Working machinery

Abstract

To provide a work machine that can improve the efficiency of parking operations. [Solution] In a wheel loader 1 comprising first to fourth cameras 41 to 44 that photograph the area around the wheel loader 1, a controller 7 that generates a composite overhead image 61 based on each image taken by the first to fourth cameras 41 to 44, and a monitor 54 that displays the composite overhead image 61 output from the controller 7 together with a model image 60 of the wheel loader 1, the controller 7 outputs guidelines 62 and 63 to the monitor 54 that indicate the opening and closing ranges of a pair of side covers 31 and 32 and a rear grille 34, respectively, and the monitor 54 displays the guidelines 62 and 63 together with the model image 60 of the wheel loader 1 and the composite overhead image 61.

Description

Technical Field

[0001] The present invention relates to a working machine provided with a surrounding monitoring device for monitoring the surroundings of the main body.

Background Art

[0002] Generally, a working machine is provided with a surrounding monitoring device for monitoring the surroundings of the main body from the viewpoints of ensuring work safety and improving work efficiency. The surrounding monitoring device includes a plurality of cameras attached to the main body and a monitor provided in the cab, and displays the images taken by the plurality of cameras on the monitor. Thereby, the operator can confirm whether there are workers, obstacles, etc. (hereinafter referred to as "obstacle targets") around the main body.

[0003] For example, the surrounding monitoring device of the working machine disclosed in Patent Document 1 converts the camera images acquired by the plurality of cameras installed on the main body so as to be in an overhead view point to obtain an overhead image, synthesizes each overhead image, and displays it on the monitor together with the character image of the working machine. In this way, by displaying the overhead image on the monitor, the operator can accurately grasp the direction in which the obstacle target is located and the distance from the main body to the obstacle target.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When inspecting or cleaning various parts housed in the machine room of a work machine, the work is performed with the side and rear covers that define the machine room open. However, when the side and rear covers are open, they extend outward beyond the main body. Therefore, when parking a work machine, it is desirable to choose a location where there are no workers or obstacles within the range where the side and rear covers can be opened.

[0006] If the surrounding monitoring device, as described in Patent Document 1, only displays an overhead view of the area around the main unit along with a character image (model image) of the work machine on the monitor, the operator cannot accurately grasp the opening and closing range of the side and rear covers. Therefore, the operator has to park the work machine by predicting the opening and closing range of the side and rear covers based on experience. Consequently, if workers or obstacles are present in the opening and closing range of the side or rear covers contrary to the operator's prediction, the parking operation must be repeated, reducing work efficiency.

[0007] Therefore, the object of the present invention is to provide a work machine that can improve the efficiency of parking operations. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a work machine comprising: a main body; a work device attached to the main body; a plurality of imaging devices for imaging the area around the main body and the work device; a controller for generating a composite overhead image based on a plurality of images captured by the plurality of imaging devices; and a display device for displaying the composite overhead image output from the controller together with a main body model image representing the main body, wherein the controller outputs guide images to the display device that indicate the opening and closing ranges of a pair of side covers arranged on both the left and right sides of the main body and the opening and closing ranges of a rear cover arranged on the rear side of the main body, and the display device displays the guide images together with the main body model image and the composite overhead image. [Effects of the Invention]

[0009] According to the present invention, the efficiency of parking operations can be improved. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of a wheel loader according to an embodiment of the present invention, as seen from a diagonal front view. [Figure 2] Figure 1 is a perspective view of the wheel loader as seen from the rear at an oblique angle. [Figure 3] This figure shows an example of the configuration inside the driver's cab. [Figure 4] This is an example of a display image shown on a monitor, where the guidelines are hidden. [Figure 5] This is an example of a display image shown on a monitor, illustrating the state where guidelines are displayed. [Figure 6] This figure shows an example of a display image shown on a monitor, where some of the guidelines are highlighted. [Figure 7] This is a functional block diagram showing the functions of the controller. [Figure 8] This flowchart shows the flow of processing performed by the controller. [Figure 9] This figure shows another example of a display image shown on a monitor, specifically a state where guidelines are displayed. [Modes for carrying out the invention]

[0011] Hereinafter, as an example of a working machine according to an embodiment of the present invention, a wheel loader used for cargo handling operations will be described.

