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 acquires a first work position indicating the position of a first work object of a work machine, controls a travel device of the work machine such that the work machine moves toward the first work position, acquires detection data of an external sensor that detects the relative position between the work machine and the first work object when the work machine moves toward the first work position, determines a first travel route on the basis of the detection data of the external sensor, corrects the first travel route on the basis of the detection data of the external sensor of the work machine, and controls the travel device such that travel is performed following the corrected first travel route.

Description

Control device for working machine, working machine, control system for working machine, and control method for working machine

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

[0002] In the technical field related to working machines, a control device for a working machine as disclosed in Patent Document 1 is known. In Patent Document 1, the control device for a working machine plans a transport route for a working machine that loads and unloads a load.

[0003] Japanese Patent Application Laid-Open No. 2023-138009

[0004] When driving a working machine to a work target, there is a demand for a technology that can drive the working machine to the work target even if the exact position of the work target is unknown.

[0005] An object of the present disclosure is to drive a working machine to a work target.

[0006] According to the present disclosure, a control device for a working machine is provided. The control device includes a processor. The processor acquires a first working position indicating the position of a first work target of the working machine, controls a traveling device of the working machine so that the working machine heads toward the first working position, acquires detection data of an external sensor that detects the relative position between the working machine and the first work target when the working machine heads toward the first working position, determines a first travel route based on the detection data of the external sensor, modifies the first travel route based on the detection data of the external sensor of the working machine, and controls the traveling device to travel following the modified first travel route.

[0007] According to the present disclosure, a working machine can be driven to a work target.

[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 correcting a travel path according to the first embodiment. Figure 8 is a diagram illustrating the operation of the work machine according to the first embodiment. Figure 9 is a flowchart illustrating the control method of the work machine according to the first embodiment. Figure 10 is a diagram illustrating a travel path for the work machine according to the second embodiment. Figure 11 is a diagram illustrating a method for correcting a travel path according to the second embodiment. Figure 12 is a flowchart illustrating the control method of 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. As the boom cylinder 16 extends and retracts, the boom 14 rotates around the boom pin 9.

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

[0024] Cab 5 is mounted on top of the rear frame 2B. Cab 5 is positioned behind the boom 14. The operator of the work machine 1 sits in cab 5.

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

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

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

[0028] The steering pump 24 is driven based on the driving force generated by the drive unit 20. The steering pump 24 is a hydraulic pump. The hydraulic fluid 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 direction of the hydraulic fluid supplied from the steering pump 24 to the steering cylinder 11. The steering cylinder 11 is operated by the hydraulic fluid from the steering pump 24.

[0029] The work equipment pump 26 is driven by the driving force generated by the drive unit 20. The work equipment pump 26 is a hydraulic pump. The hydraulic fluid discharged from the work equipment pump 26 is supplied to the boom cylinder 16 via the boom control valve 27. The hydraulic fluid discharged from the work equipment 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 direction of the hydraulic fluid supplied from the work equipment pump 26 to the boom cylinder 16. The bucket control valve 28 controls the flow rate and direction of the hydraulic fluid supplied from the work equipment pump 26 to the bucket cylinder 19. The boom cylinder 16 and the bucket cylinder 19 are each operated by the hydraulic fluid from the work equipment pump 26.

[0030] The steering cylinder 11 extends and retracts, changing the direction of travel of the traveling device 4 to the left or right. The boom cylinder 16 extends and retracts, causing the boom 14 to move up or down. The bucket cylinder 19 extends and retracts, causing a dumping operation or an digging operation.

[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 automated switching switch 132 is operated by an operator. When the automated switching switch 132 is operated, the operation mode of the working machine 1 is switched between a manual operation mode and an automatic control mode. The operation signal generated by operating the automated switching switch 132 is input to the vehicle body controller 50.

[0042] The automated sensor system 110 includes a position sensor 111, an orientation sensor 112, and an external sensor 113.

[0043] The position sensor 111 detects the position of the working machine 1. The position of the working machine 1 is detected using a global navigation satellite system (GNSS: Global Navigation Satellite System). The global navigation satellite system includes a global positioning system (GPS: Global Positioning System). The global navigation satellite system detects the position in a global coordinate system defined by coordinate data of latitude, longitude, and altitude. The global coordinate system refers to a coordinate system fixed to the earth. The position sensor 111 includes a GNSS receiver and detects the position (absolute position) of the working machine 1 in the global coordinate system. Note that the position sensor 111 may detect the position (absolute position) of the working machine 1 in a site coordinate system defined at the work site.

[0044] The orientation sensor 112 detects the orientation of the working machine 1. The orientation of the working machine 1 includes an orientation angle with respect to a reference orientation. As the orientation sensor 112, an inertial sensor (IMU: Inertial Measurement Unit) is exemplified. Note that the orientation sensor 112 may include an arithmetic unit that calculates the orientation from the position data detected by two GNSS antennas provided on the working machine 1. The arithmetic unit can calculate the orientation from the vector connecting the two GNSS antennas.

[0045] The external sensor 113 detects an object around the working machine 1. The external sensor 113 detects the relative position between the working machine 1 and an object around the working machine 1. The object around the working machine 1 includes the work target of the working machine 1.

[0046] The external sensor 113 is a three-dimensional sensor that detects the three-dimensional shape of an object around the working machine 1. As the external sensor 113, a laser sensor (LiDAR: Light Detection and Ranging) that detects an object by emitting laser light is exemplified. Note that the external sensor 113 may be a radar sensor (RADAR: Radio Detection and Ranging) that detects an object by emitting radio waves, or may be a stereo camera. As shown in FIGS. 1 and 2, in the present embodiment, the external sensor 113 is provided on the upper surface of the cab 5.

[0047] A plurality of external sensors 113 may be provided on the working machine 1. In the example shown in FIGS. 1 and 2, the external sensor 113 includes a front external sensor 113F that detects at least a front object of the working machine 1 and a rear external sensor 113R that detects at least a rear object of the working machine 1. Note that the external sensor 113 may include a left external sensor that detects at least a left object of the working machine 1 and a right external sensor that detects at least a right object of the working machine 1. The external sensor 113 may include a first external sensor that detects an object in the left front of the working machine 1, a second external sensor that detects an object in the right front of the working machine 1, and a third external sensor that detects an object behind the working machine 1.

[0048] Note that the external sensor 113 does not necessarily have to be provided on the working machine 1. The external sensor 113 only needs to be able to detect the relative position between the working machine 1 and the work target, and may be arranged outside the working machine 1. The external sensor 113 may be provided, for example, on a drone that can fly over the work site.

[0049] The vehicle body controller 50 can communicate with the vehicle state sensor system 120. The vehicle state sensor system 120 includes an articulation angle sensor 121, a vehicle speed sensor 122, a boom angle sensor 123, and a bucket angle sensor 124.

[0050] 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.

[0051] 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.

[0052] 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.

[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 tracking 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 external sensor 113. Based on the detection data from the external sensor 113, 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 113, the recognition unit 101 recognizes the work object.

[0059] 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 loading operations, where the load held in the bucket 6 is loaded onto the loading target; soil removal operations, where the load held in the bucket 6 is discharged onto the soil removal target; and excavation operations, where the bucket 6 excavates the soil removal target. An example of a work object for the work machine 1 is a dump truck 150, which is the work object for loading operations. 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 operations. An example of a work object for the work machine 1 is a stockpile 145, which is the work object for excavation operations. A stockpile 145 refers to a pile of material. Examples of material include soil, rocks, or ore excavated at the work site.

