System and method for controlling work machine, and work machine

Abstract

In this system for controlling a work machine, a controller controls a work machine using autonomous travel control, on the basis of the current position of the work machine, so that the work machine travels along a first target path. When a steering operation device is subjected to an intervening operation during the autonomous travel control, the controller suspends the autonomous travel control and causes the work machine to turn in accordance with the intervening operation performed on the steering operation device. When the intervening operation performed on the steering operation device is completed, the controller acquires, as the intervention end position, the current position of the work machine at the time when the intervening operation performed on the steering operation device was completed. The controller generates a second target path on the basis of the intervention end position and the first target path. The controller resumes the autonomous travel control and controls the work machine, on the basis of the current position of the work machine, so that the work machine travels along the second target path.

Description

System and method for controlling a work machine, and work machine

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

[0002] Conventionally, automatic cruise control is known that controls a work machine to travel along a predetermined target route. For example, in a work machine control system disclosed in Patent Document 1, multiple target routes extending parallel to one another are set. The control system controls the work machine so that the work machine travels in sequence along the multiple target routes. The work machine performs work such as excavation while traveling along the target routes, thereby constructing the topography of the work site into a desired shape.

[0003] Patent Publication No. 2020-166303

[0004] A work machine operator may want to adjust a target route, for example, when redoing work performed by the work machine. Alternatively, the operator may want to adjust the target route using the work machine controller, for example, when an obstacle is discovered along the target route. However, with the above-described control system, the work machine travels according to multiple predetermined target routes using automatic travel control. This results in a low degree of freedom in work. An object of the present disclosure is to improve the degree of freedom in work performed by a work machine.

[0005] A first aspect of the present disclosure is a system for controlling a work machine. The system includes 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 being intervened in to turn the work machine left or right. The controller acquires a first target route for the work machine. The controller acquires the current position of the work machine. The controller controls the work machine through automatic cruise control based on the current position of the work machine so that the work machine travels along the first target route. If the steering operation device is intervened in during automatic cruise control, the controller interrupts the automatic cruise control and turns the work machine in accordance with the intervening operation of the steering operation device. If the intervening operation of the steering operation device ends, the controller acquires the position of the work machine at the time the intervening operation of the steering operation device ends as an intervention end position. The controller generates a second target route based on the intervention end position and the first target route. The controller resumes automatic cruise control and controls the work machine so that the work machine travels along the second target route based on the current position of the work machine.

[0006] A second aspect of the present disclosure is a method for controlling a work machine, the method comprising: acquiring a first target route for the work machine; acquiring a current position of the work machine; controlling the work machine using automatic cruise control based on the current position of the work machine so that the work machine travels along the first target route; receiving an operation signal capable of performing an intervention operation to turn the work machine left or right; if an intervention operation is performed during the automatic cruise control, interrupting the automatic cruise control and turning the work machine in accordance with the intervention operation; if the intervention operation is terminated, acquiring the position of the work machine at the time the intervention operation was terminated as an intervention end position; generating a second target route based on the intervention end position and the first target route; and resuming the automatic cruise control and controlling the work machine based on the current position of the work machine so that the work machine travels along the second target route.

[0007] A third aspect of the present disclosure is a work machine including 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 being intervened in to turn the work machine left or right. The controller acquires a first target route for the work machine. The controller acquires the current position of the work machine. The controller controls the work machine through automatic travel control based on the current position of the work machine so that the work machine travels along the first target route. When an intervening operation of the steering operation device is performed during automatic travel control, the controller interrupts the automatic travel control and turns the work machine in accordance with the intervening operation of the steering operation device. When the intervening operation of the steering operation device is ended, the controller acquires the position of the work machine at the time the intervening operation of the steering operation device ended as an intervention end position. The controller generates a second target route based on the intervention end position and the first target route. The controller resumes automatic travel control and controls the work machine based on the current position of the work machine so that the work machine travels along the second target route.

