Control device and program for work machine

Abstract

To appropriately prevent interference between the work implement and a cabin while allowing the work implement to continue operating even when a sensor that detects the angle of the work implement fails. [Solution] A control device is disclosed that includes a first acquisition unit that acquires sensor information corresponding to the angle of the work implement relative to the work device main body, a first calculation unit that, in a first mode, calculates the position of the work implement based on the sensor information and posture information, and a second calculation unit that, in a second mode, calculates the position of the work implement when it is fixed at a predetermined angle based on the posture information, wherein in the first mode, an interference prevention control unit limits the movement range of the work implement based on the calculation result by the first calculation unit so that the work implement does not enter a first restricted range, and in the second mode, limits the posture of the work device main body based on the calculation result by the second calculation unit so that the work implement does not enter a second restricted range.

Description

[Technical Field]

[0001] The present disclosure relates to a control device and a program for a work machine. [Background technology]

[0002] In a work machine having a work implement in which the work implement is supported rotatably around a pin relative to the work implement body, a cabin, and a power source, there is known a technique for preventing interference between the work implement and the machine body based on sensor information from a sensor that detects the angle of the work implement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-22486 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the sensor that detects the angle of the work tool has a high risk of interfering with the surroundings during work and being damaged. In this regard, the above-mentioned conventional technology is unable to achieve appropriate interference control when the sensor fails.

[0005] Therefore, an object of the present disclosure is to appropriately prevent interference between the work implement and the cabin while allowing the work implement to continue operating even when a sensor that detects the angle of the work implement fails. [Means for solving the problem]

[0006] According to one aspect, there is provided a control device for a work machine having a work device in which a work implement is supported on a work device body so as to be rotatable about a pin, a cabin, and a power source that operates the work device, a first acquisition unit that acquires sensor information related to an electrical signal from a sensor that generates an electrical signal according to an angle of the work implement with respect to the work device body; a failure detection unit that detects a failure of the sensor; a second acquisition unit that acquires posture information relating to the posture of the working device body; an interference prevention control unit that performs control to prevent interference between the work tool and the cabin; a selection unit that selects a first mode or a second mode as an operation mode of the interference prevention control unit; a setting unit that sets a first limit range in the first mode and a second limit range in the second mode; a first calculation unit that calculates a position of the work tool based on the sensor information and the posture information in the first mode; a second calculation unit that calculates, in the second mode, a position of the work tool when the work tool is fixed at a predetermined angle based on the posture information, the selection unit switches from the first mode to the second mode when a failure of the sensor is detected in the first mode; In the first mode, the interference prevention control unit limits a movement range of the work tool so that the work tool does not enter the first restricted range based on a calculation result of the position of the work tool by the first calculation unit, A control device is disclosed in which, in the second mode, the interference prevention control unit restricts the posture of the work device body based on the calculation result of the position of the work tool by the second calculation unit so that the work tool does not enter the second restricted range. [Effects of the Invention]

[0007] According to the present disclosure, even in the event of a failure of a sensor that detects the angle of the work implement, it is possible to appropriately prevent interference between the work implement and the cabin while allowing the work implement to continue operating. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a driving element of a construction machine equipped with a control device of the present embodiment. [Figure 2] FIG. 1 is a diagram illustrating a mechanism of a construction machine. [Figure 3] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to the present embodiment. [Figure 4] FIG. 2 is a diagram functionally illustrating the configuration of a control device according to the present embodiment. [Figure 5] FIG. 10 is an explanatory diagram of a first restricted range. [Figure 6] FIG. 10 is an explanatory diagram of a second restricted range. [Figure 6A] FIG. 10 is an explanatory diagram of a method for calculating a reference position, and an explanatory diagram of various parameters used in the calculation. [Figure 7] 4 is a schematic flowchart showing an example of the flow of main processes that may be executed by the control device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings.

[0010] FIG. 1 is a diagram illustrating the driving elements of a construction machine 1 equipped with a control device 10 of this embodiment, and FIG. 2 is a diagram illustrating the mechanism of the construction machine 1. As shown in FIG.