[0060] The recognition unit 101 can recognize the work object by processing the detection data from the external sensor 113, for example, based on a pattern matching method. The recognition unit 101 can recognize the work object by comparing the detection data from the external sensor 113 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 dump truck 150 or a stockpile 145 by processing the detection data from the external sensor 113.

[0061] The route planning unit 102 generates a movement path for the automatically controlled work machine 1. The movement path of the work machine 1 includes the travel path 160 of the travel device 4 and the operating path of the work machine 3. The movement path of the work machine 1 (the travel path 160 of the travel device 4 and the operating path of the work machine 3) may be a continuous path defined by a line. The movement path of the work machine 1 may also be defined by a plurality of points that are spaced apart from each other. The movement path of the work machine 1 may also be defined by lines connecting a plurality of points that are spaced apart from each other.

[0062] When generating a 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 travel path 160 for the work machine 1 to the work position.

[0063] The path-following control unit 103 outputs control commands for automatically controlling the travel device 4 and the work machine 3. The path-following control unit 103 outputs a travel control command for automatically controlling the travel device 4 so that the travel device 4 of the work machine 1 travels in accordance with the travel path 160 generated by the path planning unit 102. Based on the travel control command from the path-following control unit 103, the vehicle controller 50 outputs a command signal to the travel device 4 so that the travel device 4 travels in accordance with the travel path 160. The path-following control unit 103 outputs a work machine control command for automatically controlling the work machine 3 so that the work machine 3 operates in accordance with the operation path generated by the path planning unit 102. Based on the work machine control command from the path-following control unit 103, the vehicle controller 50 outputs a command signal to the work machine 3 so that the work machine 3 operates in accordance with the operation path.

[0064] <Generating the Travel Path> Figure 6 is a diagram illustrating the method for generating the travel path 160 of the work machine 1 according to this embodiment. Below, an example will be described in which the work machine 1 travels around the work site to perform loading work to load cargo onto a dump truck 150. The work object of the work machine 1 is the dump truck 150. The dump truck 150 has a dump body 151 into which cargo is loaded. The dump body 151 is a container into which cargo is loaded. The work object of the work machine 1 may be considered to be the dump body 151 of the dump truck 150.

[0065] As shown in Figure 6, the route planning unit 102 acquires a first work position 141 indicating the position of the dump truck 150. Acquiring the first work position 141 includes acquiring detection data from the external sensor 113 that detected the dump truck 150 before the travel route 160 of the work machine 1 was generated.

[0066] The external sensor 113 can detect objects located close to it with high accuracy. However, it is difficult for the external sensor 113 to detect objects located far from it with high accuracy. As shown in Figure 6, for example, the external sensor 113 may have a fine detection range 113A and a rough detection range 113B. The rough detection range 113B is defined to be further from the external sensor 113 than the fine detection range 113A. The external sensor 113 can detect objects located in the fine detection range 113A with high accuracy. The external sensor 113 can detect objects located in the rough detection range 113B with rough accuracy. The detection accuracy of objects located in the rough detection range 113B by the external sensor 113 is lower than the detection accuracy of objects located in the fine detection range 113A by the external sensor 113.

[0067] Note that the fine detection range 113A and rough detection range 113B shown in Figure 6 are examples and conceptually represent the detection range of the external sensor 113. The external sensor 113 may have three or more detection ranges with mutually different detection accuracies. The detection accuracy of the external sensor 113 may gradually decrease as the distance from the external sensor 113 increases.

[0068] The work machine 1 is positioned at the starting position 140. The distance between the work machine 1 positioned at the starting position 140 and the dump truck 150 is long. In the example shown in Figure 6, with the work machine 1 positioned at the starting position 140, the dump truck 150 is positioned within the rough detection range 113B of the external sensor 113.

[0069] The recognition unit 101 acquires detection data from the external sensor 113 when the dump truck 150 is located in the rough detection range 113B. Based on the detection data from the external sensor 113, the recognition unit 101 recognizes a first working position 141 that indicates the position of the dump truck 150. The first working position 141 indicates the relative position of the dump truck 150 with respect to the work machine 1 located at the start position 140. The detection accuracy of the relative position between the work machine 1 and the dump truck 150 located in the rough detection range 113B by the external sensor 113 is lower than the detection accuracy of the relative position between the work machine 1 and the dump truck 150 located in the fine detection range 113A. Therefore, as shown in Figure 6, when the dump truck 150 is located in the rough detection range 113B, the position of the first working position 141 recognized based on the detection data from the external sensor 113 may deviate from the actual position of the dump truck 150.

[0070] The route planning unit 102 obtains the first work position 141 recognized when the dump truck 150 is positioned within the rough detection range 113B from the recognition unit 101. The route planning unit 102 generates a first travel route 161 that shows the travel route 160 of the work machine 1 from the start position 140 to the first work position 141.

[0071] The route planning unit 102 may, for example, obtain the first work position 141 from the input device 131. The operator can input the first work position 141 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 is generated and input to the automation controller 100. The first work position 141 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 obtain the first work position 141 from the control computer.

[0072] The first working position 141 may be the target position of the work object when the working machine 1 performs work on the work object. The first working position 141 may also be the target position of the dump truck 150 when the working machine 1 performs loading work on the dump truck 150. The first working position 141 may also be, for example, the target stopping position of the dump truck 150 on which the loading work is performed. The first working position 141 may also be considered as the target position of the working machine 1 when the working machine 1 performs work on the work object. The first working position 141 may also be considered as the target stopping position of the working machine 1 when the working machine 1 performs loading work on the dump truck 150.

[0073] If the first work position 141 is the target stopping position for the dump truck 150, the dump truck 150 enters the first work position 141 for loading and then stops at the first work position 141. Multiple dump trucks 150 enter the first work position 141 sequentially. The stopping positions of each of the multiple dump trucks 150 relative to the first work position 141 may differ from each other. If the dump truck 150 is a manned dump truck driven by a driver, the stopping positions of each of the multiple dump trucks 150 may differ from each other, for example due to differences in driving operation. If the dump truck 150 is an unmanned dump truck that operates without driver operation, the stopping positions of each of the multiple dump trucks 150 may differ from each other, for example due to control errors in the driving control of the unmanned dump truck. As shown in Figure 6, the actual stopping position of the dump truck 150 may deviate from the first work position 141.

[0074] The route planning unit 102 generates a first travel route 161 that shows the travel route 160 of the work machine 1 from the start position 140, which is the current position of the work machine 1, to the first work position 141. The route planning unit 102 generates the first travel route 161 of the work machine 1 so as to connect the start position 140 and the first work position 141.

[0075] In this embodiment, the work site is surveyed in advance. Based on the survey data, three-dimensional data representing the three-dimensional shape of the work site's terrain is calculated. The survey includes detecting the three-dimensional shape of the work site using a three-dimensional sensor. For example, if a drone equipped with a three-dimensional sensor flies over the work site and the three-dimensional sensor mounted on the drone detects the work site, the three-dimensional data of the work site may be calculated based on the detection data from the three-dimensional sensor mounted on the drone. The three-dimensional 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 travel route 160 based on the three-dimensional 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 travel route 160 so as to avoid the obstacles. The route planning unit 102 generates the travel route 160 based on an existing route search algorithm, such as the A* search algorithm.

[0076] The path-following control unit 103 controls the travel device 4 of the work machine 1 so that the work machine 1 moves toward the first work position 141. The path-following control unit 103 controls the travel device 4 of the work machine 1 so that the work machine 1 follows the first travel path 161 from the start position 140 to the first work position 141. Based on the detection data of the external sensor 113, the path-following control unit 103 outputs a travel control command to automatically control the travel device 4 so that the work machine 1 follows the first travel path 161. Based on the travel control command from the path-following control unit 103, the vehicle controller 50 outputs a command signal to the travel device 4 so that the work machine 3 operates following the first travel path 161. Based on the detection data of the external sensor 113, the steering control unit 53 outputs a command signal to the travel device 4 so that the travel device 4 travels following the first travel path 161.

