Work machine control system, work machine, and work machine control method

Abstract

This work machine control system comprises a controller for a work machine having a travel device and an implement. The controller calculates, on the basis of detection data from an external sensor for detecting a stock pile formed at a work site, a detection shape of the stock pile and compares a target shape of the stock pile with the detection shape for an evaluation value related to the shape of the stock pile to determine whether or not to correct the shape of the stock pile.

Description

Work machine control system, work machine, and work machine control method

[0001] The present disclosure relates to a work machine control system, a work machine, and a work machine control method.

[0002] In the technical field related to work machines, there is known a control system for a work vehicle as disclosed in Patent Document 1. In Patent Document 1, the control system for a work vehicle determines a loading position for a vehicle to be loaded based on the loading status of the vehicle to be loaded.

[0003] JP 2017-043887 A

[0004] One of the tasks performed by work machines is to form stockpiles, which are piles of material, at work sites. If stockpiles are not formed properly, work efficiency at the work site may decrease.

[0005] The present disclosure aims to suppress a decrease in work efficiency at a work site.

[0006] According to the present disclosure, there is provided a work machine control system including a controller for a work machine having a traveling gear and a work implement, wherein the controller calculates a detected shape of the stockpile based on detection data from an external sensor that detects a stockpile formed at a work site, compares a target shape of the stockpile with the detected shape for an evaluation value related to the stockpile shape, and determines whether to modify the stockpile shape.

[0007] According to the present disclosure, a decrease in work efficiency at a work site is suppressed.

[0008] FIG. 1 is a side view showing a work machine according to the first embodiment. FIG. 2 is a plan view showing a work machine according to the first embodiment. FIG. 3 is a configuration diagram showing a work machine according to the first embodiment. FIG. 4 is a hardware configuration diagram showing a vehicle controller according to the first embodiment. FIG. 5 is a block diagram showing a control system for a work machine according to the first embodiment. FIG. 6 is a diagram for explaining work that can be performed by a work machine according to the first embodiment. FIG. 7 is a diagram for explaining work that can be performed by a work machine according to the first embodiment. FIG. 8 is a diagram for explaining work that can be performed by a work machine according to the first embodiment. FIG. 9 is a perspective view schematically showing a stockyard according to the first embodiment. FIG. 10 is a plan view schematically showing a stockyard according to the first embodiment. FIG. 11 is a flowchart showing a control method for a work machine according to the first embodiment. FIG. 12 is a perspective view for explaining a method for acquiring map data of a work site according to the first embodiment. FIG. 13 is a plan view for explaining the method for acquiring map data of a work site according to the first embodiment. FIG. 14 is a plan view for explaining a method for generating an optimal route for a work machine according to the first embodiment. FIG. 15 is a diagram for explaining the shape of a stockpile according to the second embodiment. Fig. 16 is a flowchart showing a control method for a work machine according to the second embodiment. Fig. 17 is a diagram for explaining a method for determining the detected positions of the peaks and the bases and a method for calculating the target positions of the bases according to the second embodiment. Fig. 18 is a diagram for explaining an example of the operation of a work machine according to the second embodiment. Fig. 19 is a diagram for explaining an example of the operation of a work machine according to the second embodiment.

[0009] Hereinafter, the present embodiment according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiment. The components of the embodiment described below can be combined as appropriate. In addition, some components may not be used.

[0010] First Embodiment A first embodiment will be described.

[0011] <Working Machine> Fig. 1 is a side view showing a working machine 1 according to this embodiment. Fig. 2 is a plan view showing the working machine 1 according to this embodiment. The working machine 1 works at a work site. In this embodiment, the working machine 1 is a wheel loader.

[0012] 1 and 2 , the work machine 1 includes a body frame 2, a work implement 3, a traveling device 4, and a cab 5. The cab 5 is disposed on top of the body frame 2. The work implement 3 and the traveling device 4 are each attached to the body frame 2.

[0013] The traveling device 4 causes the work machine 1 to travel. The traveling device 4 has a pair of front wheels 4A and a pair of rear wheels 4B. The work machine 1 travels when the front wheels 4A and the rear wheels 4B rotate.

[0014] In this specification, the straight-ahead direction of the work machine 1 is defined as the fore-and-aft direction of the work machine 1. In the fore-and-aft direction, the side of the work implement 3 closer to the center of the work machine 1 is defined as the front side (forward), and the side opposite the front side is defined as the rear side (rear). The direction perpendicular to the contact surface of the front wheels 4A or rear wheels 4B that contact the flat ground is defined as the up-and-down direction of the work machine 1. In the up-and-down direction, the side closer to the contact surface than the center of the work machine 1 is defined as the down side (below), and the side opposite the down side is defined as the up side (upper). When the work machine 1 is traveling straight, the direction parallel to the rotation axis of the front wheels 4A or rear wheels 4B is defined as the left-right direction of the work machine 1. In the left-and-right direction, one side when looking from the front is defined as the left side (left), and the other side is defined as the right side (right).

[0015] The body frame 2 includes a front frame 2A and a rear frame 2B. The front frame 2A is disposed in front of the rear frame 2B. Front wheels 4A are attached to the front frame 2A. The rear wheels 4B are attached to the rear frame 2B. The front frame 2A and the rear frame 2B are connected via an articulation mechanism 8. The front frame 2A and the rear frame 2B are connected to each other so that they can bend in the left-right direction. The work machine 1 is an articulated work machine in which the front frame 2A and the rear frame 2B are connected to each other so that they can bend.

[0016] The work machine 1 has a pair of steering cylinders 11 for changing the traveling direction of the work machine 1. The steering cylinders 11 are hydraulic cylinders. A rod of the steering cylinders 11 is connected to the front frame 2A. A cylinder tube of the steering cylinders 11 is connected to the rear frame 2B. The traveling direction of the work machine 1 is changed left and right by extending and contracting the steering cylinders 11. The steering cylinders 11 function as a steering device that adjusts the steering angle (articulation angle) of the traveling device 4.

[0017] The work machine 1 performs work using a work implement 3. The work implement 3 is attached to the front frame 2A. The work implement 3 includes a boom 14, a bucket 6, a bell crank 18, and a link 15. In this embodiment, the work implement 3 is a front-loading type work implement in which the opening of the bucket 6 faces forward.

[0018] The base end of the boom 14 is rotatably connected to the front frame 2A by a boom pin 9. The boom 14 includes a left boom member 14L and a right boom member 14R. The left boom member 14L and the right boom member 14R are connected via a joint member extending in the left-right direction. The boom pins 9 include a left boom pin 9L that connects the left boom member 14L to the front frame 2A, and a right boom pin 9R that connects the right boom member 14R to the front frame 2A.

[0019] The bucket 6 is a work tool used for excavation and loading. The bucket 6 is connected to the tip of the boom 14. The bucket 6 has a cutting edge 6A and a back surface 6B. The cutting edge 6A is the tip of the bucket 6. The back surface 6B is part of the outer surface of the bucket 6. The back surface 6B is a flat surface. The back surface 6B extends rearward from the cutting edge 6A. The bucket 6 is rotatably attached to the boom 14 by a bucket pin 17. The bucket 6 has a left bracket 6L to which the left boom member 14L is attached, and a right bracket 6R to which the right boom member 14R is attached.

[0020] The center of the bell crank 18 is rotatably connected to the boom 14 by a support pin 18A. The link 15 is connected to the lower end (tip) of the bell crank 18 via a connecting pin 18C. The link 15 connects the bell crank 18 to the bucket 6. In the left-right direction, the bell crank 18 and the link 15 are each disposed between the left boom member 14L and the right boom member 14R.

[0021] The work machine 1 has a pair of boom cylinders 16 for operating the boom 14, and a bucket cylinder 19 for operating the bucket 6. The boom cylinders 16 are hydraulic cylinders. The bucket cylinder 19 is a hydraulic cylinder.

[0022] A rod of the boom cylinder 16 is connected to the boom 14. A cylinder tube of the boom cylinder 16 is connected to the front frame 2A. When the boom cylinder 16 extends and retracts, the boom 14 rotates around the boom pin 9.

[0023] The rod of the bucket cylinder 19 is connected to the bell crank 18. The cylinder tube of the bucket cylinder 19 is connected to the front frame 2A. The rod of the bucket cylinder 19 is connected to the upper end (base end) of the bell crank 18 via a connecting pin 18B. The bucket 6 rotates around the bucket pin 17 as the bucket cylinder 19 extends and retracts.