[0011] 1, a construction machine 1 equipped with the control device 10 of this embodiment is configured to include, as drive elements, a hydraulic oil tank 21, an engine 22, a hydraulic pump 23 driven by the engine 22, a tilt proportional valve 24 that controls the tilt of the hydraulic pump 23, a control valve unit 25, and various actuators 27. Hydraulic oil circulates from the hydraulic oil tank 21 via the hydraulic pump 23, the control valve unit 25, and various actuators 27, returning to the hydraulic oil tank 21.

[0012] 1, the engine 22 is used, but an electric motor may be used instead of or in addition to the engine 22. Also, an electric pump may be used instead of or in addition to the hydraulic pump 23.

[0013] FIG. 2 shows a hydraulic excavator as an example of the construction machine 1.

[0014] This hydraulic excavator comprises a lower traveling body 41 that can travel on the ground, an upper rotating body 42 that is rotatably mounted on the lower traveling body 41, and a working device 50 that is mounted on the upper rotating body 42.

[0015] The upper rotating body 42 has a rotating frame 42a and multiple elements mounted thereon. These multiple elements include an engine room 42b that houses the engine 22 (FIG. 1) and a cab 42c (cabin) that serves as a driver's compartment. The cab 42c is equipped with a space where an operator can get in and operating tools (not shown). In the case of an automatic type of construction machine that does not require an operator, the cab 42c may also refer to a space where the machine and other components are placed.

[0016] The working device 50 is capable of performing operations for excavation work and other necessary work, and includes, as operating elements, a boom 51, an arm 52, and an attachment 53. In this specification, the portion of the working device 50 excluding the attachment 53 is an example of the working device main body.

[0017] The boom 51 is supported at the front end of the revolving frame 42a so as to be able to rise and fall, that is, to be able to rotate about a horizontal axis.

[0018] The arm 52 is attached to the tip of the boom 51 so as to be rotatable around a horizontal axis.

[0019] The attachment 53 is rotatably attached to the tip of the arm 52. In the example shown in Fig. 2, the attachment 53 is a bucket, but it may have other shapes or names, such as a fork, a crusher, a breaker, or a cutter (see Fig. 5, etc.). In other words, this embodiment can be used for any work machine other than the hydraulic excavator shown in Fig. 2.

[0020] In addition, a plurality of hydraulic cylinders serving as extendable driving elements (actuators), specifically at least one boom cylinder 61, arm cylinder 62 and bucket cylinder 63, are provided corresponding to the boom 51, arm 52 and attachment 53, respectively.

[0021] The boom cylinder 61, arm cylinder 62, and bucket cylinder 63 are contracted to lower the boom, push the arm, and open the bucket, respectively. On the other hand, the boom cylinder 61, arm cylinder 62, and bucket cylinder 63 are extended to raise the boom, pull the arm, and close the bucket, respectively. Note that the extension and contraction directions of the boom cylinder 61, arm cylinder 62, or bucket cylinder 63 may be combined arbitrarily with the rotation directions of the boom 51, arm 52, or attachment 53.

[0022] A sensor 42d is attached to the upper rotating body 42 to detect the inclination (angle with respect to the horizontal plane) of the upper rotating body 42. A sensor 51a is attached to the base end of the boom 51 to detect the angle of the boom 51 with respect to the upper rotating body 42. A sensor 52a is attached to the base end of the arm 52 to detect the angle of the arm 52 with respect to the boom 51, and a sensor 53a is attached to the base end of the attachment 53 to detect the angle of the attachment 53 with respect to the arm 52. The sensor 51a, the sensor 52a, or the sensor 53a may be attached at any position and does not have to be at the base end of the boom 51, the arm 52, or the attachment 53. The sensor 54a, which detects the angle of the idler link 54 with respect to the arm 52, may be provided at a pin connection between the idler link 54 and the arm 52. The pin 70 forms a rotation axis that rotatably supports the attachment 53 with respect to the arm 52. The sensor 53 a detects the angle of the attachment 53 relative to the arm 52 around the pin 70 .