[0077] In this embodiment, the path-following control unit 103 controls the travel device 4 so that the work machine 1 follows the first travel path 161, based on the detection data of the external sensor 113, without using the detection data of the position sensor 111 and the detection data of the orientation sensor 112.

[0078] The route planning unit 102 generates the operation path for the work implement 3. The route following control unit 103 outputs work implement control commands to automatically control the work implement 3 so that it operates in accordance with the operation path generated by the route planning unit 102. Based on the work implement control commands from the route following control unit 103, the vehicle controller 50 outputs command signals to the work implement 3 so that it operates in accordance with the operation path. Based on the detection data from the boom angle sensor 123 and the bucket angle sensor 124, the work implement control unit 54 outputs command signals to the work implement 3 so that it operates in accordance with the operation path.

[0079] <Modification of Travel Path> Figure 7 is a diagram illustrating a method for modifying the travel path 160 according to this embodiment. The recognition unit 101 acquires detection data from the external sensor 113, which detects the relative position between the work machine 1 and the dump truck 150, when the work machine 1 is moving toward the first work position 141. The recognition unit 101 acquires detection data from the external sensor 113 for at least a portion of the period during which the work machine 1 is moving toward the first work position 141. The recognition unit 101 may also acquire detection data from the external sensor 113 when the work machine 1 is stationary. The recognition unit 101 may also acquire detection data from the external sensor 113 when the work machine 1 is moving toward the first travel path 161. As the work machine 1 travels toward the first work position 141, following the first travel path 161, the distance from the work machine 1 to the first work position 141 gradually decreases. Based on the detection data from the external sensor 113, the recognition unit 101 can recognize the distance from the current position 148 of the work machine 1 to the first work position 141.

[0080] When the distance from the current position 148 of the work machine 1 to the first work position 141 decreases, the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113. For example, when the distance from the current position 148 to the first work position 141 becomes less than or equal to a predetermined distance Ds, the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113. When the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113, the recognition unit 101 can recognize the dump truck 150 with high accuracy based on the detection data from the external sensor 113.

[0081] The specified distance Ds is the maximum distance between the current position 148 of the work machine 1 and the first work position 141 when the first work position 141 is positioned within the fine detection range 113A of the external sensor 113. The specified distance Ds is known data derived, for example, from the specification data of the external sensor 113 and is stored in advance in the storage unit 104. The specified distance Ds may also be determined based on the performance of the work machine 1. The performance of the work machine 1 includes the minimum distance required for the work machine 1 to perform the loading operation of loading cargo onto the loading target. The specified distance Ds may be set to, for example, two times or more and five times or less the front-to-back dimension (overall length) of the work machine 1.

[0082] The recognition unit 101 recognizes the dump truck 150 based on the detection data of the external sensor 113 when the dump truck 150 is located within the fine detection range 113A. The route planning unit 102 determines the first travel route 161 based on the detection data of the external sensor 113. Determining the first travel route 161 includes modifying at least a portion of the first travel route 161 based on the detection data of the external sensor 113. The route planning unit 102 modifies at least a portion of the first travel route 161 based on the detection data of the external sensor 113 when the dump truck 150 is located within the fine detection range 113A.

[0083] The route planning unit 102 starts modifying at least a portion of the first travel route 161 when it determines that the recognition unit 101 has recognized the dump truck 150 based on the detection data from the external sensor 113 when the dump truck 150 is located within the fine detection range 113A. The route planning unit 102 may also start modifying at least a portion of the first travel route 161 when it determines that the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to a specified distance Ds.

[0084] The route planning unit 102 modifies the first work position 141 based on the detection data from the external sensor 113, and modifies the first travel route 161 based on the modified work position 141A that indicates the modified first work position 141. The first work position 141 is modified to coincide with the specified position of the dump truck 150.

[0085] As shown in Figure 7, in this embodiment, the designated position of the dump truck 150 is the center position of the dump body 151. The first working position 141 is modified to coincide with the center position of the dump body 151. The modified working position 141A is set to the center position of the dump body 151.

[0086] In this embodiment, modifying at least a portion of the first travel path 161 includes generating a branching path 143 connecting an intermediate position 161A on the first travel path 161 and a modification work position 141A. The route planning unit 102 generates a branching path 143 connecting an intermediate position 161A on the travel path 160 and a modification work position 141A based on the detection data of the external sensor 113. The intermediate position 161A is the current position 148 of the work machine 1 at the time when the recognition unit 101 recognizes the dump truck 150 based on the detection data of the external sensor 113 when the dump truck 150 is positioned in the fine detection range 113A.

[0087] Figure 8 is a diagram illustrating the operation of the work machine 1 according to this embodiment. The path-following control unit 103 controls the travel device 4 of the work machine 1 so that the work machine 1 follows the first travel path 161. As shown in Figure 8, the path-following control unit 103 controls the travel device 4 of the work machine 1 so that the work machine 1 follows the modified first travel path 161. The path-following control unit 103 controls the travel device 4 so that the work machine 1, which has traveled from the starting position 140 to the intermediate position 161A following the first travel path 161, follows the branched path 143 from the intermediate position 161A.

[0088] As the traveling device 4 travels along the branching path 143 to approach the dump body 151, the work machine 1 is positioned opposite the dump body 151. The path-following control unit 103 outputs a travel control command to stop the traveling device 4 when the work machine 1 and the dump body 151 are facing each other. The path-following control unit 103 outputs a work machine control command to load the cargo held in the bucket 6 onto the dump body 151. Based on the travel control command and work machine control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the traveling device 4 and the work machine 3 to load the cargo held in the bucket 6 onto the dump body 151.

[0089] In the example shown in Figure 8, the first working position 141 and the center position of the dump body 151 are far apart. If the first travel path 161 is not corrected, the work machine 1 will travel toward the first working position 141 and stop at a position opposite to the first working position 141. When the work machine 1 stops at a position opposite to the first working position 141, it may be difficult for the work machine 1 to load cargo onto the dump body 151. In this embodiment, the first travel path 161 is corrected when the work machine 1 approaches the dump truck 150 to a position where the external sensor 113 can detect the dump truck 150 with high accuracy. By correcting the first travel path 161, the work machine 1 can travel toward the dump truck 150. As a result, the work machine 1 can load cargo onto the dump body 151.

[0090] When loading the cargo held in the bucket 6 onto the dump body 151, the dump truck 150 is detected by the external sensor 113. Based on the detection data from the external sensor 113, the path-following control unit 103 can output a work implement control command to control the work implement 3 so that it does not come into contact with the dump body 151.

[0091] <Control Method for the Work Machine> Figure 9 is a flowchart showing the control method for the work machine 1 according to this embodiment. The route planning unit 102 acquires the first work position 141 (step SA1). The route planning unit 102 generates the first travel route 161 of the work machine 1 from the start position 140 to the first work position 141 (step SA2).

[0092] After the first travel path 161 is generated, the path-following control unit 103 outputs a travel control command to control the travel device 4 so that the work machine 1 travels along the first travel path 161 from the start position 140 to the first work position 141, based on the detection data of the external sensor 113 (step SA3).

[0093] The path-following control unit 103 determines whether the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to a predetermined distance Ds (step SA4). As described above, the predetermined distance Ds is the maximum distance between the current position 148 and the first work position 141 when the first work position 141 is located within the fine detection range 113A of the external sensor 113. As described above, the predetermined distance Ds may be determined based on the performance of the work machine 1.