[0012] <Configuration of Wheel Loader 1> First, the configuration of the wheel loader 1 according to an embodiment of the present invention will be described with reference to Figures 1 to 3.

[0013] FIG. 1 is an external perspective view of a wheel loader 1 according to an embodiment of the present invention as viewed obliquely from the front. FIG. 2 is an external perspective view of the wheel loader 1 shown in FIG. 1 as viewed obliquely from the rear. FIG. 3 is a diagram showing an example of a configuration inside the cab 12.

[0014] The wheel loader 1 is an articulated work machine that is steered by the body being bent in the vicinity of the center. The front frame 1A at the front of the body and the rear frame 1B at the rear of the body are connected by a center joint 10 so as to be rotatable in the left - right direction, and the front frame 1A bends in the left - right direction with respect to the rear frame 1B. In the following description, among the left - right directions of the body, the direction on the left side with respect to the forward direction is referred to as the "left direction", and the direction on the right side with respect to the forward direction is referred to as the "right direction".

[0015] Four wheels 11 are provided on the body. Two wheels 11 are provided as front wheels 11A on both the left and right sides of the front frame 1A, and the remaining two wheels 11 are provided as rear wheels 11B on both the left and right sides of the rear frame 1B, respectively.

[0016] An hydraulic - driven working device 2 for performing a loading operation of excavating a work object such as earth and sand or minerals and loading the excavated work object into a loading destination such as a dump truck or a hopper is attached to the front part of the front frame 1A.

[0017] The working device 2 has a lift arm 21 rotatably attached to the front frame 1A in the vertical direction, two lift arm cylinders (not shown) for driving the lift arm 21, a bucket 22 rotatably attached to the tip of the lift arm 21 in the vertical direction, a bucket cylinder 22A for driving the bucket 22, and a bell crank 23 rotatably connected to the lift arm 21 to form a link mechanism between the bucket 22 and the bucket cylinder 22A.

[0018] The lift arm 21 rotates vertically with respect to the front frame 1A as hydraulic oil flows in and out of two lift arm cylinders and each rod expands and contracts. The posture of the lift arm 21 is detected, for example, using a lift arm angle sensor 210 attached to the base end portion of the lift arm 21 (the attachment portion to the front frame 1A).

[0019] The bucket 22 rotates vertically with respect to the lift arm 21 as hydraulic oil flows in and out of the bucket cylinder 22A and the rod expands and contracts. Thereby, the bucket 22 can scoop up and discharge (excavate and dump) work objects such as earth and sand, minerals, etc. The posture of the bucket 22 is detected, for example, using a bucket angle sensor 220 attached to the bell crank 23.

[0020] That is, the lift arm angle sensor 210 and the bucket angle sensor 220 are each an aspect of a posture detection device for detecting the posture of the working device 2. Note that the posture detection device does not necessarily have to be an angle sensor, and for example, other sensors such as sensors for detecting the cylinder lengths of the lift arm cylinder and the bucket cylinder 22A may also be used.

[0021] On the rear frame 1B, there are provided a driver's cab 12 where an operator rides, a machine room 13 that houses various devices necessary for driving the wheel loader 1 inside, and a counterweight 14 for maintaining the balance with the working device 2 so that the vehicle body does not tip over. In the rear frame 1B, the driver's cab 12 is arranged at the front, the counterweight 14 is arranged at the rear, and the machine room 13 is arranged between the driver's cab 12 and the counterweight 14.

[0022] Three cameras, designated as first, second, and third, are mounted on the ceiling 120 of the driver's cab 12. The first camera 41 is mounted projecting to the left from the left rear end of the ceiling 120 and photographs the left outer side of the wheel loader 1. The second camera 42 is mounted projecting to the right from the right rear end of the ceiling 120 and photographs the right outer side of the wheel loader 1. The third camera 43 is mounted in the center of the front end of the ceiling 120 and photographs the front outer side of the wheel loader 1.

[0023] As shown in Figure 3, the driver's cab 12 is equipped with a steering wheel 51 for steering, a console 52 which has various control switches for driving operations and a monitor that displays the driving speed, a switch box 53 which has various selector switches, a monitor 54 which displays the surroundings of the wheel loader 1, an accelerator pedal 55 which adjusts the engine speed, a brake pedal 56 which brakes the movement of the wheel loader 1, and an inching pedal 57 which controls each clutch in the transmission and also brakes the movement of the wheel loader 1.

