System and method for controlling work machine, and work machine

Abstract

To improve the degree of freedom of work by a work machine.SOLUTION: In a system for controlling a work machine, a controller controls the work machine by automatic travel control on the basis of a current position of the work machine so that the work machine travels according to a first target path. When a steering operation device is operated to intervene during automatic travel control, the controller aborts the automatic travel control and causes the work machine to turn in accordance with intervene operation to the steering operation device. When the intervene operation to the steering operation device is finished, the controller acquires the current position of the work machine at the time when the intervene operation to the steering operation device is finished, as an intervention finish position. The controller generates a second target path on the basis of the intervention finish position and the first target path. The controller resumes the automatic travel control and controls the work machine on the basis of the current position of the work machine so that the work machine travels according to the second target path.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] Conventionally, automatic driving control for controlling a working machine to travel along a predetermined target path is known. For example, in the control system of the working machine of Patent Document 1, a plurality of target paths extending parallel to each other are set. The control system controls the working machine so that the working machine travels along the plurality of target paths in order. While traveling along the target path, the working machine performs work such as excavation, whereby the terrain of the work site is constructed into a desired shape.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An operator of a working machine may want to adjust the target path when, for example, the operator wants to redo the work performed by the working machine. Alternatively, when an obstacle is found in the target path, the controller of the working machine may want to adjust the target path. However, in the above control system, the working machine travels along a plurality of predetermined target paths by automatic driving control. Therefore, the degree of freedom of work is low. An object of the present disclosure is to improve the degree of freedom of work by a working machine.

Means for Solving the Problems

[0005] A first aspect of the present disclosure is a system for controlling a working machine. The system includes a sensor, a steering operation device, and a controller. The sensor detects the current position of the working machine. The steering operation device is capable of intervening to turn the working machine left and right. The controller acquires a first target path of the working machine. The controller acquires the current position of the working machine. The controller controls the working machine by automatic driving control so that the working machine travels along the first target path based on the current position of the working machine. During the automatic driving control, when an intervening operation is performed on the steering operation device, the controller interrupts the automatic driving control and turns the working machine in response to the intervening operation on the steering operation device. When the intervening operation on the steering operation device ends, the controller acquires the position of the working machine at the time when the intervening operation on the steering operation device ends as the end position of the intervention. The controller generates a second target path based on the end position of the intervention and the first target path. The controller resumes the automatic driving control and controls the working machine so that the working machine travels along the second target path based on the current position of the working machine.

[0006] A second aspect of the present disclosure is a method for controlling a working machine. The method includes acquiring a first target path of the working machine, acquiring the current position of the working machine, controlling the working machine by automatic driving control so that the working machine travels along the first target path based on the current position of the working machine, receiving an operation signal capable of intervening to turn the working machine left and right, during the automatic driving control, when an intervening operation is performed, interrupting the automatic driving control and turning the working machine in response to the intervening operation, when the intervening operation ends, acquiring the position of the working machine at the time when the intervening operation ends as the end position of the intervention, generating a second target path based on the end position of the intervention and the first target path, and resuming the automatic driving control and controlling the working machine so that the working machine travels along the second target path based on the current position of the working machine.

[0007] A third aspect of the present disclosure is a work machine, comprising a sensor, a steering operation device, and a controller. The sensor detects the current position of the work machine. The steering operation device is capable of intervening to turn the work machine left and right. The controller acquires a first target path of the work machine. The controller acquires the current position of the work machine. The controller controls the work machine by automatic driving control so that the work machine travels along the first target path based on the current position of the work machine. When the steering operation device is intervened during the automatic driving control, the controller interrupts the automatic driving control and turns the work machine in response to the intervention operation on the steering operation device. When the intervention operation on the steering operation device ends, the controller acquires the position of the work machine when the intervention operation on the steering operation device ends as an intervention end position. The controller generates a second target path based on the intervention end position and the first target path. The controller resumes the automatic driving control and controls the work machine so that the work machine travels along the second target path based on the current position of the work machine.

Effect of the Invention

[0008] According to the present disclosure, when the steering operation device is intervened during the automatic driving control, the automatic driving control is interrupted and the work machine turns in response to the intervention operation on the steering operation device. Therefore, the degree of freedom of the work by the work machine is high. Further, when the intervention operation on the steering operation device ends, a second target path is generated based on the intervention end position indicating the position of the work machine when the intervention operation on the steering operation device ends and the first target path. Then, the automatic driving control is resumed and the work machine is controlled so that the work machine travels along the second target path.