[0094] In step SA4, if it is determined that the distance from the current position 148 of the work machine 1 to the first work position 141 is not less than or equal to the specified distance Ds (step SA4: No), the path following control unit 103 controls the travel device 4 so that the work machine 1 travels along the first travel path 161 to the first work position 141.

[0095] In step SA4, if it is determined that the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to the specified distance Ds (step SA4: Yes), the route planning unit 102 modifies the first travel route 161. The route planning unit 102 generates a branch route 143 connecting an intermediate position 161A of the first travel route 161 and the modified work position 141A set at the center position of the dump body 151 (step SA5).

[0096] After the first travel path 161 is modified, the path-following control unit 103 controls the travel device 4 so that the work machine 1 follows the modified first travel path 161 based on the detection data from the external sensor 113. The path-following control unit 103 outputs a travel control command to control the travel device 4 so that the work machine 1 follows the branched path 143 from an intermediate position 161A on the travel path 160 (step SA6).

[0097] After the work machine 1 approaches the dump truck 150, the path-following control unit 103 outputs a control command to perform a loading operation in which the load held in the bucket 6 is loaded onto the dump body 151 (step SA7). Based on the control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the travel device 4 and the work machine 3 so that the load held in the bucket 6 is loaded onto the dump body 151.

[0098] <Effects> As described above, the processor 31 of the automation controller 100 includes a route planning unit 102 that acquires a first work position 141 indicating the position of the dump truck 150, which is the first work target of the work machine 1; a recognition unit 101 that acquires detection data from an external sensor 113 that detects the relative position between the work machine 1 and the dump truck 150 when the work machine 1 is heading toward the first work position 141; and a route following control unit 103 that controls the travel device 4 of the work machine 1. The route planning unit 102 determines a first travel route 161 based on the detection data from the external sensor 113. The route following control unit 103 controls the travel device 4 so that the work machine 1 travels following the first travel route 161.

[0099] In the first state, when the work machine 1 is separated from the dump truck 150, it is difficult for the external sensor 113 to detect the exact position of the dump truck 150. The first state includes the state in which the dump truck 150 is located within the rough detection range 113B of the external sensor 113. Even if the exact position of the dump truck 150 is unknown, the route planning unit 102 can generate a first travel route 161 for the work machine 1 to the first work position 141 based on the first work position 141 of the dump truck 150.

[0100] In the second state, when the work machine 1 approaches the dump truck 150, the external sensor 113 can detect the dump truck 150 with high accuracy. The second state includes the state in which the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113. Since the relative position between the work machine 1 and the dump truck 150 is detected with high accuracy by the external sensor 113, the route planning unit 102 can determine the first travel route 161 so that the work machine 1 approaches the dump truck 150. The route following control unit 103 can bring the work machine 1 closer to the dump truck 150 by controlling the travel device 4 so that the work machine 1 travels along the first travel route 161.

[0101] Determining the first travel path 161 includes modifying at least a portion of the first travel path 161 based on detection data from the external sensor 113. If the first work position 141 and the actual position of the dump truck 150 are far apart and the first travel path 161 is not modified, the work machine 1 may arrive at the first work position 141 which is not suitable for the dump truck 150. For example, if the absolute positions of the work machine 1 and the dump truck 150 in the global coordinate system are obtained, but the relative positions of the work machine 1 and the dump truck 150 are not obtained, the work machine 1 may approach the dump truck 150 from a direction that makes it difficult to load cargo onto the dump body 151. Even if a GNSS receiver is installed on the dump truck 150 and the bearing of the dump truck 150 can be obtained based on the dump truck 150's travel history (past and present positions), the accuracy of the bearing of the dump truck 150 is low, making it difficult for the work machine 1 to move to an appropriate position where the work machine 3 and the dump truck 150 do not interfere with each other and are not too far apart. If the work machine 1 arrives at the first work position 141, which is far from the actual position of the dump truck 150, it becomes difficult for the work machine 1 to load cargo onto the dump body 151 of the dump truck 150.

[0102] In this embodiment, a first travel path 161 is generated in a first state when the work machine 1 is separated from the dump truck 150, and in a second state when the work machine 1 approaches the dump truck 150, the first travel path 161 is modified so that the work machine 1 approaches the dump truck 150. Therefore, even if the first work position 141 and the actual position of the dump truck 150 are far apart, the work machine 1 can reach the actual position of the dump truck 150. Since the work machine 1 can reach the actual position of the dump truck 150, it can load cargo onto the dump body 151 of the dump truck 150.

[0103] In this embodiment, a portion of the first travel path 161 is modified based on the detection data from the external sensor 113. In this embodiment, as a modification of the first travel path 161, a branching path 143 is generated that connects an intermediate position 161A of the first travel path 161 to a modification work position 141A. Since only a portion of the already planned first travel path 161 is modified, rather than replanning the entire first travel path 161, the computational load on the route planning unit 102 is reduced. Furthermore, the route planning unit 102 can modify the first travel path 161 while the work machine 1 is in motion.

[0104] When the work machine 1 arrives at a position facing the dump body 151, the external sensor 113 detects the three-dimensional shape of the dump truck 150. Based on the detection data from the external sensor 113, the path-following control unit 103 can load the cargo held in the bucket 6 onto the dump body 151 while suppressing contact between the bucket 6 and the dump body 151.

[0105] [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.

[0106] <Generation of Travel Path> Figure 10 is a diagram illustrating the travel path 160 of the work machine 1 according to this embodiment. In this embodiment, the route planning unit 102 acquires a first work position 141 indicating the position of the dump truck 150, which is the first work target of the work machine 1, and a second work position 142 indicating the position of the stockpile 145, which is the second work target of the work machine 1. The route planning unit 102 generates a travel path 160 that includes a first travel path 161 of the work machine 1 from the start position 140 to the first work position 141, and a second travel path 162 of the work machine 1 from the first work position 141 to the second work position 142.

[0107] In this embodiment, the first work position 141 and the second work position 142 are defined in a global coordinate system. The first work position 141 and the second work position 142 may be specified by the operator using an input device 131, or they may be specified by an external computer such as a control computer. The position of the travel path 160 is defined in a global coordinate system.

[0108] As mentioned above, a stockpile 145 refers to a pile of material. Examples of material include soil, rocks, or ore excavated at the work site.

[0109] The work machine 1 travels around the work site to perform loading operations to load cargo onto the dump truck 150 and excavation operations to excavate stock piles 145. The cargo is held in the bucket 6 of the work machine 1, which is positioned at the starting position 140. The first travel path 161 is the travel path 160 that follows the work machine 1 when it travels towards the dump truck 150 to load the cargo held in the bucket 6 onto the dump body 151. The second travel path 162 is the travel path 160 that follows the work machine 1 when it alternately repeats excavation operations to excavate stock piles 145 with the bucket 6 and loading operations to load the cargo held in the bucket 6 onto the dump body 151.

[0110] The second travel path 162 is the travel path 160 that the working machine 1, which performs a so-called V-shape operation, follows. The V-shape operation refers to the working machine 1 repeatedly performing the following actions: a first forward movement, which moves forward from the switchback position 144 towards the dump body 151 in order to load the cargo held in the bucket 6 onto the dump body 151; a first reverse movement, which moves backward to the switchback position 144 after the cargo held in the bucket 6 has been loaded onto the dump body 151 by the first forward movement; a second forward movement, which moves forward from the switchback position 144 towards the stock pile 145 in order to excavate the stock pile 145 with the bucket 6; and a second reverse movement, which moves backward to the switchback position 144 after the cargo has been held in the bucket 6 by the second forward movement.

