System and method for controlling work machine, and work machine

Abstract

This work machine includes a vehicle body and work equipment that is attached to the vehicle body so as to be operable. This system includes an attitude sensor and a controller. The attitude sensor detects the attitude of the work equipment. The controller acquires a first target route extending in the traveling direction of the vehicle body. The controller acquires the width of the work equipment. The controller acquires the attitude of the work equipment. The controller determines an offset width on the basis of the width of the work equipment and the attitude of the work equipment. The controller generates a second target route adjacent to the first target route on the basis of the first target route and the offset width.

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] There is known a control system that automatically controls a work machine so that it travels according to a target path. For example, in Patent Document 1, a controller of the control system generates multiple target paths that are aligned in the width direction of the work machine. The controller automatically controls the work machine so that it travels according to each target path. In this control system, the controller determines the interval between adjacent target paths based on the width of the work machine blade.

[0003] Japanese Patent Application Laid-Open No. 2020-166303

[0004] A work implement such as a blade is operably attached to the body of a work machine. Therefore, the attitude of the work implement relative to the body changes. Therefore, the work implement is not always parallel to the width direction of the body, and may be tilted relative to the width direction of the body. In such cases, if the spacing between adjacent target paths is determined based on the width of the work implement, it may be difficult to generate target paths at appropriate positions, as the spacing between the target paths may become too large. An object of the present disclosure is to improve work efficiency by generating target paths at appropriate positions that take into account the attitude of the work implement.

[0005] A system according to a first aspect of the present disclosure is a system for controlling a work machine. The work machine includes a vehicle body and a work implement operably attached to the vehicle body. The system includes an attitude sensor and a controller. The attitude sensor detects the attitude of the work implement. The controller acquires a first target route extending in the traveling direction of the vehicle body. The controller acquires the width of the work implement. The controller acquires the attitude of the work implement. The controller determines an offset width based on the width and attitude of the work implement. The controller generates a second target route adjacent to the first target route based on the first target route and the offset width.

[0006] A method according to a second aspect of the present disclosure is a method for controlling a work machine. The work machine includes a vehicle body and a work implement operably attached to the vehicle body. The method includes: acquiring a first target path extending in a traveling direction of the vehicle body; acquiring a width of the work implement; acquiring an attitude of the work implement; determining an offset width based on the width and the attitude of the work implement; and generating a second target path adjacent to the first target path based on the first target path and the offset width.

[0007] A work machine according to a third aspect of the present disclosure includes a vehicle body, a work implement, an attitude sensor, and a controller. The work implement is operably attached to the vehicle body. The attitude sensor detects the attitude of the work implement. The controller acquires a first target route extending in the traveling direction of the vehicle body. The controller acquires the width of the work implement. The controller acquires the attitude of the work implement. The controller determines an offset width based on the width and attitude of the work implement. The controller generates a second target route adjacent to the first target route based on the first target route and the offset width.

[0008] According to the present disclosure, work efficiency is improved by generating a target travel path at an appropriate position that takes into account the attitude of the work machine.

[0009] FIG. 1 is a side view showing a work machine according to an embodiment. FIG. 2 is a top view of the work machine. FIG. 3 is a front view of the work machine. FIG. 4 is a block diagram showing the configuration of the drive system and control system of the work machine. FIG. 5 is a flowchart showing the processing of automatic travel control. FIG. 6 is a diagram showing the processing for generating a target route. FIG. 7 is a diagram showing the processing for generating a target route. FIG. 8 is a diagram showing the processing for generating a target route. FIG. 9 is a diagram showing the processing for generating a target route. FIG. 10 is a diagram showing an example of a work machine traveling according to a target travel route. FIG. 11 is a diagram showing an example of a work machine traveling according to a target travel route.

[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 driver's cab 13, a power compartment 14, and a running device 15. A driver's seat (not shown) is disposed in the driver's cab 13. The power compartment 14 is disposed in front of the driver's cab 13. The running device 15 is provided in the lower part of the vehicle body 11. The running device 15 includes a pair of left and right wheels 16A, 16B.

[0012] The work implement 12 is attached to the vehicle body 11. The work implement 12 includes a lift frame 17, a blade 18, a lift actuator 19, an angle actuator 20, and a tilt actuator 21. The lift actuator 19, the angle actuator 20, and the tilt actuator 21 are, for example, hydraulic cylinders. However, the lift actuator 19, the angle actuator 20, and the tilt actuator 21 may be other actuators.