Brief Description of the Drawings

[0009]

Figure 1

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Mode for Carrying Out the Invention

[0010] Hereinafter, the working machine according to the embodiment will be described with reference to the drawings. FIG. 1 is a side view showing the working machine 1 according to the embodiment. The working machine 1 according to the present embodiment is a bulldozer. The working machine 1 includes a vehicle body 11 and a working device 12.

[0011] The vehicle body 11 includes a driver's cab 13, an engine room 14, and a traveling device 15. A driver's seat (not shown) is arranged in the driver's cab 13. The engine room 14 is arranged in front of the driver's cab 13. The traveling device 15 is provided at the lower part of the vehicle body 11. The traveling device 15 includes a pair of left and right crawler belts 16. In FIG. 1, only the left crawler belt 16 is shown. The work machine 1 travels by the rotation of the crawler belt 16.

[0012] The work implement 12 is attached to the vehicle body 11. The work implement 12 has a lift frame 17, a blade 18, and a lift actuator 19. The lift frame 17 is supported by the vehicle body 11 so as to be rotatable about a lift axis X1. The blade 18 is arranged in front of the vehicle body 11. The blade 18 is supported by the lift frame 17. The lift actuator 19 is connected to the vehicle body 11 and the lift frame 17. Alternatively, the lift actuator 19 may be connected to the vehicle body 11 and the blade 18. The lift actuator 19 is a hydraulic cylinder. When the lift actuator 19 expands and contracts, the lift frame 17 moves up and down. The blade 18 moves up and down along with the up and down movement of the lift frame 17.

[0013] FIG. 2 is a block diagram showing the configuration of the drive system 2 and the control system 3 of the work machine 1. As shown in FIG. 2, the drive system 2 includes a drive source 22, a hydraulic pump 23, and a power transmission device 24. The drive source 22 includes, for example, an internal combustion engine. The drive source 22 may include an electric motor. The hydraulic pump 23 is driven by the drive source 22 and discharges hydraulic oil. The hydraulic oil discharged from the hydraulic pump 23 is supplied to the lift actuator 19. In FIG. 2, one hydraulic pump 23 is shown, but a plurality of hydraulic pumps may be provided.

[0014] The power transmission device 24 transmits the driving force of the drive source 22 to the traveling device 15. The power transmission device 24 may be, for example, an HST (Hydro Static Transmission). Alternatively, the power transmission device 24 may be, for example, a torque converter or a transmission having a plurality of speed gears.

[0015] The control system 3 includes a controller 26 and a control valve 27. The controller 26 is programmed to control the work machine 1 based on the acquired data. The controller 26 includes a storage device 28 and a processor 29. The processor 29 includes, for example, a CPU. The storage device 28 includes, for example, a memory and an auxiliary storage device. The storage device 28 may be, for example, a RAM or a ROM. The storage device 28 may be a semiconductor memory or a hard disk. The storage device 28 records computer instructions executable by the processor 29 for controlling the work machine 1.

[0016] The control valve 27 is controlled by a command signal from the controller 26. The control valve 27 is disposed between a hydraulic actuator such as the lift actuator 19 and the hydraulic pump 23. The control valve 27 controls the flow rate of the hydraulic oil supplied from the hydraulic pump 23 to the lift actuator 19. Note that the control valve 27 may be a pressure proportional control valve. Alternatively, the control valve 27 may be an electromagnetic proportional control valve.

[0017] The control system 3 includes a traveling operation device 31A, a steering operation device 31B, and a work implement operation device 31C. The traveling operation device 31A is operable by an operator to manually operate the forward and reverse traveling of the work machine 1. The traveling operation device 31A includes, for example, a traveling lever. However, the traveling operation device 31A may include other members such as a switch. The traveling operation device 31A is operable from a neutral position N1 to a forward position A1 and a reverse position B1. The traveling operation device 31A outputs a traveling command according to the operator's operation to the controller 26.