[0024] The cab 5 is mounted on an upper part of the rear frame 2B. The cab 5 is disposed rearward of the boom 14. The operator of the work machine 1 sits in the cab 5.

[0025] 3 is a configuration diagram showing a work machine 1 according to this embodiment. The work machine 1 includes a driving machine 20, a power take-off (PTO) 21, a power transmission device 22, a brake device 23, a steering pump 24, a steering control valve 25, a steering cylinder 11, a work implement pump 26, a boom control valve 27, a bucket control valve 28, a boom cylinder 16, a bucket cylinder 19, a vehicle controller 50, and an automation controller 100.

[0026] The driving machine 20 generates driving force for operating the work implement 3 and the traveling device 4. The driving machine 20 is the driving source of the work machine 1. In this embodiment, the driving machine 20 is a diesel engine. However, the driving machine 20 may also be an electric motor. The power take-off 21 distributes the driving force generated by the driving machine 20 to a power transmission device 22, a steering pump 24, and a work implement pump 26.

[0027] The power transmission device 22 transmits the driving force generated by the drive machine 20 to each of the front wheels 4A and the rear wheels 4B. The power transmission device 22 controls the traveling speed and direction of travel of the work machine 1. The power transmission device 22 may be a transmission having a torque converter, or may be a transmission having a plurality of speed change gears. The brake device 23 reduces the traveling speed of the work machine 1.

[0028] The steering pump 24 is driven based on the driving force generated by the driving machine 20. The steering pump 24 is a hydraulic pump. The hydraulic oil discharged from the steering pump 24 is supplied to the steering cylinder 11 via a steering control valve 25. The steering control valve 25 controls the flow rate and direction of the hydraulic oil supplied from the steering pump 24 to the steering cylinder 11. The steering cylinder 11 operates using the hydraulic oil from the steering pump 24.

[0029] The work implement pump 26 is driven by the driving force generated by the driving machine 20. The work implement pump 26 is a hydraulic pump. The hydraulic oil discharged from the work implement pump 26 is supplied to the boom cylinder 16 via a boom control valve 27. The hydraulic oil discharged from the work implement pump 26 is supplied to the bucket cylinder 19 via a bucket control valve 28. The boom control valve 27 controls the flow rate and direction of the hydraulic oil supplied from the work implement pump 26 to the boom cylinder 16. The bucket control valve 28 controls the flow rate and direction of the hydraulic oil supplied from the work implement pump 26 to the bucket cylinder 19. The boom cylinder 16 and the bucket cylinder 19 each operate using the hydraulic oil from the work implement pump 26.

[0030] The extension and contraction of the steering cylinder 11 changes the traveling direction of the traveling device 4 to the left or right. The extension and contraction of the boom cylinder 16 causes the boom 14 to raise or lower. The extension and contraction of the bucket cylinder 19 causes the dumping or excavation operation.

[0031] The work machine 1 is equipped with an operating device 7. The operating device 7 is arranged in the cab 5. The operating device 7 generates an operating signal for operating the work machine 1 when operated by an operator. The operating signal generated in the operating device 7 is transmitted to the vehicle body controller 50. The vehicle body controller 50 outputs a command signal for operating the work machine 1 based on the operating signal from the operating device 7. The operating device 7 includes a traveling system operating device 7A and a work implement operating device 7B.

[0032] The traveling system operation device 7A generates an operation signal for operating the traveling device 4. The traveling system operation device 7A generates an operation signal for operating at least one of the drive machine 20, the power transmission device 22, the brake device 23, and the steering cylinder 11. The traveling system operation device 7A includes an accelerator pedal 71, a brake pedal 72, a steering wheel 73, and a forward / reverse selector lever 74. The accelerator pedal 71 is operated to increase the traveling speed of the work machine 1. The brake pedal 72 is operated to decrease the traveling speed of the work machine 1 or to stop the traveling of the work machine 1. The steering wheel 73 is operated to change the traveling direction of the work machine 1. The forward / reverse selector lever 74 is operated to switch the work machine 1 between forward and reverse travel.

[0033] The work implement operating device 7B generates an operation signal for operating the work implement 3. The work implement operating device 7B generates an operation signal for operating at least one of the boom cylinder 16 and the bucket cylinder 19. The work implement operating device 7B includes a boom lever 75 and a bucket lever 76. The boom lever 75 is operated to operate the boom 14. The bucket lever 76 is operated to operate the bucket 6.

[0034] <Body Controller> FIG. 4 is a hardware configuration diagram showing a body controller 50 according to this embodiment. The body controller 50 includes a computer 30. The computer 30 has a processor 31 such as a central processing unit (CPU), a main memory 32 including a nonvolatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 33, an input / output interface 34 including an input / output circuit, and a communication interface 35 including a communication circuit. The functions of the body controller 50 are stored in the storage 33 as a computer program 36. The processor 31 reads the computer program 36 from the storage 33, loads it into the main memory 32, and executes processing in accordance with the computer program 36. The computer program 36 may be distributed to the computer 30 via a network.

[0035] The automation controller 100 also includes a computer. Like the body controller 50, the automation controller 100 has a processor, a main memory, a storage device, an input / output interface, and a communication interface.

[0036] <Control System> Figure 5 is a block diagram showing a control system 10 for a work machine 1 according to this embodiment. The work machine 1 is equipped with the control system 10. The work machine 1 is automatically controlled by the control system 10. The control system 10 has an automation controller 100, an automation sensor system 110, a vehicle body controller 50, a vehicle condition sensor system 120, a user interface 130, a traveling device 4, and a work implement 3. The automation controller 100, the automation sensor system 110, the vehicle body controller 50, the vehicle condition sensor system 120, and the user interface 130 are each mounted on the work machine 1.

[0037] The automation controller 100 outputs control commands for automatically controlling the work machine 1. The automation sensor system 110 acquires detection data necessary for automatically controlling the work machine 1. The vehicle body controller 50 outputs command signals for operating the traveling device 4 and the work implement 3. The vehicle state sensor system 120 acquires detection data on the operating state of the work machine 1. The user interface 130 is located in the cab 5 and exchanges data with the operator.

[0038] The automation controller 100 is capable of communicating with the vehicle body controller 50. The automation controller 100 is capable of communicating with the automation sensor system 110. In this embodiment, the operation method of the work machine 1 can be switched between a manual operation method and an automatic control method. When operating the work machine 1 using the manual operation method, the vehicle body controller 50 outputs command signals for operating the traveling devices 4 and the work implements 3 based on operation signals from the operation device 7. When operating the work machine 1 using the automatic control method, the automation controller 100 outputs control commands. When operating the work machine 1 using the automatic control method, the vehicle body controller 50 outputs command signals for operating the traveling devices 4 and the work implements 3 based on control commands from the automation controller 100.

[0039] The automated sensor system 110 includes an external sensor 111 , a position sensor 112 , and an orientation sensor 113 .

[0040] The external sensor 111 detects objects in the vicinity of the work machine 1. The external sensor 111 detects the three-dimensional shapes of objects in the vicinity of the work machine 1. An example of the external sensor 111 is a laser sensor (LiDAR: Light Detection and Ranging) that detects objects by emitting laser light. The external sensor 111 may also be a radar sensor (RADAR: Radio Detection and Ranging) that detects objects by emitting radio waves, or a stereo camera. As shown in FIGS. 1 and 2 , in this embodiment, the external sensor 111 is disposed on the top surface of the cab 5.

[0041] The position sensor 112 detects the position of the work machine 1. The position of the work machine 1 is detected using a global navigation satellite system (GNSS). The global navigation satellite system includes a global positioning system (GPS). The global navigation satellite system detects the position in a global coordinate system defined by coordinate data of latitude, longitude, and altitude. The global coordinate system is a coordinate system fixed to the Earth. The position sensor 112 includes a GNSS receiver, and detects the position (absolute position) of the work machine 1 in the global coordinate system.

[0042] The orientation sensor 113 detects the orientation of the work machine 1. The orientation of the work machine 1 includes an orientation angle relative to a reference orientation. An example of the orientation sensor 113 is an inertial sensor (IMU: Inertial Measurement Unit). The orientation sensor 113 may include a calculator that calculates the orientation from position data detected by two GNSS antennas provided on the work machine 1. The calculator can calculate the orientation from a vector connecting the two GNSS antennas.