[0013] The lift frame 17 is supported so as to be movable about a lift axis A1 relative to the vehicle body 11. The blade 18 is disposed in front of the vehicle body 11. The blade 18 is supported by the lift frame 17. The blade 18 moves up and down as the lift actuator 19 extends and retracts.

[0014] Figure 2 is a schematic top view of the work machine 1. As shown in Figure 2, the blade 18 is supported by the lift frame 17 so as to be movable about an angle axis A2. When the angle actuator 20 extends and retracts, the blade 18 moves about the angle axis A2 (hereinafter referred to as "angle movement"). This changes the inclination angle (hereinafter referred to as "angle angle θ1") of the blade 18 relative to the width direction of the vehicle body 11 (arrow X1 shown in Figure 2).

[0015] Figure 3 is a schematic front view of the work machine 1. As shown in Figure 3, the blade 18 is supported by the lift frame 17 so as to be movable about a tilt axis A3. When the tilt actuator 21 extends and retracts, the blade 18 moves about the tilt axis A3 (hereinafter referred to as a tilt operation). This changes the tilt angle (hereinafter referred to as a tilt angle θ2) of the blade 18 relative to the horizontal direction (arrow X2 shown in Figure 3).

[0016] Figure 4 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 4, 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 4 shows one hydraulic pump 23, multiple hydraulic pumps may be provided.

[0017] 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.

[0018] 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.

[0019] The control valve 27 is controlled by a command signal from the controller 26. The control valve 27 is arranged between the hydraulic actuators, such as the lift actuator 19, the angle actuator 20, and the tilt actuator 21, 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 angle actuator 20, and the tilt actuator 21. The control valve 27 may be a pressure proportional control valve. Alternatively, the control valve 27 may be an electromagnetic proportional control valve.

[0020] The control system 3 includes a travel operation device 31A, a steering operation device 31B, and a work machine 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 switches. The travel operation device 31A outputs travel commands to the controller 26 in response to operation by the operator.

[0021] The steering operation device 31B can be operated by the 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 also include other members such as a steering wheel or a switch. The steering operation device 31B outputs a steering command to the controller 26 in accordance with the operation by the operator.

[0022] 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.

[0023] 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.

[0024] 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 wheels 16A, 16B. 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.

[0025] The controller 26 controls the control valve 27 to operate the work machine 12 in response to a work command from the work machine operating device 31C. 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. Alternatively, the work machine 12 performs an angle operation in response to the operation of the work machine operating device 31C by the operator. Alternatively, the work machine 12 performs a tilt operation in response to the operation of the work machine operating device 31C by the operator.

[0026] 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 travel control of the work machine 1. The automatic travel control of the work machine 1 will be described in detail later.

[0027] The control system 3 includes an attitude sensor 33 and 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).

[0028] The attitude sensor 33 detects the attitude of the work implement 12. The attitude of the work implement 12 includes the angle angle θ1 and tilt angle θ2 described above. The attitude sensor 33 may be, for example, a sensor that detects the stroke lengths of the lift actuator 19, the angle actuator 20, and the tilt actuator 21. Alternatively, the attitude sensor 33 may include an IMU.

[0029] 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 acquires the attitude of the work implement 12 based on the detection signal from the attitude sensor 33. The controller 26 performs automatic travel control that controls the travel direction of the work machine 1 based on the current position and orientation of the work machine 1 and the attitude of the work implement 12.

[0030] As shown in Fig. 4, 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.

[0031] The following describes the automatic travel control of the work machine 1. Fig. 5 is a flowchart showing the processing of the automatic travel control. In 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.

[0032] 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. The work machine 1 performs work such as excavation or ground leveling using the work implement 12 while traveling along the target travel route.

[0033] As shown in Fig. 5, in step S101, the controller 26 acquires the current position and orientation of the work machine 1. As shown in Fig. 2, 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, the reference point Pa1 is the centre of the blade 18 in the 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.

[0034] In step S102, the controller 26 acquires the width W1 of the work implement 12. The width W1 of the work implement 12 is the width of the cutting edge of the blade 18. The controller 26 stores the width W1 of the work implement 12 in advance. The controller 26 may acquire the width W1 of the work implement 12 from an input to the input device 32. Alternatively, the controller 26 may acquire the width W1 of the work implement 12 from an external computer.

