System and method for controlling work machine

Abstract

To facilitate operation for positioning a vehicle body in a work machine.SOLUTION: The prevent invention is a system for controlling a work machine, and the work machine includes a vehicle body and a work implement. The work implement is attached to the vehicle body. The system includes a controller. The controller acquires a design line extending on a landform to be constructed. The controller determines a line obtained by linearly extending the design line as a target line. The controller executes traveling alignment control for automatically steering the work machine so that a traveling reference point of the vehicle body is along the target line during traveling of the work machine.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to systems and methods for controlling a work machine. [Background technology]

[0002] Some work machines include a vehicle body and a working implement. The work implement includes, for example, a bucket, and performs work such as excavation. Such a work machine may be used to dig a long linear trench. An operator of the work machine operates the work machine to excavate the terrain along a design line that indicates the position where the trench is to be formed, thereby forming the trench. In this case, the operator moves the work machine so that the position of a predetermined reference point of the vehicle body is aligned with the design line. The operator excavates the terrain on the design line using the work implement. Then, the operator reverses the work machine along the design line. By repeating these excavation and reverse movements, a long linear trench is constructed on the terrain.

[0003] In the above work, it is required to align the position of the reference point of the vehicle body with the design line with high accuracy. As a technology for supporting such alignment, for example, Patent Document 1 discloses a display system that displays a screen showing the reference point of the vehicle body, the reference point of the work machine, and the design line on a display. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2017 / 010563 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned technology allows the operator to easily grasp the positional relationship between the vehicle body reference point and the design line from the screen displayed on the display. However, in order to align the position of the vehicle body reference point with the design line, the work machine needs to be precisely steered every time the work machine is driven, which places a heavy burden on the operator. An object of the present disclosure is to facilitate the operation for aligning the vehicle body in the work machine. [Means for solving the problem]

[0006] One aspect of the present disclosure is a system for controlling a work machine. The work machine includes a vehicle body and a work implement. The work implement is attached to the vehicle body. The system includes a controller. The controller obtains a design line extending on a terrain to be worked on. The controller determines a line that is a linear extension of the design line as a target line. The controller executes travel alignment control to automatically steer the work machine while the work machine is traveling so that a travel reference point included on the vehicle body is aligned with the target line.

[0007] Another aspect of the present disclosure is a method for controlling a work machine. The work machine includes a vehicle body and a work implement. The work implement is attached to the vehicle body. The method includes acquiring a design line extending on a terrain to be worked on, determining a line that is a linear extension of the design line as a target line, and executing a traveling alignment control that automatically steers the work machine while the work machine is traveling so that a traveling reference point included on the vehicle body is aligned with the target line. Effect of the Invention

[0008] According to the present disclosure, the driving alignment control automatically steers the work machine so that the driving reference point of the vehicle body is aligned with the target line, thereby facilitating the operation for aligning the vehicle body.

[0009] Further, in the present disclosure, the work machine is automatically steered not along the design line but along a target line that is a linear extension of the design line. If the work machine is automatically steered to follow the design line, the work machine may deviate from the design line if the design line includes a straight portion and a curved portion. For example, if the work machine is disposed at the front of the vehicle body, when the work machine moves backward and the travel reference point moves from the straight portion to the curved portion, the direction of the vehicle body changes and the direction of the work machine also changes. As a result, the work machine deviates from the straight portion. However, in the present disclosure, the work machine is automatically steered not along the design line but along a target line that is a straight extension of the design line. As a result, the work machine is prevented from deviating from the design line. [Brief description of the drawings]