[0043] The vehicle body controller 50 is capable of communicating with a vehicle condition sensor system 120. The vehicle condition sensor system 120 includes an articulation angle sensor 121, a vehicle speed sensor 122, a boom angle sensor 123, a bucket angle sensor 124, and a boom cylinder pressure sensor 125.

[0044] The articulation angle sensor 121 detects the articulation angle, which is the angle between the front frame 2A and the rear frame 2B. The articulation angle is the steering angle of the work machine 1. The articulation angle sensor 121 is a steering angle sensor for the work machine 1.

[0045] The vehicle speed sensor 122 detects the traveling speed of the work machine 1. The vehicle speed sensor 122 detects the traveling speed of the work machine 1 by detecting the rotational speed of the output shaft of the power transmission device 22, for example.

[0046] The boom angle sensor 123 detects the angle of the boom 14 relative to the front frame 2A. An example of the boom angle sensor 123 is a rotary encoder provided on the boom pin 9. The bucket angle sensor 124 detects the angle of the bucket 6 relative to the boom 14. An example of the bucket angle sensor 124 is a rotary encoder provided on the support pin 18A. The boom angle sensor 123 may be a stroke sensor arranged on the boom cylinder 16. The bucket angle sensor 124 may be a potentiometer or a proximity switch attached to the bucket pin 17, or may be a stroke sensor arranged on the bucket cylinder 19. The boom angle sensor 123 and the bucket angle sensor 124 are examples of work implement attitude sensors that detect the attitude of the work implement 3.

[0047] The boom cylinder pressure sensor 125 detects the boom bottom pressure, which is the pressure in the bottom chamber of the boom cylinder 16. When the bucket 6 is in a loaded state, holding a load, the boom bottom pressure is high. When the bucket 6 is in an empty state, not holding a load, the boom bottom pressure is low. The boom cylinder pressure sensor 125 functions as a load sensor that detects whether the bucket 6 is in a loaded state or an empty state. The boom cylinder pressure sensor 125 functions as a weight sensor that detects the weight of the load held in the bucket 6.

[0048] The detection data of the automation sensor system 110 is input to the automation controller 100. The detection data of the vehicle condition sensor system 120 is input to the vehicle body controller 50. The vehicle body controller 50 outputs the detection data of the vehicle condition sensor system 120 to the automation controller 100. The automation controller 100 acquires the detection data of the vehicle condition sensor system 120. The traveling device 4 and the work implement 3 each operate based on a command signal from the vehicle body controller 50.

[0049] The vehicle body controller 50 has a brake control unit 51, an accelerator control unit 52, a steering control unit 53, and a work implement control unit 54. The brake control unit 51 outputs a command signal to activate the brake device 23. Based on the command signal output from the brake control unit 51, the travel speed of the travel device 4 is reduced or the travel device 4 is stopped. The accelerator control unit 52 outputs a command signal to adjust the output of the drive machine 20. The accelerator control unit 52 outputs a command signal to control the power transmission device 22. Based on the command signal output from the accelerator control unit 52, the travel speed of the travel device 4 is increased or adjusted. The steering control unit 53 outputs a command signal to operate the steering cylinder 11. Based on the command signal output from the steering control unit 53, the travel direction of the travel device 4 is adjusted. The work implement control unit 54 outputs a command signal to operate at least one of the boom cylinder 16 and the bucket cylinder 19. Based on the command signal output from the work implement control unit 54, the work implement 3 is operated.

[0050] The automation controller 100 includes a position estimation unit 101 , a path planning unit 102 , a path following control unit 103 , and a storage unit 104 .

[0051] The position estimation unit 101 estimates the position of the work machine 1 based on detection data from the position sensor 112. The position estimation unit 101 estimates the positions of objects in the vicinity of the work machine 1 based on detection data from the external sensor 111.

[0052] The path planning unit 102 generates an optimum path for the automatically controlled work machine 1. The optimum path for the work machine 1 includes an optimum travel path for the traveling device 4 and an optimum operation path for the work implement 3.

[0053] The path following control unit 103 outputs control commands for automatically controlling the traveling device 4 and the work machine 3. The path following control unit 103 outputs control commands for automatically controlling the traveling device 4 so that the traveling device 4 travels by following the optimal traveling path generated in the path planning unit 102. The vehicle body controller 50 outputs a command signal to the traveling device 4 based on the control command from the path following control unit 103 so that the traveling device 4 travels by following the optimal traveling path. The path following control unit 103 outputs a control command for automatically controlling the work machine 3 so that the work machine 3 operates by following the optimal operation path generated in the path planning unit 102. The vehicle body controller 50 outputs a command signal to the work machine 3 based on the control command from the path following control unit 103 so that the work machine 3 operates by following the optimal operation path.

[0054] The memory unit 104 stores data required for automatically controlling the work machine 1 .

[0055] The user interface 130 is capable of communicating with the vehicle body controller 50. The user interface 130 has an automation changeover switch 131, an emergency stop switch 132, and a mode lamp 133.

[0056] The automation selector switch 131 is operated by an operator. By operating the automation selector switch 131, the operating method of the work machine 1 is switched between a manual operation method and an automatic control method. The emergency stop switch 132 is operated by an operator. If an event occurs that requires an emergency stop of the drive machine 20, the drive machine 20 is brought to an emergency stop by operating the emergency stop switch 132. An operation signal generated by operating the automation selector switch 131 and an operation signal generated by operating the emergency stop switch 132 are input to the vehicle controller 50.

[0057] The mode lamp 133 indicates whether the working machine 1 is in the manual operation mode or the automatic control mode. The vehicle controller 50 outputs a command signal for controlling the mode lamp 133 based on the operation signal from the automation changeover switch 131.

[0058] <Work of the Work Machine> Figures 6, 7, and 8 are each a diagram for explaining work that can be performed by the work machine 1 according to this embodiment. The work machine 1 works at a work site. One example of work performed by the work machine 1 is forming a stockpile 210, which is a pile of material 200, at the work site. Another example of work performed by the work machine 1 is shaping the stockpile 210. Examples of the material 200 include earth, sand, rocks, or ore excavated at the work site. Note that the material 200 may be transported to the work site by a transport machine such as a dump truck or a belt conveyor.

[0059] Figure 6 is a diagram illustrating excavation work performed by the work machine 1. Excavation work refers to work in which material 200 is scooped up with the bucket 6. As shown in Figure 6, when performing excavation work, the work machine 1 moves forward toward the material 200. The work machine 1 raises the bucket 6 while moving forward with the cutting edge 6A of the bucket 6 inserted into the material 200. Excavation work is performed by the bucket 6 moving along the bucket trajectory BL indicated by the arrow in Figure 6.

[0060] The work machine 1 can form a stockpile 210 on the ground G by discharging the material 200 scooped up in the bucket 6 onto the ground G multiple times.

[0061] FIG. 7 is a diagram illustrating shoveling work performed by the work machine 1. Shoveling work refers to work in which the travelling device 4 climbs the slope of the stockpile 210 while digging the slope of the stockpile 210 with the bucket 6, and piles up new material 200 on top of the stockpile 210. As shown in FIG. 7 , when performing shoveling work, the work machine 1 moves forward toward the stockpile 210. The work machine 1 raises the bucket 6 while moving forward, with the cutting edge 6A of the bucket 6 inserted into the stockpile 210. The travelling device 4 climbs the slope of the stockpile 210 to the middle of the stockpile 210, with the bucket 6 digging the stockpile 210. The bucket 6 moves along the bucket trajectory BL indicated by the arrow in FIG. 7 , and when it reaches the top of the stockpile 210, the work machine 1 performs a dump operation on the bucket 6 to discharge the material 200 scooped up by the bucket 6 from the bucket 6. The material 200 is discharged from the bucket 6 onto the top of the stockpile 210, thereby carrying out the shoveling work.

[0062] Figure 8 is a diagram illustrating cleaning work performed by the work machine 1. Cleaning work refers to work in which material 200 that has spilled over from the stockpile 210 is moved back to the stockpile 210 with the bucket 6 in close proximity to or in contact with the ground G. As shown in Figure 8, when material 200S has spilled over from the bottom end of the slope of the stockpile 210 onto the ground G, the work machine 1 moves forward toward the material 200S with the bucket 6 in close proximity to or in contact with the ground G. The work machine 1 moves forward toward the stockpile 210 so that the material 200S is pushed into the stockpile 210 with the bucket 6. Cleaning work is performed by pushing the material 200S into the stockpile 210 with the bucket 6.