[0018] The steering operation device 31B is operable by an operator to manually steer the working machine 1. The steering operation device 31B includes, for example, a steering lever. However, the steering operation device 31B may include other members such as a steering wheel or a switch. The steering operation device 31B is operable from the neutral position N2 in the right turning direction A2 and the left turning direction B2. The steering operation device 31B outputs a steering command according to the operator's operation to the controller 26.

[0019] The working machine operation device 31C is operable by an operator to manually operate the working machine 12. The working machine operation device 31C includes, for example, a working machine lever. However, the working machine operation device 31C may include other members such as a switch. The working machine operation device 31C outputs a working command according to the operator's operation to the controller 26. Each of the operation devices 31A - 31C may be constituted by a common member.

[0020] The controller 26 controls the drive source 22 and the power transmission device 24 so as to make the working machine 1 travel according to the travel command from the travel operation device 31A. Thereby, the working machine 1 moves forward or backward according to the operation of the travel operation device 31A by the operator.

[0021] The controller 26 controls the drive source 22 and the power transmission device 24 so as to steer the working machine 1 left and right according to the steering command from the steering operation device 31B. For example, the controller 26 turns the working machine 1 left and right by the speed difference between the left and right crawlers 16. Thereby, the working machine 1 turns left or right according to the operation of the steering operation device 31B by the operator.

[0022] The controller 26 controls the control valve 27 so as to operate the working machine 12 according to the working command from the working machine operation device 31C. Thereby, the working machine 12 moves up and down according to the operation of the working machine operation device 31C by the operator.

[0023] The control system 3 includes an input device 32. The input device 32 includes, for example, a touch panel. However, the input device 32 may include other devices such as switches. The operator can use the input device 32 to set the automatic control of the working machine 1. The automatic control of the working machine 1 will be described in detail later.

[0024] The control system 3 includes a display 33. The display 33 is, for example, an LCD or an OLED. Alternatively, the display 33 may be another type of display 33. The display 33 may be a touch panel integrated with the input device 32. The display 33 displays a screen according to the image signal from the controller.

[0025] The control system 3 includes a position sensor 34. The position sensor 34 detects the current position and orientation of the working machine 1. The position sensor 34 includes, for example, a sensor based on GNSS (Global Navigation Satellite System). The position sensor 34 may include an IMU (Inertial Measurement Unit).

[0026] The controller 26 acquires the current position and orientation of the working machine 1 based on the detection signal from the position sensor 34. The controller 26 performs automatic driving control to control the traveling direction of the working machine 1 based on the current position and orientation of the working machine 1. For example, as shown in FIG. 2, the control system 3 includes an automatic control switch 35. The automatic control switch 35 can be operated by the operator to switch the on / off of the automatic driving control. The controller 26 enables the automatic driving control when the automatic control switch 35 is in the on state. The controller 26 disables the automatic driving control when the automatic control switch 35 is in the off state.

[0027] Hereinafter, the automatic travel control of the working machine 1 will be described. FIG. 3 is a flowchart showing the process of the automatic travel control. In the automatic travel control according to the present embodiment, the forward movement, reverse movement, and stop of the working machine 1 are controlled according to the manual operation of the travel operation device 31A by the operator.

[0028] In the automatic travel control, the left and right turning of the working machine 1 is automatically controlled so that the working machine 1 moves along the target travel route described later. For example, in the automatic travel control, when the working machine 1 deviates to the right from the target travel route, the controller 26 automatically turns the working machine 1 to the left so that the working machine 1 returns to the target travel route. In the automatic travel control, when the working machine 1 deviates to the left from the target travel route, the controller 26 automatically turns the working machine 1 to the right so that the working machine 1 returns to the target travel route.

[0029] As shown in FIG. 3, in step S101, the controller 26 acquires the current position and orientation of the working machine 1. The controller 26 acquires the current position of a predetermined reference point Pa1 of the working machine 1 as the current position of the working machine 1. The reference point Pa1 of the working machine 1 is included in the blade 18. For example, as shown in FIG. 4, the reference point Pa1 is the center in the vehicle width direction of the blade 18. Alternatively, the reference point Pa1 of the working machine 1 may be the left end or the right end of the blade 18. The reference point Pa1 of the working machine 1 may be changeable by the input device 32.