[0023] Note that in a configuration equipped with an arm-side jib 512 (see FIG. 5, etc.), such as a two-piece boom, the boom may further include a sensor that calculates the angle of the arm-side jib 512. Hereinafter, in a configuration equipped with an arm-side jib 512 (see FIG. 5, etc.), unless otherwise specified, the sensor 51a will include both the sensor 510a (see FIG. 5) that detects the angle of the running body side jib 510 relative to the lower running body 41, and the sensor 512a (see FIG. 5) that calculates the angle of the arm-side jib 512 relative to the running body side jib 510.

[0024] In the hydraulic excavator shown in Fig. 2, at least the boom cylinder 61, the arm cylinder 62, and the bucket cylinder 63 are operated via various actuators 27. In this case, the control valve unit 25 shown in Fig. 1 is connected to the various actuators 27 associated with the boom cylinder 61, the arm cylinder 62, and the bucket cylinder 63. In this case, the control valve unit 25 may be formed as an assembly of a plurality of control valves that respectively control the extension and contraction of the boom cylinder 61, the arm cylinder 62, and the bucket cylinder 63.

[0025] FIG. 3 is a diagram illustrating an example of a hardware configuration of the control device 10. As shown in FIG.

[0026] 3, the control device 10 includes a control unit 101, a main memory unit 102, an auxiliary memory unit 103, a drive device 104, a network I / F unit 106, and an input unit 107. Note that part or all of the control device 10 may be in the form of a circuit in which various elements (including elements in the form of chips) are mounted on a substrate or the like.

[0027] The control unit 101 is a calculation device that executes programs stored in the main memory unit 102 and the auxiliary memory unit 103, and receives data from the input unit 107 or a storage device, calculates and processes it, and then outputs it to a storage device or the like.

[0028] The main memory unit 102 is a read-only memory (ROM), a random access memory (RAM), etc. The main memory unit 102 is a storage device that stores or temporarily saves programs and data, such as an operating system (OS), which is basic software executed by the control unit 101, and application software.

[0029] The auxiliary storage unit 103 is a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive) that stores data related to application software and the like.

[0030] The drive device 104 reads the program from a recording medium 105, such as a flexible disk, and installs it in a storage device.

[0031] A predetermined program is stored in the recording medium 105. The program stored in the recording medium 105 is installed in the control device 10 via the drive device 104. The installed predetermined program can be executed by the control device 10.

[0032] The network I / F unit 106 is an interface between the control device 10 and peripheral devices having a communication function connected via a network constructed by a data transmission path such as a wired and / or wireless line.

[0033] The input unit 107 includes a keyboard equipped with cursor keys, a numeric keypad (numeric input keys), various function keys, a mouse, a touch pad, and the like.

[0034] 3, the various processes described below can be realized by causing the control device 10 to execute a program. Alternatively, the program can be recorded on a recording medium 105, and the control device 10 can read the program from the recording medium 105 to realize the various processes described below. Various types of recording media can be used for the recording medium 105. For example, the recording medium 105 may be a recording medium that records information optically, electrically, or magnetically, such as a CD (Compact Disc)-ROM, a flexible disk, or a magneto-optical disk, or a semiconductor memory that records information electrically, such as a ROM or a flash memory.

[0035] In this embodiment, the control device 10 can be realized by one computer, but may also be realized by a combination of multiple computers. Also, an external server computer may be used.

[0036] FIG. 4 is a diagram functionally illustrating the configuration of the control device 10 of this embodiment. FIG. 5 is an explanatory diagram of the first restricted range S1, and FIG. 6 is an explanatory diagram of the second restricted range S2. FIG. 6A is an explanatory diagram of a method for calculating the reference position and various parameters used in the calculation. Note that the shape of the attachment 53 in FIGS. 5 to 6A is different from the example shown in FIG. 2, but this difference is not essential.

[0037] The control device 10 includes a fault detection unit 11, an attitude acquisition unit 12, a mode selection unit 13, a limit range setting unit 14, a first reference position calculation unit 15, a second reference position calculation unit 16, a device control unit 18, and a notification unit 19.