[0008] According to the present disclosure, when an intervention operation of the steering operation device is performed during automatic cruise control, the automatic cruise control is interrupted and the work machine turns in response to the intervention operation of the steering operation device. This provides a high degree of freedom in work performed by the work machine. Furthermore, when the intervention operation of the steering operation device is terminated, a second target route is generated based on the intervention end position, which indicates the position of the work machine when the intervention operation of the steering operation device is terminated, and the first target route. Then, automatic cruise control is resumed and the work machine is controlled so that the work machine travels along the second target route.

[0009] FIG. 1 is a side view showing a work machine according to an embodiment. FIG. 2 is a block diagram showing the configuration of the drive system and control system of the work machine. FIG. 3 is a flowchart showing processing for automatic travel control. FIG. 4 is a diagram showing a work machine and a target travel route under automatic travel control. FIG. 5 is a diagram showing a work machine and a target travel route under automatic travel control. FIG. 6 is a diagram showing a work machine and a target travel route under automatic travel control. FIG. 7 is a flowchart showing processing for generating a second target route. FIG. 8 is a diagram showing a work machine and a target travel route under automatic travel control. FIG. 9 is a diagram showing a work machine and a target travel route under automatic travel control. FIG. 10 is a diagram showing an example of a guide screen under automatic travel control. FIG. 11 is a diagram showing an example of a guide screen under automatic travel control. FIG. 12 is a diagram showing an example of a guide screen under automatic travel control. FIG. 13 is a diagram showing an example of work performed by a work machine when manual operation by an operator intervenes during automatic travel control. FIG. 14 is a diagram showing an example of work performed by a work machine when manual operation by an operator intervenes during automatic travel control. FIG. 15 is a diagram showing a target travel route according to another example. FIG. 16 is a diagram showing a target travel route according to another example.

[0010] A work machine according to an embodiment will be described below with reference to the drawings. Figure 1 is a side view showing a work machine 1 according to an embodiment. The work machine 1 according to this embodiment is a bulldozer. The work machine 1 comprises a vehicle body 11 and a work implement 12.

[0011] The vehicle body 11 includes a cab 13, an engine compartment 14, and a traveling device 15. A driver's seat (not shown) is disposed in the cab 13. The engine compartment 14 is disposed in front of the cab 13. The traveling device 15 is provided on the lower part of the vehicle body 11. The traveling device 15 includes a pair of left and right tracks 16. Note that only the left track 16 is shown in FIG. 1. The work machine 1 travels by rotating the tracks 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 on the vehicle body 11 so as to be rotatable about a lift axis X1. The blade 18 is disposed 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. The lift frame 17 moves up and down as the lift actuator 19 extends and retracts. The blade 18 moves up and down in accordance with the up and down movement of the lift frame 17.

[0013] Figure 2 is a block diagram showing the configuration of the drive system 2 and control system 3 of the work machine 1. As shown in Figure 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 also 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. Although Figure 2 shows one hydraulic pump 23, multiple 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, a hydrostatic transmission (HST). Alternatively, the power transmission device 24 may be, for example, a torque converter or a transmission having a plurality of speed change 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 memory device 28 and a processor 29. The processor 29 includes, for example, a CPU. The memory device 28 includes, for example, a memory and an auxiliary memory device. The memory device 28 may be, for example, a RAM or a ROM. The memory device 28 may be, for example, a semiconductor memory or a hard disk. The memory device 28 stores computer instructions that are executable by the processor 29 and are used to control 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 hydraulic oil supplied from the hydraulic pump 23 to the lift actuator 19. 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 travel operation device 31A, a steering operation device 31B, and a work implement operation device 31C. The travel operation device 31A can be operated by an operator to manually control the forward and reverse travel of the work machine 1. The travel operation device 31A includes, for example, a travel lever. However, the travel operation device 31A may also include other components such as a switch. The travel operation device 31A can be operated from a neutral position N1 to a forward position A1 and a reverse position B1. The travel operation device 31A outputs travel commands to the controller 26 in accordance with operation by the operator.

