the device mount 40, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (of the receivers 150a, 150b and 150c at four positions). In the present example embodiment, the third receiver 150c is located outward of a rear portion of the upper surface of the cabin 22 and located at a central portion of the cabin 22 in the lateral direction.

[0223] With this, the third receiver 150c is located at a position farthest from the device mount 40 (on the third imaginary concentric circle VC3 having the largest radius r3) and located on the cabin 22.

[0224] In contrast, the pair of second receivers 150b are located between the first receiver 150a and the third receiver 150c (on the second imaginary concentric circle VC2 having the radius r2 which is larger than the radius r1 of the first imaginary concentric circle VC1 and larger than the radius r3 of the third imaginary concentric circle VC3), and are located outside the cabin 22. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the cabin 22 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are located at four vertices of a quadrangle (lozenge) in plan view.

[0225] The first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive identifying signals transmitted from transmitters T. Specifically, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive unique identification information relating to a working device 9 from a tag T which is a transmitter T attached to the working device 9. Similar to the first example embodiment and the second example embodiment, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are combined with respective receiver main bodies 151a, 151b and 151c to accept identifying signals. That is, in the machine body 2, the first receiver 150a, the second receivers 150b, and the third receiver 150c (which are antennas) are combined with respective receiver main bodies 151a, 151b and 151c to accept identifying signals from the antennas. That is, the working machine 1 of the third example embodiment includes a first receiver 15a which is a receiver 15a located closest to the device mount 40, a third receiver 15c which is a receiver 15c located farthest from the device mount 40, and second receivers 15b which are receivers 15b located between the first receiver 15a and the third receiver 15c. Note that, also in the present example embodiment, the receivers 15a, 15b, and 15c (first receiver 15a, second receiver 15b, third receiver 15c) are the same as the receivers 15a and 15b (first receiver 15a, second receiver 15b) of the first example embodiment and the second example embodiment. Thus, the description of the first example embodiment and the second example embodiment is used as the description of the present example embodiment, and the description of the first receiver 15a, the second receivers 15b and the third receiver 15c is omitted here.

[0226] The first receiver 150a, the pair of second receivers 150b and the third receiver 150c are each a directional antenna to receive identifying signals from a particular direction. Accordingly, each receiver is positioned such that the orientation in which the receiver receives an identifying signal is directed toward the device mount 40 (in the direction toward the device mount 40). In the present example embodiment, since the device mount 40 is located forward of the machine body 2 (cabin 22), the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are each positioned such that the orientation in which the receiver receives an identifying signal is directed forward in the front-rear direction. Accordingly, the receivers 15a to 15c (first receiver 15a, second receiver 15b, third receiver 15c) are fixed to the cabin 22 such that the orientation in which the receivers 150a, 150b and 150c (first receiver 150a, pair of second receivers 150b and third receiver 150c) receive identifying signals is directed toward the side where the device mount 40 is present (directed forward).

[0227] Specifically, the first receiver 15a is fixed to the front surface of the cabin 22 such that the first receiver 150a is located in the area SA between the device mount 40 and the cabin 22 in the front-rear direction. The pair of second receivers 15b are each fixed to the cabin 22 such that the second receiver 150b or 150b is located at the center of an outer side surface of the cabin 22 in the front-rear direction. The third receiver 15c is fixed to an upper surface of a rear portion of the cabin 22 such that the third receiver 150c is located at the rear portion of the cabin 22.

[0228] Similar to the first example embodiment, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50, an input interface 52, and an output interface 53. The input interface 52 is connected to the manual operators 11 and 12 (the first manual operator 11, the second manual operator 12), the first receiver 15a (the first receiver 150a), the pair of second receivers 15b (the second receivers 150b), and the third receiver 15c (third receiver 150c).

[0229] Accordingly, in the third example embodiment, the controller 5 receives identifying signal(s) (wireless signal(s)) from four positions, i.e., from the first receiver 15a (first receiver 150a), the pair of second receivers 15b (second receivers 150b), and the third receiver 15c (third receiver 150c), and performs control based on such signal(s).

[0230] Accordingly, the storing unit 50 of the controller 5 of the present example embodiment stores combination pattern(s) of received signal strengths at the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c. The combination pattern of received signal strengths is defined such that the received signal strength at the first receiver 150a is greater than the received signal strength at each of the pair of second receivers 150b.

[0231] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a, the received signal strengths at the second receivers 150b, and the received signal strength at the third receiver 150c are respective predetermined values (respective single values) or respective predetermined ranges.

[0232] With regard to the combination pattern of received signal strengths in the third example embodiment, assuming that the first receiver 150a, the pair of second receivers 150b and the third receiver 150c each receive an identifying signal (there are received signal strengths), respective predetermined ranges are defined for the received signal strength at the first receiver 150a, for the received signal strengths at the second receivers 150b, and for the received signal strength at the third receiver 150c. The range of the received signal strength for the first receiver 150a and the ranges of the received signal strengths for the pair of second receivers 150b are defined such that they do not overlap each other. The range of the received signal strength for the third receiver 150c and the ranges of the received signal strengths for the pair of second receivers 150b are defined such that they do not overlap each other. In the present example embodiment, the ranges of the received signal strengths for the pair of second receivers 150b are defined to be the same. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for each of the pair of second receivers 150b is 55 dBm to 64 dBm and the range of the received signal strength for the third receiver 150c is 45 dBm to 54 dBm.

[0233] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the pair of second receivers 150b and the third receiver 150c, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the third example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0234] Note that the storing unit 50 stores a device list (see FIG. 14) and information relating to a plurality of types of working devices 9 (9A to 9T) (see FIG. 15) in addition to the combination pattern of the received signal strengths at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c, similar to the first example embodiment and the second example embodiment.

[0235] The working machine 1 of the third example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed.

[0236] The action of attaching (connecting) a working device 9 at the working machine 1 of the present example embodiment (control performed by the controller 5) is the same as that of the second example embodiment. Accordingly, referring to FIG. 19, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S10). Meanwhile, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S11). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S11).

[0237] Accordingly, similar to the first example embodiment and the second example embodiment, the controller 5 causes the monitor 55 to display information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about working device(s) 9 (9A to 9T) relating to the piece(s) of identification information received by the first receiver 150a (S12), to provide the user with a notification of the working device(s) 9 (9A to 9T) approached by the working machine 1 (device mount 40). In the present example embodiment, the controller 5 causes the monitor 55 to also display the position(s) of (approximate direction(s) to) the working device(s) 9 (9A to 9T) together with the information (the name(s) and piece(s) of graphics (pictogram(s)) of working device(s) 9 (9A to 9T)) about the working device(s) 9 (9A to9T) (S12).

[0238] Specifically, in the present example embodiment, the pair of second receivers 150b are located rearward of the first receiver 150a (which is located at the center of the cabin 22 in the lateral direction) and at the left and right sides of the cabin 22 (left-right symmetrical with respect to the center of the cabin 22 in the lateral direction). With such an arrangement, in the case where a tag T of a working device 9 (9A to 9T) is located right in front of the working machine 1, the shortest linear distance from the tag T to the first receiver 150a in plan view is achieved, and the linear distances from the tag T to the pair of second receivers 150b in plan view are the same and longer (greater) than the distance from the tag T to the first receiver 150a. With this, the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strengths at the pair of second receivers 150b, and the received signal strengths at the pair of second receivers 150b are the same.

[0239] In the case where the tag T of the working device 9 (9A to 9T) is located on one of opposite sides (right side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the one of the opposite sides (right side) to the tag T is shorter than the distance from the second receiver 150 at the other of the opposite sides (left side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the one of the opposite sides (right side) of the center of the cabin 22 in the lateral direction, the received signal strength at the one of the second receivers 150b is higher (greater) than the received signal strength at the other of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the one of opposite sides (right side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the one of the second receivers 150b is high.

[0240] On the contrary, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the distance from the second receiver 150b at the other of the opposite sides (left side) to the tag T is shorter than the distance from the second receiver 150 at the one of the opposite sides (right side) to the tag T. With this, in the case where the tag T of the working device 9 (9A to 9T) is located on the other of the opposite sides (left side) of the center of the cabin 22 in the lateral direction, the received signal strength at the other of the second receivers 150b is higher (greater) than the received signal strength at the one of the second receivers 150b. In the case where the tag T of the working devices 9 (9A to 9T) is located at the other of the opposite sides (left side) of the cabin 22 in the lateral direction, the received signal strength at the first receiver 150a is low (small) and the received signal strength at the other of the second receivers 150b is high.

[0241] When the tag T of the working device 9 (9A to 9T) is located at one side of the cabin 22 such that the position of the tag T corresponds to the center of the cabin 22 in the front-rear direction, the linear distance from one of the second receiver 150b that is located on the same side of the cabin 22 as the working device 9 (9A to 9T) to the tag T is the shortest, whereas the linear distance from the other second receiver 150b to the tag T is the longest. In the case where the tag T of the working device 9 (9A to 9T) is located at one side of the cabin 22 such that the position of the tag T corresponds to the center of the cabin 22 in the front-rear direction, the linear distance from the first receiver 150a to the tag T is the same or substantially the same as the linear distance from the third receiver 150c to the tag T. Thus, in such a case, the received signal strength at the one of the second receivers 150b is the highest, the received signal strength at the other second receiver 150b is the lowest, and the received signal strength at the first receiver 150a is the same or substantially the same as the received signal strength at the third receiver 150c.

[0242] Under such conditions, when the tag T of the working device 9 (9A to 9T) moves rearward along the front-rear direction of the cabin 22 or when the tag T of the working device 9 (9A to 9T) is located rearward of the cabin 22, the distance from the third receiver 150c to the tag T becomes shorter than the distance from the first receiver 150a to the tag T. When the tag T of the working device 9 (9A to 9T) moves forward along the front-rear direction or when the tag T of the working device 9 (9A to 9T) is located forward of the cabin 22, the distance from the third receiver 150c to the tag T becomes longer than the distance from the first receiver 150a to the tag T. Thus, in the case where the tag T of the working device 9 (9A to 9T) is located rearward of the cabin 22, the received signal strength at the third receiver 150c is higher (greater) than the received signal strength at the first receiver 150a, whereas, in the case where the tag T of the working device 9 (9A to 9T) is located forward of the cabin 22, the received signal strength at the third receiver 150c is lower (less) than the received signal strength at the first receiver 150a.

[0243] Thus, there is a correlation between the combination of levels of received signal strengths at the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions) and the position of the tag T of the working device 9 (9A to 9T). Therefore, the controller 5 recognizes the position of the working device 9 (9A to 9T) (the direction to the working device 9) based on the received signal strengths at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), and causes the monitor 55 to display the result of the recognition (S12).

[0244] Note that, in the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c receive identifying signals (a plurality of different identifying signals) form the respective tags T of the working devices 9 (9A to 9T). Therefore, pieces of information relating to the working devices 9 (9A to 9T) corresponding to the currently receiving identifying signals and the positions of (directions to) the working devices 9 (9A to 9T) are both displayed (S12).

[0245] Note that, in the case where the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c receive a plurality of identifying signals (receive a plurality of (a plurality of types of) identifying signals from the tags T of a plurality of working devices 9 (9A to 9T)), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the plurality of identifying signals, is the closest. Therefore, the controller 5 recognizes that the closest working device 9 (9A to 9T) is being approached, and causes the monitor 55 to display such (S12).

[0246] In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, upon switching (changing) of identifying signals with the highest received signal strength due to travel of the working machine 1, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S12).

[0247] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and each of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c changes.

[0248] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c changes, e.g., the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0249] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c, is located nearest the first receiver 150a, the pair of second receivers 150b and the third receiver 150c. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c with the highest received signal strength changes to another identifying signal.

[0250] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength (S12), to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40).

[0251] Note that, also in the present example embodiment, when the working machine 1 changes the direction of travel, in some cases, not all the first receiver 150a, the pair of second receivers 150b and the third receiver 150c can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.)

[0252] Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a, the pair of second receivers 150b and the third receiver 150c all start receiving an identifying signal or the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by all the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S12), to provide the user with a notification of the working device 9 (9A to 9T) in front of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is in front of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling forward. Thus, the working machine 1 is configured to, in view of the orientation thereof, provide the user with a notification of the working device 9 in front thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling forward).

[0253] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a, the second receivers 150b and the third receiver 150c matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the receiver 150a is equal to or greater than a preset threshold and the received signal strength at each of the pair of second receivers 150b and the third receiver 150c is within a predetermined range (S13).

[0254] Specifically, in the case where the received signal strength at the first receiver 150a, the pair of second receivers 150b and the third receiver 150c is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S13), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a, the second receivers 150b and the third receiver 150c is the working device 9 (9A to 9T) which can be attached (S12).

[0255] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c increases and matches a condition stored in the storing unit 50, the controller 5 recognizes the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (YES at S13).

[0256] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the receiver 150a is equal to or greater than a preset threshold and the received signal strength at each of the pair of receivers 150b and the third receiver 150c is within a predetermined range (YES at S13), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S14).

[0257] The controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c matches a condition stored in the storing unit 50, recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (S14).

[0258] The controller 5 then, upon recognizing that the working device 9 (9A to 9T) is to be attached to the device mount 40 (S14), if the engagement portion 412 of the linkage 41 is in the engaging position PE1 (YES at S15), determines (recognizes) that the working device 9 (9A to 9T) is attached to the device mount 40 (S15). That is, also in the third example embodiment, the controller 5 is configured or programmed to recognize the working device 9 (9A to 9T) attached to the device mount 40 under the conditions in which the working device 9 (9A to 9T) is connected to the device mount 40 via the linkage 41 (YES at S15, S16).