[0063] <Removal of Material Overflowing from the Stockyard> FIG. 9 is a perspective view schematically illustrating the stockyard 220 according to this embodiment. FIG. 10 is a plan view schematically illustrating the stockyard 220 according to this embodiment. As shown in FIGS. 9 and 10 , the stockyard 220 has a rear wall 221, a first side wall 222, and a second side wall 223. The front end of the first side wall 222 is connected to the right end of the rear wall 221. The front end of the second side wall 223 is connected to the left end of the rear wall 221. In a plane parallel to the ground G, the rear wall 221 and the first side wall 222 are substantially perpendicular to each other. In a plane parallel to the ground G, the rear wall 221 and the second side wall 223 are substantially perpendicular to each other. An open space is formed between the rear end of the first side wall 222 and the rear end of the second side wall 223. That is, an open space is formed at the rear of the stockyard 220.

[0064] A stockpile 210 is formed in a stockyard 220. As described with reference to Fig. 8, there is a possibility that material 200S may spill over from the lower end of the slope of the stockpile 210. The material 200S spilling over from the lower end of the slope of the stockpile 210 may spill out of the stockyard 220 through an open part of the stockyard 220. In the following description, the material 200S spilling over from the stockyard 220 will be referred to as stray material 200S, as appropriate.

[0065] As shown in Figure 10, a work space 230 is defined at the work site. The work space 230 is defined outside the stockyard 220. A dump truck 150 travels through the work space 230. The dump truck 150 transports materials 200 to be brought into the stockyard 220 and materials 200 taken out of the stockyard 220. Workers walk in the work space 230 and perform work in the work space 230.

[0066] The work space 230 is a space where it is recommended to prevent the intrusion of the stray material 200S. If the stray material 200S that has overflowed from the stockyard 220 intrudes into the work space 230, it may hinder the movement of the dump truck 150, hinder the walking of workers, or hinder the work of workers, thereby reducing the work efficiency of the work site. In order to prevent a decrease in the work efficiency of the work site, if there is a possibility that the stray material 200S will intrude into the work space 230, it is necessary to perform work to move the stray material 200S to the stockyard 220.

[0067] In this embodiment, the automation controller 100 acquires detection data of a stockpile 210 formed at a work site. The stockpile 210 is detected by an external sensor 111. The automation controller 100 calculates a detected shape indicating the shape of the stockpile 210 based on the detection data from the external sensor 111. The automation controller 100 compares the target shape of the stockpile 210 with the detected shape, and determines whether or not to modify the shape of the stockpile 210. If the automation controller 100 determines that the shape of the stockpile 210 should be modified, it outputs a control command to modify the shape of the stockpile 210.

[0068] The automation controller 100 calculates the difference between the target shape and the detected shape of the stockpile 210 for the evaluation value related to the shape of the stockpile 210. When the automation controller 100 determines that the difference between the target shape and the detected shape for the evaluation value related to the shape of the stockpile 210 is equal to or greater than a predetermined threshold, the automation controller 100 outputs a control command to correct the shape of the stockpile 210 so that the shape of the stockpile 210 approaches the target shape.

[0069] In this embodiment, the target shape of the stockpile 210 is a shape in which the material 200 constituting the stockpile 210 does not protrude from the target space 250. In this embodiment, the target space 250 is a space inside the stockyard 220. In other words, the target shape of the stockpile 210 includes a shape in which the stray material 200S does not exist and the stockpile 210 is contained inside the stockyard 220.

[0070] The evaluation value for the shape of the stockpile 210 is the amount of material 200 protruding from the stockyard 220, which is the target space 250. If the stockpile 210 is in the target shape, the amount of protrusion is zero. If the automation controller 100 determines that the difference between the amount of protrusion of the target shape and the amount of protrusion of the detected shape is equal to or greater than a predetermined threshold, it outputs a control command to bring the shape of the stockpile 210 closer to the target shape.

[0071] In this embodiment, bringing the shape of the stockpile 210 closer to the target shape includes moving the material 200 that has protruded beyond the target space to the inside of the target space. In other words, bringing the shape of the stockpile 210 closer to the target shape includes moving the stray material 200S to the inside of the stockyard 220.

[0072] The automation controller 100 calculates the protruding position of the material 200 constituting the stockpile 210 from the target space 250 based on the detected shape of the stockpile 210. The automation controller 100 determines whether or not to move the material 200 protruding from the target space 250 into the target space 250 based on the protruding position of the material 200 from the target space 250. That is, the automation controller 100 determines whether or not to move the material 200S protruding from the target space 250 into the target space 250 based on the difference between the target shape and the detected shape when the material 200 protrudes into an unacceptable position or direction. Even if the difference between the target shape and the detected shape is large, if the detected shape of the material 200 is recessed into the target space 250, the automation controller 100 determines not to move the material 200S protruding from the target space 250 into the target space 250. If the material 200 is protruding outside the target space 250 and the difference between the target shape and the detected shape is large, the automation controller 100 decides to move the material 200S protruding from the target space 250 to the inside of the target space 250.

[0073] When the automation controller 100 determines that deviating material 200S is present and that the difference between the amount of protrusion of the target shape and the amount of protrusion of the detected shape is greater than or equal to a threshold value, it outputs a control command to automatically control the traveling device 4 and the work machine 3 so that the deviating material 200S moves inside the stockyard 220.

[0074] <Control Method> Figure 11 is a flowchart showing a control method for the work machine 1 according to this embodiment. The position estimation unit 101 of the automation controller 100 acquires map data of the work site (step SA1).

[0075] Fig. 12 is a perspective view for explaining a method for acquiring map data of a work site according to this embodiment. Fig. 13 is a plan view for explaining a method for acquiring map data of a work site according to this embodiment.

[0076] Obtaining the map data of the work site includes obtaining position data of the stockyard 220. The position data of the stockyard 220 includes shape data and dimension data of the stockyard 220. The position data of the stockyard 220 may be two-dimensional data or three-dimensional data.

[0077] A first method for acquiring position data of the stockyard 220 is to detect the positions of multiple feature points 240 of the stockyard 220. As shown in FIG. 13 , the feature points 240 may be the four corners of the stockyard 220. The positions of the feature points 240 are detected by any method. As shown in FIG. 12 , a position detector 140 such as a GNSS rover may detect the positions of each of the multiple feature points 240. When the position detector 140 is a GNSS rover, the positions of the multiple feature points 240 are detected by having an operator carrying the position detector 140 move to each of the four corners of the stockyard 220. The position detector 140 may be a total station. The feature points 240 may be, for example, structures in the vicinity of the stockyard 220.

[0078] The position detector 140 detects the positions (absolute positions) of the feature points 240 in the global coordinate system. The detection data of the position detector 140 is wirelessly transmitted to the automation controller 100. The position estimation unit 101 of the automation controller 100 can acquire position data of the stockyard 220 in the global coordinate system based on the plurality of feature points 240 detected by the position detector 140. The position data of the stockyard 220 acquired by the first method may be two-dimensional data or three-dimensional data indicating a position on a plane substantially parallel to the ground of the work site.

[0079] A second method for acquiring position data of the stockyard 220 is to detect the stockyard 220 using a three-dimensional sensor 162 mounted on a mobile body 160. The mobile body 160 is movable within the work site. As shown in FIG. 12 , the mobile body 160 may be an unmanned aerial vehicle (UAV) such as a drone. A three-dimensional sensor 162 is mounted on the mobile body 160. The three-dimensional sensor 162 is capable of detecting three-dimensional data indicating the three-dimensional shape of the work site. An example of the three-dimensional sensor 162 is a laser sensor (LiDAR: Light Detection and Ranging) that detects objects by emitting laser light. Note that the three-dimensional sensor 162 may be a radar sensor (RADAR: Radio Detection and Ranging) that detects objects by emitting radio waves, or a stereo camera.

[0080] The three-dimensional sensor 162 detects three-dimensional data indicating the three-dimensional shape of the stockyard 220. The mobile body 160 is equipped with a position sensor 164 that detects the position of the mobile body 160. The position sensor 164 includes a GNSS receiver and detects the position (absolute position) of the mobile body 160 in the global coordinate system.

[0081] The detection data from the three-dimensional sensor 162 and the detection data from the position sensor 164 are wirelessly transmitted to the automation controller 100. The position estimation unit 101 of the automation controller 100 can acquire position data of the stockyard 220 in the global coordinate system by performing coordinate conversion on the detection data from the three-dimensional sensor 162 based on the detection data from the position sensor 164. The position data of the stockyard 220 acquired by the second method is three-dimensional data in the global coordinate system.