[0030] In step S102, the controller 26 acquires the first target route R1. The controller 26 stores the preset first target route R1. For example, the controller 26 stores the route set by the operator using the input device 32 as the first target route R1. Alternatively, the controller 26 may acquire the first target route R1 from an external computer. Alternatively, the controller 26 may automatically generate the first target route R1.

[0031] In step S103, the controller 26 sets a target travel route for the automatic driving control. The controller 26 sets the above-described first target route R1 as the target travel route.

[0032] In step S104, the controller 26 executes the automatic driving control according to the target travel route. The controller 26 moves the work machine 1 forward or backward in response to a manual operation of the travel operation device 31A by the operator, and controls the work machine 1 so that the work machine 1 travels according to the target travel route based on the current position and orientation of the work machine 1.

[0033] Specifically, as shown in FIG. 4, the controller 26 automatically turns the work machine 1 so that the reference point Pa1 moves along the first target route R1. Thereby, without the operator operating the steering operation device 31B, the work machine 1 is steered so that the work machine 1 travels according to the first target route R1 only by operating the travel operation device 31A. That is, as shown in FIG. 4, even when the steering operation device 31B is located at the neutral position N2, the work machine 1 is steered so that the work machine 1 travels according to the first target route R1 only by the operator operating the travel operation device 31A.

[0034] In step S105, the controller 26 determines whether the steering operation device 31B has been manually operated. The controller 26 determines that the steering operation device 31B has been manually operated when the steering operation device 31B is operated in the left turn direction or the right turn direction from the neutral position. When the steering operation device 31B has not been manually operated, in step S104, the controller 26 continues the automatic driving control. When the steering operation device 31B is manually operated during the automatic driving control, the process proceeds to step S106.

[0035] In step S106, the controller 26 turns the working machine 1 in response to a manual operation on the steering operation device 31B. The controller 26 temporarily interrupts the automatic travel control and turns the working machine 1 in response to a manual operation on the steering operation device 31B. For example, as shown in FIG. 5, when the steering operation device 31B is operated in the right turn direction A2, the controller 26 turns the working machine 1 to the right.

[0036] In step S107, the controller 26 determines whether the manual operation on the steering operation device 31B has ended. As shown in FIG. 6, the controller 26 determines that the manual operation on the steering operation device 31B has ended when the steering operation device 31B returns to the neutral position N2. If the manual operation on the steering operation device 31B has not ended, in step S106, the controller 26 continues to turn the working machine 1 in response to the manual operation on the steering operation device 31B. If the manual operation on the steering operation device 31B has ended, the process proceeds to step S108.

[0037] In step S108, the controller 26 generates a second target path R2. The controller 26 generates the second target path R2 based on the current position of the working machine 1 when the manual operation ends (hereinafter referred to as "intervention end position Pb1") and the first target path R1. As shown in FIG. 6, the second target path R2 is a path parallel to the first target path R1 passing through the intervention end position Pb1.

[0038] FIG. 7 is a flowchart showing the process for generating the second target path R2. As shown in FIG. 7, in step S201, the controller 26 acquires the intervention end position Pb1. The controller 26 acquires the current position of the working machine 1 when the manual operation ends as the intervention end position Pb1. In step S202, the controller 26 determines an offset reference position Pc1. As shown in FIG. 6, the controller 26 determines the position on the first target path R1 that is the shortest distance from the intervention end position Pb1 as the offset reference position Pc1.

[0039] In step S203, the controller 26 determines the offset direction. The controller 26 determines the offset direction based on the direction from the offset reference position Pc1 to the intervention end position Pb1. For example, as shown in FIG. 6, when the direction from the offset reference position Pc1 to the intervention end position Pb1 is to the right, the controller 26 determines the offset direction to the right.

[0040] In step S204, the controller 26 determines the offset distance D1. The controller 26 determines the shortest distance between the intervention end position Pb1 and the first target path R1 as the offset distance D1. In step S205, the controller 26 determines the second target path R2. The controller 26 determines the path obtained by offsetting the first target path R1 by the offset distance D1 in the offset direction as the second target path R2. For example, as shown in FIG. 6, the controller 26 determines the path obtained by offsetting the first target path R1 by the offset distance D1 to the right as the second target path R2.

[0041] As shown in FIG. 3, in step S109, the controller 26 updates the target travel path. The controller 26 updates the target travel path to the second target path R2 generated in step S108. Then, in step S104, the controller 26 executes automatic driving control according to the target travel path. That is, as shown in FIG. 8, the controller 26 uses the second target path R2 generated in step S108 as the new target travel path and executes automatic driving control according to the second target path R2.