[0111] In the first forward movement and the first reverse movement, the work machine 1 travels in a manner that follows the first portion 162A of the second travel path 162 connecting the switchback position 144 and the first work position 141. In the second forward movement and the second reverse movement, the work machine 1 travels in a manner that follows the second portion 162B of the second travel path 162 connecting the switchback position 144 and the second work position 142.

[0112] In this embodiment, the first working position 141 is the target position of the dump truck 150 when the work machine 1 performs loading work on the dump truck 150. The first working position 141 is the target stopping position of the dump truck 150 on which the loading work is performed. The first working position 141 may also be considered as the target position of the work machine 1 when the work machine 1 performs work on the work object. The first working position 141 may also be considered as the target stopping position of the work machine 1 when the work machine 1 performs loading work on the dump truck 150.

[0113] If the first work position 141 is the target stopping position for the dump truck 150, the dump truck 150 will enter the first work position 141 for loading and then stop at the first work position 141. Multiple dump trucks 150 will enter the first work position 141 sequentially. As described above, the stopping positions of each of the multiple dump trucks 150 relative to the first work position 141 may differ from each other. As shown in Figure 10, the actual stopping position of the dump truck 150 may be off from the first work position 141.

[0114] In this embodiment, the second working position 142 is the target position of the working machine 1 when it performs the excavation work on the stockpile 145. The second working position 142 may also be the target position of the working machine 1 when the bucket 6 is fitted into the stockpile 145 when it performs the excavation work on the stockpile 145. In this embodiment, the second working position 142 is not displaced. The second working position 142 is fixed.

[0115] The path-following control unit 103 controls the travel device 4 of the work machine 1 so that the work machine 1 follows the first travel path 161 from the starting position 140 to the first work position 141. After the work machine 1 has performed the loading operation on the dump body 151, the path-following control unit 103 controls the travel device 4 so that the work machine 1 follows the second travel path 162. In other words, after the work machine 1 has performed the loading operation while traveling along the first travel path 161, the path-following control unit 103 controls the travel device 4 and the work machine 3 so that the work machine 1 performs a V-shape operation.

[0116] In this embodiment, the path-following control unit 103 outputs a travel control command based on the detection data from the position sensor 111 so that the travel device 4 of the work machine 1 follows the travel path 160, which includes the first travel path 161 and the second travel path 162. The path-following control unit 103 outputs a travel control command to control the travel device 4 so that the deviation between the detected position of the work machine 1 detected by the position sensor 111 and the position on the travel path 160 is reduced. Based on the travel control command from the path-following control unit 103, the vehicle controller 50 outputs a command signal to the travel device 4 so that the work machine 1 follows the travel path 160.

[0117] The route planning unit 102 may generate a target direction for the work machine 1 when it is traveling along the travel route 160. The route following control unit 103 may output a travel control command to control the travel device 4 so as to reduce the deviation between the detected direction of the work machine 1 detected by the direction sensor 112 and the target direction defined in the travel route 160. The vehicle controller 50 may output a command signal to the travel device 4 based on the travel control command from the route following control unit 103. The steering control unit 53 may adjust the travel direction of the travel device 4 based on the detection data of the articulated angle sensor 121 so as to reduce the deviation between the detected direction of the work machine 1 and the target direction.

[0118] The route planning unit 102 may generate a target travel speed for the work machine 1 when it travels following the travel route 160. The route following control unit 103 may output a travel control command to control the travel device 4 so as to reduce the deviation between the detected travel speed of the work machine 1 detected by the vehicle speed sensor 122 and the target travel speed defined in the travel route 160. The vehicle body controller 50 may output a command signal to the travel device 4 based on the travel control command from the route following control unit 103. At least one of the brake control unit 51 and the accelerator control unit 52 may adjust the travel speed of the travel device 4 based on the detection data of the vehicle speed sensor 122 so as to reduce the deviation between the detected travel speed of the work machine 1 and the target travel speed.

[0119] <Modification of Travel Path> Figure 11 is a diagram illustrating the method for modifying the travel path 160 according to this embodiment. The work machine 1 starts traveling from the starting position 140. The work machine 1 travels from the starting position 140 toward the first work position 141, following the first travel path 161.

[0120] The recognition unit 101 acquires detection data from the external sensor 113, which detects the relative position between the work machine 1 and the dump truck 150, while the work machine 1 is traveling along the first travel path 161. As the work machine 1 travels toward the first work position 141 while following the first travel path 161, the distance from the work machine 1 to the first work position 141 gradually decreases. As described in the first embodiment above, when the distance from the current position 148 of the work machine 1 to the first work position 141 decreases, the dump truck 150 is positioned within the fine detection range 113A (not shown in Figure 11) of the external sensor 113. For example, when the distance from the current position 148 of the work machine 1 to the first work position 141 becomes less than or equal to a predetermined distance Ds, the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113. When the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113, the recognition unit 101 can recognize the dump truck 150 with high accuracy based on the detection data from the external sensor 113.

[0121] The recognition unit 101 recognizes the dump truck 150 based on the detection data from the external sensor 113 when the dump truck 150 is located within the fine detection range 113A. The route planning unit 102 modifies the travel route 160 based on the detection data from the external sensor 113 when the dump truck 150 is located within the fine detection range 113A.

[0122] The route planning unit 102 starts correcting the travel route 160 when it determines that the recognition unit 101 has recognized the dump truck 150 based on the detection data from the external sensor 113 when the dump truck 150 is located within the fine detection range 113A. The route planning unit 102 may also start correcting the travel route 160 when it determines that the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to a specified distance Ds.

[0123] In this embodiment, modifying the travel path 160 includes shifting the travel path 160 based on detection data from the external sensor 113 when the dump truck 150 is positioned within the fine detection range 113A.

[0124] The route planning unit 102 corrects the first work position 141 based on the detection data from the external sensor 113, and shifts the travel route 160 based on the corrected work position 141A which indicates the corrected first work position 141. The route planning unit 102 shifts the travel route 160 so that the corrected travel route 160 passes through the corrected work position 141A. The first work position 141 is corrected to coincide with the specified position of the dump truck 150.

[0125] As shown in Figure 11, in this embodiment, the designated position of the dump truck 150 is the center position of the dump body 151. The first working position 141 is modified to coincide with the center position of the dump body 151. The modified working position 141A is set to the center position of the dump body 151.

[0126] As shown in Figure 11, shifting the travel path 160 includes shifting the travel path 160 in a direction parallel to the imaginary line VL connecting the first work position 141 before correction and the corrected work position 141A. In other words, shifting the travel path 160 includes translating the entirety of the first travel path 161 and the second travel path 162 in a direction parallel to the imaginary line VL.

[0127] In Figure 11, the route 160A is the route 160 before modification. The route 160D is the route 160 after modification. In the following explanation, the route 160A showing the route 160 before modification will be appropriately referred to as the route 160A before modification, and the route 160D showing the route 160 after modification will be appropriately referred to as the route 160D after modification.

[0128] The starting point of the first travel path 161 of the pre-modification route 160A coincides with the start position 140. The ending point of the first travel path 161 of the pre-modification route 160A coincides with the pre-modification first work position 141. One end of the second travel path 162 of the pre-modification route 160A coincides with the ending point of the first travel path 161 of the pre-modification route 160A. The other end of the second travel path 162 of the pre-modification route 160A coincides with the second work position 142. The pre-modification route 160A passes through the first work position 141.