[0038] Each unit from the fault detection unit 11 to the device control unit 18 can be realized by the control unit 101 shown in Figure 3 executing one or more programs stored in the main memory unit 102 and / or the auxiliary memory unit 103 and / or the recording medium 105 shown in Figure 3.

[0039] The fault detection unit 11 detects various faults that affect the control functions of the device control unit 18, which will be described later. In this embodiment, the fault detection unit 11 detects a fault in the sensor 53a as one of the various faults. Note that the term "failure" is a concept that includes abnormality. The fault detection unit 11 may determine the possibility of a fault in the sensor 53a instead of or in addition to determining whether or not the sensor 53a has a fault. In this case, a state in which the possibility of a fault in the sensor 53a exceeds a threshold may be synonymous with a state in which a fault in the sensor 53a has been detected.

[0040] The attitude acquisition unit 12 acquires sensor information related to the attitude of the working device 50. The sensor information related to the attitude includes angles detected by the sensors 41d, 51a, 52a, and 53a. The sensor information related to the attitude may also include an angle detected by the sensor 54a.

[0041] In this specification, the sensor information related to the attitude of the construction machine 1 other than the sensor information from the sensor 53a is also collectively referred to as "attitude information." In other words, the sensor information from the sensor 41d, the sensor 51a, and the sensor 52a is also referred to as attitude information.

[0042] The mode selection unit 13 selects (sets) one of various operation modes of the construction machine 1. The mode selection unit 13 may select the operation mode in response to a user input and / or automatically. In this embodiment, the various operation modes include the following two modes associated with the control mode of the device control unit 18: an unrestricted mode (an example of a first mode) that can be selected when no failure of the sensor 53a is detected, and a restricted mode (an example of a second mode) that is implemented when a failure of the sensor 53a is detected. When the operation mode is the unrestricted mode and the failure detection unit 11 detects a failure of the sensor 53a, the mode selection unit 13 switches the operation mode from the unrestricted mode to the restricted mode. Note that the mode selection unit 13 may switch the operation mode from the unrestricted mode to the restricted mode in response to a user input when the operation mode is the unrestricted mode.

[0043] The limited range setting unit 14 sets a limited range (area) for the operation of the working device 50. The limited range is defined relative to a reference part of the working device 50 or a reference position related to the working device 50. The limited range is in the form of a prohibited range that does not include the reference part or the reference position. However, in a modified example, the limited range may be defined substantially by defining a movable range that does not allow the reference part or the reference position to protrude.

[0044] In this embodiment, the restricted range setting unit 14 sets a first restricted range S1 in the non-restricted mode, and sets a second restricted range S2 in the restricted mode.

[0045] The first restricted range S1 is defined with respect to the attachment 53 of the working device 50 as a reference portion of the working device 50. For example, as shown in Fig. 5, the reference portion of the working device 50 is assumed to be a polygon (e.g., a rectangle) that circumscribes the outer shape of the attachment 53 in a side view. Hereinafter, such a polygon will also be referred to as an attachment area 81.

[0046] 5, the first restricted range S1 may be defined by a boundary line 91 that covers the cab 42c (covers the attachment 53 side) in a side view, and the area closer to the cab 42c than the boundary line 91 becomes the first restricted range S1. Note that the boundary line 91 may have a closed shape such as a circle, or may be defined as a range that corresponds to the effective range.

[0047] In this embodiment, the boundary line 91 is preferably a circular arc. In this case, the center of the arc (center of curvature) may be set behind the cab 42c. In this case, the radius of the arc can be made relatively large, and the boundary line 91 can be defined to follow the front shape of the cab 42c in a side view (a relatively linear front shape).

[0048] The second limit range S2 is preferably the same as the first limit range S1. In this embodiment, as an example, the second limit range S2 is the same as the first limit range S1. In this case, the number of parameters managing the first limit range S1 and the second limit range S2 can be reduced, thereby reducing the processing load and the required storage capacity. However, in a modified example, the second limit range S2 may be set slightly larger than the first limit range S1, or may be different.