[0082] The three-dimensional sensor 162 does not have to be mounted on the mobile body 160. The three-dimensional sensor 162 only needs to be placed in a position that allows it to overlook the stockyard 220.

[0083] Note that a monocular camera may be mounted on the mobile object 160, and the position data of the stockyard 220 may be acquired based on image data captured by the monocular camera. That is, the position data of the stockyard 220 may be acquired using a Visual-SLAM (Simultaneous Localization and Mapping) technique.

[0084] A third method for acquiring the position data of the stockyard 220 is to detect the stockyard 220 using an external sensor 111 mounted on the work machine 1. The external sensor 111 may detect the stockyard 220 while the work machine 1 is traveling. In other words, the position data of the stockyard 220 may be acquired using a SLAM (Simultaneous Localization and Mapping) technique.

[0085] The position estimation unit 101 determines the target space 250 based on the map data acquired in step SA1 (step SA2).

[0086] The target space 250 is a space in which the stockpile 210 should be placed. The position of the target space 250 is defined in the global coordinate system. As described above, in this embodiment, the target space 250 is a space inside the stockyard 220. The position estimation unit 101 can determine the target space 250 based on the map data acquired in step SA1. As shown in FIG. 13 , the target space 250 is determined so as to surround the space inside the stockyard 220. The target space 250 may also be determined so as to follow the outer shape of the stockyard 220.

[0087] Next, the position estimation unit 101 acquires three-dimensional data of the work site (step SA3). The three-dimensional data of the work site includes three-dimensional data of the stockpile 210 formed in the stockyard 220. If stray material 200S exists, the three-dimensional data of the stockpile 210 includes three-dimensional data of the stray material 200S.

[0088] 13 , when acquiring three-dimensional data of the stockpile 210, the path planning unit 102 of the automation controller 100 outputs a control command to the traveling device 4 of the work machine 1 so that the stockyard 220 is detected by the external sensor 111 mounted on the work machine 1. Based on the control command, the work machine 1 moves from its initial position (standby position) to the front of the stockyard 220.

[0089] After the work machine 1 moves in front of the stockyard 220, the external sensor 111 detects the three-dimensional shapes of the stockyard 220 and the stockpile 210. If stray material 200S is present, the external sensor 111 can detect the three-dimensional shape of the stray material 200S. The work machine 1 is equipped with a position sensor 112 that detects the position of the work machine 1 in a global coordinate system and an orientation sensor 113 that detects the orientation of the work machine 1. The detection data of the external sensor 111, the detection data of the position sensor 112, and the detection data of the orientation sensor 113 are wirelessly transmitted to the automation controller 100. The position estimation unit 101 of the automation controller 100 can acquire three-dimensional data of the stockyard 220 and the stockpile 210 in the global coordinate system by coordinate transforming the detection data of the external sensor 111 based on the detection data of the position sensor 112 and the detection data of the orientation sensor 113.

[0090] The position estimation unit 101 calculates the detected shape of the stockpile 210 based on the detection data of the external sensor 111. If a deviant material 200S exists, the detected shape of the stockpile 210 includes the detected shape of the deviant material 200S. If a deviant material 200S exists, the detected shape of the stockpile 210 includes the position (protruding position) of the deviant material 200S.

[0091] The position estimation unit 101 calculates the difference between the protrusion amount of the target shape of the stockpile 210 and the protrusion amount of the detected shape. As described above, the protrusion amount of the target shape is zero. The difference between the protrusion amount of the target shape and the protrusion amount of the detected shape corresponds to the protrusion amount of the stray material 200S from the target space 250. The position estimation unit 101 calculates the protrusion amount of the stray material 200S from the target space 250 based on the target space 250 determined in step SA2 and the three-dimensional data of the stockpile 210 acquired in step SA3 (step SA4).

[0092] The position estimation unit 101 determines whether the protrusion amount of the deviating material 200S calculated in step SA4 is equal to or greater than a predetermined threshold value (step SA5).

[0093] The threshold value may be determined based on, for example, the dimensions of the work machine 1. The dimensions of the work machine 1 may be, for example, the size of the front wheels 4A or the rear wheels 4B, or the ground clearance of the work machine 1.

[0094] If it is determined in step SA5 that the protrusion amount of the deviant material 200S is equal to or greater than the threshold (step SA5: Yes), the position estimation unit 101 calculates the deviation position of the deviant material 200S, whose protrusion amount is equal to or greater than the threshold, from the target space 250. If the protrusion position of the deviant material 200S, whose protrusion amount is equal to or greater than the threshold, is outside the target space 250, the path planning unit 102 generates an optimal path for moving the deviant material 200S protruding from the target space 250 to the inside of the target space 250. In this embodiment, in order to generate the optimal path, the path planning unit 102 calculates the nearest point 260 of the deviant material 200S protruding from the target space 250 from the working space 230 (step SA6).

[0095] 14 is a plan view for explaining a method for generating an optimal path for the work machine 1 according to this embodiment. In this embodiment, the memory unit 104 stores in advance position data for a work space 230 that is defined outside a target space 250 (stockyard 220) at the work site. The memory unit 104 stores position data for the work space 230 in the global coordinate system. The position data for the work space 230 includes shape data and dimensional data for the work space 230. The path planning unit 102 generates an optimal path for the work machine 1 for moving deviant material 200S that protrudes outside the target space 250 to the inside of the target space 250, based on the relative positions of the deviant material 200S that protrudes outside the target space 250 and the work space 230.

[0096] In this embodiment, the path planning unit 102 calculates the nearest point 260 , which is the portion of the deviant material 200S that is closest to the work space 230 , based on the relative positions of the deviant material 200S and the work space 230 .

[0097] The path planning unit 102 generates an optimal path for moving the deviant material 200S of the nearest point 260 first inside the target space 250. In other words, the path planning unit 102 generates an optimal path for the work machine 1 such that the deviant material 200S of the nearest point 260 is moved first inside the target space 250.

[0098] The path planning unit 102 generates an optimal path for the work machine 1 so that the deviant material 200S at the nearest point 260 first moves inside the target space 250, and then the deviant material 200S at a location other than the nearest point 260 moves sequentially inside the target space 250 (step SA7).

[0099] The path following control unit 103 outputs a control command to the work machine 1 so as to follow the optimal path of the work machine 1 generated in step SA7. As described above, the optimal path of the work machine 1 includes the optimal travel path of the traveling device 4 and the optimal operation path of the work implement 3. The work machine 1 performs cleaning work or raking work so that the deviating material 200S that protrudes outside the target space 250 moves inside the target space 250 (step SA8).

[0100] In the cleaning or raking work of step SA8, the work machine 1 first moves the deviant material 200S at the nearest point 260 inside the target space 250. The portion of the deviant material 200S that is closest to the work space 230 is moved inside the target space 250 early, which reduces the risk of the dump truck 150 being hindered from traveling or the worker being hindered from walking or working.

[0101] In the cleaning or scraping work of step SA8, when the stray material 200S at the nearest point 260 is to be moved inside the target space 250, the work machine 1 moves forward in a direction perpendicular to the line defining the rear end of the target space 250 (the line defining the open part of the stockyard 220) (a direction perpendicular to the rear surface of the rear wall 221). This allows the portion of the stray material 200S that is closest to the work space 230 to be moved inside the target space 250 early.

[0102] After the deviating material 200S has moved inside the target space 250, the path following control unit 103 outputs a control command to return the work machine 1 to the initial position (standby position) (step SA9).

[0103] If it is determined in step SA5 that the amount of protrusion is not equal to or greater than the threshold value (step SA5: No), the work machine 1 does not perform cleaning work or scraping work, and returns to the initial position.

[0104] <Effects> As explained above, the automation controller 100 for the work machine 1 having the traveling gear 4 and the work implement 3 calculates the detected shape of the stockpile 210 based on detection data from the external sensor 111 that detects the stockpile 210 formed at the work site, compares the target shape of the stockpile 210 with the detected shape for the stockpile 210 regarding an evaluation value related to the shape of the stockpile 210, and determines whether to modify the shape of the stockpile 210. When the automation controller 100 determines that the difference between the target shape and the detected shape is equal to or greater than a predetermined threshold, it outputs a control command to bring the shape of the stockpile 210 closer to the target shape.

