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

Abstract

This work machine control device comprises a processor. The processor: outputs a control command such that a work machine works near a work target on the basis of detection data from a position sensor that detects the position of the work machine; and if the position sensor has malfunctioned, outputs a control command such that the work machine continues working on the basis of detection data from an external sensor that detected the relative positions of the work machine and the work target.

Description

Control device for a work machine, work machine, control system for a work machine, and method for controlling a work machine.

[0001] This disclosure relates to a control device for a work machine, a work machine, a control system for a work machine, and a method for controlling a work machine.

[0002] In the technical field related to industrial machinery, a control device for industrial machinery, such as the one disclosed in Patent Document 1, is known. In Patent Document 1, the control device for industrial machinery enables the industrial machinery to operate automatically.

[0003] Japanese Patent Publication No. 2023-138009

[0004] When operating machinery automatically, its own position is detected using a satellite positioning system. If a malfunction occurs in the satellite positioning system, the machinery must be stopped. When the machinery stops working, its work efficiency may decrease.

[0005] This disclosure aims to suppress the decline in work efficiency.

[0006] This disclosure provides a control device for a work machine. The control device comprises a processor. Based on detection data from a position sensor that detects the work machine's own position, the processor outputs a control command to cause the work machine to work around the work object. If a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.

[0007] According to this disclosure, the decline in work efficiency is suppressed.

[0008] Figure 1 is a side view showing a work machine according to the first embodiment. Figure 2 is a top view showing a work machine according to the first embodiment. Figure 3 is a configuration diagram showing a work machine according to the first embodiment. Figure 4 is a hardware configuration diagram showing an automation controller according to the first embodiment. Figure 5 is a block diagram showing the control system of the work machine according to the first embodiment. Figure 6 is a diagram illustrating a method for generating a travel path for the work machine according to the first embodiment. Figure 7 is a diagram illustrating a method for estimating the self-position of the work machine according to the first embodiment. Figure 8 is a flowchart illustrating a control method for the work machine according to the first embodiment. Figure 9 is a flowchart illustrating a control method for the work machine according to the second embodiment.

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

[0010] [First Embodiment] The first embodiment will now be described.

[0011] <Work Machinery> Figure 1 is a side view showing work machine 1 according to this embodiment. Figure 2 is a top view showing work machine 1 according to this embodiment. Work machine 1 works at a work site. Examples of work sites include mines or quarries. A mine is a place or business where minerals are extracted. A quarry is a place or business where stone materials are extracted. Examples of mines include metal mines where metals are extracted, non-metallic mines where limestone is extracted, and coal mines where coal is extracted. In this embodiment, work machine 1 is a wheel loader that travels around the work site.

[0012] As shown in Figures 1 and 2, the work machine 1 comprises a vehicle frame 2, a work implement 3, a travel device 4, and a cab 5. The cab 5 is positioned on top of the vehicle frame 2. The work implement 3 and the travel device 4 are each attached to the vehicle frame 2.

[0013] The travel device 4 moves the work machine 1. The travel device 4 has a pair of front wheels 4A and a pair of rear wheels 4B. Each of the front wheels 4A and rear wheels 4B rotates while in contact with the ground at the work site. The work machine 1 moves as the front wheels 4A and rear wheels 4B rotate.

[0014] In this specification, the straight-line direction of the work machine 1 is defined as the front-rear direction of the work machine 1. In the front-rear direction, the side of the work machine 3 closer to the center of the work machine 1 is defined as the front, and the opposite side of the front is defined as the rear. The direction perpendicular to the contact surface of the front wheel 4A or rear wheel 4B that contacts a flat ground is defined as the up-down direction of the work machine 1. In the up-down direction, the side of the work machine 1 closer to the contact surface is defined as the lower side, and the opposite side of the lower side is defined as the upper side. When the work machine 1 is moving straight, the direction parallel to the axis of rotation of the front wheel 4A or rear wheel 4B is defined as the left-right direction of the work machine 1. In the left-right direction, one side when looking from the front is defined as the left side, and the other side is defined as the right side.

[0015] The vehicle frame 2 includes a front frame 2A and a rear frame 2B. The front frame 2A is positioned in front of the rear frame 2B. The 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 articulated mechanism 8. The front frame 2A and the rear frame 2B are connected so as to bend from side to side. The work machine 1 is an articulated work machine in which the front frame 2A and the rear frame 2B are connected so as to bend from side to side.

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

[0017] The work machine 1 performs its work using the 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 connecting member that extends in the left-right direction. The boom pin 9 includes 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] Bucket 6 is a work tool for excavation and loading. Bucket 6 is connected to the tip of the boom 14. Bucket 6 has a cutting edge 6A and a back surface 6B. Cutting edge 6A is the tip of bucket 6. Back surface 6B is a part of the outer surface of bucket 6. Back surface 6B is flat. Cutting edge 6A extends forward from back surface 6B. Bucket 6 is rotatably attached to the boom 14 by bucket pins 17. 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 central part 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 and the bucket 6. In the left-right direction, the bell crank 18 and the link 15 are positioned between the left boom member 14L and the right boom member 14R, respectively.

[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 cylinders 19 are hydraulic cylinders.

[0022] The rod of the boom cylinder 16 is connected to the boom 14. The cylinder tube of the boom cylinder 16 is connected to the front frame 2A. When the boom cylinder 16 expands and contracts, the boom 14 rotates about 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 portion (base end portion) of the bell crank 18 via the connecting pin 18B. When the bucket cylinder 19 expands and contracts, the bucket 6 rotates about the bucket pin 17.

[0024] The cab 5 is mounted on the upper part of the rear frame 2B. The cab 5 is arranged behind the boom 14. The operator of the working machine 1 gets on the cab 5.

[0025] FIG. 3 is a configuration diagram showing the working machine 1 according to the present embodiment. The working machine 1 includes a drive machine 20, a power take-off 21 (PTO: Power Take Off), 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 body controller 50, and an automation controller 100.

[0026] The drive machine 20 generates a driving force for operating the work implement 3 and the traveling device 4. The drive machine 20 is a drive source of the working machine 1. In the present embodiment, the drive machine 20 is a diesel engine. Note that the drive machine 20 may be an electric motor. The power take-off 21 distributes the driving force generated by the drive machine 20 to the power transmission device 22, the steering pump 24, and the 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 the traveling direction of the work machine 1. The power transmission device 22 may be a transmission having a torque converter or 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 drive 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 the steering control valve 25. The steering control valve 25 controls the flow rate and the direction of the hydraulic oil supplied from the steering pump 24 to the steering cylinder 11. The steering cylinder 11 operates by the hydraulic oil from the steering pump 24.

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

[0030] When the steering cylinder 11 expands and contracts, the traveling direction of the traveling device 4 is changed to the left direction or the right direction. When the boom cylinder 16 expands and contracts, the boom 14 performs a raising operation or a lowering operation. When the bucket cylinder 19 expands and contracts, a dumping operation or an excavation operation is performed.

[0031] The work machine 1 is equipped with an operating device 7. The operating device 7 generates an operation signal for operating the work machine 1 when operated by an operator. The operation signal generated by the operating device 7 is transmitted to the vehicle controller 50. Based on the operation signal from the operating device 7, the vehicle controller 50 outputs a command signal for operating the work machine 1. The operating device 7 includes a travel system operating device 7A and a work machine operating device 7B.

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

[0033] The implement operating device 7B generates an operating signal for operating the implement 3. The implement operating device 7B generates an operating signal for operating at least one of the boom cylinder 16 and the bucket cylinder 19. The 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] <Automation Controller> Figure 4 is a hardware configuration diagram showing the automation controller 100 according to this embodiment. The automation controller 100 is an example of a control device for the work machine 1. The automation controller 100 includes a computer 30. The computer 30 has a processor 31 such as a CPU (Central Processing Unit), a main memory 32 including non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory), 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 automation controller 100 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 according to the computer program 36. The computer program 36 may be distributed to the computer 30 via a network.