[0049] The first reference position calculation unit 15 operates when the operation mode is the non-restricted mode. The first reference position calculation unit 15 calculates the position of the attachment 53 based on the sensor information (sensor information from the sensor 53a and posture information) related to the posture of the working device 50 described above. The position of the attachment 53 may be calculated based on any part of the attachment 53 as a reference. In this embodiment, the position of the attachment 53 is calculated by combining the position and orientation of the attachment region 81 described above. Specifically, the first reference position calculation unit 15 calculates the position and orientation of the attachment region 81 based on the sensor information related to the posture of the working device 50. The position of the attachment region 81 may be calculated based on any position of the attachment region 81 (for example, the tip position 53b of the attachment 53 described below).

[0050] The second reference position calculation unit 16 operates in a state where the operation mode is the restricted mode. The second reference position calculation unit 16 calculates the position of the attachment 53 when it is assumed that the attachment 53 is fixed at a predetermined angle.

[0051] The position of the attachment 53 may be calculated based on any part of the attachment 53. In this embodiment, the position of the attachment 53 is calculated by combining the position and orientation of the attachment region 82, as in the case of the first reference position calculation unit 15. The size and shape of the attachment region 82 may be the same as those of the attachment region 81.

[0052] Here, the restricted mode is established when a failure of the sensor 53a is detected as described above. Therefore, in the restricted mode, the sensor information from the sensor 53a among the sensor information related to the attitude of the working device 50 (the sensor information from the sensor 53a and the attitude information) cannot be used.

[0053] Therefore, in this embodiment, in the limited mode, the position of the attachment 53 is calculated without using sensor information from the sensor 53a, assuming that the attachment 53 is fixed at a predetermined angle. In this case, the predetermined angle is arbitrary, but is preferably an angle at which the posture of the attachment 53 corresponds to the so-called "most hugged posture." Specifically, the predetermined angle is preferably the minimum angle within the movable angle range. In this case, the posture that is most likely to cause interference with the cab 42c is assumed among all postures that the attachment 53 can take, thereby achieving safe limit control (described later).

[0054] In this way, in the present embodiment, in the restricted mode, the second reference position calculation unit 16 calculates the position of the attachment 53 using only the posture information out of the sensor information from the sensor 53a and the posture information.

[0055] Specifically, the second reference position calculation unit 16 calculates the position and orientation of the attachment region 82 based on the posture information. The position of the attachment region 81 may be calculated based on an arbitrary position of the attachment region 82 (for example, a tip position 53b of an attachment 53 described later).

[0056] In a modified example, in the restricted mode, the second reference position calculation unit 16 may calculate a predetermined position of the attachment 53 as the reference position for the working device 50. The predetermined position may be set to a position of the attachment 53 in the tucked position in a side view that is closest to the cab 42c (for example, the tip position 53b) or a position in the vicinity thereof. In this case, the predetermined position may be calculated based on the above-described posture information, assuming that the attachment 53 is fixed at a predetermined angle. However, the calculation method for the predetermined position is arbitrary and may be other methods. For example, instead of the angle detected by the sensor 53a, the predetermined position may be calculated based on a cylinder stroke acquired by a cylinder equipped with a stroke sensor. Also, a method of calculating the predetermined position using a Global Navigation Satellite System (GNSS) or a method of detecting the predetermined position based on a photographed image of the attachment 53, etc. may be used. The predetermined position may also be calculated taking into account the hydraulic pressure of the cylinder during operation.

[0057] 6A, a method for calculating the attachment area 81 and the attachment area 82 will be described. Here, in a side view, the horizontal direction is the X axis, and the vertical direction is the Y axis.