[0105] According to this embodiment, if the stockpile 210 is not properly stored inside the stockyard 220 and stray material 200S is present, a control command is output to bring the shape of the stockpile 210 closer to the target shape. The stray material 200S is cleared away by the cleaning or raking work of the work machine 1, which prevents a decrease in work efficiency at the work site.

[0106] In this embodiment, the evaluation value related to the shape of the stockpile 210 includes the amount of material 200 constituting the stockpile 210 that protrudes from the target space 250. By evaluating the amount of protrusion from the target space 250, if the amount of stray material 200S protruding is large, the work machine 1 can smoothly perform cleaning work or raking work to clear away the stray material 200S.

[0107] In this embodiment, if deviant material 200S is present, the work machine 1 first moves the deviant material 200S at the nearest point 260 from the work space 230 to the inside of the target space 250. Because the portion of the deviant material 200S that is closest to the work space 230 is moved to the inside of the target space 250 early, interference with the travel of the dump truck 150, or interference with the walking of the worker or the work of the worker is suppressed.

[0108] Second Embodiment A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0109] In the first embodiment described above, the evaluation value for the shape of the stockpile 210 is the amount of stray material 200S protruding from the target space 250. Furthermore, if it is determined that the amount of stray material 200S protruding from the target space 250 is equal to or greater than a threshold, cleaning work or raking work is performed. In the second embodiment, the evaluation value for the shape of the stockpile 210 is the inclination angle θ of the slope of the stockpile 210. The target shape of the stockpile 210 is a shape in which the inclination angle θ of the slope of the stockpile 210 is within a target inclination angle range. The target inclination angle range may be 30 degrees or more and 50 degrees or less, or 35 degrees or more and 45 degrees or less.

[0110] <Configurations of Stockpile Shape> Figure 15 is a diagram for explaining the shape of the stockpile 210 according to this embodiment. In Figure 15, [Configuration A] shows an example in which the inclination angle θ of the slope of the stockpile 210 is within the target inclination angle range, and the shape of the stockpile 210 is the target shape. In Figure 15, [Configuration B] and [Configuration C] show examples in which the inclination angle θ of the slope of the stockpile 210 is not within the target inclination angle range, and the shape of the stockpile 210 is not the target shape. [Configuration B] shows an example in which the inclination angle θ is smaller than the target inclination angle range. [Configuration C] shows an example in which the inclination angle θ is larger than the target inclination angle range. The inclination angle θ is the angle between the ground G and the slope of the stockpile 210, and is an internal angle of the stockpile 210.

[0111] 15 , when the shape of the stockpile 210 is the target shape, the movement space for the work machine 1 around the stockpile 210 is increased, and the work machine 1 can easily excavate the stockpile 210 with the bucket 6. In other words, when the shape of the stockpile 210 is the target shape, a decrease in work efficiency at the work site is suppressed.

[0112] As shown in [Configuration B] in FIG. 15 , for example, if the material 200 at the bottom end of the slope of the stockpile 210 collapses, the inclination angle θ becomes smaller than the target inclination angle range, and the shape of the stockpile 210 is no longer the target shape. If the material 200 is, for example, dry sand, the inclination angle θ is likely to become smaller than the target inclination angle range. If the inclination angle θ is smaller than the target inclination angle range, the movement space for the work machine 1 around the stockpile 210 becomes narrow. Furthermore, it becomes difficult for the work machine 1 to excavate the stockpile 210 with the bucket 6. In the case of [Configuration B], the digging distance of the bucket 6 becomes longer, making it more difficult for the bucket 6 to scoop up the material 200, and therefore the amount of material 200 scooped up by the bucket 6 may be reduced. In other words, if the stockpile 210 does not have the target shape, work efficiency at the work site may decrease.

[0113] 15 , for example, if the material 200 is highly sticky, the tilt angle θ becomes larger than the target tilt angle range, and the shape of the stockpile 210 does not match the target shape. If the tilt angle θ is larger than the target tilt angle range, it will be difficult for the work machine 1 to excavate the stockpile 210 with the bucket 6. In the case of [Configuration C], it will be difficult for the cutting edge 6A of the bucket 6 to insert into the stockpile 210, which may reduce the amount of material 200 scooped up by the bucket 6. In other words, if the stockpile 210 does not match the target shape, work efficiency at the work site may decrease.

[0114] In this embodiment, when the automation controller 100 determines that the inclination angle θ of the slope of the stockpile 210 is not within the target inclination angle range, it outputs a control command to adjust the shape of the stockpile 210 so that the inclination angle θ is within the target inclination angle range, as an operation to bring the shape of the stockpile 210 closer to the target shape.

[0115] <Control Method> Figure 16 is a flowchart showing a control method for a work machine according to this embodiment. The position estimation unit 101 of the automation controller 100 acquires three-dimensional data indicating the three-dimensional shape of the stockpile 210. The three-dimensional shape of the stockpile 210 is detected by the external sensor 111. The position estimation unit 101 can acquire the three-dimensional data of the stockpile 210 by acquiring the detection data from the external sensor 111 (step SB1).

[0116] The position estimation unit 101 determines the position of the apex of the stockpile 210 based on the three-dimensional data of the stockpile 210 acquired in step SB1. In the following description, the position of the apex of the stockpile 210 determined based on the detection data of the external sensor 111 will be referred to as the detected position 310 of the apex as appropriate (step SB2).

[0117] The position estimation unit 101 determines the position of the base of the stockpile 210 based on the three-dimensional data of the stockpile 210 acquired in step SB1. In the following description, the position of the base of the stockpile 210 determined based on the detection data of the external sensor 111 will be referred to as the detected base position 320 (step SB3).

[0118] The position estimation unit 101 calculates the target position 330 of the base based on the detected position 310 of the apex determined in step SB2 (step SB4).

[0119] Note that step SB2 may be executed after step SB3, or step SB3 may be executed after step SB4.

[0120] 17 is a diagram for explaining a method for determining the detected positions 310 of the apex and the detected positions 320 of the base, and a method for calculating the target position 330 of the base, according to this embodiment. In FIG. 17, [Configuration A] shows an example in which the shape of the stockpile 210 is the target shape. In FIG. 17, [Configuration B] and [Configuration C] show examples in which the shape of the stockpile 210 is not the target shape. [Configuration B] shows an example in which the inclination angle θ is smaller than the target inclination angle range. [Configuration C] shows an example in which the inclination angle θ is larger than the target inclination angle range.

[0121] The detected position 310 of the apex is determined based on the slope of the stockpile 210 derived from the detection data of the external sensor 111 and a predetermined height Ha from the ground G. The part of the slope of the stockpile 210 at the height Ha is determined as the detected position 310 of the apex. The height Ha is determined to be an arbitrary height on the slope of the stockpile 210.

[0122] Height Ha may be determined to be the highest position (top position) of the stockpile 210. Height Ha may be determined to be a position that is a predetermined first specified value above the ground surface G on which the work machine 1 is traveling. The first specified value may be determined, for example, based on the dimensions of the work machine 1. The first specified value may be, for example, not less than 50% and not more than 150% of the overall length of the work machine 1. Height Ha may be determined to be the highest position on the stockpile 210 at which the work machine 1 can perform lifting work. If a range of the slope of the stockpile 210 that should be set to the target inclination angle is set, height Ha may be determined to be the highest position within that range of the slope.

[0123] The base detection position 320 is determined based on the slope of the stockpile 210 derived from the detection data of the external sensor 111 and a predetermined height Hb from the ground G. The part of the slope of the stockpile 210 at the height Hb is determined as the base detection position 320. The height Hb is determined to be any height on the slope of the stockpile 210.

[0124] Height Hb may be determined to be the lowest position of the stockpile 210. Height Hb may be determined to be a position that is a predetermined second specified value above the ground surface G on which the work machine 1 travels. The second specified value may be, for example, 5 cm or more and 20 cm or less. Height Hb may be determined to be the lowest position of the stockpile 210 at which the work machine 1 can perform lifting work. If a range of the slope of the stockpile 210 that should have the target inclination angle is set, height Hb may be determined to be the lowest position of that range of the slope.

[0125] The target position 330 of the base is calculated based on the detected position 310 of the apex and the target shape of the stockpile 210. The target position 330 of the base is calculated based on the detected position 310 of the apex and the target inclination angle of the slope of the stockpile 210. If the target inclination angle is, for example, 40 degrees, a target line 300 that passes through the detected position 310 of the apex and has an inclination angle of 40 degrees is defined. The part of the target line 300 at height Hb is the target position 330 of the base.