[0024] Within the driver's cab 12, the steering wheel 51 is located in the center in front of the driver's seat (not shown), the console 52 is located in front of the steering wheel 51, the switch box 53 is located on the front right pillar, and the monitor 54 is located above the switch box 53. Additionally, the accelerator pedal 55 and brake pedal 56 are located side by side to the lower right of the steering wheel 51, and the inching pedal 57 is located to the lower left of the steering wheel 51.

[0025] As shown in Figures 1 and 2, the machine room 13 is defined by the rear of the driver's cab 12, a pair of side covers 31 and 32 covering the left and right sides, a ceiling cover 33 covering the ceiling, and a rear grille 34 located at the rear to expel air from inside the machine room 13 to the outside.

[0026] In other words, the pair of side covers 31, 32 and the rear grille 34 are all mounted on the rear frame 1B, which is on the opposite side of the work device 2 from the center joint 10 in the longitudinal direction of the vehicle body, and are positioned behind the driver's cab 12 on the rear frame 1B.

[0027] Of the pair of side covers 31 and 32, the one located on the left side of the main body is referred to as the left side cover 31, and the one located on the right side of the main body is referred to as the right side cover 32. The rear grille 34 is one form of the rear cover located at the rear of the main body.

[0028] In this embodiment, the pair of side covers 31, 32 and the rear grille 34 are opened and closed by rotating vertically around the connection point with the ceiling cover 33.

[0029] A fourth camera 44 is mounted on the upper end of the rear grille 34 to photograph the rear and outer side of the wheel loader 1. This fourth camera 44 and the aforementioned first to third cameras 41 to 43 correspond to imaging devices that photograph the body of the wheel loader 1 and the surroundings of the work device 2, respectively.

[0030] Furthermore, the first to fourth cameras 41 to 44 do not necessarily have to be mounted in the positions shown in Figures 1 and 2. As long as they can capture images of the entire area around the wheel loader 1 and the work device 2, there are no particular restrictions on their mounting positions.

[0031] The images captured by cameras 1-4 (41-44) are output to controller 7 and converted into overhead images 61A-61D (see Figures 4-6). Controller 7 combines the converted overhead images 61A-61D to create a composite overhead image 61, which is then output to monitor 54. The detailed configuration of controller 7 will be described later.

[0032] <Contents displayed on monitor 54> Next, the content displayed on monitor 54 will be explained with reference to Figures 4-6.

[0033] Figure 4 shows an example of a display image shown on monitor 54, where the guideline 62 is hidden. Figure 5 shows an example of a display image shown on monitor 54, where the guideline 62 is displayed. Figure 6 shows an example of a display image shown on monitor 54, where a portion of the guideline 62 (62B) is highlighted.

[0034] The monitor 54 is a display device that displays a composite overhead image 61 output from the controller 7, that is, an overhead image of the area around the wheel loader 1, together with a model image 60 of the wheel loader 1.

[0035] In this embodiment, model image 60 includes the main body and working device 2 of the wheel loader 1, but it is not limited to this; any image representing at least the main body (main body model image) is sufficient. In other words, model image 60 may be an image in which the working device 2 is omitted. Also, in Figures 4 to 6, model image 60 is represented by a schematic figure of the wheel loader 1, but it is not limited to this; it may be represented by a simplified figure of the wheel loader 1, such as a simple rectangle.

[0036] The composite overhead image 61 includes a left-side overhead image 61A based on an image captured by the first camera 41, a right-side overhead image 61B based on an image captured by the second camera 42, a front-side overhead image 61C based on an image captured by the third camera 43, and a rear-side overhead image 61D based on an image captured by the fourth camera 44.

[0037] In this way, a model image 60 of the wheel loader 1 and a composite overhead view image 61 of the area around the wheel loader 1 are displayed on the monitor 54 installed in the driver's cab 12, allowing the operator to check whether or not there are any obstacles such as workers or other objects around the wheel loader 1 during operation.