[0018] The steering operation device 31B can be operated by an operator to manually steer the work 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 can be operated from a neutral position N2 in a right turning direction A2 and a left turning direction B2. The steering operation device 31B outputs a steering command to the controller 26 in accordance with the operation by the operator.

[0019] The work machine operating device 31C can be operated by an operator to manually operate the work machine 12. The work machine operating device 31C includes, for example, a work machine lever. However, the work machine operating device 31C may also include other components such as a switch. The work machine operating device 31C outputs a work command to the controller 26 in response to an operation by the operator. Note that each of the operating devices 31A-31C may be configured using common components.

[0020] In response to a travel command from the travel operation device 31A, the controller 26 controls the drive source 22 and the power transmission device 24 so as to travel the work machine 1. As a result, the work machine 1 travels forward or backward in response to 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 to steer the work machine 1 to the left or right in response to a steering command from the steering operation device 31B. For example, the controller 26 turns the work machine 1 to the left or right by using a speed difference between the left and right tracks 16. As a result, the work machine 1 turns to the left or right in response to operation of the steering operation device 31B by the operator.

[0022] The controller 26 controls the control valve 27 in response to a work command from the work machine operating device 31C to operate the work machine 12. As a result, the work machine 12 moves up and down in response to the operation of the work machine operating 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 also include other devices such as switches. The operator can use the input device 32 to configure settings for automatic control of the work machine 1. Automatic control of the work 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 in response to an 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 work machine 1. The position sensor 34 includes, for example, a sensor based on the Global Navigation Satellite System (GNSS). The position sensor 34 may include an IMU (Inertial Measurement Unit).

[0026] The controller 26 acquires the current position and orientation of the work machine 1 based on the detection signal from the position sensor 34. The controller 26 performs automatic cruise control, which controls the traveling direction of the work machine 1, based on the current position and orientation of the work 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 an operator to switch the automatic cruise control on and off. The controller 26 enables the automatic cruise control when the automatic control switch 35 is in the on state. The controller 26 disables the automatic cruise control when the automatic control switch 35 is in the off state.

[0027] The following describes the automatic travel control of the work machine 1. Figure 3 is a flowchart showing the automatic travel control process. In the automatic travel control according to this embodiment, the forward travel, reverse travel, and stop of the work machine 1 are controlled in accordance with manual operation of the travel operation device 31A by the operator.

[0028] In automatic travel control, the left and right turning of the work machine 1 is automatically controlled so that the work machine 1 moves according to a target travel route, which will be described later. For example, in automatic travel control, if the work machine 1 deviates to the right from the target travel route, the controller 26 automatically turns the work machine 1 to the left so that the work machine 1 returns to the target travel route. In automatic travel control, if the work machine 1 deviates to the left from the target travel route, the controller 26 automatically turns the work machine 1 to the right so that the work 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 work machine 1. The controller 26 acquires the current position of a predetermined reference point Pa1 of the work machine 1 as the current position of the work machine 1. The reference point Pa1 of the work machine 1 is included in the blade 18. For example, as shown in Fig. 4 , the reference point Pa1 is the centre of the blade 18 in the vehicle width direction. Alternatively, the reference point Pa1 of the work machine 1 may be the left end or right end of the blade 18. The reference point Pa1 of the work machine 1 may be changeable by the input device 32.

[0030] In step S102, the controller 26 acquires a first target route R1. The controller 26 stores a preset first target route R1. For example, the controller 26 stores a route set by an 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 driving route for the automatic driving control. The controller 26 sets the first target route R1 described above as the target driving route.