[0010] [Figure 1] FIG. [Diagram 2] 1 is a block diagram showing a configuration of a work machine and its control system. [Diagram 3] 4 is a flowchart showing a process of traveling alignment control. [Figure 4] FIG. 2 is a diagram showing an example of a guide screen. [Diagram 5] FIG. 4 is an enlarged view of an icon showing a work machine displayed on the guide screen. [Figure 6] FIG. 13 is a diagram showing an example of a guide screen in traveling alignment control. [Figure 7] FIG. 13 is a diagram showing an example of a guide screen indicating a control execution area. [Figure 8] FIG. 13 is a diagram showing an example of a guide screen in a state where a traveling reference point coincides with a target line. [Figure 9] FIG. 13 shows an example of a guide screen when automatic steering is stopped. [Figure 10] 4 is a flowchart showing a process of turning alignment control. [Figure 11] FIG. 13 is a diagram showing an example of a guide screen in turning alignment control. [Figure 12]FIG. 13 is a diagram showing an example of a guide screen in a state where the operation reference point coincides with the target line. [Figure 13] FIG. 13 is a diagram showing an example of a guide screen indicating a control stop area. [Figure 14] FIG. 4 is a top view showing the operation of a work machine according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A work machine according to an embodiment will now be described with reference to the drawings. Figure 1 is a side view of a work machine 1. In this embodiment, the work machine 1 is an excavator such as a hydraulic excavator or an electric excavator.

[0012] As shown in FIG. 1, the work machine 1 includes a vehicle body 2 and a working implement 3. The vehicle body 2 includes a rotating body 4 and a running body 5. The working implement 3 is attached to the rotating body 4. The rotating body 4 is connected to the running body 5 so as to be able to rotate. The rotating body 4 is able to rotate around a rotation center C1. A cab 6 is disposed on the rotating body 4. The running body 5 includes a track 7. Note that only one of the left and right tracks 7 is shown in FIG. 1. The track 7 is driven to cause the work machine 1 to travel.

[0013] The work machine 3 is attached to the rotating unit 4 so as to be movable up and down. The work machine 3 includes a boom 11, an arm 12, and a bucket 13. The boom 11 is attached to the rotating unit 4 so as to be rotatable. The arm 12 is attached to the boom 11 so as to be rotatable. The bucket 13 is attached to the arm 12 so as to be rotatable.

[0014] The work machine 3 includes a boom cylinder 14, an arm cylinder 15, and a bucket cylinder 16. The boom cylinder 14, the arm cylinder 15, and the bucket cylinder 16 are, for example, hydraulic cylinders. The boom cylinder 14 operates the boom 11. The arm cylinder 15 operates the arm 12. The bucket cylinder 16 operates the bucket 13.

[0015] Fig. 2 is a block diagram showing the configuration of the work machine 1 and its control system. As shown in Fig. 2, the work machine 1 includes a drive source 21, a hydraulic pump 22, a power transmission device 23, and a controller 24. The drive source 21 is controlled by a command signal from the controller 24. The drive source 21 is, for example, an internal combustion engine. Alternatively, the drive source 21 may include a drive source such as an electric motor or a hydrogen engine. The hydraulic pump 22 is driven by the drive source 21 and discharges hydraulic oil. The hydraulic oil discharged from the hydraulic pump 22 is supplied to the boom cylinder 14, the arm cylinder 15, and the bucket cylinder 16.

[0016] The work machine 1 includes a swing motor 25. The swing motor 25 is, for example, a hydraulic motor. The swing motor 25 is driven by hydraulic oil from the hydraulic pump 22. Alternatively, the swing motor 25 may be an electric motor. The swing motor 25 swings the swing body 4. Note that although one hydraulic pump is illustrated in FIG. 2, multiple hydraulic pumps may be provided.

[0017] The hydraulic pump 22 is a variable displacement pump. A pump control device 26 is connected to the hydraulic pump 22. The pump control device 26 controls the tilt angle of the hydraulic pump 22. The pump control device 26 includes, for example, a solenoid valve, and is controlled by a command signal from the controller 24. The controller 24 controls the displacement of the hydraulic pump 22 by controlling the pump control device 26.

[0018] The work machine 1 includes a control valve 27. The hydraulic pump 22, the cylinders 14-16, and the swing motor 25 are connected by a hydraulic circuit via the control valve 27. The control valve 27 is controlled by a command signal from the controller 24. The control valve 27 controls the flow rate of hydraulic oil supplied from the hydraulic pump 22 to the cylinders 14-16 and the swing motor 25. The controller 24 controls the operation of the work machine 3 by controlling the control valve 27. The controller 24 controls the swing of the swing body 4 by controlling the control valve 27. It should be noted that the cylinders 14-16 are not limited to hydraulic cylinders, and may be mechanical cylinders driven by an electric motor.