[0038] Furthermore, as shown by the thick lines in Figure 5, the monitor 54 displays a model image 60 of the wheel loader 1 and a composite overhead view image 61 of the area around the wheel loader 1, along with guideline images 62 that show the opening and closing ranges of each of the pair of side covers 31 and 32, and the opening and closing range of the rear grille 34.

[0039] Guideline 62 outlines the opening and closing ranges of each of the pair of side covers 31, 32 and the opening and closing range of the rear grille 34, and includes a left guideline 62A indicating the opening and closing range of the left side cover 31, a right guideline 62B indicating the opening and closing range of the right side cover 32, and a rear guideline 62C indicating the opening and closing range of the rear grille 34.

[0040] In this way, by displaying the guidelines 62 on the monitor 54, the operator can perform parking operations while confirming whether or not an obstacle is present within the opening and closing range of each of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34. This eliminates the need for the operator to predict the opening and closing ranges of each of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34 based on experience and park the wheel loader 1 so that no obstacle is included within these ranges, thereby improving the efficiency of parking operations.

[0041] In this embodiment, the guide image is a guideline 62 that displays only outlines, but it is not limited to this, and there are no particular restrictions as long as it is an image that shows the opening and closing range of each of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34. However, by displaying the opening and closing range of each of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34 with guideline 62, an overhead image 61 of the opening and closing range of each of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34 is displayed, making it easier for the operator to grasp the environment around the vehicle body.

[0042] Furthermore, in this embodiment, as shown in Figure 6 with sandy ground, if an object is present within the opening and closing range of each of the pair of side covers 31 and 32, and within the opening and closing range of the rear grille 34, the corresponding area within the guideline 62 is highlighted. In Figure 6, the area within the right guideline 62B is highlighted, indicating that an object is present within the opening and closing range of the right side cover 32. By highlighting the area within the guideline 62 where an object is present, the operator can confirm the presence of the object at a glance.

[0043] Furthermore, in this embodiment, the wheel loader 1 is equipped with a display switching device, a display switching switch 530, which switches whether or not to display the guideline 62 on the monitor 54. This display switching switch 530 is located in a switch box 53 inside the driver's cab 12 (see Figure 3). Therefore, the guideline 62 is displayed on the monitor 54 only when the display switching switch 530 is ON (as shown in Figures 5 and 6), and is not displayed on the monitor 54 when the display switching switch 530 is OFF (as shown in Figure 4).

[0044] This allows the operator to display the guidelines 62 on the monitor 54 by switching the display switch 530 to ON when the guidelines 62 need to be displayed, such as when performing parking operations. On the other hand, when the guidelines 62 do not need to be displayed (or are bothersome), such as when driving or performing work using the work device 2 (for example, excavation work or loading work), the operator can switch the display switch 530 to OFF to hide the guidelines 62.

[0045] <Controller 7 Configuration> Next, the configuration of controller 7 will be explained with reference to Figure 7.

[0046] Figure 7 is a functional block diagram showing the functions of the controller 7.

[0047] The controller 7 is configured with a CPU, RAM, ROM, HDD, input interface, and output interface connected to each other via a bus. Various operating devices such as a forward / reverse switch 520 and a display switch 530, as well as various sensors such as a vehicle speed sensor 45, a load sensor 46, a lift arm angle sensor 210, and a bucket angle sensor 220, and the first to fourth cameras 41 to 44 are connected to the input interface, and the monitor 54 is connected to the output interface.

[0048] In this hardware configuration, the CPU reads the control program (software) stored on a recording medium such as ROM, HDD, or optical disc, expands it onto RAM, and executes the expanded control program. The control program and hardware then work together to realize the functions of the controller 7.

[0049] In this embodiment, the configuration of the controller 7 is described as a combination of software and hardware, but it is not limited to this, and may be configured using an integrated circuit that realizes the functions of the control program executed on the wheel loader 1.

[0050] The forward / reverse selector switch 520 corresponds to a forward / reverse selector device that switches the forward / reverse movement of the wheel loader 1 (main unit), and outputs a switching signal to the controller 7 indicating one of the following: forward, neutral, or reverse. When the forward / reverse selector switch 520 is switched to neutral, the wheel loader 1 will be in a stopped state.