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

[0036] <Control System> Figure 5 is a block diagram showing the control system 10 of the 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 includes an automation controller 100, an automation sensor system 110, a vehicle body controller 50, a vehicle state sensor system 120, a user interface 130, a travel device 4, and a work machine 3. The automation controller 100, the automation sensor system 110, the vehicle body controller 50, the vehicle state 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 controller 50 outputs command signals for operating the travel device 4 and the work machine 3. The vehicle status sensor system 120 acquires detection data of the operating status of the work machine 1. The user interface 130 exchanges data with the operator.

[0038] The automation controller 100 can communicate with the vehicle controller 50. The automation controller 100 can communicate with the automation sensor system 110. In this embodiment, the operation mode of the work machine 1 can be switched between manual operation mode and automatic control mode. When the work machine 1 is operated in manual operation mode, the vehicle controller 50 outputs command signals to operate the travel device 4 and the work machine 3 based on the operation signals from the operation device 7. When the work machine 1 is operated in automatic control mode, the automation controller 100 outputs control commands. When the work machine 1 is operated in automatic control mode, the vehicle controller 50 outputs command signals to operate the travel device 4 and the work machine 3 based on the control commands from the automation controller 100.

[0039] The user interface 130 can communicate with the vehicle body controller 50 and the automation controller 100, respectively. The user interface 130 includes an input device 131 and an automation changeover switch 132.

[0040] The input device 131 is operated by an operator. The operation of the input device 131 generates input data. Examples of input devices 131 include a touch panel, buttons, and a computer keyboard. The input data generated by the operation of the input device 131 is input to the automation controller 100.

[0041] The automation changeover switch 132 is operated by the operator. When the automation changeover switch 132 is operated, the operating mode of the work machine 1 is switched between manual operation mode and automatic control mode. The operation signal generated when the automation changeover switch 132 is operated is input to the vehicle controller 50.

[0042] The automated sensor system 110 includes a position sensor 111 and an external environment sensor 112.

[0043] The position sensor 111 detects the position (self-position) of the work machine 1. The position sensor 111 detects the position of the work machine 1 using a satellite positioning system. An example of a satellite positioning system is the Global Navigation Satellite System (GNSS). The Global Navigation Satellite System includes the Global Positioning System (GPS). The satellite positioning system detects the position in a global coordinate system defined by latitude, longitude, and altitude coordinate data. A global coordinate system refers to a coordinate system fixed to the Earth. The position sensor 111 includes a receiver for the satellite positioning system. In this embodiment, the position sensor 111 includes a GNSS receiver. The position sensor 111 detects the position (absolute position) of the work machine 1 in the global coordinate system. Alternatively, the position sensor 111 may detect the position of the work machine 1 in a site coordinate system defined for the work site.

[0044] The external sensor 112 detects objects in the vicinity of the work machine 1. The external sensor 112 detects the relative position between the work machine 1 and the objects in the vicinity of the work machine 1. The objects in the vicinity of the work machine 1 include the work object of the work machine 1.

[0045] The external sensor 112 is a three-dimensional sensor that detects the three-dimensional shape of objects around the work machine 1. An example of the external sensor 112 is a laser sensor (LiDAR: Light Detection and Ranging) that detects objects by emitting laser light. Alternatively, the external sensor 112 may be a radar sensor (RADAR: Radio Detection and Ranging) that detects objects by emitting radio waves, or a stereo camera. As shown in Figures 1 and 2, in this embodiment, the external sensor 112 is provided on the upper surface of the cab 5.

[0046] Multiple external sensors 112 may be provided on the work machine 1. In the example shown in Figures 1 and 2, the external sensor 112 includes a front external sensor 112F that detects objects at least in front of the work machine 1, and a rear external sensor 112R that detects objects at least behind the work machine 1. The external sensor 112 may also include a left external sensor that detects objects at least to the left of the work machine 1, and a right external sensor that detects objects at least to the right of the work machine 1. The external sensor 112 may also include a first external sensor that detects objects to the left front of the work machine 1, a second external sensor that detects objects to the right front of the work machine 1, and a third external sensor that detects objects behind the work machine 1.

[0047] The external sensor 112 does not necessarily have to be installed on the work machine 1. The external sensor 112 only needs to be capable of detecting the relative position between the work machine 1 and the work object, and may be placed outside the work machine 1. The external sensor 112 may be installed, for example, on a drone capable of flying over the work site.

[0048] The vehicle controller 50 can communicate with the vehicle condition sensor system 120. The vehicle condition sensor system 120 includes an articulated 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.

[0049] The articulated angle sensor 121 detects the articulated angle, which is the angle between the front frame 2A and the rear frame 2B. The articulated angle is the steering angle of the work machine 1. The articulated angle sensor 121 is the steering angle sensor of the work machine 1.

[0050] The vehicle speed sensor 122 detects the travel speed of the work machine 1. The vehicle speed sensor 122 detects the travel speed of the work machine 1 by, for example, detecting the rotational speed of the output shaft of the power transmission device 22. In addition, the vehicle speed sensor 122 can detect the direction of travel (forward or backward) of the work machine 1 by, for example, detecting the rotational direction of the output shaft of the power transmission device 22.

[0051] The boom angle sensor 123 and the bucket angle sensor 124 are examples of work equipment posture sensors that detect the posture of the work equipment 3. 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 also be a stroke sensor located on the boom cylinder 16. The bucket angle sensor 124 may be a potentiometer or proximity switch attached to the bucket pin 17, or a stroke sensor located on the bucket cylinder 19.

[0052] 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 loaded and holding a load, the boom bottom pressure is high. When the bucket 6 is empty and not holding a load, the boom bottom pressure is low. The boom cylinder pressure sensor 125 functions as a load sensor to detect whether the bucket 6 is loaded or empty. The boom cylinder pressure sensor 125 also functions as a weight sensor to detect the weight of the load held in the bucket 6.

[0053] The detection data from the automated sensor system 110 is input to the automated controller 100. The detection data from the vehicle condition sensor system 120 is input to the vehicle body controller 50. The vehicle body controller 50 outputs the detection data from the vehicle condition sensor system 120 to the automated controller 100. The automated controller 100 acquires the detection data from the vehicle condition sensor system 120. The traveling device 4 and the work machine 3 each operate based on command signals from the vehicle body controller 50.

[0054] The vehicle controller 50 has multiple functional units. The functions of the vehicle controller 50 are performed by the processor 31 of the computer 30. The functional units of the vehicle controller 50 include a brake control unit 51, an accelerator control unit 52, a steering control unit 53, and a work equipment control unit 54.

[0055] 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 unit 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 machine 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 machine control unit 54, the work machine 3 is operated.

[0056] The automation controller 100 has multiple functional units. The functions of the automation controller 100 are performed by the processor 31 of the computer 30. The functional units of the automation controller 100 include a recognition unit 101, a route planning unit 102, a route following control unit 103, and a storage unit 104.

[0057] The memory unit 104 stores the data necessary for automatically controlling the work machine 1.

[0058] The recognition unit 101 acquires detection data from the position sensor 111. Based on the detection data from the position sensor 111, the recognition unit 101 recognizes the position of the work machine 1.

[0059] The recognition unit 101 acquires detection data from the external sensor 112. Based on the detection data from the external sensor 112, the recognition unit 101 recognizes objects around the work machine 1. As described above, the objects around the work machine 1 include the work object of the work machine 1. Based on the detection data from the external sensor 112, the recognition unit 101 recognizes the work object.

[0060] Recognizing the work object includes recognizing the relative position between the work machine 1 and the work object. Recognizing the work object includes recognizing the type of work object. Recognizing the type of work object includes recognizing the shape and size of the work object. Examples of operations that the work machine 1 can perform include excavation work, in which the bucket 6 excavates the excavation target; loading work, in which the bucket 6 loads the excavated material onto the loading target; and soil removal work, in which the bucket 6 discharges the excavated material onto the soil removal target. An example of a work object for the work machine 1 is a stockpile 144, which is the work object for excavation work. A stockpile 144 refers to a pile of material. Examples of material include soil, rock, or ore excavated at the work site. An example of a work object for the work machine 1 is a dump truck 150, which is the work object for loading work. Examples of work objects for the work machine 1 are a hopper, a belt conveyor, and the ground at the work site, which are the work objects for soil removal work.