[0259] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40 (S16), reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T) (S17). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S18). This allows the user to operate the working device 9 under appropriate conditions.Fourth Example Embodiment

[0260] The following description discusses a working machine according to a fourth example embodiment of the present invention. Note that the working machine according to the fourth example embodiment is an agricultural tractor different from the first to third example embodiments, but includes features to achieve the same functions as the working machine 1 of the first to third example embodiments. Accordingly, in the fourth example embodiment, the features to achieve the same functions as those of the first to third example embodiments are regarded as the feature corresponding to those of the first to third example embodiments, and assigned the same names and reference signs as in the first to third example embodiments. The description of the features corresponding to those of the first to third example embodiments or features to achieve the same functions (processes) as the first to third example embodiments is omitted here, and the corresponding description in the first to third example embodiments is applied mutatis mutandis to the fourth example embodiment.

[0261] As illustrated in FIGS. 22 and 23, the working machine 1 according to the fourth example embodiment includes a machine body 2. The working machine 1 includes traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes device mount(s) 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work (see FIG. 23). That is, the working machine 1 includes a device mount 40 to attach thereto each of a plurality of types of working devices 9 independently.

[0262] In the fourth example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61 to cause the device mount 40 to move along the path (see FIG. 23). The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0263] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a manual operator 11 to be operated by the user to perform operations relating to travel of the traveling device 3 (which may be hereinafter referred to as a first manual operator). The working machine 1 includes a manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path (which may be hereinafter referred to as a second manual operator).

[0264] In the present example embodiment, the first manual operator 11 includes a steering operator, which is rotated to pivotally control the direction of travel of the traveling device 3. The second manual operator 12 includes a group of switches, which are configured such that when a predetermined switch is turned ON or OFF, the working device 9 attached to the support structure 4 and the device mount 40 is caused to perform a predetermined action.

[0265] The machine body 2 include a frame chassis 20, a seat 21 provided on the frame chassis 20, and a seat protection structure 22 to protect the seat 21. The machine body 2 includes receivers 150a and 150b to receive identifying signals from transmitters T.

[0266] In the present example embodiment, the frame chassis 20 supports the prime mover 10 to drive the traveling device 3. In the present example embodiment, the prime mover 10 is located at a front portion of the frame chassis 20. The working machine 1 of the present example embodiment is an agricultural tractor, and therefore includes a PTO shaft (not illustrated) to transmit power to the working device 9 (9A or the like) attached to the device mount 40. The actuators 61 in the present example embodiment each include a hydraulic cylinder.

[0267] Thus, the working machine 1 includes a hydraulic system 6 including a hydraulic pump to supply hydraulic fluid to actuators 61 and a control valve to control the flow of hydraulic fluid. Accordingly, the prime mover 10 functions as a drive source to drive (rotate) the PTO shaft and as a drive source to drive (rotate) the hydraulic pump included in the hydraulic system 6. Note that the hydraulic system 6 (hydraulic pump) is driven by the prime mover 10, and the hydraulic system 6 (control valve) is controlled by the controller 5.

[0268] In the present example embodiment, the machine body 2 includes a hood 25 to cover apparatuses (such as the prime mover 10 and the hydraulic system 6, in the present example embodiment) supported on the frame chassis 20. The hood 25 covers a substantially front-half portion of the frame chassis 20 in the front-rear direction, and defines a prime mover room MR to hose the hydraulic system 6 and the prime mover 10. Note that, in the present example embodiment, the prime mover 10 includes an internal combustion engine (diesel engine). The prime mover 10 may include an electric motor.

[0269] The seat 21 is located rearward of the prime mover room MR (prime mover 10) and is fixed to the frame chassis 20. In the present example embodiment, the seat protection structure 22 is a cabin to surround the seat 21. Since the seat 21 is located rearward of the prime mover room MR as described above, the cabin 22 (seat protection structure 22) is also located rearward of the prime mover room MR. That is, the cabin 22 defines, at a location rearward of the prime mover room MR, an operator cab OR in which the user seated in the seat 21 stays. Note that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12), and the like are provided within the cabin 22 (operator cab OR) such that the monitor 55, the manual operators 11 and 12 (first manual operator 11, second manual operator 12) and the like can be operated by the user.

[0270] The cabin 22 includes front, rear, left and right windows, and one or both of the opposite side windows in the lateral direction is / are door(s) openable and closable. This allows the user to enter and exit the operator cab OR via a side of the cabin 22.

[0271] The receivers 150a and 150b are located at two positions at the front and rear of the center of the cabin 22 in the front-rear direction. In the present example embodiment, the device mount 40 (hook 40) is located rearward of the machine body 2 (cabin 22) along the front-rear direction. Accordingly, the receivers 150a and 150b are located at two positions at different distances from the device mount 40. Specifically, the receivers 150a and 150b at two positions are at increasing distances from the device mount 40. In the present example embodiment, the receivers 150a and 150b are located at two positions at increasing distance from the device mount 40 in the forward direction. Note that the device mount 40 is located rearward of the machine body 2 (cabin 22) along the front-rear direction. as described earlier. In the following description, one (receiver 150a) of the receivers 150a and 150b at the two positions that is closest to the device mount 40 is referred to as a first receiver 150a, and the other (receiver 150b) of the receivers 150a and 150b that is farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 150b, as with the case of the first example embodiment.

[0272] More specifically, the first receiver 150a and the second receiver 150b are located such that the first receiver 150a and the second receiver 150b are on (located at) two imaginary concentric circles VC1 and VC2 having different radii r1 and r2 and centered on a rotation shaft S2 which is the rotational axis of the working device 9 (9A or the like) supported by the device mount 40 (centered on the axis of the shaft S2 that is engaged with the hook 40 which is the device mount 40 attached to an upper link (described later) and that extends in the lateral direction, in the present example embodiment).

[0273] The first receiver 150a and the second receiver 150b may be arranged on a single imaginary straight line that extends from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in a direction perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40, and may be located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40. The latter case is used in the present example embodiment. That is, the first receiver 150a and the second receiver 150b in the present example embodiment are located at points on two imaginary straight lines VL1 and VL2 that extend from a single point on the rotation shaft S2 (the axis of the shaft S2) of the device mount 40 in different directions each of which is perpendicular to the rotation shaft S2 (the axis of the shaft S2) of the device mount 40.

[0274] More specifically, in the present example embodiment, the first receiver 150a and the second receiver 150b are located at the following two positions: a position in an area SA between the device mount 40 and the cabin 22 in the front-rear direction, and a position at a front portion of the cabin 22.

[0275] The device mount 40 is located rearward of the machine body 2 in the front-rear direction, as described earlier. More specifically, the device mount 40 is located rearward of the cabin 22, and is raised and lowered at a position rearward of the cabin 22. Accordingly, the first receiver 150a is located outward of (rearward of) the rear surface (back surface) of the cabin 22. In the fourth example embodiment, the first receiver 150a is located outward of (rearward of) an upper portion of the cabin 22. With this, the first receiver 150a is located such that the first receiver 150a is the closest, of the receivers, to the device mount 40 (i.e., the first receiver 150a is located on the imaginary concentric circle VC1 having a smaller radius r1) and is within the area SA between the device mount 40 and the cabin 22 in the front-rear direction.

[0276] In contrast, the second receiver 150b is located at a position farther from the device mount 40 than the other receiver 150a (i.e., the second receiver 150b is located on the imaginary concentric circle VC2 having a larger radius r2) and outside the cabin 22. In the present example embodiment, the second receiver 150b is located at an upper surface (roof) of a front portion of the cabin 22. In the present example embodiment, the first receiver 150a and the second receiver 150b are displaced from each other in the front-rear direction, but are each located at a central portion of the cabin 22 in the lateral direction.

[0277] The first receiver 150a and the second receiver 150b receive unique identification information relating to a working device 9 from a tag T which is a transmitter T attached to the working device 9, as with the first example embodiment. The first receiver 150a and the second receiver 150b are combined with respective receiver main bodies 151a and 151b to accept identifying signals. That is, the machine body 2 includes receivers 15a and 15b each of which is an assembly of an antenna which is the first or second receiver 150a or 150b, and the receiver main body 151a or 151b to accept identifying signals from the antenna. Note that, also in the present example embodiment, the receiver 15a including the first receiver 150a which is located closest to the device mount 40 is referred to as a first receiver 15a, and the receiver 15b including the second receiver 150b located farther from the device mount 40 than the first receiver 150a is referred to as a second receiver 15b. The first receiver 15a and the second receiver 15b are the same as the receivers 15a, 15b and 15c of the first to third example embodiments. Accordingly, the description of the configuration of the receivers 15a and 15b and the relationship between the receivers 15a and 15b and the controller 5 is not repeated here, and the description in the first example embodiment is also used in the present example embodiment.

[0278] In the present example embodiment, since the device mount 40 is located rearward of the machine body 2 (cabin 22), the first receiver 150a and the second receiver 150b are each positioned such that the orientation in which the receiver receives an identifying signal is directed rearward in the front-rear direction. Accordingly, the first receiver 15a and the second receiver 15b are fixed to the cabin 22 such that the orientation in which the first receiver 150a and the second receiver 150b (antennas) receive identifying signals is directed toward the side where the device mount 40 is present (directed rearward).

[0279] In the present example embodiment, the traveling device 3 is a tire traveling device, which includes front wheels and rear wheels at opposite sides of the machine body 2 in the lateral direction (at left and right sides of the machine body 2). In the present example embodiment, the front wheels are steered wheels, and the angle of steering of a pair of left and right front wheels is changed by operation of the first manual operator 11 (steering operator). In the present example embodiment, the traveling device 3 can switch between two-wheel drive and four-wheel drive. In the case of the two-wheel drive, the drive force is transmitted from the prime mover 10 to the rear wheels, and, in the case of the four-wheel drive, the drive force is transmitted from the prime mover 10 to all the four wheels including the front wheels and the rear wheels.

[0280] The device mount 40 is supported on the machine body 2 via the support structure 4. In the present example embodiment, the device mount 40 is a structure including hooks configured to engage with the shafts S2 extending in the lateral direction.

[0281] More specifically, the support structure 4 of the present example embodiment is a three-point linkage, which includes an upper link and a pair of lower links connected to a rear portion of the machine body 2 via shafts extending in the lateral direction. The pair of lower links are arranged with a space therebetween in the lateral direction, and the upper link is located higher than the pair of lower links such that the upper link is located between the pair of lower links. The device mount 40 is joined to the distal portions of the upper link and of the pair of lower links.

[0282] With this, a working device 9 is connected such that the working device 9 is engaged with a hook 40 (which is included in the device mount 40) joined to the distal portion of the upper link and engaged with a set of hooks 40 (which are included in the device mount 40) joined to the distal portions of the pair of lower links, i.e., such that the working device 9 is supported at three points. Note that the actuator(s) 61 is / are hydraulic cylinder(s), which extend or retract to swing the pair of lower links. With this, the working device 9 is raised or lowered in the up-down direction by the swinging movement of the pair of lower links.

[0283] The controller 5 is the same as that of the first example embodiment. Accordingly, referring to FIG. 13, the controller 5 includes an arithmetic controller 51, a storing unit (memory and / or storage) 50 to store information for use in processes performed by the arithmetic controller 51, an input interface 52 electrically connected to the arithmetic controller 51 to input, into the arithmetic controller 51, an electric signal which is input information from an external electric device, and an output interface 53 electrically connected to the arithmetic controller 51 to output, to an external electric device, a command signal (electric signal) which is output information from the arithmetic controller 51.

[0284] The arithmetic controller 51 may be a so-called CPU, and may include a calculator 510 and a controller 511. In the controller 5 of the present example embodiment, the storing unit 50 includes a first storing unit 500 and a second storing unit 501. The first storing unit 500 is a so-called memory, and the second storing unit 501 is a storage such as a hard disc or solid state drive (SSD).

[0285] The storing unit 50 stores a device list which is a list of a plurality of working devices 9 (9A to 9T) and which is to be displayed on the monitor 55. Note that, since the working machine 1 of the present example embodiment is an agricultural tractor different from the first example embodiment, working devices 9 attached to the device mount 40 are different from those in the first example embodiment. However, the device list includes a plurality of devices also in the present example embodiment. That is, the pictographs illustrated in the device list in FIG. 14 are replaced by pieces of graphics representing agricultural working devices 9. Furthermore, the pieces of information relating to the plurality of types of working devices 9 (9A to 9T) attachable to the device mount 40 in FIG. 15 are replaced by pieces of information about agricultural working devices 9. Thus, the storing unit 50 stores information similar to that in the first example embodiment.

[0286] Examples of the plurality of types of working devices 9 (9A to 9T) recorded in the storing unit 50 include a rotary, a plow, a harrow, a broadcaster, a manure spreader, a planter, a rice transplanter, a lister, a mulcher, a speed sprayer, a boom sprayer, a trailer, a front loader, and a roll baler. The pieces of information (pieces of graphics) in FIGS. 14 and 15 are replaced by pieces of information about these devices. Also in such a case, the names of the working devices 9 (9A to 9T), the pieces of identification information 9A to 9T, the working devices 9 (9A to 9T), and the pieces of graphics of the working devices 9 (i.e., pieces of information arranged horizontally in FIG. 15) are stored such that they are associated with each other, similar to the first example embodiment.