[0051] The vehicle speed sensor 45 corresponds to a vehicle speed detection device that detects the travel speed of the wheel loader 1 (main unit) and outputs the detected value to the controller 7. The vehicle speed sensor 45 may include, for example, a sensor that detects the rotational speed of the wheels 11 or a sensor that detects the amount the accelerator pedal is pressed.

[0052] The load sensor 46 corresponds to a load measuring device that measures the load applied to the work device 2 and outputs the measured value to the controller 7. The load applied to the work device 2 is the weight of the work device 2 when the bucket 22 is empty and there is no load in it, and when there is a load in the bucket 22, it is the weight of the work device 2 plus the weight of the load. For example, the load sensor 46 may be a sensor that measures the cylinder pressure of the lift arm cylinder or a sensor that measures the discharge pressure of the hydraulic pump.

[0053] As shown in Figure 7, the controller 7 includes a data acquisition unit 71, an overhead image conversion unit 72, an overhead image synthesis unit 73, a switch operation determination unit 74, a parked state determination unit 75, a storage unit 75A, a guideline synthesis unit 76, a fault target determination unit 77, a highlight generation unit 78, and a display image output unit 79.

[0054] The data acquisition unit 71 acquires the images captured by the first to fourth cameras 41 to 44, the lift arm angle detected by the lift arm angle sensor 210, the bucket angle detected by the bucket angle sensor 220, the travel speed of the wheel loader 1 detected by the vehicle speed sensor 45, and data related to the load of the work device 2 measured by the load sensor 46, as well as the switching signal output from the forward / reverse switch 520 and the switching signal (on / off signal) output from the display switch 530.

[0055] The overhead image conversion unit 72 converts each captured image acquired by the data acquisition unit 71 into overhead images 61A to 61D. Specifically, the overhead image conversion unit 72 converts the image captured by the first camera 41 into a left overhead image 61A, the image captured by the second camera 42 into a right overhead image 61B, the image captured by the third camera 43 into a front overhead image 61C, and the image captured by the fourth camera 44 into a rear overhead image 61D.

[0056] The overhead image synthesis unit 73 synthesizes the overhead images 61A to 61C converted by the overhead image conversion unit 72 to generate a single composite overhead image 61.

[0057] The switch operation determination unit 74 determines whether or not the display changeover switch 530 has been switched to ON, based on the switching signal from the display changeover switch 530 acquired by the data acquisition unit 71.

[0058] The parking state determination unit 75 determines whether the wheel loader 1 is in a state that satisfies parking conditions or parking preparation conditions, based on the data related to the lift arm angle, bucket angle, travel speed, and load of the work device 2 acquired by the data acquisition unit 71, as well as the switching signal from the forward / reverse selector switch 520.

[0059] Here, "parking conditions" refer to the conditions that indicate the wheel loader 1 is parked, specifically that the forward / reverse switch 520 is switched to neutral, the working device 2 is in a horizontal position on the ground, and the travel speed of the main unit detected by the vehicle speed sensor 45 is below a predetermined stopping speed threshold.

[0060] The "predetermined stopping speed threshold" is a threshold set based on the stopping speed (zero) that indicates a complete stop, and may be zero (the stopping speed itself) or a value that includes an error. Furthermore, "ground horizontal posture" refers to a posture in which the lift arm 21 is lowered toward the ground and the bottom surface of the bucket 22 is in horizontal contact with the ground.

[0061] Furthermore, "parking preparation conditions" refer to conditions indicating the state of the wheel loader 1 in the parking preparation stage, where the forward / reverse selector switch 520 is switched to forward or reverse, the working device 2 is in a driving position, the load measured by the load sensor 46 is below a predetermined load threshold, and the driving speed of the main unit detected by the vehicle speed sensor 45 is below a predetermined low speed threshold (for example, 10 km / h or less).

[0062] The "predetermined load threshold" is a threshold set based on the load indicating an unloaded state, and the "predetermined low-speed threshold" is a threshold set based on the speed indicating a low-speed state toward parking (stopping) the wheel loader 1. Furthermore, "travel posture" refers to the posture in which the lift arm 21 is horizontal to the ground and the bucket 22 is tilted to its most rearward position (most tilted).

[0063] The memory unit 75A is a memory that stores various thresholds indicating parking conditions and parking preparation conditions. Specifically, the memory unit 75A stores the lift arm angle and bucket angle when the work device 2 is in a horizontal position on the ground and a traveling position, respectively, as well as a predetermined stopping speed threshold, a predetermined load threshold, and a predetermined low-speed threshold.