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

[0033] In detail, 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. As a result, the work machine 1 is steered so that the work machine 1 travels along the first target route R1 simply by operating the travel operation device 31A, without the operator having to operate the steering operation device 31B. In other words, as shown in Fig. 4, even if the steering operation device 31B is located in the neutral position N2, the work machine 1 is steered so that the work machine 1 travels along the first target route R1 simply 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. If the steering operation device 31B has been operated from the neutral position in a left turning direction or a right turning direction, the controller 26 determines that the steering operation device 31B has been manually operated. If the steering operation device 31B has not been manually operated, in step S104, the controller 26 continues the automatic driving control. If the steering operation device 31B has been manually operated during automatic driving control, the process proceeds to step S106.

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

[0036] In step S107, the controller 26 determines whether the manual operation of the steering operation device 31B has ended. As shown in Fig. 6, the controller 26 determines that the manual operation of the steering operation device 31B has ended when the steering operation device 31B has returned to the neutral position N2. If the manual operation of the steering operation device 31B has not ended, in step S106 the controller 26 continues to turn the work machine 1 in accordance with the manual operation of the steering operation device 31B. If the manual operation of the steering operation device 31B has ended, the processing proceeds to step S108.

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

[0038] Fig. 7 is a flowchart showing the processing for generating the second target route R2. As shown in Fig. 7, in step S201, the controller 26 acquires an intervention end position Pb1. The controller 26 acquires the current position of the work machine 1 when 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 route 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, if the direction from the offset reference position Pc1 to the intervention end position Pb1 is rightward, the controller 26 determines the offset direction to be rightward.

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

[0041] As shown in Fig. 3, in step S109, the controller 26 updates the target driving route. The controller 26 updates the target driving route to the second target route R2 generated in step S108. Then, in step S104, the controller 26 executes automatic driving control in accordance with the target driving route. That is, as shown in Fig. 8, the controller 26 sets the second target route R2 generated in step S108 as a new target driving route and executes automatic driving control in accordance with the second target route R2.

[0042] 6 shows an example in which 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, as the second target route R2, a route obtained by offsetting the first target route R1 to the left by the offset distance D1.

[0043] The controller 26 displays a guide screen showing the target travel route described above on the display. Fig. 10 is a diagram showing an example of the guide screen 40. As shown in Fig. 10, the guide screen 40 includes a first route image 41 and a machine image 42. The first route image 41 shows the first target route R1. The machine image 42 shows the work machine 1. During automatic travel control, the work machine 1 sets the first target route R1 as the target travel route and travels in accordance with the first target route R1. Therefore, the controller 26 displays the first route image 41 and the machine image 42 superimposed on each other on the display 33.

[0044] When the work machine 1 is manually steered, as shown in Figures 11 and 12 , the controller 26 changes the machine image 42 in accordance with the current position and orientation of the work machine 1. During manual operation, the controller 26 also displays a third route image 43 on the display 33, superimposed on the machine image 42. The third route image 43 indicates the predicted position of the second target route R2, which is generated based on the current position of the work machine 1 and the first target route R1. As shown in Figures 11 and 12 , the controller 26 moves the third route image 43 in accordance with changes in the current position of the work machine 1 due to manual operation.

[0045] When the manual operation is completed, the controller 26 generates a second target route R2 based on the current position of the work machine 1 at the time the manual operation was completed, 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 and displays a second route image 44 indicating the second target route R2 and the machine image 42 superimposed on each other on the display 33.

[0046] The controller 26 displays the third route image 43 on the display 33 in a display format different from that of the first route image 41 and the second route image 44. For example, the controller 26 displays the third route image 43 on the display 33 in a color different from that of the first route image 41 and the second route image 44. Alternatively, the controller 26 may display the third route image 43 on the display 33 in a shape (solid line, dashed line, etc.) different from that of the first route image 41 and the second route image 44.