[0287] The storing unit 50 stores combination pattern(s) of received signal strengths at the first receiver 150a and the second receiver 150b (the receivers 150a and 150b at two positions). Specifically, the storing unit 50 stores a combination of levels of received signal strengths for the first receiver 150a and the second receiver 150b. The combination pattern of received signal strengths is such that the received signal strength at the first receiver 150a is greater than the received signal strength at the second receiver 150b.

[0288] The combination pattern of received signal strengths may be defined such that, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b are respective predetermined values (respective single values) or respective predetermined ranges.

[0289] With regard to the combination pattern of received signal strengths in the fourth example embodiment, assuming that the first receiver 150a and the second receiver 150b each receive an identifying signal (there are received signal strengths), similar to the second example embodiment, respective predetermined ranges are defined for the received signal strength at the first receiver 150a and the received signal strength at the second receiver 150b. The range of the received signal strength for the first receiver 150a and the range of the received signal strength for the second receiver 150b are defined such that they do not overlap each other. For example, if the range of the received signal strength for the first receiver 150a is 65 dBm to 75 dBm, then the range of the received signal strength for the second receiver 150b is 55 dBm to 64 dBm.

[0290] The storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a. Specifically, the storing unit 50 stores threshold(s) of the received signal strength of the identifying signal received by the first receiver 150a, as a reference based on which a working device 9 (9A to 9T) to be attached to or attached to the device mount 40 is to be recognized (identified). The storing unit 50 stores the received signal strength(es) of the identifying signal received by the second receiver 150b, as judgment-reference information which is information for use with the threshold(s) and which is a reference based on which a working device 9 (9A to 9T) is to be recognized (identified), such that the received signal strength(es) is / are associated with the threshold(s). In the fourth example embodiment, the threshold is a single value, but the judgment-reference information is a range of values lower than the threshold. That is, the judgment-reference information is a range with the upper-limit and lower-limit values which are lower than the threshold.

[0291] The monitor 55 includes a touchscreen monitor, which is operable to receive input of information. The monitor 55 displays a device list read from the storing unit 50. As described above, the monitor 55 includes a touchscreen monitor, and therefore, upon the user selecting (touching) the icon of the working device 9 to be used from the device list displayed on the monitor 55, the controller 5 (arithmetic controller 51) recognizes the type of the working device 9 to be used (the selected working device 9).

[0292] Accordingly, the controller 5 (arithmetic controller 51) recognizes (the type of) the working device 9 to be used (the selected working device 9), based on the identification information received by the first receiver 150a and the second receiver 150b.

[0293] The controller 5 retrieves operation conditions (control conditions) for the working device 9 corresponding the selected icon selected via the monitor 55 (reads the operation conditions (control conditions) from the storing unit 50). Note that the controller 5 is configured or programmed to, if a working device 9 is selected from the device list displayed on the monitor 55, recognize the selected working device 9 as the working device 9 intended by the user, and prioritize this recognition over the recognition of the working device 9 based on reading the identification information received by the receivers 15a and 15b (the first receiver 150a and the second receiver 150b).

[0294] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information. The unique identification information here is used to identify the working device 9, and includes, for example, unique ID, model name, model number, and / or the like. Also in the fourth example embodiment, the tag T is a beacon tag to transmit unique identification information as a wireless signal (advertisement signal Q1) compliant with Bluetooth (registered trademark) Low Energy.

[0295] The following discusses the working devices 9. Each of the plurality of types of working devices 9 includes (i) a mount base 91 attachable to the device mount 40 and (ii) a functioning portion 93 connected to the mount base 91 and operable to perform a function corresponding to work.

[0296] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mount 40 of the working machine 1. In the present example embodiment, the device mount 40 of the working machine 1 includes hooks 40, and therefore the mount base 91 of each working device 9 includes shafts S2 (rotation shafts S2) to be engaged with the hooks 40 (of the device mount 40). Since this is a well-known configuration, a detailed description thereof is omitted here.

[0297] The working machine 1 of the fourth example embodiment has been described. While no working devices 9 are attached to the device mounts 40, the action of attaching (connecting) a desired working device 9 is performed. The processes performed by the controller 5 to perform the action of connecting are similar to those of the first example embodiment. Accordingly, referring to FIG. 16, the working machine 1 is caused by the user operation to travel toward a device storage space where working device(s) 9 is / are present (S1). Meanwhile, the first receiver 150a and the second receiver 150b receive identifying signal(s) (wireless signal(s)) transmitted from tag(s) T of the working device(s) 9 in the device storage space (S2). In the case where a plurality of working devices 9 (9A to 9T) are present in the device storage space, the tags T of the respective working devices 9 (9A to 9T) transmit pieces of identification information. Thus, the first receiver 150a and the second receiver 150b of the working machine 1 receive the pieces of identification information transmitted from the tags T of the respective working devices 9 (9A to 9T) (S2).

[0298] The received signal strength of identification information increases as the distance to the tag T that is the source of the identification information decreases. Therefore, in the case where the first receiver 150a and the second receiver 150b receive a plurality of pieces of identification information, the controller 5 recognizes that the piece of identification information with the highest received signal strength, of the pieces of identification information received by the first receiver 150a and the second receiver 150b, is the piece of information of the closest working device 9 (9A to 9T).

[0299] Under such circumstances, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S3).

[0300] As the working machine 1 travels (moves), the distance between the tag T of the working device 9 (9A to 9T) at a fixed position and the first receiver 150a and the second receiver 150b of the working machine 1 which is currently traveling changes. Therefore, for example, when the working machine 1 passes behind, in front of or by the side of the working device 9 (9A to 9T), the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes.

[0301] Specifically, as the working machine 1 travels, the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b changes, e.g., the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes higher (increases) as the working machine 1 approaches the working device 9 (9A to 9T), whereas the received signal strength of the identification information received by the first receiver 150a and the second receiver 150b becomes lower (decreases) as the working machine 1 moves away from the working device 9 (9A to 9T).

[0302] This means that when the working machine 1 passes behind, in front of or by the side of a plurality of working devices 9 (9A to 9T), the working device 9 (9A to 9T) that corresponds to the identifying signal with the highest received signal strength, of the identifying signals received by the first receiver 150a and the second receiver 150b, is located nearest the first receiver 150a and the second receiver 150b. However, as the working machine 1 travels, the working machine 1 moves away from the tag T that transmits the identifying signal with the highest received signal strength and approaches another tag T, and therefore the identifying signal received by the first receiver 150a and the second receiver 150b with the highest received signal strength changes to another identifying signal.

[0303] Accordingly, upon switching (changing) of identifying signals with the highest received signal strength, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the piece of identification information with the highest received signal strength, to provide the user with a notification of the working device 9 (9A to 9T) approached by the working machine 1 (device mount 40) (S3).

[0304] Note that, when the working machine 1 changes the direction of travel, in some cases, not both the first receiver 150a and the second receiver 150b can receive the same identifying signal anymore. In such a case, the controller 5 stops causing the monitor 55 to display the indication (the name of the working device 9 (9A to 9T), etc.) Then, if the working machine 1 changes the direction of travel and therefore the first receiver 150a and the second receiver 150b both start receiving an identifying signal or the identifying signal received by the first receiver 150a and the second receiver 150b changes, the controller 5 causes the monitor 55 to display information (the name and a piece of graphics (pictogram) of the working device 9 (9A to 9T)) about the working device 9 (9A to 9T) relating to the identifying signal received by both the first receiver 150a and the second receiver 150b, to provide the user with a notification of the working device 9 (9A to 9T) located rearward of the working machine 1 (device mount 40), i.e., the working device 9 (9A to 9T) which is located rearward of the cabin 22 and which can be attached to the device mount 4 by the working machine 1 (device mount 40) traveling rearward. Thus, the working machine 1 is configured to, based on the orientation thereof, provide the user with a notification of the working device 9 located rearward thereof (the working device 9 located such that the working device 9 can be attached to the device mount 4 by the working machine 1 traveling rearward).

[0305] Under such circumstances, the controller 5 determines whether or not the combination of the received signal strengths at the first receiver 150a and the second receiver 150b matches a predetermined condition, and determines whether or not the received signal strength of the identifying signal received by the first receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the second receiver 150b outside the cabin 22 is within a predetermined range (S4).

[0306] Specifically, in the case where the received signal strength at the first receiver 150a and the second receiver 150b is not sufficient (weak), the distance between the device mount 40 and the working device 9 (9A to 9T) is large and the working device 9 (9A to 9T) cannot be attached to the device mount 40. Therefore, the working machine 1 (controller 5) does not recognize that the working device 9 (9A to 9T) associated with the identification information received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 (NO at S4), and causes the monitor 55 to display information indicating that the working device 9 (9A to 9T) corresponding to the identifying signal with a high received signal strength received by the first receiver 150a and the second receiver 150b is the working device 9 (9A to 9T) which can be attached (S3).

[0307] Then, as the working machine 1 approaches the working device 9 (9A to 9T), when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b increases and matches a condition stored in the storing unit 50 (YES at S4), the controller 5 recognizes the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0308] Specifically, the controller 5 is configured or programmed to, if the combination of the received signal strengths matches the predetermined condition or if the received signal strength of the identifying signal received by the first receiver 150a in the area SA between the device mount 40 and the cabin 22 is equal to or greater than a preset threshold and the received signal strength at the second receiver 150b outside the cabin 22 is within a predetermined range (YES at S4), recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0309] In the fourth example embodiment, the controller 5 is configured or programmed to, when the received signal strength of the identifying signal received by the first receiver 150a and the second receiver 150b matches a condition stored in the storing unit 50 (YES at S4), recognize the working device 9 (9A to 9T) to be attached to the device mount 40 based on (using) the identifying signal received by the first receiver 150a and the second receiver 150b (S5).

[0310] The controller 5 then recognizes that the working device 9 (9A to 9T) is to be attached to the device mount 40 (YES at S6), and determines (recognizes) that the working devices 9 (9A to 9T) has been connected (attached) to the device mounts 40 (S7). In the present example embodiment, the device mounts 40 are hooks 40 and include no actuators to be driven to achieve connection such as the linkage 41 of the first to third example embodiments. Therefore, the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) (S5), when the receivers 150a and 150b at two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined period of time, determine that the position of the working device 9 (9A or the like) has been identified (determined) and recognizes that the working device 9 is now attached to the device mount 40 as well as recognizing the attached working device 9 (9A to 9T).

[0311] Thus, the controller 5, upon recognizing the working device 9 (9A to 9T) attached to the device mount 40, reads the operation condition (control condition) for the recognized working device 9 (9A to 9T) from the storing unit 50, and defines the read operation condition as the operation condition (control condition) to be used hereafter for the working device 9 (9A to 9T). The controller 5 also causes the monitor 55 to display information relating to the recognized working device 9 (9A to 9T) (S9). This allows the user to operate the working device 9 under appropriate conditions.Fifth Example Embodiment

[0312] The following description discusses a working machine according to a fifth example embodiment of the present invention. Note that the working machine according to the fifth example embodiment is an agricultural tractor similar to the fourth example embodiment, but is an agricultural tractor without a cabin, i.e., including no cabins 22. The fifth example embodiment is the same as the fourth example embodiment except for the above, and therefore, as with the fourth example embodiment, the features corresponding to those of the first to fourth example embodiments are assigned the identical names and reference sings as those in the first to fourth example embodiments. The description of the features corresponding to those of the first to fourth example embodiments or features to achieve the same functions (processes) as the first to fourth example embodiments is omitted here, and the corresponding description in the first to fourth example embodiments is applied mutatis mutandis to the fifth example embodiment.

[0313] As illustrated in FIGS. 24 and 25, the working machine 1 according to the fifth example embodiment includes a machine body 2 and traveling device(s) 3 to support the machine body 2 such that the machine body 2 is allowed to travel. The working machine 1 includes a device mount 40 to replaceably (detachable) attach thereto a working device 9 to perform a function corresponding to work.

[0314] In the fifth example embodiment, the working machine 1 includes a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and actuator(s) 61 to cause the device mount 40 to move along the path. The working machine 1 includes a controller 5. The working machine 1 includes a monitor 55 to display information relating to operation and work, etc.

[0315] The working machine 1 includes manual operators 11 and 12 to be operated by a user. Specifically, the working machine 1 includes a first manual operator 11 to be operated by the user to perform operations relating to travel of the traveling device 3, and a second manual operator 12 to be operated by the user to perform operations relating to the movement of the device mount 40 along the predetermined path. The first manual operator 11 in the present example embodiment includes a steering operator, as with the fourth example embodiment, whereas the second manual operator 12 includes an operating lever. Accordingly, when the operating lever is operated, the second manual operator 12 causes the working device 9 attached to the support structure 4 and the device mount 40 to perform a predetermined action.

[0316] The machine body 2 includes a frame chassis 20, and a seat 21 provided on the frame chassis 20. The machine body 2 includes receivers 150a and 150b to receive identifying signals from transmitters T. The seat 21 is located rearward of the prime mover room MR (prime mover 10), and fixed to the frame chassis 20. As mentioned earlier, the present example embodiment does not include a cabin 22, and the other features are the same as those of the agricultural tractor of the fourth example embodiment. Specifically, the working machine 1 includes a PTO shaft, a hood 25 is provided at a substantially front-half of the frame chassis 20 in the front-rear direction to define a machine room MR, and the prime mover 10 and the hydraulic system 6 are provided in the machine room MR. Note that a detailed description of these features is omitted here, and the description in the fourth example embodiment is applied to the present example embodiment.