[0061] The recognition unit 101 can recognize the work object by processing the detection data of the external sensor 112, for example, based on a pattern matching method. The recognition unit 101 can recognize the work object by comparing the detection data of the external sensor 112 with a reference pattern pre-stored in the storage unit 104. The recognition unit 101 can recognize that the type of work object is, for example, a stockpile 144 or a dump truck 150 by processing the detection data of the external sensor 112.

[0062] The route planning unit 102 generates target operation data indicating the target operating conditions for the automatically controlled work machine 1. The target operating conditions for work machine 1 include the target movement path of work machine 1. The target operation data for work machine 1 includes the target travel conditions for the travel device 4 and the target operation conditions for work machine 3. The target travel conditions for travel device 4 include the target travel path 160, which is the target movement path of travel device 4. The target operation conditions for work machine 3 include the target operation path, which is the target movement path of work machine 3.

[0063] The target movement path of the work machine 1 (the target travel path 160 of the travel device 4 and the target operation path of the work machine 3) may be defined by a line or by a plurality of points separated from each other.

[0064] When generating a target travel path 160 for the travel device 4, the route planning unit 102 acquires a work position indicating the location of the work target. Based on the work position, the route planning unit 102 generates a target travel path 160 for the work machine 1 to the work position.

[0065] The path-following control unit 103 outputs control commands for automatically controlling the traveling device 4 and the work machine 3. Based on the detection data from the position sensor 111, the path-following control unit 103 outputs control commands for automatically controlling the traveling device 4 and the work machine 3 so that the work machine 1 works around the work target.

[0066] The route-following control unit 103 outputs a control command to automatically control the work machine 1 so that it works around the work target, based on the target operation data generated by the route planning unit 102. The vehicle controller 50 outputs a command signal to at least one of the travel device 4 and the work machine 3 so that the work machine 1 works based on the target operation data, based on the travel control command from the route-following control unit 103.

[0067] The route-following control unit 103 outputs a control command to automatically control the travel device 4 of the work machine 1 so that it travels following the target travel route 160 generated by the route planning unit 102. Based on the control command from the route-following control unit 103, the vehicle controller 50 outputs a command signal to the travel device 4 so that it travels following the target travel route 160.

[0068] The path-following control unit 103 outputs control commands to automatically control the work implement 3 so that it operates in accordance with the target operation path generated by the path planning unit 102. Based on the control commands from the path-following control unit 103, the vehicle controller 50 outputs command signals to the work implement 3 so that it operates in accordance with the target operation path.

[0069] <Generation of Travel Path> Figure 6 is a diagram illustrating the method for generating the target travel path 160 of the work machine 1 according to this embodiment. In this embodiment, the work machine 1 alternately performs a first operation related to the stock pile 144 and a second operation related to the dump truck 150. The first operation is an excavation operation in which the bucket 6 excavates the stock pile 144. The second operation is a loading operation in which the excavated material of the stock pile 144 excavated by the bucket 6 is loaded onto the dump truck 150. The work machine 1 travels around the work site in order to alternately perform the excavation operation and the loading operation.

[0070] In this embodiment, the work targets of the work machine 1 are the stock pile 144 and the dump truck 150. The stock pile 144 is the first work target (excavation target) excavated by the bucket 6 of the work machine 3. The dump truck 150 is the second work target (loading target) into which the excavated material excavated by the bucket 6 is loaded.

[0071] As described above, the stockpile 144 refers to a pile of material. The dump truck 150 has a dump body 151 into which the cargo is loaded. The dump body 151 is a container into which the cargo is loaded. The second work object (loading object) may be considered to be the dump body 151 of the dump truck 150.

[0072] In this embodiment, the work machine 1 repeats excavation and loading operations by performing a so-called V-shape operation. The target travel path 160 is the travel path followed by the work machine 1 performing the V-shape operation. A switchback position 143, which is a reference position, is set at the work site. In the V-shape operation, the excavation operation includes the work machine 1 traveling between the switchback position 143 and the stockpile 144. In the V-shape operation, the loading operation includes the work machine 1 traveling between the switchback position 143 and the dump truck 150.

[0073] V-shape operation refers to the repeated operation of the work machine 1, which consists of a first forward movement, where the bucket 6 moves forward from the switchback position 143 towards the stock pile 144 in order to excavate the stock pile 144; a first backward movement, where the bucket 6 moves backward to the switchback position 143 after the excavated material is held in the bucket 6 by the first forward movement; a second forward movement, where the bucket 6 moves forward from the switchback position 143 towards the dump body 151 in order to load the excavated material held in the bucket 6 into the dump body 151; and a second backward movement, where the bucket 6 moves backward to the switchback position 143 after the excavated material is loaded into the dump body 151 by the second forward movement.

[0074] The switchback position 143 refers to the position where the work machine 1 performs a switchback. A switchback is an action in which the work machine 1, which is moving in reverse, makes a sharp change in direction and begins to move forward.

[0075] As shown in Figure 6, when generating the target travel route 160, the route planning unit 102 acquires a first work position 141 indicating the position of the stockpile 144, which is the first work target of the work machine 1, a second work position 142 indicating the position of the dump truck 150, which is the second work target of the work machine 1, and a switchback position 143, which is the reference position of the work machine 1.

[0076] The route planning unit 102 may acquire the first work position 141, the second work position 142, and the switchback position 143 from, for example, the input device 131. The operator can input the first work position 141, the second work position 142, and the switchback position 143 to the automation controller 100 by operating the input device 131. When the input device 131 is operated, input data indicating the first work position 141, the second work position 142, and the switchback position 143 is generated and input to the automation controller 100. The first work position 141, the second work position 142, and the switchback position 143 may also be input to the automation controller 100 from an external computer located outside the work machine 1. If there is a control computer that manages the work site, the route planning unit 102 may acquire the first work position 141, the second work position 142, and the switchback position 143 from the control computer.

[0077] In this embodiment, the first working position 141 is the target position of the working machine 1 when it performs the excavation work on the stockpile 144. The first working position 141 may also be the target position of the working machine 1 when the bucket 6 is fitted into the stockpile 144 when performing the excavation work on the stockpile 144. In this embodiment, the first working position 141 is not displaced. The first working position 141 is fixed.

[0078] In this embodiment, the second working position 142 is the target position of the working machine 1 when it is loading the dump truck 150. The second working position 142 may also be the target stopping position of the working machine 1 when it is loading the dump truck 150. The second working position 142 may also be the target stopping position of the dump truck 150 when it is loading the dump truck 150. In this embodiment, the second working position 142 is not displaced. The second working position 142 is fixed.

[0079] The switchback position 143 is set around the first working position 141 and the second working position 142. In this embodiment, the switchback position 143 does not move. The switchback position 143 is fixed.

[0080] In this embodiment, the first work position 141, the second work position 142, and the switchback position 143 are each defined in a global coordinate system. The route planning unit 102 generates a target travel route 160 based on the first work position 141, the second work position 142, and the switchback position 143. The position of the target travel route 160 is defined in a global coordinate system.

[0081] In this embodiment, the target travel path 160 includes a first travel path 161 of the work machine 1 connecting the switchback position 143 and the first work position 141, and a second travel path 162 of the work machine 1 connecting the switchback position 143 and the second work position 142.

[0082] Based on pre-measured survey data of the work site, 3D data representing the 3D shape of the work site's terrain is calculated. The survey includes detecting the 3D shape of the work site using a 3D sensor. For example, if a drone equipped with a 3D sensor flies over the work site and the 3D sensor on the drone detects the work site, the 3D data of the work site may be calculated based on the detection data from the 3D sensor on the drone. The 3D data of the work site may be calculated by the automation controller 100 or by an external computer such as a control computer. The route planning unit 102 calculates the optimal target travel route 160 based on the 3D data of the work site. If there are obstacles in the work site that obstruct the movement of the work machine 1, the location and size of the obstacles are calculated based on the survey data. The route planning unit 102 calculates the target travel route 160 so as to avoid the obstacles. The route planning unit 102 generates the target travel route 160 based on an existing route search algorithm, such as the A* search algorithm.

[0083] <Route Following> The route following control unit 103 outputs control commands to control the travel device 4 so that the work machine 1 follows the target travel route 160. Based on the target operation data generated in the route planning unit 102, the route following control unit 103 outputs control commands to control the travel device 4 and the work machine 3 so that the work machine 1 performs V-shape operation.