[0058] The tip position (X, Y) of the attachment 53 can be calculated using the following formula based on the boom foot. X=L1*cos(Θ1)+L2*cos(Θ1+Θ2-180°)+L3*sin(Θ1+Θ2+Θ3-270°)-L4*cos(Θ1+Θ2+Θ3+Θ4) Y=L1*sin(Θ1)+L2*sin(Θ1+Θ2-180°)-L3*cos(Θ1+Θ2+Θ3-270°)-L4*sin(Θ1+Θ2+Θ3+Θ4) Here, Θ1 corresponds to the angle of the vehicle-side jib 510, and an angle based on sensor information from sensor 510a can be used. Θ2 corresponds to the angle of the arm-side jib 512, and an angle based on sensor information from sensor 512a can be used. Θ3 corresponds to the angle of the arm 52, and an angle based on sensor information from sensor 52a can be used. Θ4 corresponds to the angle of the attachment 53, and an angle based on sensor information from sensor 53a can be used. Note that lengths L1 to L4 are as shown in the figure, and design values ​​or actual measured values ​​can be used.

[0059] Note that the positions of the attachment regions 81 and 82 are determined when the tip position (X, Y) of the attachment 53 is calculated. The orientations of the attachment regions 81 and 82 are determined based on the values ​​(sensor information) of the angle-related parameters Θ1, Θ2, Θ3, and Θ4.

[0060] In this embodiment, for Θ4, a value based on sensor information from sensor 53a is used in the non-restricted mode, and a fixed value is used in the restricted mode. According to this calculation method, the tip position (X, Y) of attachment 53 can be calculated without changing the parameters used in the non-restricted mode and the restricted mode. Therefore, according to this embodiment, the restricted mode can be realized while minimizing the processing load and the need for an increase in storage area.

[0061] The device control unit 18 controls the working device 50 in response to input from the operator. The device control unit 18 may also control the working device 50 automatically or semi-automatically.

[0062] In this embodiment, the device control unit 18 determines whether the restriction condition based on the first restriction range S1 or the second restriction range S2 is met while controlling the operation of the working device 50 in response to input from the operator. Then, when the restriction condition is met, the device control unit 18 executes restriction control to restrict the operation of the working device 50 regardless of input from the operator.

[0063] The limit control is a control for preventing the attachment 53 and the like from entering the first limit range S1 or the second limit range S2. The limit control is optional and may include, for example, outputting an alarm, stopping or slowing down the work implement 50, etc. For example, the limit control limits the movement of the attachment 53 in a direction that would cause the attachment 53 to further enter the first limit range S1 or the second limit range S2 by outputting an alarm, stopping or slowing down the work implement 50, etc. For example, in the case of the bucket cylinder 63, the movement of the bucket excavation side may be stopped or slowed down.

[0064] When the operating mode is the non-restricted mode, the device control unit 18 executes restriction control based on the angle detected by the sensor 53a and the posture information to prevent the attachment 53 from entering the first restricted range S1. That is, the restriction control restricts the movement range of the attachment 53 to prevent the attachment 53 from entering the first restricted range S1. Note that "preventing the attachment 53 from entering the first restricted range S1" not only includes the concept of completely preventing the attachment 53 from entering the first restricted range S1, but also the concept of preventing the attachment 53 from entering the first restricted range S1 as much as possible. Therefore, "preventing the attachment 53 from entering the first restricted range S1" may also include the concept of "preventing the attachment 53 from leaving the first restricted range S1." The same applies to the second restricted range S2.

[0065] Specifically, when the operating mode is the non-restricted mode, the device control unit 18 performs restriction control so that the attachment area 81 (see FIG. 5) does not enter the first restricted range S1 (or if it does enter, so that it leaves).

[0066] When the operation mode is the restricted mode, the device control unit 18 executes restriction control so that the attachment area 82 (see FIG. 6) does not enter the second restricted range S2 (or, if it does enter, so that it leaves the second restricted range S2).

[0067] The notification unit 19 provides various notifications to the operator. The various notifications are optional, and may, for example, notify the operator of the state in which the above-mentioned restriction control is being executed (restricted mode), or may notify the operator when the non-restricted mode is switched to the restricted mode. The notification method is optional, and may be realized acoustically and / or optically. Note that optical notifications may be notifications using light, images, videos, etc.

[0068] In this embodiment, the mode of the limit control may be selectable by the operator from several modes. In this case, for example, when a mode with a relatively low degree of intervention (e.g., an alarm) is selected, the relationship between the second limit range S2 and the position of the attachment 53 (and / or the attachment area 82) may be displayed on a display (not shown) or the like.