[0317] In the present example embodiment, the receivers 150a, 150b and 150c are located at the following four positions: positions forward of and rearward of the seat 21 in the front-rear direction, and positions on the opposite sides of the seat 21 in the lateral direction. Specifically, the receivers 150a, 150b and 150c of the machine body 2 include a first receiver 150a located rearward of the seat 21 and closest to the device mount 40, a pair of second receivers 150b located farther from the device mount 40 than the first receiver 150a, and a third receiver 150c located farther from the device mount 40 than the first receiver 150a and the pair of second receivers 150b.

[0318] Specifically, in the present example embodiment, the device mount 40 is located rearward of the machine body 2 along the front-rear direction, and the first receiver 150a is located within an area SA between the device mount 40 and the seat 21. Such a first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are arranged in the order named in a rear-to-front direction. The pair of second receivers 150b are located at the midpoint or substantially at the midpoint between the first receiver 150a and the third receiver 150c in the front-rear direction.

[0319] The first receiver 150a, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), is located forward of the device mount 40 but rearward of the seat 21, and is closest to the device mount 40. In the present example embodiment, the first receiver 150a is located rearward of the seat 21 at the center of the machine body 2 in the lateral direction.

[0320] The third receiver 150c, of the first receiver 150a, the pair of second receivers 150b and the third receiver 150c (the receivers 150a, 150b, and 150c at four positions), is located farthest to the device mount 40. In the present example embodiment, the third receiver 150c is located forward of the seat 21. In the present example embodiment, the third receiver 150c is located at the center, in the lateral direction, of a dashboard located in front of the seat 21 (located between the seat 21 and the hood 25). With this, the first receiver 150a and the third receiver 150c are arranged along a centerline of the machine body 2 that extends in the front-rear direction.

[0321] In contrast, the pair of second receivers 150b are located between the first receiver 150a and the third receiver 150c, and are located on opposite sides of the seat 21. Specifically, the pair of second receivers 150b are arranged in the lateral direction with the seat 21 between them. The pair of second receivers 150b are arranged symmetrical with respect to an imaginary plane that passes through the center of the machine body 2 in the lateral direction and that extends in the front-rear direction and the up-down direction. With this, the first receiver 150a, the pair of second receivers 150b and the third receiver 150c are located at four vertices of a quadrangle (lozenge) in plan view.

[0322] The controller 5 is the same as the controller 5 of the first to fourth example embodiments, and information stored in the storing unit 50 can be estimated based on similar information stored in the storing unit 50 of the third example embodiment, as with the case of the fourth example embodiment, and therefore the description of the controller 5 and the description of the information stored in the storing unit 50 are omitted here, and the descriptions in the first example embodiment and the third example embodiment are applied to the present example embodiment. Note that, similar to the fourth example embodiment, also in the working machine 1 of the present example embodiment, the device mounts 40 are located rearward of the machine body 2 differently from the first to third example embodiments. The locations of the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are defined based on this location of the device mounts 40. That is, in the present example embodiment, the locations of the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c are described such that front and rear are opposite to those in the first to third example embodiments. Therefore, there is no inconsistency between the description in the present example embodiment and the first and third example embodiments.

[0323] Each of the plurality of types of working devices 9 has an individual function corresponding to the content of work. Each of the plurality of types of working devices 9 has attached thereto a tag T which is a transmitter T to transmit unique identification information, similar to the first to fourth example embodiments.

[0324] The mount bases 91 of the plurality of types of working devices 9 have the same configuration (have the common configuration), and can each be replaceably attached to the device mounts 40 of the working machine 1. In the present example embodiment, similar to the fourth example embodiment, the device mounts 40 of the working machine 1 are hooks 40, and therefore the mount base 91 of each working device 9 includes a shaft S2 (rotation shaft S2) to be engaged with the hooks 40 (device mounts 40). Since this is a well-known configuration, a detailed description thereof is omitted here.

[0325] The working machine 1 of the fifth example embodiment has been described. While no working devices 9 are attached to the device mount 40, the action of attaching (connecting) a desired working device 9 is performed. In the present example embodiment, the action of attaching (connecting) a working device 9 (i.e., processes performed by the controller 5) is the same as that in the third example embodiment of the working machine 1 including the first receiver 150a, the pair of second receivers 150b, and the third receiver 150c (receivers 150a, 150b, and 150c at four positions), and the same effects as the third example embodiment are achieved.

[0326] Note that the present invention is not limited to the above-described example embodiments, and can be modified without departing from the gist of the present invention.

[0327] In the above-described example embodiments, a working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 is recognized based on the received signal strengths of identifying signal(s) received by two or more receivers located at two or more positions. Note, however, that this does not imply any limitation. For example, a working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 may be recognized based on the received signal strengths of identifying signal(s) received by one of the receivers 150a, 150b and 150c located at two or more positions (a plurality of positions). Specifically, since the received signal strength of the identifying signal received by the receivers 150a, 150b and 150c increases as the distance between the tag T (transmitter T) and the receivers 150a, 150b and 150c decreases, the controller 5 is able to recognize the working device 9 (9A to 9T) attached to or to be attached to the device mount(s) 40 by checking the peak (the highest value) of the received signal strength at a single receiver (a receiver at a single position).

[0328] In the above-described example embodiments, the receivers (first receiver 150a, second receiver 150b, third receiver 150c) are directional antennas, and the orientations in which the receivers (first receiver 150a, second receiver 150b, third receiver 150c) receive identifying signals are all directed toward the side where the device mount 40 is present. Note, however, that this does not imply any limitation. For example, in another example embodiment of the present invention, as illustrated in FIGS. 26 to 29, the orientation of the first receiver 150a (which is closest to the device mount 40) in which the first receiver 150a receives identifying signals may be directed toward the side where the device mount 40 is present, whereas the orientation of the receiver(s) 150b, 150c (second receiver(s) 150b, third receiver 150c) (which is farther from the device mount 40 than the first receiver 150a) in which the receiver receives identifying signals may be directed in a direction different from the direction toward the side where the device mount 40 is present. More specifically, the orientation of the receiver(s) 150b, 150c (second receiver 150b, third receiver 150c) (which is farther from the device mount 40 than the first receiver 150a) in which the receiver receives identifying signals may be directed away from the device mount 40.

[0329] With this, the receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) which are farther from the device mount 40 than the first receiver 150a have low sensitivity to receive identifying signals coming from the side where the device mount 40 is present.

[0330] Specifically, the first receiver 150a has high sensitivity to receive an identifying signal from the tag T of a working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength increases), whereas the other receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) have low sensitivity to receive the identifying signal from the tag T of the working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength decreases). Thus, under the conditions in which the other receivers 150b, 150c (second receiver(s) 150b, third receiver 150c) receive identifying signals coming from the side where the device mount 40 is present, when the first receiver 150a and the receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40.

[0331] In the agricultural tractor 1 (working machine 1) of the above-described fourth example embodiment, the device mount 40 (support structure 4) is located rearward of the machine body 2, but this does not imply any limitation. In another example embodiment of the present invention, in the case where the working machine 1 is an agricultural tractor, the agricultural tractor may be a working machine 1 (agricultural tractor 1) which includes a device mount 40 (a three-point linkage which is a support structure 4) in front of the machine body 2, as illustrated in FIG. 30.

[0332] In such a case, since the device mount 40 is located in front of the machine body 2 similar to the working machine 1 (compact track loader 1) of the first example embodiment, the receivers 150a, 150b, and / or 150c may be located at two to four positions and processes (control) corresponding to the number of the receivers may be performed, similar to the first to third example embodiments. Specifically, in the case where the receivers 150a and 150b are located at two positions arranged in the front-rear direction, the same processes as in the first or second example embodiment may be performed. In the case where the receivers 150a and 150b are located at four positions arranged in the front-rear direction, the same processes as in the third example embodiment may be performed. In the case where the receivers 150a and 150b are located at three positions arranged in the front-rear direction, the same processes as in the fourth example embodiment or the fifth example embodiment may be performed.

[0333] In the case where the working machine 1 is an agricultural tractor, the agricultural tractor may be a working machine 1 (agricultural tractor 1) including device mounts 40 (three-point linkages 4 which are support structures 4) both in front of and rearward of the machine body 2 (see FIG. 31). The receivers 150a and 150b are located with a space therebetween in the front-rear direction, similar to the foregoing example embodiments. Specifically, the receivers 150a and 150b are located within an area SA between the front device mount 40 and the cabin 22 (seat 21), and within an area SA between the rear device mount 40 and the cabin 22 (seat 21), respectively.

[0334] With this, the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the front device mount 40, and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a second receiver 150b located farther from the front device mount 40 than the first receiver 150a. On the other hand, the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the rear device mount 40, and the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a second receiver 150b located farther from the rear device mount 40 than the first receiver 150a.

[0335] Thus, in the case of a working machine 1 including the front and rear device mounts 40, the working machine 1 is configured such that, depending on which of the front and rear device mounts 40 has attached thereto a working device 9 (9A or the like), a switch or the like allows switching between (i) a state in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a and (ii) a state in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a. In such a case in which one of the receivers at two positions is regarded as a first receiver 150a (in the case where the states are switchable), the other receiver is defined as a second receiver 150b.

[0336] With this, when a working device 9 (9A or the like) is attached to one of the front and rear device mounts 40, it is possible to perform the same processes as in the second example embodiment using the smallest number of receivers 150a and 150b possible. Note that, although the receivers 150a and 150b are located at two positions at the front and rear of the cabin 22 in FIG. 31, receivers 150a, 150b, and 150c (first receiver 150a, a pair of second receivers 150b, third receiver 150c) may be located at four positions at the front and rear and on opposite sides of the cabin 22, as with the fourth example embodiment (see FIG. 32).

[0337] In such a case, the receiver located within the area SA1 between the front device mounts 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the front device mount 40, and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a third receiver 150c located farther from the front device mount 40 than the first receiver 150a. On the other hand, the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a located closest to the rear device mount 40, and the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a third receiver 150c located farther from the rear device mount 40 than the first receiver 150a.

[0338] Thus, in the case of a working machine 1 including the front and rear device mounts 40, the working machine 1 is configured such that, depending on which of the front and rear device mounts 40 has attached thereto a working device 9 (9A or the like), a switch or the like allows switching between (i) a state in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a and (ii) a state in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) is regarded as a first receiver 150a. In such a case in which one of the receivers at two positions is regarded as a first receiver 150a (in the case where the states are switchable), the other receiver is defined as a second receiver 150b. Note that, because the pair of second receivers 150b are located between the front and rear receivers in the front-rear direction, the pair of second receivers 150b are regarded as second receivers 150b regardless of which of the front and rear device mounts 40 has a working device 9 (9A or the like) attached thereto. With this, when a working device 9 (9A or the like) is attached to one of the front and rear device mounts 40, it is possible to perform the same processes as in the fourth example embodiment using the smallest number of receivers 150a, 150b and 150c possible.

[0339] In each of such cases, in a case that the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) are both directional antennas and that the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) and the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) are directional in the orientation in which the receiver receives identifying signals, the orientation in which the receiver located within the area SA1 between the front device mount 40 and the cabin 22 (seat 21) receives identifying signals is directed toward the side where the front device mount 40 is present, whereas the orientation in which the receiver located within the area SA2 between the rear device mount 40 and the cabin 22 (seat 21) receives identifying signals is directed toward the side where rear device mount 40 is present. With this, the receiver 150c (third receiver 150c) located farther from the device mount 40 than the first receiver 150a has low sensitivity to receive identifying signals coming from the side where the device mount 40 is present, as described earlier.

[0340] Specifically, the first receiver 150a has high sensitivity to receive an identifying signal from the tag T of a working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength increases), whereas the other receivers 150b, 150c have low sensitivity to receive the identifying signal from the tag T of the working device 9 (9A or the like) approaching the device mount 40 (i.e., received signal strength decreases). Thus, when the first receiver 150a and the other receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40. Note that, in such a case, when the pair of second receivers 150b are omnidirectional antennas, the receivers have the same or substantially the same sensitivity to receive identifying signals from the front and from the rear, making it possible to cause one of the front and rear receivers in the front-rear direction to function as a first receiver 150a and the other to function as a second receiver 150b.

[0341] In the fifth example embodiment, the receivers 150a, 150b and 150c are located at three positions on the agricultural tractor without cabin, but this does not imply any limitation. For example, the receivers 150a and 150b may be located at two positions forward of and rearward of the seat 21, based on the position of the device mount 40 (see FIG. 33), and the receivers 150a and 150b may be located at the following three positions: a position rearward of the seat 21, and two positions forward of the seat 21 or on opposite sides of the seat 21 in the lateral direction, based on the position of the device mount 40 (see FIG. 34). Also in such cases, the same effects as in the first example embodiment and the second example embodiment can be achieved by performing the same processes as in the first example embodiment and the second example embodiment.

[0342] In the above-described example embodiments, the receivers 150a, 150b, and 150c (first receiver 150a, second receivers 150b, third receiver 150c), which are antennas, and the receiver main bodies 151a and 151b are combined to define receivers 15a, 15b, and 15c (first receiver 15a, second receivers 15b, third receiver 15c), and the receivers 15a, 15b, and 15c are arranged such that the receivers 150a, 150b, and 150c (first receiver 150a, second receivers 150b, third receiver 150c) are located at appropriate positions. Note, however, that this does not imply any limitation.