[0084] During the first forward movement and the first reverse movement, the work machine 1 travels along the first travel path 161. During the second forward movement and the second reverse movement, the work machine 1 travels along the second travel path 162.

[0085] The path-following control unit 103 outputs a control command to automatically control the travel device 4 of the work machine 1 so that it follows the target travel path 160, based on the detection data from the position sensor 111. The path-following control unit 103 outputs a control command to control the travel device 4 so that the deviation between the work machine 1's own position detected by the position sensor 111 and the position of the target travel path 160 is reduced. The vehicle controller 50 outputs a command signal to the travel device 4 so that the work machine 1 follows the target travel path 160, based on the control command from the path-following control unit 103.

[0086] The path-following control unit 103 outputs control commands to the work machine 1 to alternately perform the excavation work of the stock pile 144 and the loading work of the dump truck 150, based on the detection data of the position sensor 111 and the target operation data that defines the V-shape operation. The path-following control unit 103 outputs control commands to perform the first forward movement, the first reverse movement, the second forward movement, and the second reverse movement, based on the self position of the work machine 1 detected by the position sensor 111 and the target operation data.

[0087] The recognition unit 101 may estimate the self-position of the work machine 1 based on the detection data from the position sensor 111, the detection data from the external sensor 112, the detection data from the articulated angle sensor 121, and the detection data from the vehicle speed sensor 122. The path following control unit 103 may output control commands to control the travel device 4 so as to reduce the deviation between the self-position of the work machine 1 estimated by the recognition unit 101 and the position of the target travel path 160.

[0088] FIG. 7 is a diagram for explaining a method of estimating the self-position of the working machine 1 according to the present embodiment. FIG. 7 is a diagram for explaining an estimation method of calculating an estimated value of the self-position of the working machine 1 based on the detection data of the position sensor 111, the detection data of the external sensor 112, the detection data of the articulation angle sensor 121, and the detection data of the vehicle speed sensor 122. As shown in FIG. 7, the recognition unit 101 is an observation value y ｋ , ｋ (y １ｋ ), the observation value y ｋ (y ２ｋ ), which is the detection data of the external sensor 112, and the state x ｋ of the working machine 1 calculated by odometry are input to the extended Kalman filter, and an estimated value x^ about the current state of the working machine 1 is calculated. ｋ The estimated value x^[[ID=~13]] ｋ means the current self-position of the working machine 1. Note that the symbol " ^ " in this specification means the hat symbol written directly above the alphabetic characters in FIG. 7 and the following equations (1) and (2).

[0089] Odometry refers to a technique for estimating the current state of the traveling working machine 1 based on the detection data of an internal sensor that detects the traveling state of the working machine 1. The detection data of the internal sensor is input to the odometry as the input u ｋ . In the present embodiment, the internal sensors are the articulation angle sensor 121 and the vehicle speed sensor 122. The state x ｋ calculated by odometry is the position and orientation of the working machine 1.

[0090] The extended Kalman filter refers to an algorithm for estimating the state of a non-linear system based on the observation value y ｋ . The state x ｋ estimated by odometry is likely to accumulate errors due to the noise ω ｋ . The noise ω ｋExamples include the slippage of the tires of the running gear 4 relative to the ground, changes in the weight of the bucket 6 (whether the bucket 6 is loaded or empty), noise from the articulated angle sensor 121, and noise from the vehicle speed sensor 122. The extended Kalman filter is used to analyze state x ｋ The cumulative error (drift) is corrected.

[0091] Note that the observed value y ｋ Noise ν ｋ It may contain noise ν. ｋ Examples of such noise include noise from the position sensor 111 and noise from the external environment sensor 112.

[0092] The extended Kalman filter uses the state x at the previous time, estimated by odometry. ｋ and error covariance matrix Q ｋ Based on this, the current state x^ ｋ＋１ After predicting the state x^, the predicted state x^ is determined using the observed value y detected by the position sensor 111 and the external sensor 112. ｋ＋１ Update.

[0093] As shown in equation (1), the state x at the previous time is determined based on the nonlinear function f. ｋ , previous time input u ｋ , and noise ω from the previous time ｋ The current state x^ is calculated as follows: ｋ＋１ The following is calculated: Noise ω ｋ This is the error covariance matrix Q ｋ It is represented by [this].

[0094]

[0095] As shown in equation (2), the current observed value y is obtained based on the nonlinear function h. ｋ , and the current noise ν ｋ Therefore, the estimated value of the current observation y^ ｋ This is calculated. Noise ν ｋ This is the error covariance matrix R ｋ It is represented by [this].

[0096]

[0097] (1) Current state x^ calculated based on equationｋ＋１ The estimated value of the current observation, y^, is calculated based on equation (2). ｋ The estimated value x^, which indicates the current self-position of the work machine 1, is updated by this. ｋ＋１ This is calculated.

[0098] As shown in Figure 7, the estimated value x^ ｋ This is represented by a posterior error distribution with one peak value. Similarly, the observed value y^ from the position sensor 111 １ｋ and the observed value y^ from the external sensor 112 ２ｋ This is represented by the observation error distribution, and the state x^ at the previous time point. － ｋ This is represented by the prior error distribution.

[0099] <Position Sensor Malfunction> As described above, the path following control unit 103 controls the travel device 4 so that the work machine 1 follows the target travel path 160, based at least on the detection data of the position sensor 111. A malfunction may occur in the position sensor 111. A malfunction in the position sensor 111 includes the failure of the position sensor 111. A malfunction in the position sensor 111 includes a decrease in the detection accuracy of the position sensor 111. If a malfunction occurs in the position sensor 111, it may become difficult for the path following control unit 103 to make the work machine 1 travel along the target travel path 160 based on the detection data of the position sensor 111.

[0100] The position sensor 111 includes a receiver for a satellite positioning system. Examples of causes for a decrease in the detection accuracy of the position sensor 111 include ionospheric anomalies due to solar flares and communication anomalies with the satellite positioning system. For example, in work sites such as open-pit mines or underground mines, the likelihood of communication anomalies with the satellite positioning system is higher. Also, if there are obstacles at or around the work site, the likelihood of communication anomalies with the satellite positioning system is higher.

[0101] In this embodiment, the recognition unit 101 determines whether or not a malfunction has occurred in the position sensor 111. If the recognition unit 101 determines that a malfunction has occurred in the position sensor 111, the path-following control unit 103 outputs a control command to have the work machine 1 continue working, based on the detection data of the external sensor 112 which detects the relative position between the work machine 1 and the work object. If the path-following control unit 103 determines that a malfunction has occurred in the position sensor 111, it outputs a control command to have the work machine 1 continue V-shape operation, based on the detection data of the external sensor 112 and the target operation data.

[0102] <Control Method for the Work Machine> Figure 8 is a flowchart showing the control method for the work machine 1 according to this embodiment. The path-following control unit 103 outputs a control command to the work machine 1 to perform the excavation work of the stock pile 144 and the loading work onto the dump truck 150, based on the detection data of the position sensor 111 and the target operation data. That is, the path-following control unit 103 outputs a control command to the work machine 1 to perform V-shape operation, based on the detection data of the position sensor 111 and the target operation data. The path-following control unit 103 controls the travel device 4 so that the work machine 1 travels following the target travel path 160, based on the detection data of the position sensor 111.

[0103] The path-following control unit 103 determines whether or not the work (V-shape operation) of the work machine 1 is in an automatic work state based on the target operation data (step SA0). If it is determined in step SA0 that the automatic work state is not in place (step SA0: No), the process returns to step SA0.

[0104] If it is determined in step SA0 that the machine is in an automatic operation state (step SA0: Yes), the recognition unit 101 determines whether or not a malfunction has occurred in the position sensor 111 that detects the position of the work machine 1 using a satellite positioning system (step SA1).

[0105] In step SA1, if it is determined that there is no malfunction in the position sensor 111 (step SA1: No), the recognition unit 101 estimates the position of the work machine 1 based on the detection data from the position sensor 111. Alternatively, as explained with reference to Figure 7, the recognition unit 101 may estimate the position of the work machine 1 based on the detection data from the position sensor 111, the detection data from the external sensor 112, the detection data from the articulated angle sensor 121, and the detection data from the vehicle speed sensor 122 (step SA2).