[0069] In this embodiment, the limit control may be released by an input from the operator (for example, by operating a button). In this case, the relationship between the second limit range S2 and the position of the attachment 53 (and / or the attachment area 82) may be displayed on a display (not shown) or the like.

[0070] Incidentally, since the sensor 53a is attached closer to the attachment 53 than the other sensors (for example, the sensor 52a, etc.), it tends to malfunction more easily than the other sensors. For example, it tends to interfere with rocks or the like during work, which can easily cause malfunctions such as broken wires.

[0071] In this regard, in this embodiment, when a failure of the sensor 53a is detected, the operation of the working implement 50 can be continued in the restricted mode. In the restricted mode, the restriction control is executed based on the relationship between the second restricted range S2 and the attachment area 82, so that interference between the attachment 53 and the cab 42c can be appropriately prevented even in a situation where sensor information from the sensor 53a cannot be obtained.

[0072] In this way, according to this embodiment, even in the event of a failure of the sensor 53a that detects the angle of the attachment 53, it is possible to continue operating the attachment 53 while appropriately preventing interference between the attachment 53 and the cab 42c.

[0073] In this embodiment, as described above, even if the sensor 53a that detects the angle of the attachment 53 fails, the operation of the attachment 53 can continue, so in the case of an ultra-long building demolition machine, for example, the attachment 53 can be lowered to the ground to repair the sensor 53a.

[0074] Next, an example of the operation of the control device 10 of this embodiment will be described with reference to FIG.

[0075] 7 is a schematic flowchart showing an example of the flow of main processes that may be executed by the control device 10 of this embodiment. For the sake of simplicity, it is assumed here that there are only two possible operation modes: a restricted mode and an unrestricted mode.

[0076] In step S700, the control device 10 acquires sensor information relating to the attitude of the working device 50.

[0077] In step S702, the control device 10 determines whether the operation mode is the non-restricted mode. If the determination result is "YES", the process proceeds to step S704, and otherwise (i.e., if the operation mode is the restricted mode), the process proceeds to step S710.

[0078] In step S704, the control device 10 determines whether a failure of the sensor 53a has been detected. Note that any method for determining a failure of the sensor 53a may be used. For example, a failure of the sensor 53a may be detected when the electrical signal from the sensor 53a is interrupted or when the value (angle) indicated by the electrical signal is abnormal. If the determination result is "YES," the process proceeds to step S706; otherwise, the process proceeds to step S707.

[0079] In step S706, the control device 10 switches the operation mode from the non-restricted mode to the restricted mode, and then proceeds to step S710.

[0080] In step S707, the control device 10 calculates the position and orientation (side view) of the attachment region 81 based on the sensor information related to the attitude of the working device 50 obtained in step S700.

[0081] In step S708, the control device 10 operates in the non-restricted mode. Specifically, the control device 10 determines whether the restriction condition based on the first restricted range S1 is met while controlling the operation of the working device 50 in response to input from the operator. The restriction condition based on the first restricted range S1 is arbitrary, but may be met, for example, when the attachment area 81 approaches the first restricted range S1 within a predetermined distance D1 (not shown). Then, when the restriction condition is met, the device control unit 18 executes the restriction control described above regardless of input from the operator.

[0082] In step S710, the control device 10 calculates the position and orientation of the attachment region 82 based on the attitude information of the sensor information relating to the attitude of the working device 50 obtained in step S700.

[0083] In step S712, the control device 10 operates in the restricted mode. Specifically, the control device 10 determines whether the restricted condition based on the second restricted range S2 is met while controlling the operation of the working device 50 in response to input from the operator. The restricted condition based on the second restricted range S2 is arbitrary, but may be met, for example, when the attachment area 82 approaches the second restricted range S2 within a predetermined distance D2 (not shown). Note that the predetermined distance D2 may be the same as or different from the predetermined distance D1 in step S708 described above. Then, when the restricted condition is met, the device control unit 18 executes the restricted control described above regardless of input from the operator.