[0343] For example, in another example embodiment of the present invention, as illustrated in FIG. 35, the receivers 150a, 150b and 150c may be antennas 150a, 150b and 150c, the working machine 1 may include receiver(s) 15a, 15b, 15c including receiver main body(bodies) 151a, 151b and 151c to accept identifying signals from the antennas 150a, 150b and 150c, and the receiver(s) 15a, 15b, 15c may include a plurality of input interfaces 153a, 153b, and 153c connected to the antennas 150a, 150b, and 150c and an output interface 154 to output, to the controller 5, identifying signals inputted into the input interfaces 153a, 153b, and 153c. That is, the receivers 150a, 150b and 150c (first receiver 150a, second receiver 150b, third receiver 150c) and the receiver main bodies 151a, 151b and 151c (first receiver main body 151a, second receiver main body 151b, third receiver main body 151c) may be provided independently of each other.

[0344] In such a case, since the receiver 15a, 15b, 15c (receiver main body 151a, 151b, 151c) is a multi-channel receiver and includes a plurality of input interfaces 153a, 153b and 153c, a plurality of coaxial cables are connected to the plurality of receivers 150a, 150b and 150c (first receiver 150a, second receiver(s) 150b, third receiver 150c). This allows the receivers 150a, 150b and 150c and the receiver 15a, 15b, 15c (receiver main body 151a, 151b and 151c) to be located at different positions. Also in such a case, the receiver main body 151a, 151b, 151c (first receiver main body 151a, second receiver main body 151b, third receiver main body 151c) is connected to the controller 5 via a signal wire (CAN bus).

[0345] In the above-described example embodiments, the receivers 150a, 150b and 150c are directional antennas to receive identifying signals from a particular direction. Note, however, that this does not imply any limitation. For example, in another example embodiment of the present invention, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c may be omnidirectional antennas. In such a case, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c are capable of receiving signals from particular directions (signals coming from the side where the device mount 40 is present), making it possible to also receive signals not necessary to recognize a working device 9.

[0346] In view of the above, as illustrated in FIGS. 36 and 37, the machine body 2 preferably includes a cover 16 which covers the first receiver 150a, the second receiver 150b, or the third receiver 150c, which blocks identifying signals, and which includes an opening 160. In such a case, the cover 16 is positioned such that the opening 160 faces toward the side where the device mount 40 is present. With this, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c each only receive identifying signals that have passed through the opening 160. Thus, even in the case where the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c are omnidirectional antennas, the first receiver 150a, the second receiver(s) 150b, and the third receiver 150c do not receive signals unnecessary to recognize a working device 9, improving the accuracy of identification of the working device 9. Even in the case where the first receiver 150a, the second receivers 150b, and the third receiver 150c are directional antennas, the first receiver 150a, the second receivers 150b, and the third receiver 150c may be covered by such covers 16.

[0347] In such a case, at least the cover 16 that covers the first receiver 150a is positioned such that the opening 160 faces toward the side where the device mount 40 is present. The covers 16 that cover the receivers 150b, 150c which are distant from the device mount 40 are positioned such that the opening 160 faces in a direction different from a direction toward the side where the device mount 40 is present, making it possible to lower (reduce) the sensitivity of the receivers 150b, 150c to receive identifying signals from the side where the device mount 40 is present.

[0348] Thus, when the first receiver 150a and the other receivers 150b, 150c are arranged such that they receive an identifying signal (a single identifying signal) transmitted from a single tag T with different received signal strengths, it is possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40. Note that, when the receivers 150b, 150c distant from the device mount 40 are positioned such that the opening 160 (the orientation in which the receiver receives identifying signals) is directed away from the device mount 40, the sensitivity of the receivers 150b, 150c to receive identifying signals from the side where the device mount 40 is present can be reduced, making it possible to accurately determine the direction to the working device 9 (9A or the like) and how close the working device 9 (9A or the like) is to the device mount 40.

[0349] In the foregoing first to third example embodiments, the device mount 40 includes a linkage 41 to connect a working device 9 (9A or the like) thereto, the linkage 41 includes an engagement portion 412 movable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 (9A or the like) to connect the working device 9 (9A or the like) thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 (9A or the like) to disconnect the working device 9 (9A or the like) therefrom, and the controller 5 is configured or programmed to determine that the working device 9 (9A or the like) is attached to the device mount 40 when the engagement portion 412 is in the engaging position PE1. Note, however, that this does not imply any limitation.

[0350] For example, in another example embodiment of the present invention, similar to the fourth and fifth example embodiments, the controller 5 may be configured or programmed to, after recognizing the working device 9 (9A or the like), when the receivers 150a, 150b and / or 150c (first receiver 150a, second receiver 150b, third receiver 150c) at at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device (9A or the like) is attached to the device mount 40.

[0351] Specifically, the level of the received signal strength of an identifying signal received by each of the receivers 150a, 150b and 150c is correlated with the distance between the tag T and the receiver 150a, 150b or 150c. That is, the received signal strength of an identifying signal received by each receiver 150a, 150b or 150c increases as the distance between the tag T and the receiver 150a, 150b or 150c decreases, whereas the received signal strength of an identifying signal received by each receiver 150a, 150b or 150c decreases as the distance between the tag T and the receiver 150a, 150b or 150c increases.

[0352] Thus, in the case where the received signal strength of an identifying signal received by the receiver(s) 150a, 150b, 150c is a predetermined received signal strength (high received signal strength) and does not change even after a predetermined time period, it is possible to estimate that the working device 9 (9A or the like) is now attached to the device mount 40. Note that the relative distance between the tag T and each receiver 150a, 150b or 150c with the working device 9 (9A or the like) attached to the device mount 40 is fixed. Therefore, it is possible to improve reliability by measuring received signal strength with the working device 9 (9A or the like) connected to the device mount 40 in advance and setting the measured value as the predetermined received signal strength.

[0353] As another example, the controller 5 may be configured or programmed to directly or indirectly recognize a load on the actuator 61 (which causes the device mount 40 to move along a path) and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40 (whether the working device 9 (9A or the like) is attached to the device mount 40).

[0354] Specifically, when a working device 9 (9A or the like) is attached to the device mount 40, the weight of the working device 9 (9A or the like) is applied as a load to the actuator 61 via the support structure 4, so that a change occurs in pressure in a pipe which is included in the hydraulic system 6 and via which hydraulic fluid is supplied to and discharged from the actuator 61.

[0355] Therefore, when a pressure sensor provided in the pipe connected to the actuator 61 is connected to the controller 5 (input interface 52) and the controller 5 receive the detection from the pressure sensor, the controller 5 is able to recognize the load on the actuator 61, and, based on the recognition, determine whether the working device 9 (9A or the like) is attached to or detached from (whether the working device 9 (9A or the like) is attached to) the device mount 40. Note that the working machine 1 (agricultural tractor 1) of the fourth and fifth example embodiments also includes an actuator 61 to actuate the support structure 4, and therefore the above-described configuration (manner) can also be applied to the fourth and fifth example embodiments.

[0356] In the first to fourth example embodiments, the receivers 150a, 150b and 150c are arranged with reference to the cabin 22, and, in the fifth example embodiment, the receivers 150a, 150b and 150c are arranged with reference to the seat 21. Note, however, that this does not imply any limitation. For example, assuming that the device mount 40 is provided at at least one of the positions forward and rearward of the machine body 2, the receivers 150a, 150b and / or 150c may be located at increasing distances from the device mount 40, e.g., (i) located at two positions at the front and rear of the machine body 2 in the front-rear direction, (ii) located at vertices of a triangle in plan view (at three positions) as in the second example embodiment, or (iii) located at vertices of a quadrangle (lozenge) in plan view (at four positions) as in the third example embodiment. That is, the receiver 150a (first receiver 150a), which is closest to the device mount 40, may be located at one of the positions at the front and rear of the machine body 2, and the receiver 150b, 150c (second receiver 150b or third receiver 150c) farthest from the device mount 40 may be located at the other of the positions at the front and rear of the machine body 2. In the case where receivers 150b are provided between the receiver 150a (first receiver 150a) closest to the device mount 40 and the receiver 150c (third receiver 150c) farthest from the device mount 40, the receivers 150b may be located on opposite sides of the machine body 2 in the lateral direction. With this, the reference based on which the receivers 150a, 150b and 150c are arranged merely changes from the cabin 22 or the seat 21 to the machine body 2, making it possible to achieve similar effects to the foregoing example embodiments.

[0357] In the third example embodiment and the fifth example embodiment, a pair of second receivers 150b provided on opposite sides of the cabin 22 or the seat 21 in the lateral direction are oriented forward in the front-rear direction. Note, however, that this does not imply any limitation. For example, as illustrated in FIGS. 38 and 39, the pair of second receivers 150b provided on opposite sides of the cabin 22 or the seat 21 in the lateral direction may be oriented sideward (outward in the lateral direction). Specifically, one of the pair of second receivers 150b arranged with a space therebetween in the lateral direction that is located at one of opposite sides in the lateral direction (that is located at the right side) may be oriented rightward, and the other of the pair of second receivers 150b that is located at the other of the opposite sides in the lateral direction (that is located at the left side) may be oriented leftward. With this, the one of the second receivers 150b receives identifying signals coming from the right with high received signal strength, and receives identifying signals coming from the front and left with low received signal strength. On the other hand, the other of the second receivers 150b receives identifying signals coming from the left with high received signal strength, and receives identifying signals coming from the front and right with low received signal strength. With this, in the case where the working device 9 (9A or the like) is located at a side (right side or left side) of the machine body, the second receiver 150b on the same side of the machine body as the working device 9 (9A or the like) receives identifying signals with high received signal strength, so that the accuracy of determining the position (location) of the working device 9 (9A or the like) increases.

[0358] The third receiver 150c may be oriented in a direction opposite to the direction in which the first receiver 150a is oriented. Specifically, in the case where the third receiver 150c is provided at the rear of the machine body 2 (the cabin 22 or the seat 21), the third receiver 150c may be oriented rearward in the front-rear direction, whereas in the case where the third receiver 150c is provided forward of (or at a front portion of) the machine body 2 (forward of the cabin 22 or the seat 21), the third receiver 150c may be oriented forward of the machine body 2 (the cabin 22 or the seat 21). With this, when a working device 9 (9A or the like) is present on the same side of the machine body 2 (the cabin 22 or the seat 21) as the third receiver 150c, the third receiver 150c receives an identifying signal with a higher received signal strength than the first receiver 150a, making it possible to accurately determine whether the working device 9 (9A or the like) is present forward of or rearward of the machine body 2 (the cabin 22 or the seat 21). It is also possible to determine whether the working device 9 (9A or the like) is present diagonally forward or diagonally rearward of the machine body 2 using the combination of (the ratio between) the received signal strengths of the identifying signals received by the first receiver 150a and the second receiver 150b or using the combination of (the ratio between) the received signal strengths of the identifying signals received by the second receiver 150b and the third receiver 150c.

[0359] As illustrated in FIG. 40, in the case where a working device 9 (9A or the like) is attached at a position rearward of the machine body 2 and a hood 25 is provided forward of the seat 21, by providing the third receiver 150c at a position farthest from the first receiver 150a (at the front end of the hood 25 in the case of FIG. 40), it is possible to reduce the received signal strength of identifying signals received by the third receiver 150c when the working device 9 (9A or the like) is present on the same side of the machine body 2 as the first receiver 150a, and possible to increase the received signal strength of identifying signals received by the third receiver 150c when the working device 9 (9A or the like) is present on the same side of the machine body 2 as the third receiver 150c. With this, it is possible to accurately determine whether the working device 9 (9A or the like) is present forward of or rearward of the machine body 2 (the cabin 22 or the seat 21).

[0360] The controller 5 may be configured or programmed to, based on an identifying signal received by the receivers 150a, 150b and / or 150c and based on the received signal strength(s) (the level(s) of the received signal strength(s)) of the identifying signal, determine the location of the working device 9 (9A or the like) including the transmitter T which transmits the identifying signal and cause the monitor 33 to display the determined location (position) of the working device 9 (9A or the like).

[0361] As illustrated in FIG. 41, the monitor 55 may be operable to display pieces of device information 9A and the like corresponding to respective working devices 9 (9A and the like) and allow selection of one of the pieces of device information 9A (selection of a working device 9 (9A or the like) for which the user wishes to know the location). In the example illustrated in FIG. 41, similar to the foregoing example embodiments, the monitor 55 is a touchscreen, the pieces of device information 9A and the like are icons of the working devices 9 (9A or the like), and touching (selecting) an icon allows selection of a working device for which the user wishes to know the location. The pieces of device information 9A and the like may be displayed in text form (names of devices) in a table form. In such a case, the controller 5 may be configured or programmed to, based on an identifying signal from the transmitter T of the working device 9 (9A or the like) corresponding to the piece of device information 9A or the like selected via the monitor 55 and based on the received signal strength(s) of the identifying signal, determine the location of the working device 9 (9A or the like) including the transmitter T which transmits the identifying signal and cause the monitor 33 to display the determined information (location of the working device 9 (9A or the like)).