[0019] The power transmission device 23 transmits the driving force of the drive source 21 to the traveling body 5. The crawler belt 7 is driven by the driving force from the power transmission device 23 to travel the work machine 1. The power transmission device 23 may be, for example, a torque converter or a transmission having a plurality of speed change gears. Alternatively, the power transmission device 23 may be another type of transmission such as a hydrostatic transmission (HST) or a hydraulic mechanical transmission (HMT).

[0020] The controller 24 includes a processor 31 such as a CPU, and a storage device 32. The processor 31 performs processing for controlling the work machine 1. The storage device 32 includes a memory such as a RAM or a ROM, and an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage device 32 stores data and programs for controlling the work machine 1.

[0021] The control system includes an operation device 33, an input device 34, and a display 35. The operation device 33, the input device 34, and the display 35 are arranged in the cab 6. The operation device 33 can be operated by an operator. The operation device 33 includes a travel operation device 33A, a steering operation device 33B, a turning operation device 33C, and a work machine operation device 33D.

[0022] The travel operation device 33A can be operated by an operator to manually operate the forward and reverse travel of the work machine 1. The travel operation device 33A includes, for example, a switch. However, the travel operation device 33A may include other members such as a lever. The travel operation device 33A can be operated from a neutral position N1 in a forward direction A1 and a reverse direction B1. The travel operation device 33A outputs an operation signal to the controller 24 in response to the operation of the operator.

[0023] The steering operation device 33B can be operated by an operator to manually operate the steering of the work machine 1. The steering operation device 33B includes, for example, a switch. However, the steering operation device 33B may include other members such as a lever. The steering operation device 33B can be operated in a right steering direction A2 and a left steering direction B2 from a neutral position N2. The steering operation device 33B outputs an operation signal to the controller 24 in response to the operation of the operator.

[0024] The swing operation device 33C can be operated by an operator to manually operate the swing of the swing body 4. The swing operation device 33C includes, for example, a lever. However, the swing operation device 33C may include other members such as a switch. The swing operation device 33C can be operated from the neutral position N3 in a right swing direction A3 and a left swing direction B3. The swing operation device 33C outputs an operation signal to the controller 24 according to the operation of the operator.

[0025] The work machine operating device 33D can be operated by an operator to manually operate the work machine 3. The work machine operating device 33D includes, for example, a lever. However, the work machine operating device 33D may include other members such as a switch. For example, the work machine operating device 33D can be operated in a lifting direction A4 and a lowering direction B4 from a neutral position N4. The swing operating device 33C outputs an operation signal to the controller 24 in response to the operation of the operator. Note that each of the operating devices 33A-33D may be configured by a common member.

[0026] The controller 24 controls the drive source 21 and the power transmission device 23 to make the work machine 1 travel in response to the operation of the travel operation device 33A by the operator. As a result, the work machine 1 travels forward or backward in response to the operation of the travel operation device 33A. The controller 24 controls the drive source 21 and the power transmission device 23 to steer the work machine 1 to the left or right in response to the operation of the steering operation device 33B by the operator. For example, the controller 24 steers the work machine 1 to the left or right based on the speed difference between the left and right tracks 7. As a result, the work machine 1 is steered to the left or right in response to the operation of the travel operation device 33A.

[0027] The controller 24 controls the control valve 27 in response to the operation of the swing operation device 33C by the operator so as to swing the swing body 4 relative to the traveling body 5. As a result, the swing body 4 swings clockwise or counterclockwise in response to the operation of the swing operation device 33C. The controller 24 controls the control valve 27 in response to the operation of the work machine operation device 33D by the operator so as to operate the work machine 3. As a result, the work machine 3 moves up and down in response to the operation of the work machine operation device 33D.

[0028] The input device 34 can be operated by an operator. The input device 34 is a touch screen. However, the input device 34 may also include hardware keys. The operator inputs various settings related to the work machine 1 by operating the input device 34. The input device 34 outputs an input signal in response to the operation of the operator. The display 35 is, for example, an LCD, an OELD, or another type of display. The display 35 displays a screen in response to a display signal from the controller 24.