[0106] The path-following control unit 103 outputs a control command to the work machine 1 to continue its work, based on the self-position of the work machine 1 estimated based on the detection data of the position sensor 111. In other words, the path-following control unit 103 outputs a control command to the work machine 1 to continue its V-shape operation based on the detection data of the position sensor 111 and the target operation data (step SA3).

[0107] The path-following control unit 103 determines whether or not to terminate the operation. That is, the path-following control unit 103 determines whether or not to terminate the V-shape operation (step SA4). If it is determined in step SA4 to continue the operation (step SA4: No), the process returns to step SA1. If it is determined in step SA4 to terminate the operation (step SA4: Yes), the path-following control unit 103 terminates the V-shape operation.

[0108] In step SA1, if it is determined that a malfunction has occurred in the position sensor 111 (step SA1: Yes), the recognition unit 101 switches from estimating the self-position of the work machine 1 based on the detection data of the position sensor 111 to estimating the self-position of the work machine 1 based on the detection data of the external sensor 112. Also, if it is determined that a malfunction has occurred in the position sensor 111, the recognition unit 101 determines the working state of the work machine 1 at the time Tj in which the malfunction of the position sensor 111 was determined (step SA5).

[0109] The working state of the work machine 1 includes the first working state (excavation work state) in which the work machine 1 is performing the first operation (excavation work), and the second working state (loading work state) in which the work machine 1 is performing the second operation (loading work).

[0110] The first working state (excavation working state) includes a first forward movement and a first reverse movement. The first working state includes a state in which the working machine 1 is traveling in accordance with the first travel path 161.

[0111] The second working state (loading state) includes a second forward movement and a second reverse movement. The second working state includes a state in which the work machine 1 is traveling in accordance with the second travel path 162.

[0112] The recognition unit 101 can determine, based on the target operation data, whether the work performed by the work machine 1 when a malfunction occurs in the position sensor 111 is the first work or the second work. The recognition unit 101 can determine, based on the target operation data, whether the work performed by the work machine 1 at the determination time Tj when it is determined that a malfunction has occurred in the position sensor 111 is the first work or the second work. For example, if the work machine 1 is controlled to sequentially perform a first forward movement, a first reverse movement, a second forward movement, and the second reverse movement based on the target operation data, the recognition unit 101 can determine, based on the target operation data, whether the work state of the work machine 1 at the determination time Tj is the first work state or the second work state. The recognition unit 101 can determine, based on the target operation data, whether the work machine 1 is performing the first forward movement, the first reverse movement, the second forward movement, or the second reverse movement.

[0113] The recognition unit 101 may determine the working state of the work machine 1 at determination time Tj based, for example, on the direction of travel of the work machine 1 (forward or backward) and the self-position of the work machine 1 at determination time Tj (immediately before determination time Tj). As described above, the vehicle speed sensor 122 can detect the direction of travel of the work machine 1 (forward or backward) by, for example, detecting the rotation direction of the output shaft of the power transmission device 22. The recognition unit 101 can recognize the direction of travel of the work machine 1 based on the detection data of the vehicle speed sensor 122. The recognition unit 101 can recognize the self-position of the work machine 1 at determination time Tj (immediately before determination time Tj) based on the detection data of the position sensor 111. As described above, the position of the target travel path 160 is defined in the global coordinate system. For example, if the self-position of the work machine 1 immediately before determination time Tj is on the first travel path 161 and the recognition unit 101 determines that the work machine 1 is moving forward, the recognition unit 101 can determine that the work machine 1 is performing a first forward movement at determination time Tj. If the recognition unit 101 determines that the work machine 1 is on the first travel path 161 at the determination time Tj and that the work machine 1 is moving backward, then the recognition unit 101 can determine that the work machine 1 is performing a first reverse movement at the determination time Tj. If the recognition unit 101 determines that the work machine 1 is on the second travel path 162 and that the work machine 1 is moving forward at the determination time Tj, then the recognition unit 101 can determine that the work machine 1 is performing a second forward movement at the determination time Tj. If the recognition unit 101 determines that the work machine 1 is on the second travel path 162 and that the work machine 1 is moving backward at the determination time Tj, then the recognition unit 101 can determine that the work machine 1 is performing a second reverse movement at the determination time Tj.

[0114] The recognition unit 101 may also determine the working state of the work machine 1 at the determination time Tj based on the direction of travel of the work machine 1 (forward or backward) and the weight of the load held in the bucket 6 at the determination time Tj. As described above, the boom cylinder pressure sensor 125 can detect whether the bucket 6 is loaded or empty. For example, if the recognition unit 101 determines that the bucket 6 is empty and the work machine 1 is moving forward at the determination time Tj, it can determine that the work machine 1 is performing a first forward movement at the determination time Tj. If the recognition unit 101 determines that the bucket 6 is loaded and the work machine 1 is moving backward at the determination time Tj, it can determine that the work machine 1 is performing a first backward movement at the determination time Tj. If the recognition unit 101 determines that the bucket 6 is loaded and the work machine 1 is moving forward at the determination time Tj, it can determine that the work machine 1 is performing a second forward movement at the determination time Tj. If the recognition unit 101 determines that the bucket 6 is empty and the work machine 1 is moving in reverse at the determination time Tj, it can determine that the work machine 1 is performing a second reverse movement at the determination time Tj.

[0115] In step SA5, the recognition unit 101 determines whether the working state of the work machine 1 when a malfunction occurs in the position sensor 111 is the first working state. The recognition unit 101 determines whether the working state of the work machine 1 at the determination time Tj is the first working state. In step SA5, if it is determined that the working state of the work machine 1 when a malfunction occurs in the position sensor 111 is the first working state (excavation work state) (step SA5: Yes), the recognition unit 101 estimates the self-position of the work machine 1 based on the relative position between the work machine 1 and the first work target (stock pile 144) detected by the external sensor 112 (step SA6).

[0116] In the first working state, there is a high probability that the external sensor 112 and the stockpile 144 are directly facing each other. That is, in the first working state, there is a high probability that the stockpile 144 is positioned within the detection range 112A of the external sensor 112. If the recognition unit 101 determines that the work performed by the work machine 1 at the determination time Tj is the first work, it can recognize the relative position between the work machine 1 and the first work target (stockpile 144) based on the detection data of the external sensor 112. Based on the relative position between the work machine 1 and the first work target (stockpile 144), the recognition unit 101 can estimate the self-position of the work machine 1 on the first travel path 161.

[0117] If the recognition unit 101 determines that the work of the work machine 1 is the first work (excavation work), the path following control unit 103 outputs a control command to have the work machine 1 continue the first work (excavation work) based on the relative position between the work machine 1 and the first work target (stock pile 144) recognized based on the detection data of the external sensor 112. If the work machine 1 was performing the first forward movement at the determination time Tj, the path following control unit 103 outputs a control command to have the work machine 1 continue the first forward movement. If the work machine 1 was performing the first reverse movement at the determination time Tj, the path following control unit 103 outputs a control command to have the work machine 1 continue the first reverse movement.

[0118] As described above, if the recognition unit 101 determines that the work performed by the work machine 1 is the first work, it can estimate the work machine 1's own position on the first travel path 161 based on the relative position between the work machine 1 and the first work target (stock pile 144). Based on the work machine 1's own position on the first travel path 161 estimated from the detection data of the external sensor 112, the path-following control unit 103 outputs a control command to the work machine 1 to continue the first work (excavation work) (step SA3). After the processing of step SA3 is performed, the processing of step SA4 is performed.

[0119] In step SA5, if the recognition unit 101 determines that the working state of the work machine 1 is not the first working state (excavation work state) (step SA5: No), the recognition unit 101 determines that the working state of the work machine 1 when the position sensor 111 malfunctions is the second working state (loading work state). If the recognition unit 101 determines that the working state of the work machine 1 is the second working state (loading work state), it estimates the self-position of the work machine 1 based on the relative position between the work machine 1 and the second work target (dump truck 150) detected by the external sensor 112 (step SA7).