[0047] According to the work machine 1 according to the present embodiment described above, if the steering operation device 31B is manually operated during automatic travel control, the work machine 1 turns in response to the manual operation of the steering operation device 31B. This provides a high degree of freedom in work performed by the work machine 1. Furthermore, when the manual operation of the steering operation device 31B ends, a second target route R2 is generated based on the first target route R1 and the current position of the work machine 1 at the time the manual operation of the steering operation device 31B ended. Then, the work machine 1 is controlled by automatic travel control so that the work machine 1 travels according to the second target route R2. This reduces the operational burden on the operator.

[0048] Figure 14 is a diagram showing an example of work performed by the work machine 1 when manual operation by the operator intervenes during automatic travel control. As shown in Figure 14, the work machine 1 performs work such as excavation, leveling, or ground grading while moving forward from a first start point Ps1 on the first target route R1 along the first target route R1. At this time, the controller 26 causes the work machine 1 to travel along the first target route R1 under automatic travel control. After reaching a first end point Pe1 on the first target route R1, the work machine 1 moves backward along the first target route R1. At this time, the controller 26 causes the work machine 1 to travel along the first target route R1 under automatic travel control.

[0049] When the work machine 1 reaches the first waypoint Pm1 on the first target route R1, the operator manually operates the steering operation device 31B to move the work machine 1 a distance W1 from the first target route R1, and then ends the manual operation. This causes the controller 26 to generate a second target route R2 that passes through the intervention end position Pb1, and updates the target traveling route to the second target route R2. The work machine 1 then moves backward along the second target route R2. At that time, the controller 26 causes the work machine 1 to travel along the second target route R2 by automatic traveling control.

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

[0051] When the work machine 1 reaches the second waypoint Pm2 on the second target route R2, the operator manually operates the steering operation device 31B to move the work machine 1 a distance W2 from the second target route R2, and then ends the manual operation. This causes the controller 26 to generate a third target route R3 that passes through the intervention end position Pb2, and updates the target traveling route to the third target route R3. The work machine 1 moves backward along the third target route R3. At that time, the controller 26 causes the work machine 1 to travel along the third target route R3 by automatic traveling control.

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

[0053] Thereafter, in a similar manner, the operator manually operates the steering operation device 31B at the third intermediate point Pm3 to move the work machine 1 by the width W1 from the third target route R3. This causes the controller 26 to generate a fourth target route R4 that passes through the intervention end position Pb3. After work along the fourth target route R4 is completed, the operator manually operates the steering operation device 31B at the fourth intermediate point Pm4 to move the work machine 1 by the width W2 from the fourth target route R4. This causes the controller 26 to generate a fifth target route R5 that passes through the intervention end position Pb4.

[0054] The width W1 corresponds to, for example, the length of the blade in the vehicle width direction. This allows the work machine 1 to perform work efficiently. The width W2 is smaller than the width W1. For example, the operator determines the width W2 taking into account 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 working range C1 of the work implement 12 according to the previous target route (second target route R2) and the working range C2 of the work implement 12 according to the next target route (third target route R3) overlap. For example, if the operator wants to partially modify the working range C1 according to the previous target route, the operator determines the width W2 taking into account the overlap distance D2.

[0055] Next, another example of the target travel route will be described. FIG. 16 is a diagram showing a target travel route according to this example. As shown in FIG. 16, the first target route 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 route R2 based on the intervention end position Pb1 and the first target route R1. As shown in FIG. 16, the second target route R2 is a route parallel to the first target route R1 and passes through the intervention end position Pb1.

[0056] Specifically, the controller 26 determines, as the offset reference position Pc1, a position on the first target route R1 that is the shortest distance from the intervention end position Pb1. 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. 16 , if 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 be right.

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

[0058] The second target route 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 positioned in an offset direction relative 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 positioned in an offset direction relative 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 positioned in an offset direction relative 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 bending portion R1A, the controller 26 makes the diameter of the second bending portion R2A smaller than the diameter of the first bending portion R1A. The controller 26 also makes the length of the second bending portion R2A shorter than the length of the first bending 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 bending portion R1A, the controller 26 makes the diameter of the second bending portion R2A larger than the diameter of the first bending portion R1A. The controller 26 also makes the length of the second bending portion R2A longer than the length of the first bending portion R1A.