[0035] In step S103, the controller 26 acquires the angle angle θ1 of the work machine 12. In step S104, the controller 26 of the work machine 12 acquires the tilt angle θ2. The controller 26 acquires the angle angle θ1 and the tilt angle θ2 based on the detection signal from the attitude sensor 33.

[0036] In step S105, the controller 26 calculates the offset distance D1. When the width direction of the work implement 12 is parallel to the width direction of the vehicle body 11 as shown in Fig. 6 and when the width direction of the work implement 12 is parallel to the horizontal direction as shown in Fig. 7, the controller 26 determines the width W1 of the work implement 12 as the offset distance D1. In other words, when the angle angle θ1 and the tilt angle θ2 are both 0 degrees, the controller 26 determines the width W1 of the work implement 12 as the offset distance D1.

[0037] As shown in Fig. 8 , when the work implement 12 is tilted at an angle θ1 with respect to the width direction of the vehicle body 11, the controller 26 calculates a first projected length of the work implement 12 based on the angle θ1. The first projected length of the work implement 12 is the magnitude of the vector component of the width W1 of the work implement 12 in the width direction of the vehicle body 11. In other words, the first projected length of the work implement 12 is the projection length of the width W1 of the work implement 12 onto a plane PL1 that extends in the width direction and the up-down direction of the vehicle body 11. The controller 26 determines the first projected length of the work implement 12 as the offset distance D1. In this case, the offset distance D1 is smaller than the width W1 of the work implement 12.

[0038] As shown in Figure 9 or 10, when the work implement 12 is inclined at a tilt angle θ2 with respect to the horizontal direction, the controller 26 calculates a second projected length of the work implement 12. The second projected length of the work implement 12 is the magnitude of the vector component of the width W1 of the work implement 12 in the horizontal direction. In other words, the second projected length of the work implement 12 is the projection length of the width W1 of the work implement 12 onto the horizontal plane PL2. The controller 26 determines the second projected length of the work implement 12 as the offset distance D1.

[0039] In Fig. 9, the width direction of the work implement 12 is parallel to the width direction of the vehicle body 11, but the entire work machine 1 is tilted at a tilt angle θ2 with respect to the horizontal direction, so that the work implement 12 is tilted at a tilt angle θ2 with respect to the horizontal direction. In Fig. 10, the width direction of the vehicle body 11 is parallel to the horizontal direction, but the width direction of the work implement 12 is tilted at a tilt angle θ2 with respect to the width direction of the vehicle body 11, so that the work implement 12 is tilted at a tilt angle θ2 with respect to the horizontal direction.

[0040] When the work implement 12 is inclined at an angle θ1 with respect to the width direction of the vehicle body 11 and at a tilt angle θ2 with respect to the horizontal direction, the controller 26 calculates the magnitude of the vector component of the width W1 of the work implement 12 in the horizontal direction of the first projection length of the work implement 12 as the third projection length of the work implement 12. In other words, the third projection length of the work implement 12 is the projection length of the first projection length onto the horizontal plane PL2. The controller 26 determines the third projection length as the offset distance D1.

[0041] In step S106, the controller 26 determines the offset width W2. For example, the controller 26 determines the offset distance D1 as the offset width W2. Alternatively, as shown in FIG. 11 , the controller 26 may determine the offset width W2 so that it is smaller than the offset distance D1 by an overlap D2 of the target travel path. The overlap D2 may be set by the operator operating the input device 32. The controller 26 may calculate the offset width W2 by multiplying the offset distance D1 by a predetermined reduction rate that takes the overlap D2 into account. Alternatively, the controller 26 may calculate the offset width W2 by subtracting a predetermined subtraction value that takes the overlap D2 into account from the offset distance D1.

[0042] In step S107, the controller 26 acquires a first target route R1. As shown in FIGS. 6 to 11 , the first target route R1 extends in the traveling direction of the vehicle body 11 during work. The controller 26 stores a preset first target route R1. For example, the controller 26 may store 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.

[0043] In step S108, the controller 26 determines the offset direction. The controller 26 determines one of the directions on the horizontal plane that is perpendicular to the first target route R1 as the offset direction.

[0044] In step S109, the controller 26 generates a second target route R2 based on the first target route R1 and the offset width W2. The second target route R2 extends parallel to the first target route R1 in the traveling direction of the vehicle body 11 and is adjacent to the first target route R1 in the width direction of the vehicle body 11. The controller 26 displaces the first target route R1 in the offset direction by the offset width W2 to generate the second target route R2.