[0120] In the second work state, there is a high probability that the external sensor 112 and the dump truck 150 are facing each other directly. That is, in the second work state, there is a high probability that the dump truck 150 is positioned within the detection range 112A of the external sensor 112. If the recognition unit 101 determines that the work of the work machine 1 at the determination time Tj is the second work, it can recognize the relative position between the work machine 1 and the second work target (dump truck 150) based on the detection data of the external sensor 112. Based on the relative position between the work machine 1 and the second work target (dump truck 150), the recognition unit 101 can estimate the self-position of the work machine 1 on the second travel path 162.

[0121] If the recognition unit 101 determines that the work of the work machine 1 is the second work (loading work), the path following control unit 103 outputs a control command to have the work machine 1 continue the second work (loading work) based on the relative position between the work machine 1 and the second work target (dump truck 150) recognized based on the detection data of the external sensor 112. If the work machine 1 was performing the second forward movement at the determination time Tj, the path following control unit 103 outputs a control command to have the work machine 1 continue the second forward movement. If the work machine 1 was performing the second reverse movement at the determination time Tj, the path following control unit 103 outputs a control command to have the work machine 1 continue the second reverse movement.

[0122] As described above, if the recognition unit 101 determines that the work performed by the work machine 1 is the second work, it can estimate the work machine 1's own position on the second travel path 162 based on the relative position of the work machine 1 and the second work target (dump truck 150). Based on the work machine 1's own position on the second travel path 162 estimated from the detection data of the external sensor 112, the path-following control unit 103 outputs a control command to the work machine 1 to continue the second work (excavation work) (step SA3). After the processing of step SA3 is performed, the processing of step SA4 is performed.

[0123] In this embodiment, even if a malfunction occurs in the position sensor 111, the path-following control unit 103 can output a control command to allow the work machine 1 to continue V-shape operation based on the relative position between the work machine 1 and the first work target (stockpile 144) recognized based on the detection data of the external sensor 112, and the relative position between the work machine 1 and the second work target (dump truck 150) recognized based on the detection data of the external sensor 112. When the work machine 1 is on the first travel path 161, the path-following control unit 103 can continue V-shape operation based on the relative position between the work machine 1 and the first work target (stockpile 144) recognized based on the detection data of the external sensor 112. When the work machine 1 is on the second travel path 162, the path-following control unit 103 can continue V-shape operation based on the relative position between the work machine 1 and the second work target (dump truck 150) recognized based on the detection data of the external sensor 112.

[0124] <Effects> As described above, the processor 31 of the automation controller 100 includes a path-following control unit 103 that outputs a control command to have the work machine 1 work around the work target based on detection data from a position sensor 111 that detects the self-position of the work machine 1, and a recognition unit 101 that determines whether or not a malfunction has occurred in the position sensor 111. If the path-following control unit 103 determines that a malfunction has occurred in the position sensor 111, it outputs a control command to have the work machine 1 continue working based on detection data from an external sensor 112 that detects the relative position between the work machine 1 and the work target.

[0125] According to this embodiment, even if a malfunction occurs in the satellite positioning system, the work of the work machine 1 can continue. Therefore, a decrease in the work efficiency of the work machine 1 is suppressed.

[0126] In this embodiment, the route planning unit 102 generates target operation data indicating the target operating conditions for the automatically controlled work machine 1. The target operation data for the work machine 1 includes the target travel route 160 of the travel device 4 and the target operation route of the work machine 3. Based on the target operation data, the route following control unit 103 outputs a control command so that the work machine 1 performs V-shape operation. If there is no malfunction in the position sensor 111, the route following control unit 103 outputs a control command so that the work machine 1 follows the target travel route 160, based on the self-position of the work machine 1 recognized based on the detection data of the position sensor 111 and the target operation data. If there is a malfunction in the position sensor 111, the route following control unit 103 outputs a control command so that the work machine 1 follows the target travel route 160, based on the relative position of the work machine 1 and the work object (at least one of the stock pile 144 and the dump truck 150) recognized based on the detection data of the external sensor 112 and the target operation data. As a result, even if a malfunction occurs in the position sensor 111, the operation of the work machine 1 can continue based on the detection data of the external sensor 112.

[0127] The target travel path 160 includes a first travel path 161 connecting the switchback position 143 and the first work position 141, and a second travel path 162 connecting the switchback position 143 and the second work position 142. When the recognition unit 101 determines that the work of the work machine 1 when a malfunction occurs in the position sensor 111 is the first work (excavation work), it can estimate the self-position of the work machine 1 on the first travel path 161 based on the relative position of the work machine 1 and the first work target (stockpile 144) recognized based on the detection data of the external sensor 112. The path following control unit 103 can continue the first work based on the self-position of the work machine 1 on the first travel path 161 estimated based on the detection data of the external sensor 112. If the recognition unit 101 determines that the work performed by the work machine 1 when a malfunction occurs in the position sensor 111 is the second work (loading work), it can estimate the work machine 1's own position on the second travel path 162 based on the relative position of the work machine 1 and the second work target (dump truck 150) recognized based on the detection data of the external sensor 112. The path following control unit 103 can continue the second work based on the work machine 1's own position on the second travel path 162 estimated based on the detection data of the external sensor 112.

[0128] [Second Embodiment] A second embodiment will now be described. In the following description, components that are the same as or equivalent to those in the first embodiment described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0129] Figure 9 is a flowchart showing the control method for the work machine 1 according to this embodiment. In this embodiment, the work of the work machine 1 is not limited to V-shape operation. The work of the work machine 1 includes work that approaches at least one of the first work target and the second work target. The first work target may be the stockpile 144 or a work target other than the stockpile 144. The second work target may be the dump truck 150 or a work target other than the dump truck 150.

[0130] Based on the detection data from the position sensor 111, the path-following control unit 103 outputs a control command to the work machine 1 to work around at least one of the first work target and the second work target. Based on the detection data from the position sensor 111, the path-following control unit 103 outputs a control command to the travel device 4 to travel around at least one of the first work target and the second work target.

[0131] The path-following control unit 103 determines whether or not the work of the work machine 1 is in an automatic work state based on the target operation data (step SB0). If it is determined in step SB0 that the work is not in an automatic work state (step SB0: No), the process returns to step SB0.

[0132] If it is determined in step SB0 that the machine is in an automatic operation state (step SB0: Yes), the recognition unit 101 determines whether or not a malfunction has occurred in the position sensor 111 that detects the position of the work machine 1 using a satellite positioning system (step SB1).

[0133] In step SB1, if it is determined that there is no malfunction in the position sensor 111 (step SB1: No), the recognition unit 101 estimates the position of the work machine 1 based on the detection data from the position sensor 111. Alternatively, as explained with reference to Figure 7, the recognition unit 101 may estimate the position of the work machine 1 based on the detection data from the position sensor 111, the detection data from the external sensor 112, the detection data from the articulated angle sensor 121, and the detection data from the vehicle speed sensor 122 (step SB2).

[0134] The path-following control unit 103 outputs a control command (step SB3) to allow the work machine 1 to continue working, based on the self-position of the work machine 1 estimated based on the detection data of the position sensor 111.

[0135] The route following control unit 103 determines whether or not to terminate the operation (step SB4). If it is determined in step SB4 to continue the operation (step SB4: No), the process returns to step SB1. If it is determined in step SB4 to terminate the operation (step SB4: Yes), the route following control unit 103 terminates the operation.

[0136] If the recognition unit 101 determines in step SB1 that a malfunction has occurred in the position sensor 111 (step SB1: Yes), the recognition unit 101 switches from estimating the self-position of the work machine 1 based on the detection data of the position sensor 111 to estimating the self-position of the work machine 1 based on the detection data of the external sensor 112. If the recognition unit 101 determines that a malfunction has occurred in the position sensor 111, it starts recognizing at least one of the first work target and the second work target based on the detection data of the external sensor 112.

[0137] In step SB5, the recognition unit 101 determines whether or not it has recognized the first work object based on the detection data from the external sensor 112 (step SB5). If it determines in step SB5 that it has recognized the first work object (step SB5: Yes), the recognition unit 101 estimates the position of the work machine 1 based on the relative position between the work machine 1 and the first work object detected by the external sensor 112 (step SB6).