[0064] The guideline synthesis unit 76 synthesizes the guidelines 62 (specifically, the left guideline 62A, the right guideline 62B, and the rear guideline 62C) when the parking condition determination unit 75 determines that the parking conditions or parking preparation conditions are met.

[0065] The fault detection unit 77 determines, based on each captured image acquired by the data acquisition unit 71, whether or not there are any fault targets such as workers or obstacles within the opening and closing ranges of the pair of side covers 31 and 32 and the opening and closing range of the rear grille 34.

[0066] The highlight generation unit 78 highlights the corresponding guideline 62 when the fault target determination unit 77 determines that a fault target exists within at least one of the opening / closing ranges of the pair of side covers 31 and 32 and the opening / closing range of the rear grille 34.

[0067] If the switch operation determination unit 74 determines that the display switching switch 530 is switched to the OFF position, or if the switch operation determination unit 74 determines that the display switching switch 530 is switched to the ON position and the parking state determination unit 75 determines that neither the parking condition nor the parking preparation condition is met, the display image output unit 79 outputs only the composite overhead image 61 generated by the overhead image synthesis unit 73 to the monitor 54 along with the model image 60 of the wheel loader 1.

[0068] Furthermore, the display image output unit 79 outputs the composite overhead image 61 generated by the overhead image synthesis unit 73 and the guideline 62 synthesized by the guideline synthesis unit 76 to the monitor 54 along with the model image 60 of the wheel loader 1, when the switch operation determination unit 74 determines that the display switching switch 530 has been switched to ON, and the parking state determination unit 75 determines that the parking conditions or parking preparation conditions have been met.

[0069] At this time, in order to prevent the guideline 62 from being hidden by the composite overhead image 61, the display image output unit 79 outputs image data to the monitor 54 so that the guideline 62 is displayed superimposed on the composite overhead image 61.

[0070] In addition, if the fault detection unit 77 determines that a fault exists within the opening / closing range of at least one of the opening / closing ranges of the pair of side covers 31 and 32 and the opening / closing range of the rear grille 34, the display image output unit 79 outputs the composite overhead image 61 and guideline 62, as well as the highlights generated by the highlight generation unit 78, to the monitor 54 along with the model image 60 of the wheel loader 1.

[0071] In this embodiment, the controller 7 outputs the composite overhead image 61, the guideline 62, and the model image 60 data separately to the monitor 54. However, it is not limited to this, and the controller 7 may also generate an image by superimposing the composite overhead image 61, the guideline 62, and the model image 60, and output a single image data to the monitor 54.

[0072] Furthermore, in this embodiment, the controller 7 outputs the guideline 62 data to the monitor 54 only when the display switching switch 530 is switched ON and the parking conditions or parking preparation conditions are met. However, it is not limited to this, and the guideline 62 data may always be output to the monitor 54, and the display of the guideline 62 may be switched on and off by controlling the monitor 54.

[0073] In other words, "the controller 7 outputs the guideline 62 to the monitor 54" includes (1) the controller 7 outputting the guideline 62 data to the monitor 54 only when the above conditions are met, and (2) the controller 7 always outputting the guideline 62 data to the monitor 54, switching the display of the guideline 62 on the monitor 54 to ON when the above conditions are met, and switching the display of the guideline 62 on the monitor 54 to OFF (hidden) when the above conditions are not met.

[0074] <Processing executed by Controller 7> Next, the processing flow executed by controller 7 will be explained with reference to Figure 8.

[0075] Figure 8 is a flowchart showing the processing flow executed by controller 7.

[0076] In the controller 7, first, the data acquisition unit 71 acquires the captured images output from each of the first to fourth cameras 41 to 44 (step S701).

[0077] Next, the overhead image conversion unit 72 converts each captured image acquired in step S701 into overhead images 61A to 61D (step S702).

[0078] Next, the overhead image synthesis unit 73 processes each overhead image 61A converted in step S702. ~61D are combined to generate a composite overhead image 61 (step S703).

[0079] Next, the switch operation determination unit 74 determines whether the switching signal from the display switching switch 530 acquired by the data acquisition unit 71 is an ON signal, that is, whether the display switching switch 530 has been switched ON (step S704).