[0029] The control system includes a position sensor 36, an attitude sensor 37, and a work machine sensor 38. The position sensor 36 detects the position and orientation of the work machine 1. The position sensor 36 includes, for example, a sensor based on a Global Navigation Satellite System (GNSS). In detail, the position sensor 36 detects the position and orientation of the rotating unit 4. The position sensor 36 outputs position data indicating the position and orientation of the rotating unit 4.

[0030] The attitude sensor 37 is attached to the revolving structure 4. The attitude sensor 37 detects the attitude of the revolving structure 4. The attitude of the revolving structure 4 includes, for example, a yaw angle, a pitch angle, and a roll angle of the revolving structure 4. The attitude sensor 37 is, for example, an IMU (Inertial Measurement Unit). The attitude sensor 37 outputs first attitude data indicating the attitude of the revolving structure 4.

[0031] The work machine sensor 38 detects the attitude of the work machine 3. The attitude of the work machine 3 includes a boom angle, an arm angle, and a bucket angle. The boom angle is the angle of the boom 11 relative to the revolving body 4. The arm angle is the angle of the arm 12 relative to the boom 11. The bucket angle is the angle of the bucket 13 relative to the arm 12. The work machine sensor 38 outputs second attitude data indicating the boom angle, the arm angle, and the bucket angle. The work machine sensor 38 may detect, for example, the stroke length of each of the cylinders 14-16, and the controller 24 may calculate the boom angle, the arm angle, and the bucket angle from the stroke length of each of the cylinders 14-16. Alternatively, the work machine sensor 38 may be an angle sensor that directly detects the boom angle, the arm angle, and the bucket angle.

[0032] The controller 24 receives an operation signal from the operation device 33. The controller 24 receives an input signal from the input device 34. The controller 24 outputs a display signal to the display 35. The controller 24 receives position data from the position sensor 36. The controller 24 receives first attitude data from the attitude sensor 37. The controller 24 receives second attitude data from the work machine sensor 38.

[0033] The controller 24 calculates the position and orientation of the work machine 1 from the position data, the first attitude data, and the second attitude data. For example, the controller 24 calculates the position and orientation of the running body 5 and the position and orientation of the rotating body 4 based on the position data and the first attitude data. The controller 24 calculates the position and orientation of the work machine 3 based on the position data, the first attitude data, and the second attitude data. Note that the position and orientation of the work machine 3 may be detected directly by a position sensor attached to the work machine 3. The position of the work machine 1 is indicated by planar coordinates and altitude at the work site. The orientation of the work machine 1 is indicated by east-west-north-south azimuth coordinates.

[0034] Next, the automatic control of the work machine 1 will be described. The controller 24 executes the automatic control of the work machine 1 based on the position and orientation of the work machine 1. In this embodiment, the work machine 1 performs work to form a long trench at the work site by excavating the terrain along a design line extending on the terrain to be worked on. At that time, the automatic control assists the manual operation by the operator. The design line is set, for example, based on a work plan. Alternatively, the design line may be set based on a survey of the terrain at the work site.

[0035] The automatic control includes travel alignment control and swing alignment control. In the travel alignment control, the controller 24 automatically controls the steering of the work machine 1 when the work machine 1 is traveling so that the travel direction of the work machine 1 matches the direction in which the design line extends. In the swing alignment control, the controller 24 automatically stops the rotating body 4 when the work machine 1 is performing excavation work so that the bucket 13 matches the position of the design line. The operator can set the travel alignment control and the swing alignment control to be enabled or disabled by operating the input device 34.

[0036] Fig. 3 is a flowchart showing the process of the traveling alignment control. As shown in Fig. 3, in step S101, the controller 24 acquires a design line. The position of the design line is stored in the storage device 32. For example, the controller 24 acquires data indicating the position of the design line from an external computer. Alternatively, the controller 24 may acquire the position of the design line via the input device 34.

[0037] As shown in Fig. 4, the controller 24 causes the display 35 to display a guide screen 40 indicating the positional relationship between a design line 41 and the work machine 1. The guide screen 40 indicates the work machine 1 and the design line 41 in a top view. The work machine 1 is indicated by an icon having the shape of the work machine 1 in a top view. The controller 24 displays the work machine 1 and the design line 41 on the guide screen 40 in accordance with the actual position and orientation of the work machine 1.