[0060] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

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

[0062] The processing of the automatic travel control by the controller 26 is not limited to that of the above embodiment and may be modified. For example, the forward movement, reverse movement, and stopping of the work machine 1 may be controlled automatically by the controller 26, without the operator manually operating the travel operation device 31A. The intervention operation is not limited to manual operation by the operator, but may be automatic operation. For example, if the controller 26 detects an obstacle in the direction of travel of the work machine 1 while the work machine 1 is traveling along the first target route R1 under automatic travel control, the controller 26 may intervene by automatic operation to avoid the obstacle. In this case, the controller 26 may set the position where the automatic operation to avoid the obstacle ends as an intervention end position Pb1, and generate the second target route R2 based on the intervention end position Pb1.

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

[0064] In the above embodiment, the controller 26 determines the shortest distance between the intervention end position Pb1 and the first target route R1 as the offset distance D1. However, the controller 26 may determine the offset distance D1 as a distance obtained by increasing or decreasing the shortest distance between the intervention end position Pb1 and the first target route 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 by the operator using the input device 32, for example. Alternatively, the controller 26 may determine the preset distance based on the length of the work implement 12 in the vehicle width direction.

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

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

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

Claims

1. A system for controlling a working machine, comprising: a sensor for detecting the current position of the working machine; a steering operation device that can be intervened to turn the working machine left and right; and a controller, wherein the controller: acquires a first target path of the working machine; acquires the current position of the working machine; based on the current position of the working machine, controls the working machine by automatic driving control so that the working machine travels along the first target path; during the automatic driving control, when an intervention operation is performed on the steering operation device, interrupts the automatic driving control and turns the working machine in response 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 working machine at the time 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; and based on the current position of the working machine, resumes the automatic driving control and controls the working machine so that the working machine travels along the second target path.

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

3. The system according to claim 2, wherein 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, and generates the second target path by offsetting the first target path in the offset direction.

4. The first target path includes a first curved portion, and the controller generates the second target path such that the second target path includes 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, the diameter of the second curved portion is made 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, the diameter of the second curved portion is made larger than the diameter of the first curved portion. The system according to claim 2.

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

6. When the offset direction is a direction toward the inner diameter side of the first curved portion, the controller 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, the controller 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 work machine includes a working device, and the controller determines the offset distance based on the length of the working device in the vehicle width direction. The system according to claim 7.

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

12. The system according to claim 1, further comprising a display, wherein the controller overlays a first path image indicating the first target path and a machine image indicating the work machine and displays the overlay on the display, and when the second target path is generated, overlays a second path image indicating the second target path and the machine image and displays the overlay on the display.

13. The system according to claim 1, further comprising a display, wherein the controller overlays 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 during the intervention operation and the machine image and displays the overlay on the display.

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

15. A method for controlling a work machine, the method comprising: obtaining a first target path of the work machine; obtaining a 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 capable of being intervened to turn the work machine left and right; interrupting the automatic driving control and turning the work machine in response to the intervention operation when the intervention operation is performed during the automatic driving control; obtaining, as an intervention end position, the current position of the work machine when the intervention operation ends when the intervention operation ends; generating a second target path based on the intervention end position and the first target path; and 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.

16. An operating machine, comprising: a sensor that detects the current position of the operating machine; a steering operation device that can be intervened to turn the operating machine left and right; and a controller, wherein the controller: acquires a first target path of the operating machine; acquires the current position of the operating machine; controls the operating machine by automatic driving control so that the operating machine travels along the first target path based on the current position of the operating machine; when the steering operation device is intervened during the automatic driving control, interrupts the automatic driving control and turns the operating machine in response 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 operating machine at the time 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; and resumes the automatic driving control and controls the operating machine so that the operating machine travels along the second target path based on the current position of the operating machine.

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