[0045] In step S110, the controller 26 generates a third target route R3. The third target route R3 extends parallel to the second target route R2 in the traveling direction of the vehicle body 11 and is adjacent to the second target route R2 in the width direction of the vehicle body 11. The controller 26 displaces the second target route R2 in the offset direction by an offset width W2 to generate the third target route R3. Note that the number of target routes generated by the controller 26 is not limited to three. The number of target routes generated by the controller 26 may be less than three or more than three.

[0046] In step S111, the controller 26 starts automatic travel control. For example, the controller 26 may start automatic travel control when the automatic control switch 35 is operated. In automatic travel control, the controller 26 sets one of the plurality of target routes R1-R3 described above as the target travel route. For example, as shown in FIG. 12 , the controller 26 sets the first target route R1 as 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 also controls the work machine 1 so that the work machine 1 travels along the target travel route based on the current position and direction of the work machine 1.

[0047] In detail, 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 operator can steer the work machine 1 so that it travels along the first target route R1 simply by operating the travel operation device 31A, without having to operate the steering operation device 31B.

[0048] When work along the first target route R1 is completed, the controller 26 sets the second target route R2 as the target travel route. For example, the controller 26 may set the second target route R2 as the target travel route by an operator manually operating the input device 32. Alternatively, the controller 26 may automatically set the second target route R2 as the target travel route. When the second target route R2 is set as the target travel route, as shown in FIG. 13 , the controller 26 automatically turns the work machine 1 based on the current position and orientation of the work machine 1 so that the reference point Pa1 moves along the second target route R2. Thereafter, similarly, when work along the second target route R2 is completed, the controller 26 sets the third target route R3 as the target travel route. Then, the controller 26 automatically turns the work machine 1 so that the reference point Pa1 moves along the third target route R3.

[0049] In the work machine according to the present embodiment described above, the offset width W2 is determined based on the width W1 of the work implement 12 and the posture of the work implement 12. Then, the second target route R2 is generated based on the first target route R1 and the offset width W2. Therefore, the second target route R2 is generated at an appropriate position that takes into account the posture of the work implement 12, thereby improving work efficiency.

[0050] 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.

[0051] 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 that case, the operation devices 31A-31C, the input device 32, and the automatic control switch 35 may be located outside the work machine 1. 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.

[0052] The processing of the automatic travel control by the controller 26 is not limited to that in the above embodiment and may be modified. For example, 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. The reference point Pa1 of the work machine 1 may be the center of the vehicle body 11.

[0053] 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. In the example of automatic travel control described above, the work machine 1 travels forward. However, the same automatic travel control processing as described above is also executed when the work machine 1 travels in reverse.

[0054] Target routes may be generated not only for one work machine, but also for multiple work machines. For example, a second target route R2 may be generated based on the blade width of a second work machine in addition to the first target route R1, the blade width W1 of the first work machine, and the work implement attitude. The generated second target route R2 and work implement attitude information may then be transmitted to the second work machine as command information. The second work machine may be automatically controlled in accordance with the second target route R2 and the work implement attitude information. The work implement attitude information may follow the attitude of the work implement 12 of the first work machine 1, or may be a separately instructed attitude.

[0055] Alternatively, if reference point Pa1 is set at the left or right edge of the blade, the second target route R2 may be generated based on the first target route R1, the blade width W1 of the first work machine, and the attitude of the work machine. The generated second target route R2 and attitude information of the work machine may then be transmitted to the second work machine as command information. The second work machine may be automatically controlled in accordance with the second target route R2 and the attitude information of the work machine.

[0056] According to the present disclosure, work efficiency is improved by generating a target travel path at an appropriate position that takes into account the attitude of the work machine.

[0057] 1: Work machine 11: Vehicle body 12: Work equipment 26: Controller 33: Attitude sensor 34: Position sensor R1: First target path R2: Second target path

Claims

1. A system for controlling a work machine including a vehicle body and a work implement operably attached to the vehicle body, comprising: an attitude sensor that detects the attitude of the work implement; and a controller, wherein the controller: acquires a first target route extending in the traveling direction of the vehicle body; acquires the width of the work implement; acquires the attitude of the work implement; determines an offset width based on the width and attitude of the work implement; and generates a second target route adjacent to the first target route based on the first target route and the offset width.

2. The system according to claim 1, wherein the controller generates the second target path by displacing the first target path by the offset width in the width direction of the vehicle body.