[0042] Note that FIG. 6 shows an example where the intervention end position Pb1 is located to the right of the offset reference position Pc1. As shown in FIG. 9, when the intervention end position Pb1 is located to the left of the offset reference position Pc1, the controller 26 determines the path obtained by offsetting the first target path R1 by the offset distance D1 to the left as the second target path R2.

[0043] The controller 26 causes a display to show a guidance screen indicating the above-described target travel route. FIG. 10 is a diagram showing an example of the guidance screen 40. As shown in FIG. 10, the guidance screen 40 includes a first route image 41 and a machine image 42. The first route image 41 indicates the first target route R1. The machine image 42 indicates the working machine 1. During automatic travel control, the working machine 1 travels along the first target route R1 with the first target route R1 as the target travel route. Therefore, the controller 26 overlays the first route image 41 and the machine image 42 and displays them on the display 33.

[0044] When the working machine 1 is manually steered, as shown in FIGS. 11 and 12, the controller 26 changes the machine image 42 according to the current position and orientation of the working machine 1. Further, during manual operation, the controller 26 overlays a third route image 43 with the machine image 42 and displays it on the display 33. The third route image 43 indicates the predicted position of a second target route R2 generated based on the current position of the working machine 1 and the first target route R1. As shown in FIGS. 11 and 12, the controller 26 moves the third route image 43 according to the change in the current position of the working machine 1 due to manual operation.

[0045] When the manual operation ends, the controller 26 generates a second target route R2 based on the current position of the working machine 1 when the manual operation ends, and updates the target travel route to the second target route R2. As shown in FIG. 13, when the target travel route is updated to the second target route R2, the controller 26 erases the first route image 41, overlays a second route image 44 indicating the second target route R2 and the machine image 42, and displays them on the display 33.

[0046] Note that the controller 26 displays the third path image 43 on the display 33 in a display form different from that of the first path image 41 and the second path image 44. For example, the controller 26 displays the third path image 43 on the display 33 in a color different from that of the first path image 41 and the second path image 44. Alternatively, the controller 26 may display the third path image 43 on the display 33 in a shape (such as a solid line or a dashed line) different from that of the first path image 41 and the second path image 44.

[0047] According to the working machine 1 according to the present embodiment described above, when the steering operation device 31B is manually operated during the automatic driving control, the working machine 1 turns in response to the manual operation on the steering operation device 31B. Therefore, the degree of freedom of the work by the working machine 1 is high. Further, when the manual operation on the steering operation device 31B is completed, the second target path R2 is generated based on the current position of the working machine 1 when the manual operation on the steering operation device 31B is completed and the first target path R1. Then, the working machine 1 is controlled by the automatic driving control so as to travel along the second target path R2. Therefore, the operation burden on the operator is reduced.

[0048] FIG. 14 is a diagram showing an example of the work by the working machine 1 when a manual operation by the operator intervenes during the automatic driving control. As shown in FIG. 14, the working machine 1 performs operations such as excavation, leveling, or land leveling while moving forward along the first target path R1 from the first starting point Ps1 on the first target path R1. At this time, the controller 26 causes the working machine 1 to travel along the first target path R1 by the automatic driving control. After the working machine 1 reaches the first end point Pe1 on the first target path R1, it moves backward along the first target path R1. At this time, the controller 26 causes the working machine 1 to travel along the first target path R1 by the automatic driving control.

[0049] When the work machine 1 reaches the first intermediate point Pm1 on the first target path R1, the operator manually operates the steering operation device 31B to move the work machine 1 by a width W1 from the first target path R1 and then ends the manual operation. Thereby, the controller 26 generates a second target path R2 passing through the intervention end position Pb1 and updates the target travel path to the second target path R2. The work machine 1 reverses according to the second target path R2. At that time, the controller 26 causes the work machine 1 to travel according to the second target path R2 by automatic travel control.

[0050] Next, the work machine 1 performs work while moving forward from the second start point Ps2 on the second target path R2 according to the second target path R2. At that time, the controller 26 causes the work machine 1 to travel according to the second target path R2 by automatic travel control. After the work machine 1 reaches the second end point Pe2 on the second target path R2, it reverses according to the second target path R2. At that time, the controller 26 causes the work machine 1 to travel according to the second target path R2 by automatic travel control.