[0362] Specifically, when the user selects a working device 9 (9A or the like) for which the user wishes to know the location on the monitor 55, the controller 5 determines whether or not an identifying signal is received from the transmitter T of the selected working device 9 (9A or the like). Next, when the receivers 150a, 150b and / or 150c receive that identifying signal, the controller 5 determines the location of the working device 9 (9A or the like) based on that identifying signal and the received signal strength(s) of the identifying signal. For example, in the case where the receivers 150a, 150b and 150c are provided at front, rear, left and right, as illustrated in FIG. 42, when the working device 9 (9A or the like) is located at a side of the machine body 2 (the right side in the example illustrated in FIG. 42), the working device 9 (9A or the like) is closest to the right second receiver 150b, so that the right second receiver 150b receives the identifying signal with the highest received signal strength. The controller 5 is configured or programmed to, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal, cause the monitor 55 to display, as illustrated in FIG. 43, the direction toward the location of the working device 9 (9A or the like) (the rightward direction, which is one of opposite lateral directions in FIG. 43). The direction is represented by arrow AR in the present example embodiment.

[0363] When, as illustrated in FIG. 44, the working device 9 (9A or the like) is present diagonally forward of the machine body 2 (diagonally forward and rightward in the case of FIG. 44), the working device 9 (9A or the like) is closest to at least one of (i) the first receiver 150a or (ii) one of the second receivers 150b, so that the at least one of (i) the first receiver 150a or (ii) one of the second receivers 150b receives the identifying signal with the highest received signal strength. Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal, as illustrated in FIG. 45, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (diagonally rightward and forward in FIG. 45). The direction is represented by arrow AR in the present example embodiment.

[0364] Thus, with the use of the combination of the levels of the received signal strengths of the identifying signal received by the receivers 150a, 150b and 150c located at four positions at front, rear, left and right, it is possible to accurately determine the location (position) of the working device 9 (9A or the like) and allow the user to recognize the position of the working device 9 (9A or the like) (the direction toward the working device 9 (9A or the like)) via the indication (arrow AR) on the monitor 55.

[0365] In another example embodiment, in the case where the working machine 1 includes receivers 150a and 150b located at three positions at front and rear, i.e., a first receiver 150a and a left and right pair of second receivers 150b, for example, as illustrated in FIG. 46, when the working device 9 (9A or the like) is present at a side of (just beside) the machine body 2 (the cabin 22 or the seat 21) in the lateral direction, one of the second receivers 150b that is on the same side of the machine body 2 as the working device 9 (9A or the like) receives the identifying signal with the highest received signal strength, and the received signal strength of the identifying signal decreases in the order of the first receiver 150a and the other second receiver 150b. Specifically, as illustrated in FIG. 46, when the working device 9 (9A or the like) is located at the right side of the machine body 2 (the cabin 22 or the seat 21), the one of the second receivers 150b that is located at the right side of the machine body 2 receives the identifying signal with the highest received signal strength, and the received signal strength of the identifying signal decreases in the order of the first receiver 150a closest to the device mount 40 and the other second receiver 150b at the left side of the machine body 2.

[0366] Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the location of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 47, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (rightward direction in FIG. 47). The direction is represented by arrow AR in the present example embodiment.

[0367] As illustrated in FIG. 48, in the case where the working device 9 (9A or the like) is present diagonally forward of the machine body 2 (the cabin 22 or the seat 21), at least one of (i) one of the pair of second receivers 150b or (ii) the first receiver 150a located forward of (or at a front portion of) the machine body 2 receives the identifying signal with the highest received signal strength, and the other second receiver 150b receives the identifying signal with the lowest received signal strength.

[0368] For example, as illustrated in FIG. 48, when the working device 9 (9A or the like) is present diagonally rightward and forward of the machine body 2 (the cabin 22 or the seat 21), at least one of the right second receiver 150b or the first receiver 150a receives the identifying signal with the highest received signal strength. Specifically, in the case where the strengths of the identifying signal at the first receiver 150a and the right second receiver 150b are equal or substantially equal, the working device 9 (9A or the like) is present at a position diagonally forward of the machine body 2 at equal distances from the first receiver 150a and the right second receiver 150b. In the case where the received signal strength of the identifying signal at the first receiver 150a is higher than the received signal strength of the identifying signal at the right second receiver 150b, the working device 9 (9A or the like) is located at a position diagonally forward of the machine body 2 but closer to the position directly in front of the machine body 2 than to the position rightward of the machine body 2. On the contrary, in the case where the received signal strength of the identifying signal at the right second receiver 150b is higher than the received signal strength of the identifying signal at the first receiver 150a, the working device 9 (9A or the like) is located at a position diagonally forward of the machine body 2 but closer to the position sideward of (directly beside) the machine body 2 than to the position directly in front of the machine body 2. Note that, in the case where the working device 9 (9A or the like) is present diagonally leftward and forward of the machine body 2 (the cabin 22 or the seat 21), at least one of (i) the left second receiver 150b instead of the right second receiver 150b or (ii) the first receiver 150a receives the identifying signal with the highest received signal strength. Thus, the relationship between the level of the received signal strength of the identifying signal at the left second receiver 150b and the level of the received signal strength of the identifying signal at the first receiver 150a is the same as in the case where the working device 9 (9A or the like) is present diagonally rightward and forward of the machine body 2. Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the position of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 49, causes the monitor 55 to display the direction to the working device 9 (9A or the like) (diagonally rightward and forward direction in the example illustrated in FIG. 49). The direction is represented by arrow AR in the present example embodiment.

[0369] As illustrated in FIG. 50, in the case where the working device 9 (9A or the like) is present rearward of the machine body 2 (the cabin 22 or the seat 21), at least one of the pair of second receivers 150b receives the identifying signal with the highest received signal strength, and the first receiver 150a receives the identifying signal with the lowest received signal strength. That is, the pair of second receivers 150b receive the signal with the same or substantially the same strength, and the first receiver 150a receives the identifying signal with a received signal strength lower than those at the pair of second receivers 150b. For example, as illustrated in FIG. 50, in the case where the working device 9 (9A or the like) is present directly rearward of the machine body 2 (the cabin 22 or the seat 21), the pair of second receivers 150b receive the identifying signal with the same or substantially the same strength. On the contrary, in the case where the working device 9 (9A or the like) is present rearward of the machine body 2 (the cabin 22 or the seat 21) and is offset in one of the first and second lateral directions, one of the second receivers 150b that is on the same side as the working device 9 (or the like 9A) receives the identifying signal with a higher received signal strength than the other second receiver 150b.

[0370] Accordingly, the controller 5, based on the levels of (the combination of the levels of) the received signal strengths of the identifying signal received by the receivers 150a and 150b, determines the location of (direction to) the working device 9 (9A or the like), and, as illustrated in FIG. 51, causes the monitor 55 to display the direction toward the working device 9 (9A or the like) (directly rearward in FIG. 51). The direction is represented by arrow AR in the present example embodiment.

[0371] Since the controller 5 determines the location of the working device 9 (9A or the like) corresponding to the selected one of the pieces of device information 9A and the like displayed on the monitor 55 and causes the monitor 55 to display the determined location of the working device 9 (9A or the like) in such a manner, the user can quickly know the location of the intended working device 9 (9A or the like). With this, even in the case where a plurality of working devices 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0372] In the case where the monitor 55 displays the position of (direction to) the working device 9 (9A or the like), the screen displayed on the monitor 55 may be a dedicated screen. Note, however, that as illustrated in FIGS. 43, 45, 47, 49, and 51, the position of (direction to) the working device 9 (9A or the like) may be displayed on a screen to display other items. Note that, in FIGS. 43, 45, 47, 49, and 51, the monitor 55 displays the arrow AR representing the position of (direction to) the working device 9 (9A or the like), and also displays the type of the attached working device 9 (9A or the like) attached to the device mount 40 (text “Sweeper” and the icon in FIGS. 43, 45, 47, 49, and 51) as well as an indication that the position of (direction to) the working device 9 (9A or the like) is currently displayed (the text “Displaying direction to 9B Pallet fork” in FIGS. 43, 45, 47, 49, and 51). The monitor 55 also displays a fuel meter, a water temperature meter, an oil temperature meter, and the like, in digital form.

[0373] In FIGS. 43, 45, 47, and 49, the arrow AR representing the direction toward the location of the working device 9 (9A or the like) is displayed at a certain position or a fixed position of the screen displayed on the monitor 55 (right corner in FIGS. 43, 45, 47, and 49). Note, however, that the position of (direction to) the working device 9 (9A or the like) and the arrow AR may be displayed in a manner that is more easily visually recognizable. for example, as illustrated in FIGS. 51 and 52, the monitor 55 may display a circular or substantially circular area or a boundary line that defines a circular or substantially circular area, and display the arrow AR such that the arrow AR rotates around the center of the circular or substantially circular area according to the position of (direction to) the working device 9 (9A or the like), i.e., such that the arrow AR moves along the boundary line defining the circular or substantially circular area according to the position of (direction to) the working device 9 (9A or the like). That is, the monitor 55 may display the arrow AR such that the arrow AR indicates the direction to the location of the working device 9 (9A or the like) in a manner similar to the needle of a compass indicating a direction. Note that FIG. 51 shows that the working device 9 (9A or the like) is present rearward of the machine body 2, and FIG. 52 shows that the working device 9 (9A or the like) is present rightward of the machine body 2. In the above-described example embodiments, although the monitor 55 displays the direction to the location of the working device 9 (9A or the like) using the arrow AR, this does not imply any limitation. For example, the monitor 55 may display a map and display a symbol representing the location of the working device 9 (9A or the like) on the map.

[0374] Example embodiments of the present invention have been described so far. Example embodiments of the present invention provide working machines described in the following items.

[0375] (Item 1) A working machine 1 including a machine body 2, a device mount 40 to replaceably attach a working device 9 (9A or the like) thereto, the working device 9 (9A or the like) including a transmitter T to transmit a unique identifying signal and being operable to perform a function corresponding to work, and a controller 5 configured or programmed to control the machine body 2, wherein the machine body 2 includes receivers 150a, 150b, 150c to receive the identifying signal from the transmitter T, the receivers 150a, 150b, 150c are located at respective at least two positions separated from the device mount 40 by different distances, and the controller 5 is configured or programmed to recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on a received signal strength of the identifying signal received by at least one of the receivers 150a, 150b, 150c that is located at at least one of the at least two positions.

[0376] With the working machine 1 described in item 1, since the receivers 150a, 150b and / or 150c located at respective at least two positions receive an identifying signal transmitted from a single transmitter T, it is possible to eliminate or reduce the likelihood that the working device 9 (9A or the like) will be difficult to identify because, for example, the identifying signal from the transmitter T is not received sufficiently. Furthermore, since the controller 5 recognizes the received signal strengths in addition to the information included in the identifying signal received by at least one of the receivers 150a, 150b and 150c located at least one of the two positions, the controller 5 recognizes the relative distance between the machine body 2 and the working device 9 (9A or the like) (recognizes the position of the working device 9 (9A or the like)). That is, the controller 5 is able to appropriately determine whether the working device 9 (9A or the like) is located at a position at which the working device 9 (9A or the like) can be attached to the device mount 40. Thus, it is possible to eliminate or reduce the likelihood that the working device 9 (9A or the like) will be recognized in a wrong manner and also possible to appropriately determine whether or not the working device 9 (9A or the like) is located at a position at which the working device 9 (9A or the like) can be attached to the device mount 40. Therefore, with the working machine 1 of item 1, it is possible to accurately recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40. That is, the working machine 1 of item 1 is able to accurately recognize the working device 9 (9A or the like) to be attached to the device mount 40.

[0377] (Item 2) The working machine 1 according to item 1, wherein the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, and the receivers 150a, 150b, 150c are located at the at least two positions at increasing distances from the device mount 40 in the front-rear direction of the machine body 2.

[0378] With the working machine 1 according to item 2, since the receivers 150a, 150b and / or 150c are located at at least two positions at increasing distances from the device mount 40 in the front-rear direction of the machine body 2, the receivers 150a, 150b and / or 150c receive an identical identifying signal but the received signal strength of the identifying signal received by each of them differs depending on the distance from the device mount 40. Specifically, in order to attach a working device 9 (9A or the like) to the device mount 40, the working machine 1 moves the device mount 40 such that the device mount 40 approaches the working device 9 (9A or the like). Under such conditions, the receivers 150a, 150b and / or 150c are located at increasing distances also from the working device 9 (9A or the like). Thus, since the distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a, 150b and / or 150c is different, the received signal strength of the identifying signal received by each of the receivers 150a, 150b and / or 150c differs depending on the distance. Specifically, the received signal strength at the receiver 150a, 150b or 150c increases as the distance to the device mount 40 decreases. Therefore, it is possible to appropriately recognize the position of the working device 9 (9A or the like) relative to the working machine 1 (the direction from the working machine 1 to the working device 9 (9A or the like)) and the distance to the working device 9 (9A or the like) based on the received signal strengths at the receivers 150a, 150b and / or 150c located at least two positions.

[0379] (Item 3) The working machine 1 according to item 1, wherein the receivers 150a, 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances, and the controller 5 is configured or programmed to determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b at the at least three positions, based on a combination of levels of received signal strengths at the receivers 150a, 150b at the at least three positions.

[0380] With the working machine 1 according to item 3, since the receivers 150a and 150b are located at respective at least three different positions which include the at least two positions separated from the device mount 40 by different distances, the receivers 150a and 150b are located at vertices of a triangle. Thus, the received signal strength of the identifying signal at each of the receivers 150a and 150b at the vertices of the triangle depends on the length of a corresponding one of three imaginary straight lines that connects the receiver 150a, 150b and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b and the transmitter T). It is therefore possible to appropriately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0381] (Item 4) The working machine 1 according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions one of which is in an area SA between the device mount 40 and the cabin 22 in the front-rear direction and the other of which is within the cabin 22, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength of the identifying signal received by one of the receivers (receiver 150a) that is in the area SA between the more device mount 40 and the cabin 22 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) that is within the cabin 22 is within a predetermined range.