[0126] After determining the base detection position 320 and calculating the base target position 330, the position estimation unit 101 calculates the distance between the base detection position 320 and the base target position 330. In this embodiment, the evaluation value related to the shape of the stockpile 210 includes the distance between the base detection position 320 and the base target position 330. When the inclination angle θ of the slope of the stockpile 210 is within the target inclination angle range, the distance between the base detection position 320 and the base target position 330 is equal to or less than a predetermined threshold.

[0127] The position estimation unit 101 determines whether the distance between the detected position 320 of the foot and the target position 330 of the foot is equal to or greater than a predetermined threshold (step SB5).

[0128] In step SB5, if it is determined that the distance between the detected position 320 of the base and the target position 330 of the base is greater than or equal to a threshold value (step SB5: Yes), the path planning unit 102 generates an optimal path for bringing the stockpile 210 into the target shape (step SB6).

[0129] 17, [Configuration A] shows an example in which the distance between the base detection position 320 and the base target position 330 is less than a threshold value. In FIG. 17, [Configuration B] and [Configuration C] show examples in which the distance between the base detection position 320 and the base target position 330 is equal to or greater than a threshold value. [Configuration B] shows an example in which the distance from the center of the stockpile 210 to the base detection position 320 in a plane parallel to the ground G is longer than the distance from the center of the stockpile 210 to the base target position 330. [Configuration C] shows an example in which the distance from the center of the stockpile 210 to the base detection position 320 in a plane parallel to the ground G is shorter than the distance from the center of the stockpile 210 to the base target position 330. When the slope shape of the stockpile 210 is [Configuration B] or [Configuration C], the path planning unit 102 generates an optimal path for setting the inclination angle θ of the slope of the stockpile 210 to the target inclination angle.

[0130] The path following control unit 103 outputs a control command to change the shape of the stockpile 210 to the target shape, based on the optimal path for the work machine 1 generated in step SB6. The path following control unit 103 outputs a control command to the work machine 1 so as to follow the optimal path for the work machine 1 generated in step SB6. As described above, the optimal path for the work machine 1 includes the optimal travel path for the traveling devices 4 and the optimal operation path for the work implement 3. The work machine 1 performs raking work so that the stockpile 210 becomes the target shape, i.e., so that the inclination angle θ of the slope of the stockpile 210 becomes the target inclination angle (step SB7).

[0131] After the distance between the detected position 320 of the base and the target position 330 of the base becomes less than the threshold value and the shape of the stockpile 210 becomes the target shape, the path following control unit 103 outputs a control command to return the work machine 1 to the initial position (standby position) (step SB8).

[0132] In step SB5, if it is determined that the distance between the detection position 320 of the foot and the target position 330 of the foot is not greater than the threshold value (step SB5: No), the work machine 1 does not perform the scraping work and returns to the initial position.

[0133] <Operation of the Work Machine> FIGS. 18 and 19 are diagrams for explaining an example of the operation of the work machine 1 according to this embodiment.

[0134] Figure 18 shows an example in which a stockpile 210 is formed in a stockyard 220. The upper view of Figure 18 is a view of the stockyard 220 and the work machine 1 as seen from the side, and the lower view of Figure 18 is a view of the stockyard 220 and the work machine 1 as seen from above. As shown in Figure 18, multiple apex detection positions 310 may be determined in the left-right direction parallel to the ground surface G. In the example shown in Figure 18, five apex detection positions 310 are determined at equal intervals in the left-right direction.

[0135] A plurality of base detection positions 320 are determined to correspond to the plurality of apex detection positions 310, and a plurality of base target positions 330 are calculated. One apex detection position 310, the base detection position 320 corresponding to that apex detection position 310, and the base target position 330 corresponding to that apex detection position 310 are defined at the same position in the left-right direction. That is, one apex detection position 310, the base detection position 320 corresponding to that apex detection position 310, and the base target position 330 corresponding to that apex detection position 310 are located on a line perpendicular to the rear wall 221 and extending in the front-rear direction. The determination of whether the distance between the base detection position 320 and the base target position 330 is equal to or greater than a threshold may be performed for each of the plurality (five) base detection positions 320 and base target positions 330.

[0136] The work machine 1 performs the raking work for the foot detection positions 320 of the plurality (five) foot detection positions 320 and the foot target positions 330 that are determined to have a distance from the foot target positions 330 equal to or greater than a threshold value. The work machine 1 performs the raking work by moving forward in a direction perpendicular to the rear surface of the inner wall 221.

[0137] The determination of whether the distance between base detection position 320 and base target position 330 is equal to or greater than a threshold value may be performed for some of the multiple (five) base detection positions 320 and base target positions 330. As shown in Fig. 18 , it may be determined whether the distance between base detection position 320A, of the multiple (five) detection positions 320, that is closest to rear wall 221 in the front-to-rear direction and base target position 330 corresponding to base detection position 320A, is equal to or greater than a threshold value, and it may also be determined whether the distance between base detection position 320B, the farthest from rear wall 221 in the front-to-rear direction, and base target position 330 corresponding to base detection position 320B, is equal to or greater than a threshold value.

[0138] FIG. 19 shows an example in which a stockpile 210 is formed from material 200 transported by a belt conveyor 400 to the ground G at a work site. The upper view of FIG. 19 is a side view of the belt conveyor 400 and the work machine 1, and the lower view of FIG. 19 is a top view of the belt conveyor 400 and the work machine 1. As shown in FIG. 19, the stockpile 210 formed from material 200 transported by the belt conveyor 400 is often conical in shape. In the example shown in FIG. 19, the apex detection position 310 is determined to be the top of the stockpile 210. In a plane parallel to the ground G, multiple base detection positions 320 are determined around the apex detection position 310, and multiple base target positions 330 are positioned around the apex detection position 310. A base detection position 320 and a base target position 330 corresponding to the detection position 320 are arranged along the generatrix of the conical stockpile 210. The determination of whether the distance between the base detection position 320 and the base target position 330 is equal to or greater than a threshold may be performed for each of the multiple base detection positions 320 and base target positions 330.

[0139] The work machine 1 performs raking work for a base detection position 320, of the plurality of base detection positions 320 and base target positions 330, that is determined to have a distance from the base target position 330 equal to or greater than a threshold value. The work machine 1 performs raking work by moving forward in a direction along the generatrix of the conical stockpile 210.

[0140] <Effects> As described above, according to this embodiment, when the stockpile 210 is not formed into the target shape and the inclination angle θ of the slope of the stockpile 210 is not within the target inclination angle range, a control command is output to bring the shape of the stockpile 210 closer to the target shape. Since the raking work is performed so that the inclination angle θ of the slope of the stockpile 210 approaches the target inclination angle, a decrease in work efficiency at the work site is suppressed.

[0141] [Other Embodiments] In the above-described embodiment, the steering cylinder 11, the boom cylinder 16, and the bucket cylinder 19 are each a hydraulic cylinder. At least one of the steering cylinder 11, the boom cylinder 16, and the bucket cylinder 19 may be an electric cylinder that is operated by electricity.

[0142] In the above-described embodiment, the work machine 1 is automatically controlled by the automation controller 100. Also, the operation method of the work machine 1 can be switched between a manual operation method and an automatic control method. In the manual operation method, the work machine 1 is operated by an operator inside the cab 5 operating an operation device 7 located in the cab 5. Note that the work machine 1 may also be remotely operated. The operation device 7 may be located outside the work machine 1, and an operation signal generated by operating the operation device 7 may be transmitted to the vehicle controller 50 via a wireless communication system.

[0143] In the above-described embodiment, the automation controller 100 outputs a control command to the vehicle controller 50 to cause the shape of the stockpile 210 to approach the target shape. The automation controller 100 may also output a control command to the outside of the work machine 1 to cause the shape of the stockpile 210 to approach the target shape.

[0144] In the above-described embodiment, the work machine 1 is a wheel loader. However, the work machine 1 may be a front-loading bulldozer.