[0051] When the work machine 1 reaches the second intermediate point Pm2 on the second target path R2, the operator manually operates the steering operation device 31B to move the work machine 1 by a width W2 from the second target path R2 and then ends the manual operation. Thereby, the controller 26 generates a third target path R3 passing through the intervention end position Pb2 and updates the target travel path to the third target path R3. The work machine 1 reverses according to the third target path R3. At that time, the controller 26 causes the work machine 1 to travel according to the third target path R3 by automatic travel control.

[0052] Next, the work machine 1 performs work while moving forward from the third start point Ps3 on the third target path R3 according to the third target path R3. At that time, the controller 26 causes the work machine 1 to travel according to the third target path R3 by automatic travel control. After the work machine 1 reaches the third end point Pe3 on the third target path R3, it reverses according to the third target path R3. At that time, the controller 26 causes the work machine 1 to travel according to the third target path R3 by automatic travel control.

[0053] Thereafter, similarly, the operator manually operates the steering device 31B at the third intermediate point Pm3 to move the work machine 1 by a width W1 from the third target path R3. Thereby, the controller 26 generates a fourth target path R4 passing through the intervention end position Pb3. After the work according to the fourth target path R4 is completed, the operator manually operates the steering device 31B at the fourth intermediate point Pm4 to move the work machine 1 by a width W2 from the fourth target path R4. Thereby, the controller 26 generates a fifth target path R5 passing through the intervention end position Pb4.

[0054] Note that the width W1 corresponds to, for example, the length of the blade in the vehicle width direction. Thereby, the work machine 1 can perform work efficiently. Also, the width W2 is smaller than the width W1. For example, the operator determines the width W2 in consideration of the overlap distance. As shown in FIG. 15, the overlap distance D2 is the distance in the vehicle width direction of the overlapping range C3 where the work range C1 by the work machine 12 according to the previous target path (second target path R2) and the work range C2 by the work machine 12 according to the next target path (third target path R3) overlap. For example, when the operator wants to partially correct the work range C1 according to the previous target path, the operator determines the width W2 in consideration of the overlap distance D2.

[0055] Next, another example of the target travel path will be described. FIG. 16 is a diagram showing a target travel path according to another example. As shown in FIG. 16, the first target path R1 includes a first curved portion R1A, a first front straight portion R1B, and a first rear straight portion R1C. The first front straight portion R1B extends forward from the first curved portion R1A. The first rear straight portion R1C extends rearward from the first curved portion R1A. The controller 26 generates a second target path R2 based on the intervention end position Pb1 and the first target path R1. As shown in FIG. 16, the second target path R2 is a path parallel to the first target path R1 passing through the intervention end position Pb1.

[0056] Specifically, the controller 26 determines a position on the first target path R1 that is the shortest distance from the intervention end position Pb1 as the offset reference position Pc1. The controller 26 determines the offset direction based on the direction from the offset reference position Pc1 toward the intervention end position Pb1. For example, as shown in FIG. 16, when the direction from the offset reference position Pc1 toward the intervention end position Pb1 is to the right, the controller 26 determines the offset direction to the right.

[0057] The controller 26 determines the shortest distance between the intervention end position Pb1 and the first target path R1 as the offset distance D1. The controller 26 determines a path obtained by offsetting the first target path R1 by the offset distance D1 in the offset direction as the second target path R2. For example, as shown in FIG. 16, the controller 26 determines a path obtained by offsetting the first target path R1 by the offset distance D1 to the right as the second target path R2.

[0058] The second target path R2 includes a second curved portion R2A, a second front straight portion R2B, and a second rear straight portion R2C. The second curved portion R2A is located in the offset direction with respect to the first curved portion R1A and is parallel to the first curved portion R1A. The second front straight portion R2B extends forward from the second curved portion R2A. The second front straight portion R2B is located in the offset direction with respect to the first front straight portion R1B and is parallel to the first front straight portion R1B. The second rear straight portion R2C extends rearward from the second curved portion R2A. The second rear straight portion R2C is located in the offset direction with respect to the first rear straight portion R1C and is parallel to the first rear straight portion R1C.