3. The system described in claim 1, wherein the controller obtains an angle angle indicating the inclination angle of the work implement relative to the width direction of the vehicle body as the attitude of the work implement, calculates the magnitude of the vector component of the width of the work implement in the width direction of the vehicle body based on the angle angle as a first projection length of the work implement, and determines the offset width based on the first projection length of the work implement.

4. The system described in claim 1, wherein the controller acquires a tilt angle indicating the inclination angle of the work machine relative to the horizontal direction as the attitude of the work machine, calculates the magnitude of the vector component of the width of the work machine in the horizontal direction based on the tilt angle as a second projection length of the work machine, and determines the offset width based on the second projection length of the work machine.

5. The system according to claim 1, further comprising a position sensor that detects the current position of the work machine, wherein the controller acquires the current position of the work machine and automatically controls the work machine based on the position of the work machine and the second target route so that the work machine follows the second target route.

6. The system according to claim 5, wherein the controller acquires the position of a predetermined part of the work machine as the current position of the work machine, and automatically controls the work machine so that the predetermined part follows the second target path.

7. The system according to claim 1, wherein the second target route extends in the traveling direction and is adjacent to the first target route in the width direction of the vehicle body.

8. A method for controlling a work machine including a vehicle body and a work implement operably attached to the vehicle body, the method comprising: obtaining a first target route extending in a traveling direction of the vehicle body; obtaining a width of the work implement; obtaining an attitude of the work implement; determining an offset width based on the width of the work implement and the attitude of the work implement; and generating a second target route adjacent to the first target route based on the first target route and the offset width.

9. The method according to claim 8, further comprising generating the second target path by displacing the first target path by the offset width in the width direction of the vehicle body.

10. A method according to claim 8, comprising: obtaining an angle angle indicating the inclination angle of the work implement relative to the width direction of the vehicle body as the attitude of the work implement; calculating the magnitude of the vector component of the width of the work implement in the width direction of the vehicle body based on the angle angle as a first projection length of the work implement; and determining the offset width based on the first projection length of the work implement.

11. A method according to claim 8, comprising: acquiring a tilt angle indicating the inclination angle of the work machine relative to the horizontal direction as the attitude of the work machine; calculating the magnitude of the vector component of the width of the work machine in the horizontal direction based on the tilt angle as a second projection length of the work machine; and determining the offset width based on the second projection length of the work machine.

12. The method according to claim 8, comprising: acquiring a current position of the work machine; and automatically controlling the work machine based on the position of the work machine and the second target route so that the work machine follows the second target route.

13. The method according to claim 12, comprising: acquiring the position of a predetermined portion of the work machine as the current position of the work machine; and automatically controlling the work machine so that the predetermined portion follows the second target path.

14. The method according to claim 8, wherein the second target route extends in the traveling direction and is adjacent to the first target route in the width direction of the vehicle body.

15. A work machine comprising: a vehicle body; a work implement operably attached to the vehicle body; an attitude sensor that detects the attitude of the work implement; and a controller, wherein the controller acquires a first target route extending in the traveling direction of the vehicle body; acquires the width of the work implement; acquires the attitude of the work implement; determines an offset width based on the width and attitude of the work implement; and generates a second target route adjacent to the first target route based on the first target route and the offset width.

16. A work machine according to claim 15, wherein the controller generates the second target path by displacing the first target path by the offset width in the width direction of the vehicle body.

17. A work machine as described in claim 15, wherein the controller obtains an angle angle indicating the inclination angle of the work machine relative to the width direction of the vehicle body as the attitude of the work machine, calculates the magnitude of the vector component of the width of the work machine in the width direction of the vehicle body based on the angle angle as a first projection length of the work machine, and determines the offset width based on the first projection length of the work machine.

18. A work machine according to claim 15, wherein the controller acquires a tilt angle indicating the inclination angle of the work machine relative to the horizontal direction as the attitude of the work machine, calculates the magnitude of the vector component of the width of the work machine in the horizontal direction based on the tilt angle as a second projection length of the work machine, and determines the offset width based on the second projection length of the work machine.

19. A work machine according to claim 15, further comprising a position sensor that detects the current position of the work machine, wherein the controller acquires the current position of the work machine and automatically controls the work machine based on the position of the work machine and the second target route so that the work machine follows the second target route.

20. A work machine according to claim 19, wherein the controller acquires the position of a predetermined part of the work machine as the current position of the work machine, and automatically controls the work machine so that the predetermined part follows the second target path.

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