[0129] The starting point of the first travel path 161 of the modified route 160D is positioned at a location offset from the start position 140. The ending point of the first travel path 161 of the modified route 160D coincides with the modified work position 141A, which indicates the modified first work position 141. One end of the second travel path 162 of the modified route 160D coincides with the ending point of the first travel path 161 of the modified route 160D. The other end of the second travel path 162 of the modified route 160D is positioned at a location offset from the second work position 142. The modified route 160D passes through the modified work position 141A.

[0130] In this embodiment, the route planning unit 102 generates an intermediate route showing a travel route 160 obtained by shifting the pre-correction route 160A in a direction parallel to the virtual line VL between the pre-correction route 160A and the post-correction route 160D. The end of the first travel route 161 of the intermediate route is located between the first work position 141 before correction and the corrected work position 141A which indicates the first work position 141 after correction. The end of the first travel route 161 of the intermediate route may also be located on the virtual line VL between the first work position 141 and the corrected work position 141A.

[0131] In this embodiment, two intermediate paths are generated. The intermediate paths include a first intermediate path 160B and a second intermediate path 160C. The first intermediate path 160B is generated at a position closer to the original path 160A than the second intermediate path 160C.

[0132] The starting end of the first travel path 161 of the first intermediate path 160B is positioned at a location offset from the start position 140. The ending end of the first travel path 161 of the first intermediate path 160B is positioned on the imaginary line VL between the first work position 141 and the correction work position 141A. One end of the second travel path 162 of the first intermediate path 160B coincides with the ending end of the first travel path 161 of the first intermediate path 160B. The other end of the second travel path 162 of the first intermediate path 160B is positioned at a location offset from the second work position 142.

[0133] The starting end of the first travel path 161 of the second intermediate path 160C is positioned at a location offset from the start position 140. The ending end of the first travel path 161 of the second intermediate path 160C is positioned on the imaginary line VL between the ending end of the first intermediate path 160B and the correction work position 141A. One end of the second travel path 162 of the second intermediate path 160C coincides with the ending end of the first travel path 161 of the second intermediate path 160C. The other end of the second travel path 162 of the second intermediate path 160C is positioned at a location offset from the second work position 142.

[0134] When the path-following control unit 103 makes the work machine 1 travel along the first travel path 161, it first makes it travel along the first travel path 161 of the pre-correction path 160A, and then makes it travel along the first travel path 161 of the corrected path 160D. As shown by the dashed line in Figure 11, in this embodiment, when the path-following control unit 103 makes the work machine 1 travel along the first travel path 161, it makes it travel along the first travel path 161 of the pre-correction path 160A, the first travel path 161 of the first intermediate path 160B, the first travel path 161 of the second intermediate path 160C, and the first travel path 161 of the corrected path 160D, in sequence. The work machine 1 travels following the first travel path 161 of the pre-correction route 160A, then following the first travel path 161 of the first intermediate route 160B, then following the first travel path 161 of the second intermediate route 160C, and finally following the first travel path 161 of the corrected route 160D. This allows the work machine 1 to travel in a manner that approaches the corrected work position 141A set on the dump body 151.

[0135] After the work machine 1 approaches the dump body 151, the path-following control unit 103 outputs a travel control command so that the travel device 4 stops when the work machine 1 and the dump body 151 are facing each other. The path-following control unit 103 outputs a work machine control command so that the load held in the bucket 6 is loaded onto the dump body 151. Based on the travel control command and work machine control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the travel device 4 and the work machine 3 so that the load held in the bucket 6 is loaded onto the dump body 151.

[0136] After the load held in the bucket 6 is loaded onto the dump body 151, the route-following control unit 103 controls the travel device 4 so that the work machine 1 travels following the second travel path 162. When the route-following control unit 103 makes the work machine 1 travel to follow the second travel path 162, it first makes it travel to follow the second travel path 162 of the modified route 160D, and then makes it travel to follow the second travel path 162 of the unmodified route 160A. In this embodiment, when the route-following control unit 103 makes the work machine 1 travel to follow the second travel path 162, it makes it travel to follow the second travel path 162 of the modified route 160D, the second travel path 162 of the second intermediate route 160C, the second travel path 162 of the first intermediate route 160B, and the second travel path 162 of the unmodified route 160A in sequence. The work machine 1 travels following the second travel path 162 of the modified route 160D, then following the second travel path 162 of the second intermediate route 160C, then following the second travel path 162 of the first intermediate route 160B, and finally following the second travel path 162 of the pre-modification route 160A. This allows the work machine 1 to travel in a manner that approaches the second working position 142 set on the stock pile 145.

[0137] After the work machine 1 approaches the stockpile 145, the path-following control unit 103 outputs a control command to control the traveling device 4 and the work machine 3 so that the bucket 6 excavates the stockpile 145 when the work machine 1 and the stockpile 145 are facing each other. Based on the control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the traveling device 4 and the work machine 3 so that the bucket 6 excavates the stockpile 145.

[0138] <Control Method for the Work Machine> Figure 12 is a flowchart showing the control method for the work machine 1 according to this embodiment. The route planning unit 102 acquires the first work position 141 and the second work position 142 (step SB1). The route planning unit 102 generates a travel route 160 that includes the first travel route 161 of the work machine 1 from the start position 140 to the first work position 141, and the second travel route 162 from the first work position 141 to the second work position 142 (step SB2).

[0139] After the first travel path 161 and the second travel path 162 are generated, the path-following control unit 103 outputs a travel control command to control the travel device 4 of the work machine 1 so that the work machine 1 travels along the first travel path 161 from the start position 140 to the first work position 141 (step SB3).

[0140] The path-following control unit 103 determines whether the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to a predetermined distance Ds (step SB4). The predetermined distance Ds is the maximum distance between the current position 148 and the first work position 141 when the first work position 141 is located within the fine detection range 113A of the external sensor 113. The predetermined distance Ds is known data derived, for example, from the specification data of the external sensor 113, and is stored in advance in the storage unit 104.

[0141] In step SB4, if it is determined that the distance from the current position 148 of the work machine 1 to the first work position 141 is not less than or equal to the specified distance Ds (step SB4: No), the path following control unit 103 controls the travel device 4 so that the work machine 1 travels along the first travel path 161 to the first work position 141.

[0142] In step SB4, if it is determined that the distance from the current position 148 of the work machine 1 to the first work position 141 is less than or equal to the specified distance Ds (step SB4: Yes), the route planning unit 102 modifies the travel route 160. The route planning unit 102 calculates the modified work position 141A based on the detection data of the external sensor 113. As a modification of the travel route 160, the route planning unit 102 generates multiple travel routes 160 by shifting the original route 160A based on the modified work position 141A (step SB5).

[0143] In this embodiment, the route planning unit 102 generates a first intermediate route 160B obtained by shifting the pre-correction route 160A toward the correction work position 141A in a direction parallel to the virtual line VL, a second intermediate route 160C obtained by shifting the first intermediate route 160B toward the correction work position 141A, and a corrected route 160D obtained by shifting the second intermediate route 160C toward the correction work position 141A.

[0144] After multiple travel paths 160 (160A, 160B, 160C, 160D) are generated, each in a different position in a direction parallel to the virtual line VL, the path-following control unit 103 outputs a control command to cause the work machine 1 to travel following each of the first travel paths 161 of the multiple travel paths 160 (160A, 160B, 160C, 160D) (step SB6).

[0145] Based on the travel control command output from the route-following control unit 103, the work machine 1 travels to follow the first travel path 161 of the pre-correction route 160A, then travels to follow the first travel path 161 of the first intermediate route 160B, then travels to follow the first travel path 161 of the second intermediate route 160C, and finally travels to follow the first travel path 161 of the corrected route 160D. As a result, the work machine 1 can travel to approach the corrected work position 141A specified on the dump body 151.