[0059] As shown in FIG. 16, when the offset direction is a direction toward the inner diameter side of the first curved portion R1A, the controller 26 makes the diameter of the second curved portion R2A smaller than the diameter of the first curved portion R1A. Further, the controller 26 makes the length of the second curved portion R2A shorter than the length of the first curved portion R1A. On the other hand, as shown in FIG. 17, when the offset direction is a direction toward the outer diameter side of the first curved portion R1A, the controller 26 makes the diameter of the second curved portion R2A larger than the diameter of the first curved portion R1A. Further, the controller 26 makes the length of the second curved portion R2A longer than the length of the first curved portion R1A.

[0060] As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

[0061] The working machine 1 is not limited to a bulldozer, and may be other vehicles such as a wheel loader or a motor grader. The working machine 1 may be operable remotely. In that case, the operating devices 31A - 31C, the input device 32, the display 33, and the automatic control switch 35 may be arranged outside the working machine 1. The intervention operation of the steering operating device 31B may be a manual operation from a remote location. The working machine 1 may have a plurality of controllers that are separate from each other. The processing by the above-described controller 26 may be executed in a distributed manner by a plurality of controllers.

[0062] The process of automatic driving control by the controller 26 is not limited to that of the above-described embodiment and may be changed. For example, the forward movement, backward movement, and stop of the working machine 1 may be automatically controlled by the controller 26 without depending on the manual operation of the travel operation device 31A by the operator. The intervention operation is not limited to the manual operation by the operator and may be an automatic operation. For example, when the controller 26 detects an obstacle in the traveling direction of the working machine 1 while traveling along the first target path R1 by automatic driving control, the controller 26 may intervene with an automatic operation to avoid the obstacle. In that case, the controller 26 may set the position where the automatic operation to avoid the obstacle ends as the intervention end position Pb1, and generate a second target path R2 based on the intervention end position Pb1.

[0063] The reference point Pa1 of the working machine 1 is not limited to the working machine 12 and may be included in the vehicle body 11. For example, the reference point Pa1 of the working machine 1 may be the center of the vehicle body 11. The working machine 12 may include a ripper attached to the rear part of the vehicle body 2. The reference point Pa1 of the working machine 1 may be included in the ripper.

[0064] In the above-described embodiment, the controller 26 determines the shortest distance between the intervention end position Pb1 and the first target path R1 as the offset distance D1. However, the controller 26 may determine, as the offset distance D1, a distance obtained by increasing or decreasing the shortest distance between the intervention end position Pb1 and the first target path R1.

[0065] Alternatively, the controller 26 may store a preset distance and determine the offset distance D1 based on the preset distance. The preset distance may be set, for example, by the operator using the input device 32. Alternatively, the controller 26 may determine the preset distance based on the length of the working machine 12 in the vehicle width direction.

[0066] Alternatively, the controller 26 may determine the offset distance D1 based on the overlap distance D2 described above and the length of the work implement 12 in the vehicle width direction. For example, the controller 26 may determine, as a preset distance, a value obtained by subtracting the overlap distance D2 from the length of the work implement 12 in the vehicle width direction. The predetermined overlap distance D2 may be stored in the controller 26 in advance. The predetermined overlap distance D2 may be set by the operator using the input device 32.

Industrial Applicability

[0067] According to the present disclosure, the degree of freedom in work by the work machine is improved.

Explanation of Signs

[0068] 1: Work machine, 12: Work implement, 26: Controller, 31B: Steering operation device, 33: Display, 34: Position sensor, R1: First target path, R1A: First curved portion, R1B: First straight portion ahead, R2: Second target path, R2A: Second curved portion, R2B: Second straight portion ahead

Claims

1. A system for controlling a work machine, comprising: a sensor for detecting the current position of the work machine; a steering operation device that can be intervened to turn the work machine left and right; a controller; and the controller: acquires a first target path of the work machine; acquires the current position of the work machine; based on the current position of the work machine, controls the work machine by automatic driving control so that the work machine travels along the first target path; during the automatic driving control, when the steering operation device is intervened, interrupts the automatic driving control and turns the work machine according to the intervention operation on the steering operation device; when the intervention operation on the steering operation device ends, acquires the current position of the work machine when the intervention operation on the steering operation device ends as an intervention end position; generates a second target path based on the intervention end position and the first target path; restarts the automatic driving control based on the current position of the work machine and controls the work machine so that the work machine travels along the second target path. A system.