[0382] With the working machine 1 according to item 4, the receiver 150a that is located at a position within the area SA between the device mount 40 and the cabin 22 in the front-rear direction is closest to the device mount 40 of the two receivers 150a and 150b. With this, the received signal strength of the identifying signal from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 is higher (greater) at the receiver 150a than at the other receiver 150b. In contrast, the receiver 150b located within the cabin 22 is at a position distant from the device mount 40, and the received signal strength of the identifying signal from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 is lower (less) at the receiver 150b than at the other receiver 150a which is closest to the device mount 40. Furthermore, since the cabin 22 reduces the rate of the identifying signal entering the cabin22, the received signal strength at the receiver 150b within the cabin 22 decreases further. With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with greatly different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0383] (Item 5) The working machine 1 according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions one of which is forward of a center of the cabin 22 in the front-rear direction and the other of which is rearward of the center, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers (receiver 150a) that is closest to the device mount 40 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) is within a predetermined range.

[0384] With the working machine 1 according to item 5, the receivers 150a and 150b are located at two positions one of which is forward of a center of the cabin 22 in the front-rear direction and the other of which is rearward of the center. That is, one (receiver 150a) of the two receivers 150a and 150b is located closest to the device mount 40 of the two receivers 150a and 150b, and the other receiver 150b is located farther from the device mount 40 than the one receiver 150a is from the device mount 40. With this, the received signal strength of the identifying signal transmitted from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 and received by the one receiver 150a is higher (greater) than that of the other receiver 150b, whereas the received signal strength at the other receiver 150b is lower (less) than the received signal strength at the one receiver 150a.

[0385] With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0386] (Item 6) The working machine according to item 1, wherein the machine body 2 includes a cabin 22 to surround a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b, 150c are located at at least four positions including positions at a front and a rear of the cabin 22 in the front-rear direction and on opposite sides of the cabin 22 in a lateral direction perpendicular to the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b, 150c at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four receivers, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the cabin 22 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0387] With the working machine 1 according to item 6, the receivers 150a, 150b, and 150c are located at at least four positions including positions at the front and rear of the cabin 22 in the front-rear direction and on opposite sides of the cabin 22 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver 150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more accurately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0388] With this, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0389] (Item 7) The working machine 1 according to item 1, wherein the machine body 2 includes a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b are located at two positions forward of and rearward of the seat 21 in the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b at the two positions each receive the identifying signal, recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b at the two positions, when (i) a combination of received signal strengths at the receivers 150a, 150b at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers (receiver 150a) that is closest to the device mount 40 is equal to or greater than a preset threshold and a received signal strength at the other of the receivers (receiver 150b) is within a predetermined range.

[0390] With the working machine 1 according to item 7, the receivers 150a and 150b are located at two positions forward of and rearward of the seat 21 in the front-rear direction. That is, one (receiver 150a) of the two receivers 150a and 150b is located closest to the device mount 40 of the two receivers 150a and 150b, and the other receiver 150b is located farther from the device mount 40 than the one receiver 150a is from the device mount 40. With this, the received signal strength of the identifying signal transmitted from the transmitter T of the working device 9 (9A or the like) approached by the device mount 40 and received by the one receiver 150a is higher (greater) than that of the other receiver 150b, whereas the received signal strength at the other receiver 150b is lower (less) than the received signal strength at the one receiver 150a.

[0391] With this, although the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the same identifying signal, the two receivers 150a and 150b (the receivers 150a and 150b at two positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strength, making it possible to accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a and 150b at two positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40.

[0392] (Item 8) The working machine 1 according to item 1, wherein the machine body 2 includes a seat 21 for a user, the device mount 40 is located at at least one of forward of or rearward of the machine body 2 in a front-rear direction of the machine body 2, the receivers 150a, 150b, 150c are located at at least four positions including positions forward of and rearward of the seat 21 in the front-rear direction and on opposite sides of the seat 21 in a lateral direction perpendicular to the front-rear direction, and the controller 5 is configured or programmed to, when the receivers 150a, 150b, 150c at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four positions, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located forward of and / or rearward of the seat 21 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0393] With the working machine 1 according to item 8, the receivers 150a, 150b, and 150c are located at at least four positions including positions forward of and rearward of the seat 21 in the front-rear direction and on opposite sides of the seat 21 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver 150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more appropriately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0394] With this, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strength, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0395] (Item 9) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c are located at at least four positions including positions at a front and a rear of the machine body 2 in a front-rear direction and on opposite sides of the machine body 2 in a lateral direction perpendicular to the front-rear direction, the device mount 40 is located at at least one of (i) in front of one of the receivers that is at the front of the machine body 2 or (ii) rearward of another of the receivers that is at the rear of the machine body 2, and the controller 5 is configured or programmed to, when the receivers at the at least four positions each receive the identifying signal, determine a position of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal received by the receivers 150a, 150b, 150c at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers 150a, 150b, 150c at the at least four positions, and recognize the working device 9 (9A or the like) attached to or to be attached to the device mount 40 based on the identifying signal received by the receivers 150a, 150b, 150c, when (i) a combination of received signal strengths at the receivers 150a, 150b, 150c at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the machine body 2 (receiver 150a) is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers (receivers 150b, 150c) is within a predetermined range.

[0396] With the working machine 1 according to item 9, the receivers 150a, 150b, and 150c are located at at least four positions including positions at the front and rear of the machine body 2 in the front-rear direction and on opposite sides of the machine body 2 in a lateral direction perpendicular to the front-rear direction. Therefore, the receivers 150a, 150b, and 150c are located at vertices of a quadrangle (or a lozenge). Thus, the received signal strength of the identifying signal at each of the receivers 150a, 150b, and 150c depends on the length of a corresponding one of four imaginary straight lines that connects the receiver150a, 150b, 150c at a vertex of the quadrangle (or a lozenge) and the transmitter T of the working device 9 (9A or the like) (depends on the linear distance between the receiver 150a, 150b, 150c and the transmitter T). It is therefore possible to more accurately determine the position of the working device 9 (9A or the like) based on the combination of the levels of these received signal strengths.

[0397] Furthermore, although the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the same identifying signal, the four receivers 150a, 150b, and 150c (the receivers 150a, 150b, and 150c at four positions) receive the signal with different received signal strengths. This results in an increase in the number of combinations of the levels of received signal strengths, making it possible to more accurately determine the position of (the distance to) the working device 9 (9A or the like). Since the number of combinations of received signal strengths is large, the combination of received signal strengths at the receivers 150a, 150b, and 150c at four positions does not easily match the predetermined condition, but the controller 5 recognizes the working device 9 (9A or the like) when the combination of received signal strengths matches the predetermined condition. Thus, the working device 9 (9A or the like) is recognized when it is highly likely that the working device 9 (9A or the like) is at a position at which the working device 9 (9A or the like) is attached to or to be attached to the device mount 40. That is, the position of the working device 9 (9A or the like) is more accurately determined, and then the working device 9 (9A or the like) is recognized.

[0398] (Item 10) The working machine according to item 1, wherein the receivers 150a, 150b at the at least two positions include respective directional antennas to receive identifying signals from a particular direction, and are each positioned such that an orientation in which the receiver 150a, 150b receives the identifying signals is directed toward the device mount 40.

[0399] With the working machine 1 according to item 10, the receivers 150a and 150b include respective directional antennas, and are each positioned such that the orientation in which the receiver receives the identifying signal is directed toward the device mount 40. Therefore, when the working device 9 (9A or the like), the device mount 40, and the receivers 150a and 150b are arranged in a line, the shortest linear distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a and 150b is achieved, and the highest received signal strength of the identifying signal at each of the receivers 150a and 150b is achieved. Thus, by determining the position of the working device 9 (9A or the like) based on the highest received signal strength, it is possible to accurately recognize the position of the working device 9 (9A or the like).

[0400] (Item 11) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c at the at least two positions include respective directional antennas to receive identifying signals from a particular direction, a first receiver of the receivers 150a, 150b, 150c at the at least two positions that is closest to the device mount 40 (receiver 150a) is positioned such that an orientation in which the first receiver 150a receives the identifying signals is directed toward the device mount 40, and one or more second receivers of the receivers 150a, 150b, 150c that are distant from the device mount (receivers 150b, 150c) are each positioned such that the orientation in which the second receiver 150b, 150c receives the identifying signal is directed in a different direction from a direction toward a side where the device mount 40 is present.

[0401] With the working machine 1 according to item 11, when the working device 9 (9A or the like), the device mount 40, and the receivers 150a and 150b are arranged in a line, the shortest linear distance from the transmitter T of the working device 9 (9A or the like) to each of the receivers 150a and 150b is achieved, and therefore the highest received signal strength of the identifying signal is achieved at the first receiver 150a closest to the device mount 40. On the contrary, with regard to the second receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is directed in a direction differing from the direction toward the side where the device mount 40 is present, and the sensitivity of the second receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is lower than the first receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0402] (Item 12) The working machine 1 according to item 11, wherein the one or more second receivers 150b, 150c that are distant from the device mount 40 are each positioned such that the orientation in which the second receiver 150b, 150c receives the identifying signals is directed in a direction away from the device mount 40.

[0403] With the working machine 1 according to item 12, with regard to the second receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is spaced away from the device mount 40, and the sensitivity of the second receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is even lower than the first receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with greatly different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0404] (Item 13) The working machine 1 according to item 1, further including a cover 16 to cover each of one or more of the receivers 150a, 150b, 150c at the at least two positions that are farther from the device mount 40 than the other one or more of the receivers (cover the receivers 150b, 150c), the cover 16 being positioned to block the identifying signal, and the cover 16 includes an opening 160 which faces in a direction different from a direction toward a side where the device mount 40 is present.

[0405] With the working machine 1 according to item 13, with regard to the receivers 150b, 150c each covered by the cover 16, identifying signals that reach the portion of the cover 16 that is other than the opening 160 are blocked by the cover 16, and the receivers 150b, 150c each only receive identifying signals that have passed through the opening 160. Thus, the cover 16 increases the directivity of the receiver 150b, 150b in receiving identifying signals.

[0406] (Item 14) The working machine 1 according to item 13, wherein the opening 160 faces away from the device mount 40.

[0407] With the working machine 1 according to item 14, with regard to the receivers 150b and 150c distant from the device mount 40, since the orientation in which the receiver receives identifying signals is spaced away from the side where the device mount 40 is present, and the sensitivity of the receivers 150b and 150c to receive identifying signals from the side where the device mount 40 is present is even lower than the receiver 150a closest to the device mount 40, so that the receivers 150a, 150b and 150c at at least two positions receive the same identifying signal with greatly different received signal strengths. With this, it is possible to accurately determine the position of the working device 9 (9A or the like) (the position of the transmitter T which is the source of the identifying signal).

[0408] (Item 15) The working machine 1 according to item 1, wherein the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) to be attached to the device mount 40 based on one or more received signal strengths of the identifying signal received by the receivers 150a, 150b, 150c at the at least two positions, when the receivers 150a, 150b, 150c at the at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device 9 (9A or the like) is attached to the device mount 40.

[0409] With the working machine 1 according to item 15, the controller 5 is configured or programmed to, after recognizing the working device 9 (9A or the like) to be attached to the device mount 40, when the receivers 150a, 150b, 150c at the at least two positions have received an identical identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device 9 (9A or the like) is attached to the device mount 40. Therefore, using a series of processes relating to the receivers 150a, 150b and 150c receiving an identifying signal, it is possible to recognize the working device 9 (9A or the like) and appropriately recognize that the working device 9 (9A or the like) is attached to the device mount 40.

[0410] (Item 16) The working machine 1 according to item 1, further including a support structure 4 supported by the machine body 2 to support the device mount 40 to allow the device mount 40 to move along a predetermined path, and an actuator 61 to cause the device mount 40 to move along the path, wherein the controller 5 is configured or programmed to directly or indirectly recognize a load on the actuator 61 and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40.

[0411] With the working machine 1 according to item 16, the controller 5 is configured or programmed to directly or indirectly recognize a load on the actuator 61 and determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40. Thus, whether the working device 9 (9A or the like) is attached to or detached from the device mount 40 is determined based on the actual conditions. Specifically, when a working device 9 (9A or the like) is attached to the device mount 40, the load (weight) of the working device 9 (9A or the like) is applied to the actuator 61 via the support structure 4. The load of the working device 9 (9A or the like) is the load on the actuator 61, and therefore, when the load on the actuator 61 is directly or indirectly recognized to determine whether the working device 9 (9A or the like) is attached to or detached from the device mount 40, the result of determination that matches the actual conditions is obtained.

[0412] (Item 17) The working machine 1 according to item 1, wherein the device mount 40 includes a linkage 41 to connect the working device 9 (9A or the like) thereto, and the linkage 41 includes an engagement portion 412 movable between an engaging position PE1 in which the engagement portion 412 engages with the working device 9 (9A or the like) to connect the working device 9 (9A or the like) thereto and a disengaging position PE2 in which the engagement portion 412 disengages from the working device 9 (9A or the like) to disconnect the working device 9 (9A or the like) therefrom, and the controller 5 is configured or programmed to determine that the working device 9 (9A or the like) is attached to the device mount 40 when the engagement portion 412 is in the engaging position PE1.