[0080] If it is determined in step S704 that the display switching switch 530 has been switched to ON (step S704 / YES), the parking state determination unit 75 determines whether the wheel loader 1 is in a state that satisfies the parking conditions (parked state) or not (step S705).

[0081] If it is determined in step S705 that the wheel loader 1 is in a state that satisfies the parking conditions (step S705 / YES), the guideline synthesis unit 76 synthesizes the guideline 62 (step S706).

[0082] Next, the fault detection unit 77 determines, based on each captured image acquired by the data acquisition unit 71, whether or not a fault exists within the opening and closing range of each of the pair of side covers 31 and 32 and within the opening and closing range of the rear grille 34 (step S707).

[0083] If, in step S707, it is determined that an object is present within the opening / closing range of at least one of the opening / closing ranges of the pair of side covers 31 and 32 and the opening / closing range of the rear grille 34 (step S707 / YES), the highlight generation unit 78 highlights the corresponding guideline 62 (step S708).

[0084] Then, the display image output unit 79 outputs the model image 60 of the wheel loader 1, the composite overhead image 61 synthesized in step S703, the guideline 62 synthesized in step S706, and the highlights generated in step S708 as a display image to the monitor 54 (step S709), and the processing in the controller 7 is completed.

[0085] On the other hand, if it is determined in step S707 that there is no obstruction within the opening and closing range of either the pair of side covers 31 and 32 or the opening and closing range of the rear grille 34 (step S707), the display image output unit 79 outputs the model image 60 of the wheel loader 1, the composite overhead image 61 synthesized in step S703, and the guideline 62 synthesized in step S706 as a display image to the monitor 54 (step S709), and the processing in the controller 7 ends.

[0086] Furthermore, if it is determined in step S704 that the display switching switch 530 is switched off (not switched on) (step S704 / NO), the display image output unit 79 outputs the model image 60 of the wheel loader 1 and the composite overhead image 61 combined in step S703 as a display image to the monitor 54 (step S709), and the processing in the controller 7 ends.

[0087] Furthermore, if it is determined in step S705 that the wheel loader 1 does not meet the parking conditions, the parking condition determination unit 75 then determines whether or not the wheel loader 1 meets the parking preparation conditions (step S710).

[0088] If it is determined in step S710 that the wheel loader 1 is in a state that satisfies the parking preparation conditions (step S710 / YES), the process proceeds to step S706, where the guideline synthesis unit 76 synthesizes the guideline 62, and the subsequent processing is as described above.

[0089] On the other hand, if it is determined in step S710 that the wheel loader 1 does not meet the parking preparation conditions, the display image output unit 79 outputs the model image 60 of the wheel loader 1 and the composite overhead image 61 combined in step S703 as a display image to the monitor 54 (step S709), and the processing in the controller 7 ends.

[0090] In this way, when the controller 7 determines that the wheel loader 1 is in a state where it meets the parking conditions or parking preparation conditions, it synthesizes the guideline 62, allowing the operator to park the wheel loader 1 while checking the monitor 54 and avoiding the obstacle, thereby improving the efficiency of the parking operation.

[0091] <Variation> Next, we will explain guideline 63 relating to the modified example with reference to Figure 9.

[0092] Figure 9 shows another example of the display image shown on the monitor 54, specifically the state in which the guideline 63 is displayed. In Figure 9, components that are common to those described in the embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0093] In this modified example, the opening and closing directions of the pair of side covers 31, 32 and the rear grille 34 differ from those in the embodiment. Specifically, the pair of side covers 31, 32 open and close so as to rotate in the front-rear direction around their rear ends, and the rear grille 34 opens and closes so as to rotate in the left-right direction around its left end.

[0094] Therefore, as shown by the thick lines in Figure 9, the guidelines 63 displayed on the monitor 54 indicate the opening and closing range along the rotational trajectory centered on the rear ends of the pair of side covers 31 and 32 for the left guideline 63A and the right guideline 63B, and the opening and closing range along the rotational trajectory centered on the left end of the rear grille 34 for the rear guideline 63C.