[0138] If the work target recognized by the recognition unit 101 is the first work target, the path-following control unit 103 outputs a control command (step SB3) to the work machine 1 to continue the first work related to the first work target, based on the self-position of the work machine 1 estimated based on the relative position between the work machine 1 and the first work target. In this embodiment, the first work related to the first work target includes the work machine 1 traveling so as to approach the first work target. After the processing of step SB3 is performed, the processing of step SB4 is performed.

[0139] If, in step SB5, it is determined that the first work target is not recognized (step SB5: No), the recognition unit 101 determines whether or not the second work target has been recognized based on the detection data from the external sensor 112 (step SB7).

[0140] If the recognition unit 101 determines that it has recognized the second work target in step SB7 (step SB7: Yes), it estimates the position of the work machine 1 based on the relative position between the work machine 1 and the second work target detected by the external sensor 112 (step SB8).

[0141] If the work target recognized by the recognition unit 101 is the second work target, the path-following control unit 103 outputs a control command (step SB3) to the work machine 1 to continue the second work related to the second work target, based on the self-position of the work machine 1 estimated based on the relative position between the work machine 1 and the second work target. In this embodiment, the second work related to the second work target includes the work machine 1 traveling so as to approach the second work target. After the processing of step SB3 is performed, the processing of step SB4 is performed.

[0142] If, in step SB7, it is determined that the second work target is not recognized (step SB7: No), the recognition unit 101 continues searching for the work target using the external sensor 112 (step SB9). When continuing to search for the work target, the path following control unit 103 may operate the steering cylinder 11 to change the direction of the work machine 1 or switch the work machine 1 between forward and reverse movement. The work target searched by the external sensor 112 may be the first work target, the second work target, or a work target different from the first and second work targets.

[0143] The recognition unit 101 determines whether the external sensor 112 was able to locate the work target (step SB10). If it is determined in step SB10 that the work target was found (step SB10: Yes), the recognition unit 101 estimates the self-position of the work machine 1 based on the relative position between the work machine 1 detected by the external sensor 112 and the searched work target (step SB11).

[0144] The path-following control unit 103 outputs a control command (step SB3) to the work machine 1 to continue working on the work target, based on the work machine 1's own position estimated based on the relative position between the work machine 1 and the searched work target. In this embodiment, the work on the work target includes the work machine 1 traveling so as to approach the work target. After the processing in step SB3 is performed, the processing in step SB4 is performed.

[0145] If it is determined in step SB10 that the work target cannot be found (step SB10: No), the path following control unit 103 stops the movement of the work machine 1 (step SB12).

[0146] In this embodiment, the process of step SB5 is executed after the process of step SB1, and the process of step SB7 is executed after the process of step SB5. The order in which the processes of step SB1, step SB5, and step SB7 are executed is arbitrary. For example, the process of step SB7 may be executed after the process of step SB1, and the process of step SB5 may be executed after the process of step SB7. After the process of step SB5, one of the processes of step SB1 and step SB7 may be executed, and then the other process may be executed. After the process of step SB7, one of the processes of step SB1 and step SB5 may be executed, and then the other process may be executed.

[0147] As described above, even in this embodiment, if a malfunction occurs in the position sensor 111, the path-following control unit 103 can output a control command to allow the work machine 1 to continue working based on the relative position of the work machine 1 and the work object recognized based on the detection data of the external sensor 112. Therefore, a decrease in the work efficiency of the work machine 1 is suppressed.

[0148] [Other Embodiments] In the embodiments described above, the steering cylinder 11, boom cylinder 16, and bucket cylinder 19 are all hydraulic cylinders. At least one of the steering cylinder 11, boom cylinder 16, and bucket cylinder 19 may be an electrically operated cylinder.

[0149] In the above-described embodiment, the work machine 1 is automatically controlled by the automation controller 100. Furthermore, the operation mode of the work machine 1 can be switched between manual operation mode and automatic control mode. In manual operation mode, the work machine 1 is operated by an operator riding in the cab 5 using an operating device 7 located in the cab 5. The work machine 1 may also be remotely operated. The operating device 7 may be located outside the work machine 1, and the operation signal generated by operating the operating device 7 may be transmitted to the vehicle controller 50 via a wireless communication system.

[0150] In the above-described embodiment, the functions of the automation controller 100 may be provided on an external computer located outside the work machine 1. At least one of the functions of the recognition unit 101, the route planning unit 102, the route following control unit 103, and the storage unit 104 may be located on the external computer.

[0151] In the above embodiment, the work machine 1 is assumed to be a wheel loader. The work machine 1 may also be a front-loading bulldozer, a motor grader, an excavator, or a forklift.

[0152] [Note] The present disclosure may also adopt the following configurations: (Note 1) A control device for a work machine, comprising a processor, wherein the processor outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the self-position of the work machine, and, if a malfunction occurs in the position sensor, outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object. (Note 2) The control device for a work machine according to Note 1, wherein the work object includes at least one of an excavation target to be excavated by the work machine of the work machine and a loading target to which the excavated material from the work machine is loaded. (Note 3) The control device for a work machine as described in Note 1 or Note 2, wherein the work object includes a first work object and a second work object, the processor outputs a control command to cause the work machine to perform a first work related to the first work object and a second work related to the second work object based on the detection data of the position sensor and target operation data, if the work of the work machine is the first work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the first work based on the relative position between the work machine and the first work object recognized based on the detection data of the external sensor, and if the work of the work machine is the second work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the second work based on the relative position between the work machine and the second work object recognized based on the detection data of the external sensor. (Note 4) The control device for a work machine as described in Note 3, wherein the first operation includes traveling between a reference position and the first work target, the second operation includes traveling between the reference position and the second work target, and the processor outputs control commands to cause the work machine to alternately perform the first operation and the second operation based on the target operation data. (Note 5) The control device for a work machine as described in Note 4, wherein the first work target is an excavation target excavated by the work machine of the work machine, and the second work target is a loading target onto which the excavated material excavated by the work machine is loaded.(Note 6) The control device for a work machine according to Note 4 or Note 5, wherein the processor generates a target travel path for the work machine, which includes a first travel path connecting the reference position and a first work position indicating the position of the first work object, and a second travel path connecting the reference position and a second work position indicating the position of the second work object; outputs a control command to control the travel device of the work machine so that the work machine travels following the target travel path; estimates the self-position of the work machine in the first travel path based on the relative position between the work machine and the first work object when the work of the work machine is the first work; and estimates the self-position of the work machine in the second travel path based on the relative position between the work machine and the second work object when the work of the work machine is the second work. (Note 7) The work object includes a first work object and a second work object, and the processor, when a malfunction occurs in the position sensor, recognizes at least one of the first work object and the second work object based on the detection data of the external sensor, and outputs a control command to cause the work machine to continue working based on the relative position between the work machine and the recognized work object, as described in any one of Notes 1 to 6. (Note 8) The processor, when the recognized work object is the first work object, outputs a control command to cause the work machine to continue the first work relating to the first work object, and when the recognized work object is the second work object, outputs a control command to cause the work machine to continue the second work relating to the second work object, as described in Note 7. (Note 9) A work machine comprising a work machine, a traveling device, and a control device for a work machine as described in any one of Notes 1 to 8. (Note 10) A control system for a work machine, comprising a processor, wherein the processor outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the work machine's own position, and if a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.(Note 11) The control system for the work machine described in Note 10, wherein the work target includes at least one of the excavation target to be excavated by the work machine of the work machine and the loading target to which the excavated material excavated by the work machine is loaded. (Note 12) The control system for a work machine according to Note 10 or Note 11, wherein the work object includes a first work object and a second work object, the processor outputs a control command to cause the work machine to perform a first work related to the first work object and a second work related to the second work object based on the detection data of the position sensor and target operation data, if the work of the work machine is the first work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the first work based on the relative position between the work machine and the first work object recognized based on the detection data of the external sensor, and if the work of the work machine is the second work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the second work based on the relative position between the work machine and the second work object recognized based on the detection data of the external sensor. (Note 13) The control system for a work machine according to Note 12, wherein the first operation includes traveling between a reference position and the first work target, the second operation includes traveling between the reference position and the second work target, and the processor outputs control commands to cause the work machine to alternately perform the first operation and the second operation based on the target operation data. (Note 14) The control system for a work machine according to Note 13, wherein the first work target is an excavation target excavated by the work machine of the work machine, and the second work target is a loading target into which the excavated material excavated by the work machine is loaded.(Note 15) A control method for a work machine, comprising a control device equipped with a processor for the work machine, which outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the work machine's own position, and, if a malfunction occurs in the position sensor, outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.