[0084] The limit control that can be executed in step S712 may be the same as or different from the limit control that can be executed in the above-described step S708. For example, the limit control that can be executed in step S712 may be more restrictive than the limit control that can be executed in the above-described step S708.

[0085] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments. [Explanation of symbols]

[0086] 1. Construction machinery 42c Cab (cabin) 50 Work equipment 53 Attachments (Work Tools) 70 pins 53a Sensor 10 Control device 11 Fault detection section 12 Attitude acquisition part (1st acquisition part, 2nd acquisition part) 13 Mode selection section (selection section) 14 Restriction range setting section 15 Reference position calculation section 18 Device control section (interference prevention control section) 19 Notification Department S1 First restricted range 91 Boundary line (arc) S2 Second limit range

Claims

1. A control device for a work machine having a work device in which a work implement is supported on a work device body so as to be rotatable about a pin, a cabin, and a power source that operates the work device, a first acquisition unit that acquires sensor information related to an electrical signal from a sensor that generates an electrical signal according to an angle of the work tool with respect to the work device body; a failure detection unit that detects a failure of the sensor; a second acquisition unit that acquires posture information relating to the posture of the working device body; an interference prevention control unit that performs control to prevent interference between the work tool and the cabin; a selection unit that selects a first mode or a second mode as an operation mode of the interference prevention control unit; a setting unit that sets a first limit range in the first mode and a second limit range in the second mode; a first calculation unit that calculates a position of the work tool based on the sensor information and the posture information in the first mode; a second calculation unit that calculates, in the second mode, a position of the work tool when the work tool is fixed at a predetermined angle based on the posture information, the selection unit switches from the first mode to the second mode when a failure of the sensor is detected in the first mode; In the first mode, the interference prevention control unit limits a movement range of the work tool so that the work tool does not enter the first restricted range based on a calculation result of the position of the work tool by the first calculation unit, In the second mode, the interference prevention control unit restricts the posture of the work device body based on the calculation result of the position of the work tool by the second calculation unit so that the work tool does not enter the second restricted range.

2. The control device according to claim 1 , wherein the second limit range is defined by an arc that lies in a plane along the direction of movement of the work implement and at least partially surrounds the cabin.

3. The control device according to claim 1 , wherein the second limit range is set to the same range as the first limit range.

4. The control device according to claim 1 , wherein in the second mode, the interference prevention control section limits the allowable direction of angle change of the work implement to one direction.

5. The control device according to claim 1 , wherein the predetermined angle is a limit angle within a movable angle range of the implement at a side where the implement approaches the cabin.

6. The control device according to claim 1 , further comprising a notification unit that notifies an operator of the operation mode selected by the selection unit.

7. A program that causes a computer to execute a control method for a work machine having a work device in which a work implement is supported on a work device body so as to be rotatable about a pin, a cabin, and a power source that operates the work device, The control method includes: a first acquisition step of acquiring sensor information relating to an electrical signal from a sensor that generates an electrical signal in accordance with an angle of the work implement relative to the work device body; a fault detection step of detecting a fault in the sensor; a second acquisition step of acquiring posture information relating to the posture of the working device body; an interference prevention control step of performing control to prevent interference between the work implement and the cabin; a selection step of selecting a first mode or a second mode as an operation mode of the interference prevention control step; a setting step of setting a first limit range in the first mode and a second limit range in the second mode; a first calculation step of calculating a position of the work tool based on the sensor information and the posture information in the first mode; a second calculation step of calculating, in the second mode, a position of the work tool when the work tool is fixed at the predetermined angle based on the posture information, the selecting step includes switching from the first mode to the second mode when a failure of the sensor is detected in the first mode; In the first mode, the interference prevention control step limits a movement range of the work tool so that the work tool does not enter the first restricted range based on a calculation result of the position of the work tool in the first calculation step, In the second mode, the interference prevention control step limits the posture of the work device body based on the calculation result of the position of the work tool by the second calculation step so that the work tool does not enter the second limit range.

Images