[0095] In this way, the controller 7 synthesizes guidelines 63 that accurately indicate the opening and closing range of the pair of side covers 31, 32 and the rear grille 34, respectively, according to the opening and closing directions of the pair of side covers 31, 32 and the rear grille 34.

[0096] Embodiments of the present invention have been described above. It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the described configurations. Furthermore, it is possible to replace some of the configurations of this embodiment with those of other embodiments, and it is also possible to add configurations from other embodiments to the configuration of this embodiment. Moreover, it is possible to add, delete, or replace some of the configurations of this embodiment with those of other embodiments.

[0097] For example, in the above embodiment, a wheel loader 1 was used as an example of a work machine, but it is not limited to this, and other work machines such as a hydraulic excavator may also be used. [Explanation of Symbols]

[0098] 1: Wheel loader (work machine) 1A: Front frame (main body) 1B: Rear frame (main body) 2: Working equipment 7: Controller 31,32: Side cover 34: Rear grille (rear cover) 41-44: Cameras 1-4 (imaging devices) 45: Vehicle speed sensor (vehicle speed detection device) 46: Load sensor (load measuring device) 54: Monitor (display device) 60: Model image (Main model image) 61: Composite overhead image 61A~61D: Overhead view 62, 62A~62C, 63, 63A~63C: Guidelines 210: Lift arm angle sensor (attitude detection device) 220: Bucket angle sensor (attitude detection device) 520: Forward / reverse selector switch (forward / reverse selector device) 530: Display changeover switch (display changeover device)

Claims

1. The main unit and A work device attached to the main body, Multiple imaging devices for photographing the area around the main body and the work apparatus, A controller that generates a composite overhead image based on multiple images captured by the aforementioned multiple imaging devices, A display device that displays the composite overhead image output from the controller together with a main unit model image representing the main unit, In the work machine, The aforementioned controller, Guide images indicating the opening and closing ranges of a pair of side covers located on both the left and right sides of the main body, and the opening and closing ranges of the rear cover located on the rear side of the main body, are output to the display device. The aforementioned display device is The guide image is displayed along with the main body model image and the composite overhead image. A work machine characterized by the following features.

2. In the work machine described in claim 1, A forward / reverse switching device for switching the forward and reverse movement of the main unit, A posture detection device for detecting the posture of the work device, A vehicle speed detection device for detecting the travel speed of the main unit, Furthermore, The aforementioned controller, Based on the switching signal output from the forward / reverse switching device, the posture of the work device detected by the posture detection device, and the travel speed of the main unit detected by the vehicle speed detection device, the guide image is output to the display device. A work machine characterized by the following features.

3. In the work machine described in claim 2, The aforementioned controller, The guide image is output to the display device when the switching signal output from the forward / reverse switching device is a neutral signal, the attitude of the work device detected by the attitude detection device is a horizontal ground attitude, and the travel speed of the main unit detected by the vehicle speed detection device is less than or equal to a predetermined stopping speed threshold. A work machine characterized by the following features.

4. In the work machine described in claim 2, The system further includes a load measuring device for measuring the load applied to the aforementioned work device, The aforementioned controller, The guide image is output to the display device when the switching signal output from the forward / reverse switching device is a signal indicating forward or reverse, the posture of the work device detected by the posture detection device is a driving posture, the load measured by the load measuring device is below a predetermined load threshold, and the driving speed of the main unit detected by the vehicle speed detection device is below a predetermined low speed threshold. A work machine characterized by the following features.

5. In the work machine described in claim 1, The aforementioned controller, Based on the multiple images captured by the multiple imaging devices, it is determined whether or not an object of obstruction exists within the opening / closing range of the pair of side covers or within the opening / closing range of the rear cover. If it is determined that the object of the obstruction is located within the opening / closing range of the pair of side covers or within the opening / closing range of the rear cover, the corresponding guide image is highlighted. A work machine characterized by the following features.

6. In the work machine described in claim 1, The device further includes a display switching device that switches whether or not to display the guide image on the display device, The aforementioned controller, If the switching signal output from the display switching device is a signal indicating the display of the guide image, the guide image is output to the display device. A work machine characterized by the following features.

7. In the work machine described in claim 1, The aforementioned guide image is These are guidelines that represent the contours of the opening and closing ranges of the pair of side covers and the opening and closing ranges of the rear cover. A work machine characterized by the following features.

Images