2. The controller: determines an offset direction based on the intervention end position with respect to the first target path; generates the second target path by offsetting the first target path in the offset direction. The system according to claim 1.

3. The controller: determines a position on the first target path that is the shortest distance from the intervention end position as an offset reference position; determines an offset direction based on the direction from the offset reference position to the intervention end position; generates the second target path by offsetting the first target path in the offset direction. The system according to claim 2.

4. The first target path includes a first curved portion, and the controller: generates the second target path so as to include a second curved portion corresponding to the first curved portion; when the offset direction is a direction toward the inner diameter side of the first curved portion, makes the diameter of the second curved portion smaller than the diameter of the first curved portion; when the offset direction is a direction toward the outer diameter side of the first curved portion, makes the diameter of the second curved portion larger than the diameter of the first curved portion. The system according to claim 2.

5. The first target path: a first curved portion, A first straight portion extending forward or backward from the first curved portion, including the controller generates the second target path such that the second curved portion is located in the offset direction with respect to the first curved portion and is parallel to the first curved portion, and the second straight portion is located in the offset direction with respect to the first straight portion and is parallel to the first straight portion. The system according to claim 2.

6. The controller when the offset direction is a direction toward the inner diameter side of the first curved portion, makes the length of the second curved portion shorter than the length of the first curved portion, when the offset direction is a direction toward the outer diameter side of the first curved portion, makes the length of the second curved portion longer than the length of the first curved portion. The system according to claim 5.

7. The controller determines a predetermined offset distance, and determines the second target path based on a path obtained by offsetting the first target path by the offset distance in the offset direction. The system according to claim 2.

8. The controller determines the offset distance based on the shortest distance between the intervention end position and the first target path. The system according to claim 7.

9. The controller stores a preset distance, and determines the offset distance based on the preset distance. The system according to claim 7.

10. The working machine includes a working implement, and the controller determines the offset distance based on the length of the working machine in the vehicle width direction. The system according to claim 7.

11. The controller acquires a predetermined overlap distance, and determines the offset distance based on the overlap distance and the length of the working machine in the vehicle width direction. The system according to claim 10.

12. further includes a display, the controller superimposes a first path image indicating the first target path and a machine image indicating the working machine and displays the result on the display, and when generating the second target path, superimposes a second path image indicating the second target path and the machine image and displays the result on the display. The system according to claim 1.

13. further includes a display, the controller During the intervention operation, a third path image indicating a predicted position of the second target path generated based on the current position of the work machine and the first target path is superimposed on the machine image and displayed on the display. The system according to claim 1.

14. The controller displays the third path image on the display in a display form different from that of the second path image. The system according to claim 13.

15. A method for controlling a work machine, comprising: acquiring a first target path of the work machine; acquiring the current position of the work machine; controlling the work machine by automatic driving control so that the work machine travels along the first target path based on the current position of the work machine; receiving an operation signal that can be intervened to turn the work machine left and right; during the automatic driving control, when an intervention operation is performed, interrupting the automatic driving control and turning the work machine according to the intervention operation; when the intervention operation ends, acquiring the current position of the work machine at the end of the intervention operation as an intervention end position; generating a second target path based on the intervention end position and the first target path; resuming the automatic driving control and controlling the work machine so that the work machine travels along the second target path based on the current position of the work machine. A method comprising the above steps.

16. A work machine, comprising: a sensor for detecting the current position of the work machine; a steering operation device that can be intervened to turn the work machine left and right; a controller; The work machine is provided with the above components. The controller: acquires the first target path of the work machine; acquires the current position of the work machine; controls the work machine by automatic driving control so that the work machine travels along the first target path based on the current position of the work machine; during the automatic driving control, when the steering operation device is intervened, interrupting the automatic driving control and turning the work machine according to the intervention operation on the steering operation device; when the intervention operation on the steering operation device ends, acquiring the current position of the work machine at the end of the intervention operation on the steering operation device as an intervention end position; generating a second target path based on the intervention end position and the first target path. Based on the current position of the work machine, resume the automatic driving control so that the work machine travels along the second target path, and control the work machine. Work machine.

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