[0153] 1...Working machine, 2...Vehicle frame, 2A...Front frame, 2B...Rear frame, 3...Working machine, 4...Traction system, 4A...Front wheels, 4B...Rear wheels, 5...Cab, 6...Bucket, 6A...Blade tip, 6B...Rear, 6L...Left bracket, 6R...Right bracket, 7...Operating device, 7A...Traction system operating device, 7B...Working machine operating device, 8...Articulation 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...drive unit, 21...power take-off, 22...power transmission unit, 23...brake unit, 24...steering pump, 25...steering control valve, 26...work equipment 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 control unit, 52...Accelerator control unit, 53...Steering control unit, 54...Work machine control unit, 71...Accelerator pedal, 72...Brake pedal, 73...Steering wheel, 74...Forward / reverse lever, 75...Boom lever, 76...Bucket lever, 100...Automation controller (control device for work machine), 101...Recognition unit, 102...Route planning unit, 103...Route following control unit, 104...Storage unit, 110...Automation sensor system, 111...Position sensor, 112...External environment sensor, 112A...Detection range, 112F...Front external environment sensor, 112R...Rear external environment sensor, 12 0...Vehicle status sensor system, 121...Articulated angle sensor, 122...Vehicle speed sensor, 123...Boom angle sensor, 124...Bucket angle sensor, 125...Boom cylinder pressure sensor, 130...User interface, 131...Input device, 132...Automation changeover switch, 141...First work position, 142...Second work position, 143...Switchback position, 144...Stock pile (First work target, excavation target), 150...Dump truck (Second work target, loading target), 151...Dump body, 160...Target travel path, 161...First travel path,162...Second route.

Claims

1. A control device for a work machine, comprising a processor, wherein the processor outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the work machine's own position, and, if a malfunction occurs in the position sensor, outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.

2. The control device for a work machine according to claim 1, wherein the work object includes at least one of an excavation target excavated by the work machine of the work machine and a loading target into which the excavated material excavated by the work machine is loaded.

3. The control device for a work machine according to claim 1, wherein the work object includes a first work object and a second work object, the processor outputs a control command to cause the work machine to perform a first work related to the first work object and a second work related to the second work object based on the detection data of the position sensor and target operation data, if the work of the work machine is the first work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the first work based on the relative position between the work machine and the first work object recognized based on the detection data of the external sensor, and if the work of the work machine is the second work when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the second work based on the relative position between the work machine and the second work object recognized based on the detection data of the external sensor.

4. The control device for a work machine according to claim 3, wherein the first operation includes traveling between a reference position and the first work object, the second operation includes traveling between the reference position and the second work object, and the processor outputs control commands to cause the work machine to alternately perform the first operation and the second operation based on the target operation data.

5. The control device for a work machine according to claim 4, wherein the first work target is an excavation target excavated by the work machine of the work machine, and the second work target is a loading target onto which the excavated material excavated by the work machine is loaded.

6. The control device for a work machine according to claim 4, wherein the processor generates a target travel path for the work machine, which includes a first travel path connecting the reference position and a first work position indicating the position of the first work object, and a second travel path connecting the reference position and a second work position indicating the position of the second work object; outputs a control command to control the travel device of the work machine so that the work machine travels following the target travel path; estimates the self-position of the work machine in the first travel path based on the relative position between the work machine and the first work object when the work of the work machine is the first work; and estimates the self-position of the work machine in the second travel path based on the relative position between the work machine and the second work object when the work of the work machine is the second work.

7. The control device for a work machine according to claim 1, wherein the work object includes a first work object and a second work object, and the processor, in the event of a malfunction in the position sensor, recognizes at least one of the first work object and the second work object based on the detection data of the external sensor, and outputs a control command to allow the work machine to continue working based on the relative position between the work machine and the recognized work object.

8. The control device for a work machine according to claim 7, wherein the processor outputs a control command to the work machine to continue the first work relating to the first work when the recognized work object is the first work object, and outputs a control command to the work machine to continue the second work relating to the second work object when the recognized work object is the second work object.

9. A work machine comprising a work machine, a traveling device, and a control device for the work machine described in claim 1.

10. A control system for a work machine, comprising a processor, wherein the processor outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the work machine's own position, and, if a malfunction occurs in the position sensor, outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.

11. The control system for a work machine according to claim 10, wherein the work object includes at least one of an excavation target excavated by the work machine of the work machine and a loading target into which the excavated material excavated by the work machine is loaded.

12. The control system for a work machine according to claim 10, wherein the work object includes a first work object and a second work object, the processor outputs a control command to cause the work machine to perform a first operation related to the first work object and a second operation related to the second work object based on the detection data of the position sensor and target operation data, if the work of the work machine is the first operation when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the first operation based on the relative position between the work machine and the first work object recognized based on the detection data of the external sensor, and if the work of the work machine is the second operation when a malfunction occurs in the position sensor, the processor outputs a control command to cause the work machine to continue the second operation based on the relative position between the work machine and the second work object recognized based on the detection data of the external sensor.

13. A control system for a work machine according to claim 12, wherein the first operation includes traveling between a reference position and the first work object, the second operation includes traveling between the reference position and the second work object, and the processor outputs control commands to cause the work machine to alternately perform the first operation and the second operation based on the target operation data.

14. The control system for a work machine according to claim 13, wherein the first work target is an excavation target excavated by the work machine of the work machine, and the second work target is a loading target into which the excavated material excavated by the work machine is loaded.

15. A control system for a work machine according to claim 13, wherein the processor generates a target travel path for the work machine, which includes a first travel path connecting the reference position and a first work position indicating the position of the first work object, and a second travel path connecting the reference position and a second work position indicating the position of the second work object; outputs a control command to control the travel device of the work machine so that the work machine travels following the target travel path; estimates the self-position of the work machine in the first travel path based on the relative position between the work machine and the first work object when the work of the work machine is the first work; and estimates the self-position of the work machine in the second travel path based on the relative position between the work machine and the second work object when the work of the work machine is the second work.

16. The control system for a work machine according to claim 10, wherein the work object includes a first work object and a second work object, and the processor, in the event of a malfunction in the position sensor, recognizes at least one of the first work object and the second work object based on the detection data of the external sensor, and outputs a control command to allow the work machine to continue working based on the relative position between the work machine and the recognized work object.

17. The control system for a work machine according to claim 16, wherein the processor outputs a control command to the work machine to continue the first work relating to the first work when the recognized work object is the first work object, and outputs a control command to the work machine to continue the second work relating to the second work object when the recognized work object is the second work object.

18. A control method for a work machine, comprising a control device equipped with a processor for the work machine, which outputs a control command to cause the work machine to work around a work object based on detection data from a position sensor that detects the work machine's own position, and, if a malfunction occurs in the position sensor, outputs a control command to cause the work machine to continue working based on detection data from an external sensor that detects the relative position between the work machine and the work object.

19. The method for controlling a work machine according to claim 18, wherein the work object includes at least one of an excavation target to be excavated by the work machine of the work machine and a loading target to which the excavated material excavated by the work machine is loaded.

20. A method for controlling a work machine according to claim 18, wherein the work object includes a first work object and a second work object, and the control device outputs a control command to cause the work machine to perform a first work related to the first work object and a second work related to the second work object based on the detection data of the position sensor and target operation data; when a malfunction occurs in the position sensor and the work of the work machine is the first work, outputs a control command to cause the work machine to continue the first work based on the relative position between the work machine and the first work object recognized based on the detection data of the external sensor; and when a malfunction occurs in the position sensor and the work of the work machine is the second work, outputs a control command to cause the work machine to continue the second work based on the relative position between the work machine and the second work object recognized based on the detection data of the external sensor.

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