[0146] After the work machine 1 approaches the dump body 151, the path-following control unit 103 outputs a control command to load the cargo held in the bucket 6 onto the dump body 151. Based on the control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the travel device 4 and the work machine 3 to load the cargo held in the bucket 6 onto the dump body 151. As a result, the loading operation of loading the cargo held in the bucket 6 onto the dump body 151 is performed (step SB7).

[0147] After the loading operation is completed, the route-following control unit 103 outputs a control command to cause the work machine 1 to follow each of the second travel paths 162 of the multiple travel paths 160 (160A, 160B, 160C, 160D) (step SB8).

[0148] Based on the control command output from the path-following control unit 103, the work machine 1 travels to follow the second travel path 162 of the modified path 160D, then travels to follow the second travel path 162 of the second intermediate path 160C, then travels to follow the second travel path 162 of the first intermediate path 160B, and finally travels to follow the second travel path 162 of the original path 160A. As a result, the work machine 1 can travel to approach the second working position 142 defined on the stockpile 145.

[0149] After the work machine 1 approaches the stockpile 145, the path-following control unit 103 outputs a control command to have the bucket 6 excavate the stockpile 145. Based on the control command from the path-following control unit 103, the vehicle controller 50 outputs command signals to the traveling device 4 and the work machine 3 to have the bucket 6 excavate the stockpile 145. As a result, the excavation work in which the bucket 6 excavates the stockpile 145 is carried out (step SB9).

[0150] The route planning unit 102 generates a second travel route 162 that includes the corrected work position 141A, the switchback position 144, and the second work position 142. The work machine 1 performs a V-shape operation while traveling along the second travel route 162 that includes the corrected work position 141A, the switchback position 144, and the second work position 142.

[0151] In this embodiment, the intermediate paths consist of two paths: a first intermediate path 160B and a second intermediate path 160C. The number of intermediate paths is arbitrary. The spacing between adjacent pairs of intermediate paths is also arbitrary. The number of intermediate paths and the spacing between them may be arbitrarily set according to the dimensions of the work machine 1. Furthermore, intermediate paths may be omitted. For example, if a first travel path 161 is generated that does not involve a sharp turn of the work machine 1, intermediate paths may be omitted.

[0152] <Effects> As described above, in this embodiment, the route planning unit 102 acquires a first work position 141 indicating the position of the dump truck 150, which is the first work target of the work machine 1, and a second work position 142 indicating the stock pile 145, which is the second work target, and generates a travel route 160 that includes a first travel route 161 from the start position 140 to the first work position 141 and a second travel route 162 from the first work position 141 to the second work position 142. The recognition unit 101 acquires detection data from the external sensor 113 while the work machine 1 is traveling in accordance with the first travel route 161, recognizes the dump truck 150, and calculates a corrected work position 141A. The route planning unit 102 shifts the travel route 160 based on the corrected work position 141A calculated based on the detection data from the external sensor 113.

[0153] In this embodiment as well, a first travel path 161 is generated in a first state when the work machine 1 is separated from the dump truck 150, and in a second state when the work machine 1 approaches the dump truck 150, the first travel path 161 is shifted so that the work machine 1 approaches the dump truck 150. Therefore, even if the first work position 141 and the actual position of the dump truck 150 are far apart, the work machine 1 can reach the actual position of the dump truck 150. Since the work machine 1 can reach the actual position of the dump truck 150, it can load cargo onto the dump body 151 of the dump truck 150.

[0154] In this embodiment, the entire travel path 160 is shifted based on the detection data from the external sensor 113. Rather than replanning the entire travel path 160, the already planned travel path 160 is shifted in a direction parallel to the virtual line VL, thereby reducing the computational load on the path planning unit 102.

[0155] [Other Embodiments] In the above-described embodiment, when the work machine 1 moves toward the first work position 141, a first travel path 161 is generated from the start position 140, which is the current position of the work machine 1, to the first work position 141, and the travel device 4 of the work machine 1 is controlled to move in accordance with the first travel path 161. The first travel path 161 from the start position 140 to the first work position 141 does not have to be generated. For example, a target direction from the start position 140 to the first work position 141 may be determined, and the travel device 4 may be controlled so that the work machine 1 moves toward the first work position 141 based on the determined target direction. After the work machine 1 approaches the first work position 141 and the dump truck 150 is positioned within the fine detection range 113A of the external sensor 113, the route planning unit 102 may determine the first travel path 161 connecting the work machine 1 and the dump truck 150.

[0156] In the above-described embodiment, 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] [Note] The present disclosure may also adopt the following configurations: (Note 1) A control device for a work machine, comprising a processor, the processor acquires a first work position indicating the position of a first work object of the work machine, controls the travel device of the work machine so that the work machine moves toward the first work position, acquires detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine is moving toward the first work position, determines a first travel path based on the detection data from the external sensor, modifies the first travel path based on the detection data from the external sensor of the work machine, and controls the travel device so that the work machine travels following the modified first travel path. (Note 2) The control device for a work machine according to Note 1, wherein the processor acquires detection data from the external sensor while the work machine is traveling following the first travel path. (Note 3) The control device for a work machine according to Note 1 or Note 2, wherein the processor generates a first travel path for the work machine from the current position of the work machine to the first work position, and determining the first travel path includes modifying at least a portion of the first travel path based on the detection data of the external sensor. (Note 4) The control device for a work machine according to Note 3, wherein the processor controls the travel device so that the work machine travels following the modified first travel path. (Note 5) The control device for a work machine according to Note 3 or Note 4, wherein acquiring the first work position includes acquiring detection data of the external sensor that detected the first work object before the first travel path was generated. (Note 6) The control device for a work machine according to any one of Notes 3 to 5, wherein the processor modifies the first work position based on the detection data of the external sensor, and modifies at least a portion of the first travel path based on the modified first work position. (Note 7) A control device for the work machine described in Note 6, wherein the first work position is modified to coincide with a specified position of the first work object.(Note 8) The processor acquires a second work position indicating the position of the second work object of the work machine, generates a travel path including the first travel path and the second travel path of the work machine from the first work position to the second work position, acquires detection data from the external sensor while the work machine is traveling so as to follow the first travel path, and shifts the travel path based on the detection data from the external sensor as a correction to the travel path, the control device for a work machine according to any one of Notes 3 to 7. (Note 9) The processor corrects the first work position based on the detection data from the external sensor, and shifts the travel path based on the corrected first work position, the control device for a work machine according to Note 8. (Note 10) The control device for a work machine as described in Note 9, wherein the first work position is modified to coincide with a specified position of the first work object, the end of the first travel path of the pre-modification path indicating the travel path before modification coincides with the first work position before modification, the end of the first travel path of the modified path indicating the travel path after modification coincides with the first work position after modification, and the processor, when causing the work machine to travel in accordance with the first travel path, causes it to travel in accordance with the first travel path of the pre-modification path, and then causes it to travel in accordance with the first travel path of the modified path, and when causing the work machine to travel in accordance with the second travel path, causes it to travel in accordance with the second travel path of the modified path, and then causes it to travel in accordance with the second travel path of the pre-modification path. (Note 11) The control device for the work machine according to Note 10, wherein shifting the travel path includes shifting the travel path in a direction parallel to a virtual line connecting the first work position before modification and the first work position after modification.(Note 12) The processor generates an intermediate path between the pre-correction path and the post-correction path, which shows the travel path obtained by shifting the pre-correction path in a direction parallel to the virtual line, the end of the first travel path of the intermediate path is positioned between the first work position before correction and the first work position after correction, and when the processor makes the work machine travel to follow the first travel path, it makes it travel to sequentially follow the first travel path of the pre-correction path, the first travel path of the intermediate path, and the first travel path of the post-correction path, and when the processor makes the work machine travel to follow the second travel path, it makes it travel to sequentially follow the second travel path of the post-correction path, the second travel path of the intermediate path, and the second travel path of the pre-correction path, the control device for the work machine as described in Note 11. (Note 13) A work machine comprising a work machine, a travel device, and the control device for the work machine as described in any one of Notes 1 to 12. (Note 14) A control system for a work machine, comprising a processor, the processor acquires a first work position indicating the position of a first work object of the work machine, controls the travel device of the work machine so that the work machine moves toward the first work position, acquires detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine is moving toward the first work position, determines a first travel path based on the detection data from the external sensor, modifies the first travel path based on the detection data from the external sensor of the work machine, and controls the travel device so that the work machine moves in accordance with the modified first travel path.(Note 15) A control method for a work machine, comprising a control device equipped with a processor for the work machine, which performs the following: acquiring a first work position indicating the position of a first work object of the work machine; controlling the travel device of the work machine so that the work machine moves toward the first work position; acquiring detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine moves toward the first work position; determining a first travel path based on the detection data from the external sensor; correcting the first travel path based on the detection data from the external sensor of the work machine; and controlling the travel device so that the work machine moves in accordance with the corrected first travel path.