[0145] [Supplementary Notes] The present disclosure may also adopt the following configurations. (Supplementary Note 1) A control system for a work machine comprising a controller for a work machine having a traveling device and a work implement, wherein the controller calculates a detected shape of a stockpile formed at a work site based on detection data from an external sensor that detects the stockpile, and compares a target shape of the stockpile with the detected shape using an evaluation value related to the stockpile shape to determine whether to modify the stockpile shape. (Supplementary Note 2) The control system for a work machine described in (Supplementary Note 1), wherein the controller outputs a control command to bring the shape of the stockpile closer to the target shape when it determines that the difference between the target shape and the detected shape is equal to or greater than a predetermined threshold. (Supplementary Note 3) The work machine control system described in (Supplementary Note 2), wherein the evaluation value includes an amount of material constituting the stockpile protruding from a target space, the target shape includes a shape in which the material does not protrude from the target space, and bringing the shape of the stockpile closer to the target shape includes moving the material protruding from the target space to inside the target space. (Supplementary Note 4) The work machine control system described in (Supplementary Note 3), wherein the controller calculates the amount of protrusion based on the detection data, and when it is determined that the amount of protrusion is equal to or greater than a threshold, outputs a control command to move the material protruding from the target space to inside the target space. (Supplementary Note 5) A control system for a work machine comprising a controller for a work machine having a traveling device and a work implement, wherein the controller calculates a detected shape of a stockpile formed at a work site based on detection data from an external sensor that detects the stockpile, calculates a protruding position of material constituting the stockpile from a target space based on the detected shape, and determines whether or not to move the material protruding from the target space toward the inside of the target space based on the protruding position.(Supplementary Note 6) The work machine control system described in (Supplementary Note 4) or (Supplementary Note 5), wherein the controller stores position data of a work space defined outside the target space at the work site, and generates an optimal path for the work machine to move the material that has overflowed the target space into the target space based on the relative position of the work space and the material that has overflowed the target space. (Supplementary Note 7) The work machine control system described in (Supplementary Note 6), wherein the controller calculates the point from the work space to the material that has overflowed the target space, and outputs a control command to first move the material at the nearest point into the target space. (Supplementary Note 8) The work machine control system described in any one of (Supplementary Note 1) to (Supplementary Note 7), wherein the evaluation value includes an inclination angle of the slope of the stockpile, the target shape includes a shape where the inclination angle is within a target inclination angle range, and bringing the shape of the stockpile closer to the target shape includes adjusting the shape of the stockpile so that the inclination angle is within the target inclination angle range. (Supplementary Note 9) The construction machine control system according to (Supplementary Note 8), wherein the controller: determines a detected position of an apex and a detected position of a base of the stockpile based on the detection data; calculates a target position of the base based on the detected position of the apex and the target shape; the evaluation value includes a distance between the detected position of the base and the target position of the base; and if it is determined that the distance is equal to or greater than a threshold, outputs a control command to make the shape of the stockpile into the target shape. (Supplementary Note 10) A construction machine comprising: the construction machine control system according to any one of (Supplementary Note 1) to (Supplementary Note 9); a traveling device; and a work implement.(Supplementary Note 11) A control method for a work machine having a traveling device and a work implement, the control method comprising: calculating a detected shape of a stockpile formed at a work site based on detection data from an external sensor that detects the stockpile; and comparing a target shape of the stockpile with the detected shape of the stockpile for an evaluation value related to the shape of the stockpile, and determining whether to modify the shape of the stockpile.

[0146] 1...work machine, 2...body frame, 2A...front frame, 2B...rear frame, 3...work implement, 4...traveling device, 4A...front wheel, 4B...rear wheel, 5...cab, 6...bucket, 6A...cutting edge, 6B...rear face, 6L...left bracket, 6R...right bracket, 7...operating device, 7A...traveling system operating device, 7B...work implement operating device, 8...articulating mechanism, 9...boom pin, 9L...left boom pin, 9R...right boom pin, 10...control system, 11...steering cylinder, 14...boom, 14L...left boom member, 14R...right boom member, 15...link, 16...boom cylinder, 17... Bucket pin, 18...bell crank, 18A...support pin, 18B...connecting pin, 18C...connecting pin, 19...bucket cylinder, 20...driver, 21...power take-off, 22...power transmission device, 23...brake device, 24...steering pump, 25...steering control valve, 26...work implement pump, 27...boom control valve, 28...bucket control valve, 30...computer, 31...processor, 32...main memory, 33...storage, 34...input / output interface, 35...communication interface, 36...computer program, 50...vehicle controller, 51...brake Rake control unit, 52...accelerator control unit, 53...steering control unit, 54...work implement control unit, 71...accelerator pedal, 72...brake pedal, 73...steering wheel, 74...forward / reverse switch lever, 75...boom lever, 76...bucket lever, 100...automation controller, 101...position estimation unit, 102...path planning unit, 103...path following control unit, 104...memory unit, 110...automation sensor system, 111...external sensor, 112...position sensor, 113...orientation sensor, 120...vehicle state sensor system, 121...articulate angle sensor, 12 2...vehicle speed sensor, 123...boom angle sensor, 124...bucket angle sensor, 125...boom cylinder pressure sensor, 130...user interface, 131...automation changeover switch, 132...emergency stop switch, 133...mode lamp, 140...position detector, 150...dump truck, 160...mobile body, 162...three-dimensional sensor, 164...position sensor, 200...material, 200S...stray material, 210...stockpile, 220...stockyard, 221...rear wall, 222...first side wall, 223...second side wall, 230...work space, 240...feature point,250...target space, 260...closest point, 300...target line, 310...detected position, 320...detected position, 320A...detected position, 320B...detected position, 330...target position, 400...belt conveyor, BL...bucket trajectory, G...ground, Ha...height, Hb...height, θ...inclination angle.

Claims

1. A control system for a work machine comprising a controller for the work machine having a traveling device and a work implement, the controller calculating a detected shape of the stockpile based on detection data from an external sensor that detects a stockpile formed at a work site, and comparing a target shape of the stockpile with the detected shape for an evaluation value related to the shape of the stockpile to determine whether to modify the shape of the stockpile.

2. A work machine control system as set forth in claim 1, wherein the controller outputs a control command to bring the shape of the stockpile closer to the target shape when it determines that the difference between the target shape and the detected shape is equal to or greater than a predetermined threshold.

3. A work machine control system as described in claim 2, wherein the evaluation value includes the amount of material constituting the stockpile that protrudes from a target space, the target shape includes a shape in which the material does not protrude from the target space, and bringing the shape of the stockpile closer to the target shape includes moving the material that protrudes from the target space to inside the target space.

4. A work machine control system as described in claim 3, wherein the controller calculates the amount of overhang based on the detection data, and if it determines that the amount of overhang is equal to or greater than a threshold, outputs a control command to move the material overhanging the target space toward the inside of the target space.

5. A control system for a work machine comprising a controller for a work machine having a traveling device and a work implement, the controller calculating a detected shape of the stockpile based on detection data from an external sensor that detects the stockpile formed at a work site, calculating a protruding position of material constituting the stockpile from a target space based on the detected shape, and determining whether or not to move the material protruding from the target space toward the inside of the target space based on the protruding position.

6. A work machine control system as described in claim 4 or claim 5, wherein the controller stores position data of a work space defined outside the target space at the work site, and generates an optimal path for the work machine to move the material that has protruded beyond the target space to the inside of the target space based on the relative position of the material that has protruded beyond the target space and the work space.

7. A control system for a work machine according to claim 6, wherein the controller calculates the nearest point from the working space of the material that has protruded outside the target space, and outputs a control command to move the material at the nearest point first inside the target space.

8. A work machine control system according to claim 1, wherein the evaluation value includes an inclination angle of the slope of the stockpile, the target shape includes a shape in which the inclination angle is within a target inclination angle range, and bringing the shape of the stockpile closer to the target shape includes adjusting the shape of the stockpile so that the inclination angle is within the target inclination angle range.

9. A work machine control system as set forth in claim 8, wherein the controller determines the detected position of the top and the detected position of the base of the stockpile based on the detection data, calculates the target position of the base based on the detected position of the top and the target shape, the evaluation value includes the distance between the detected position of the base and the target position of the base, and if it determines that the distance is equal to or greater than a threshold, outputs a control command to change the shape of the stockpile to the target shape.

10. A work machine comprising: the work machine control system according to claim 1; a traveling device; and a work implement.

11. A control method for a work machine having a traveling gear and a work implement, the control method comprising: calculating a detected shape of a stockpile formed at a work site based on detection data from an external sensor that detects the stockpile; and comparing a target shape of the stockpile with the detected shape of the stockpile using an evaluation value related to the shape of the stockpile to determine whether to modify the shape of the stockpile.

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