[0413] With the working machine 1 according to item 17, the controller 5 determines whether the working device 9 (9A or the like) is attached to the device mount 40 based on the state of the linkage 41 which connects the working device 9 (9A or the like). Therefore, the result of determination that matches the actual conditions is obtained.

[0414] (Item 18) The working machine 1 according to item 1, further including receivers 15a, 15b, 15c each including an assembly of an antenna 150a, 150b, 150c which is one of the receivers 150a, 150b, 150c and a receiver main body 151a, 151b, 151c to receive the identifying signal from the antenna 150a, 150b, 150c, and the receivers 15a, 15b, 15c are located at the respective at least two positions, and connected to the controller 5 such that the identifying signal is transmittable to the controller 5.

[0415] With the working machine 1 according to item 18, since the receivers 15a, 15b and 15c are independent units, even in case of trouble in any of the receivers 15a, 15b and 15c, the other(s) of the receivers 15a, 15b and 15c can still receive the identifying signal from the transmitter T of the working device 9 (9A or the like) and transmit the identifying signal to the controller 5.

[0416] (Item 19) The working machine 1 according to item 1, wherein the receivers 150a, 150b, 150c include antennas 150a, 150b, 150c, the working machine 1 includes a receiver 15a, 15b, 15c including: a receiver main body 151a, 151b, 151c to receive the identifying signal from the antennas 150a, 150b, 150c, input interfaces 153a, 153b, 153c to connect thereto the antennas 150a, 150b, 150c at the at least two positions, and an output interface 154 to output, to the controller 5, the identifying signal inputted into the input interfaces 153a, 153b, 153c.

[0417] With the working machine 1 according to item 19, the receiver 15a, 15b, 15c includes input interfaces 153a, 153b, 153c to connect thereto the antennas 150a, 150b, 150c at the at least two positions, and includes an output interface 154 to output, to the controller 5, the identifying signals inputted into the input interfaces 153a, 153b, 153c. With this, the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) can be connected to the input interfaces 153a, 153b, 153c (to the receiver 15a, 15b, 15c)) via coaxial cables. This makes it possible to provide the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) and the receiver main body 151a, 151b, 151b (receiver 15a, 15b, 15c), independently of each other, at different positions. With this, even if there are only limited spaces for the receivers 150a, 150b and 150c (antennas 150a, 150b, 150c) (even if there is no space for the receivers 15a, 15b and 15c (receiver main bodies 151a, 151b and 151c), it is still possible to provide the receivers 150a, 150b and 150c at appropriate positions.

[0418] (Item 20) The working machine 1 according to item 1, further including a monitor 55, wherein the controller 5 is configured or programmed to determine a location of the working device 9 (9A or the like) which includes the transmitter T transmitting the identifying signal based on the identifying signal received by one or more of the receivers 150a, 150b, 150c and based on one or more received signal strengths of the identifying signal, and cause the monitor 55 to display the determined location of the working device 9 (9A or the like).

[0419] With the working machine 1 according to item 20, the display on the monitor 55 allows the user to know the location of the working device 9 (9A or the like) to be attached to the device mount 40. With this, even in the case where a plurality of working device 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0420] (Item 21) The working machine 1 according to item 20, wherein the monitor 55 is operable to display pieces of device information 9A and the like corresponding to a plurality of the working devices 9 (9A and the like) and to allow a selection of one of the pieces of device information 9A and the like, and the controller 5 is configured or programmed to, based on the identifying signal from the transmitter T of a corresponding one of the plurality of working devices 9 (9A and the like) that corresponds to the selected piece of device information 9A and the like selected on the monitor 55 and based on the one or more received signal strengths of the identifying signal, determine a location of the corresponding one of the plurality of working devices 9 (9A and the like) that includes the transmitter T transmitting the identifying signal.

[0421] With the working machine 1 according to item 21, the location of the working device 9 (9A or the like) corresponding to the selected one of the pieces of device information 9A and the like displayed on the monitor 55 is determined, and the determined location of the working device 9 (9A or the like) is displayed on the monitor 55, allowing the user to quickly know the location of the intended working device 9 (9A or the like). With this, even in the case where a plurality of working device 9A and the like are present in a large area, the user can know the location of the intended working device 9, making it possible to improve the efficiency of work to replace working devices 9 (9A or the like).

[0422] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

first example embodiment

[0084]The following description discusses a working machine according to a first example embodiment of the present invention with reference to drawings. Note that, assuming that the working machine is able to travel, the direction of straight travel (direction of forward travel or rearward travel) is hereinafter referred to as a front-rear direction, a direction perpendicular to the front-rear direction and an up-down direction is hereinafter referred to as a lateral direction. One of such lateral directions that is on the right side when the user faces forward is hereinafter referred to as a rightward direction (right), and the other of the lateral directions that is on the left side when the user faces forward is hereinafter referred to as a leftward direction (left).

[0085]A working machine 1 according to the first example embodiment is a compact track loader for use in construction work, civil engineering work or the like, as illustrated in FIGS. 1 to 10. The working machine 1 in...

second example embodiment

[0172]The following description discusses a working machine according to a second example embodiment of the present invention. Note that the working machine according to the second example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine of the first example embodiment except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the second example embodiment only discusses the differences from the first example embodiment, and the description for the same configurations as the first example embodiment is not repeated here but the description in the first example embodiment is applied as that for the second example embodiment. Furthermore, the features identical to or corresponding to those of the first example embodiment are assigned the same names and reference signs as in the first example embodimen...

third example embodiment

[0213]The following description discusses a working machine according to a third example embodiment of the present invention. Note that the working machine according to the third example embodiment is a compact track loader for use in construction work, civil engineering work or the like, and has the same configuration as the working machine 1 of the first example embodiment and the working machine 1 of the second example embodiment, except for the locations and the number of receivers and processes performed by the controller. Accordingly, the following description of the third example embodiment only discusses the differences from the first example embodiment and the second example embodiment, and the description for the same configurations as the first example embodiment and the second example embodiment is not repeated here but the description in the first example embodiment and the second example embodiment is applied as that for the third example embodiment. Furthermore, the f...

Claims

1. A working machine comprising:a machine body;a device mount to replaceably attach a working device thereto, the working device including a transmitter to transmit a unique identifying signal and being operable to perform a function corresponding to work; anda controller configured or programmed to control the machine body; whereinthe machine body includes receivers to receive the identifying signal from the transmitter;the receivers are located at respective at least two positions separated from the device mount by different distances; andthe controller is configured or programmed to recognize the working device attached to or to be attached to the device mount based on a received signal strength of the identifying signal received by at least one of the receivers that is located at at least one of the at least two positions.

2. The working machine according to claim 1, whereinthe device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body; andthe receivers are located at the at least two positions at increasing distances from the device mount in the front-rear direction of the machine body.

3. The working machine according to claim 1, whereinthe receivers are located at respective at least three different positions which include the at least two positions separated from the device mount by different distances; andthe controller is configured or programmed to determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least three positions, based on a combination of levels of received signal strengths at the receivers at the at least three positions.

4. The working machine according to claim 1, whereinthe machine body includes a cabin to surround a seat for a user;the device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body; the receivers are located at two positions one of which is in an area between the device mount and the cabin in the front-rear direction and the other of which is within the cabin; andthe controller is configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength of the identifying signal received by one of the receivers that is in the area between the device mount and the cabin is equal to or greater than a preset threshold and a received signal strength at the other of the receivers that is within the cabin is within a predetermined range.

5. The working machine according to claim 1, whereinthe machine body includes a cabin to surround a seat for a user;the device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body;the receivers are located at two positions one of which is forward of a center of the cabin in the front-rear direction and the other of which is rearward of the center; andthe controller is configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

6. The working machine according to claim 1, whereinthe machine body includes a cabin to surround a seat for a user;the device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body;the receivers are located at at least four positions including positions at a front and a rear of the cabin in the front-rear direction and on opposite sides of the cabin in a lateral direction perpendicular to the front-rear direction; andthe controller is configured or programmed to, when the receivers at the at least four positions each receive the identifying signal:determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions; andrecognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the cabin is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

7. The working machine according to claim 1, whereinthe machine body includes a seat for a user;the device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body;the receivers are located at two positions forward of and rearward of the seat in the front-rear direction; andthe controller is configured or programmed to, when the receivers at the two positions each receive the identifying signal, recognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers at the two positions, when (i) a combination of received signal strengths at the receivers at the two positions satisfies a predetermined condition or (ii) a received signal strength at one of the receivers that is closest to the device mount is equal to or greater than a preset threshold and a received signal strength at the other of the receivers is within a predetermined range.

8. The working machine according to claim 1, whereinthe machine body includes a seat for a user;the device mount is located at at least one of forward of or rearward of the machine body in a front-rear direction of the machine body;the receivers are located at at least four positions including positions forward of and rearward of the seat in the front-rear direction and on opposite sides of the seat in a lateral direction perpendicular to the front-rear direction; andthe controller is configured or programmed to, when the receivers at the at least four positions each receive the identifying signal:determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions; andrecognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located forward of and / or rearward of the seat is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

9. The working machine according to claim 1, whereinthe receivers are located at at least four positions including positions at a front and a rear of the machine body in a front-rear direction and on opposite sides of the machine body in a lateral direction perpendicular to the front-rear direction;the device mount is located at at least one of (i) in front of one of the receivers that is at the front of the machine body or (ii) rearward of another of the receivers that is at the rear of the machine body; andthe controller is configured or programmed to, when the receivers at the at least four positions each receive the identifying signal:determine a position of the working device which includes the transmitter transmitting the identifying signal received by the receivers at the at least four positions, based on a combination of levels of received signal strengths of the identifying signal received by the respective receivers at the at least four positions; andrecognize the working device attached to or to be attached to the device mount based on the identifying signal received by the receivers, when (i) a combination of received signal strengths at the receivers at the at least four positions satisfies a predetermined condition or (ii) a received signal strength at at least one of the receivers located at the front and / or the rear of the machine body is equal to or greater than a preset threshold and a received signal strength at each of the other ones of the receivers is within a predetermined range.

10. The working machine according to claim 1, wherein the receivers at the at least two positions include respective directional antennas to receive identifying signals from a particular direction, and are each positioned such that an orientation in which the receiver receives the identifying signals is directed toward the device mount.

11. The working machine according to claim 1, whereinthe receivers at the at least two positions include respective directional antennas to receive identifying signals from a particular direction;a first receiver of the receivers at the at least two positions that is closest to the device mount is positioned such that an orientation in which the first receiver receives the identifying signals is directed toward the device mount; andone or more second receivers of the receivers that are distant from the device mount are each positioned such that the orientation in which the one or more second receivers receive the identifying signal is directed in a different direction from a direction toward a side where the device mount is present.

12. The working machine according to claim 11, wherein the one or more second receivers that are distant from the device mount are each positioned such that the orientation in which the one or more second receivers receive the identifying signals is directed in a direction away from the device mount.

13. The working machine according to claim 1, further comprising a cover to cover each of one or more of the receivers at the at least two positions that are farther from the device mount than the other one or more of the receivers, the cover being positioned to block the identifying signal; andthe cover includes an opening which faces in a direction different from a direction toward a side where the device mount is present.

14. The working machine according to claim 13, wherein the opening faces away from the device mount.

15. The working machine according to claim 1, wherein the controller is configured or programmed to, after recognizing the working device to be attached to the device mount based on one or more received signal strengths of the identifying signal received by the receivers at the at least two positions, when the receivers at the at least two positions have received the same identifying signal with respective predetermined received signal strengths for a predetermined time period, recognize that the working device is attached to the device mount.

16. The working machine according to claim 1, further comprising:a support structure supported by the machine body to support the device mount to allow the device mount to move along a predetermined path; andan actuator to cause the device mount to move along the path; whereinthe controller is configured or programmed to directly or indirectly recognize a load on the actuator and determine whether the working device is attached to or detached from the device mount.

17. The working machine according to claim 1, whereinthe device mount includes a linkage to connect the working device thereto; andthe linkage includes an engagement portion movable between an engaging position in which the engagement portion engages with the working device to connect the working device thereto and a disengaging position in which the engagement portion disengages from the working device to disconnect the working device therefrom; andthe controller is configured or programmed to determine that the working device is attached to the device mount when the engagement portion is in the engaging position.

18. The working machine according to claim 1, further comprising:receivers each including an assembly of an antenna which is one of the receivers and a receiver main body to receive the identifying signal from the antenna; andthe receivers are located at the respective at least two positions, and connected to the controller such that the identifying signal is transmittable to the controller.

19. The working machine according to claim 1, wherein the receivers include antennas;the working machine comprises a receiver including:a receiver main body to receive the identifying signal from the antennas;input interfaces to connect thereto the antennas at the at least two positions; andan output interface to output, to the controller, the identifying signal inputted into the input interfaces.

20. The working machine according to claim 1, further comprising a monitor; whereinthe controller is configured or programmed to determine a location of the working device which includes the transmitter transmitting the identifying signal based on the identifying signal received by one or more of the receivers and based on one or more received signal strengths of the identifying signal, and cause the monitor to display the determined location of the working device.

21. The working machine according to claim 20, wherein the monitor is operable to display pieces of device information corresponding to a plurality of the working devices and to allow a selection of one of the pieces of device information; andthe controller is configured or programmed to, based on the identifying signal from the transmitter of a corresponding one of the plurality of working devices that corresponds to the selected piece of device information selected on the monitor and based on the one or more received signal strengths of the identifying signal, determine a location of the corresponding one of the plurality of working devices that includes the transmitter transmitting the identifying signal.

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