[0161] 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, 5 1...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...Path planning unit, 103...Path following control unit, 104...Memory unit, 110...Automation sensor system, 111...Position sensor, 112...Orientation sensor, 113...External environment sensor, 113A...Fine detection range, 113B...Rough detection range, 1 13F...Front external sensor, 113R...Rear external sensor, 120...Vehicle status sensor system, 121...Articulated angle sensor, 122...Vehicle speed sensor, 123...Boom angle sensor, 124...Bucket angle sensor, 130...User interface, 131...Input device, 132...Automation changeover switch, 140...Start position, 141...First work position, 141A...Correction work position, 142...Second work position, 143...Branching route, 144...Switchback position, 145...Stock pile (second work target), 148...Current position, 150...Dump truck151...Dump body, 160...Travel route, 160A...Route before modification, 160B...First intermediate route, 160C...Second intermediate route, 160D...Route after modification, 161...First travel route, 161A...Intermediate position, 162...Second travel route, 162A...First part, 162B...Second part, Ds...Specified distance, VL...Imaginary line.

Claims

1. A control device for a work machine, comprising a processor, the processor acquires a first work position indicating the position of a first work object of the work machine, controls the travel device of the work machine so that the work machine moves toward the first work position, acquires detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine is moving toward the first work position, determines a first travel path based on the detection data from the external sensor, modifies the first travel path based on the detection data from the external sensor of the work machine, and controls the travel device so that the work machine moves in accordance with the modified first travel path.

2. The control device for a work machine according to claim 1, wherein the processor acquires detection data from the external sensor while the work machine is traveling along the first travel path.

3. The control device for a work machine according to claim 1, wherein the processor generates a first travel path for the work machine from the current position of the work machine to the first work position, and determining the first travel path includes modifying at least a portion of the first travel path based on detection data from the external sensor.

4. The control device for a work machine according to claim 3, wherein the processor controls the travel device so that the work machine travels following the modified first travel path.

5. The control device for a work machine according to claim 3, wherein acquiring the first work position includes acquiring detection data from the external sensor that detected the first work object before the first travel path was generated.

6. The control device for a work machine according to claim 3, wherein the processor modifies the first work position based on the detection data of the external sensor, and modifies at least a portion of the first travel path based on the modified first work position.

7. The control device for a work machine according to claim 6, wherein the first work position is modified to coincide with a specified position of the first work object.

8. The control device for a work machine according to claim 3, wherein the processor acquires a second work position indicating the position of a second work object of the work machine, generates a travel path including the first travel path and the second travel path of the work machine from the first work position to the second work position, acquires detection data from the external sensor while the work machine is traveling so as to follow the first travel path, and shifts the travel path based on the detection data from the external sensor as a correction to the travel path.

9. The control device for a work machine according to claim 8, wherein the processor corrects the first work position based on the detection data of the external sensor and shifts the travel path based on the corrected first work position.

10. The control device for a work machine according to claim 9, wherein the first work position is modified to coincide with a specified position of the first work object, the end of the first travel path of the pre-modification path indicating the travel path before modification coincides with the first work position before modification, the end of the first travel path of the modified path indicating the travel path after modification coincides with the first work position after modification, and the processor, when causing the work machine to travel in accordance with the first travel path, causes it to travel in accordance with the first travel path of the pre-modification path, and then causes it to travel in accordance with the first travel path of the modified path, and when causing the work machine to travel in accordance with the second travel path, causes it to travel in accordance with the second travel path of the modified path, and then causes it to travel in accordance with the second travel path of the pre-modification path.

11. The control device for a work machine according to claim 10, wherein shifting the travel path includes shifting the travel path in a direction parallel to a virtual line connecting the first work position before modification and the first work position after modification.

12. The processor generates an intermediate path between the pre-correction path and the post-correction path, which represents the travel path obtained by shifting the pre-correction path in a direction parallel to the virtual line, the end of the first travel path of the intermediate path is positioned between the first work position before correction and the first work position after correction, and when the processor makes the work machine travel to follow the first travel path, it makes the machine travel to sequentially follow the first travel path of the pre-correction path, the first travel path of the intermediate path, and the first travel path of the post-correction path, and when the processor makes the work machine travel to follow the second travel path, it makes the machine travel to sequentially follow the second travel path of the post-correction path, the second travel path of the intermediate path, and the second travel path of the pre-correction path, the control device for a work machine according to claim 11.

13. The control device for a work machine according to claim 3, wherein the processor determines that the distance from the work machine to the first work position has become less than or equal to a specified distance, and begins to modify at least a portion of the first travel path.

14. The control device for a work machine according to claim 3, wherein the processor recognizes the first work object based on the detection data of the external sensor, and when it determines that the first work object has been recognized, it starts correcting at least a portion of the first travel path.

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

16. A control system for a work machine, comprising a processor, the processor acquires a first work position indicating the position of a first work object of the work machine, controls the travel device of the work machine so that the work machine moves toward the first work position, acquires detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine is moving toward the first work position, determines a first travel path based on the detection data from the external sensor, modifies the first travel path based on the detection data from the external sensor of the work machine, and controls the travel device so that the work machine moves in accordance with the modified first travel path.

17. The control system for a work machine according to claim 16, wherein the processor acquires detection data from the external sensor while the work machine is traveling along the first travel path.

18. The control system for a work machine according to claim 16, wherein the processor generates a first travel path for the work machine from the current position of the work machine to the first work position, and determining the first travel path includes modifying at least a portion of the first travel path based on detection data from the external sensor.

19. The control system for a work machine according to claim 18, wherein the processor controls the travel device so that the work machine travels following the modified first travel path.

20. A control method for a work machine, comprising a control device equipped with a processor for the work machine, which performs the following: acquiring a first work position indicating the position of a first work object of the work machine; controlling the travel device of the work machine so that the work machine moves toward the first work position; acquiring detection data from an external sensor that detects the relative position between the work machine and the first work object when the work machine moves toward the first work position; determining a first travel path based on the detection data from the external sensor; correcting the first travel path based on the detection data from the external sensor of the work machine; and controlling the travel device so that the work machine moves in accordance with the corrected first travel path.

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