[0038] The guide screen 40 also includes assist images 51-53. The assist images 51-53 indicate the position or orientation of a specific portion of the work machine 1. Fig. 5 is an enlarged view of an icon indicating the work machine 1 and the assist images 51-53. As shown in Fig. 5, the assist images include a work assist image 51, a driving assist image 52, and an orientation assist image 53.

[0039] The work assist image 51 indicates the position of a work reference point P1 included in the work machine 3. The work reference point P1 is, for example, the center in the left-right direction of the blade edge of the bucket 13. Alternatively, the work reference point P1 may be the left end or right end of the blade edge of the bucket 13. The work reference point P1 may be selectable from the left end, center, or right end of the bucket 13 by the input device 34. The work assist image 51 has a crosshair shape. The intersection of the crosshairs on the work assist image 51 indicates the position of the work reference point P1.

[0040] The driving assist image 52 indicates the positions of the turning center C1 and a driving reference point P2 included in the vehicle body 2. The driving assist image 52 has a shape that combines a crosshair and a circular arc. The intersection of the crosshairs on the driving assist image 52 indicates the position of the turning center C1. The driving reference point P2 is a position that is offset from the turning center C1 in the left-right direction of the traveling body 5. The apex of the circular arc of the crosshairs on the driving assist image 52 indicates the driving reference point P2.

[0041] The traveling reference point P2 is indicated by the point of contact between the work machine plane PL1 and an arc centered on the turning center C1. The work machine plane PL1 is a plane that includes the trajectory of the work reference point P1 when the work machine 3 moves up and down. In a top view of the work machine 1, the work machine plane PL1 is indicated by a straight line that passes through the work reference point P1 and extends in the fore-and-aft direction of the work machine 1 with the work machine 3 arranged along the fore-and-aft direction of the traveling body 5.

[0042] The orientation assist image 53 indicates the orientation of the traveling object 5. The orientation assist image 53 indicates the direction of the crawler belt 7. The orientation assist image 53 is shown in the shape of, for example, a triangle.

[0043] In step S102, the controller 24 determines whether the traveling alignment control is enabled. For example, when the traveling alignment control is set to on and the operator touches the design line 41 on the guide screen 40, the controller 24 determines that the traveling alignment control is enabled. The traveling alignment control is set to on / off by, for example, the input device 34. If the traveling alignment control is enabled, the process proceeds to step S103.

[0044] In step S103, the controller 24 determines the target line 42. The controller 24 determines a line that is a linear extension of the design line 41 as the target line 42. As shown in Fig. 6, the controller 24 displays the target line 42 on the guide screen 40. When the design line 41 includes a straight line portion 41A and a curved line portion 41B and the straight line portion 41A is touched, the controller 24 determines a line that is an extension of the straight line portion 41A as the target line 42.

[0045] As shown in Fig. 6, the controller 24 displays the target line 42 on the guide screen 40 in a manner different from the design line 41 shown in Fig. 4. For example, the controller 24 displays the target line 42 on the guide screen 40 in a color different from that of the design line 41. The controller 24 also displays a control icon IC1 indicating that traveling alignment control has started on the guide screen 40. The operator operates the traveling operation device 33A to move the work machine 1 forward or backward so that the work machine 1 approaches the target line 42.

[0046] In step S104, the controller 24 determines whether the traveling reference point P2 is located within the control execution region 43. The control execution region 43 is a region extending from the target line 42 to a position separated by an allowable width in both directions to the left and right of the target line 42. The allowable width can be set, for example, by the input device 34. When the traveling reference point P2 is located within the control execution region 43, the controller 24 displays the control execution region 43 on the guide screen 40, as shown in FIG. 7. The control execution region 43 is separated from the target line 42 in both directions to the left and right, and is indicated by two straight lines L1 and L2 extending in a direction parallel to the target line 42.

[0047] When the traveling reference point P2 is located outside the control execution region 43, the controller 24 does not execute automatic steering, but steers the work machine 1 in accordance with manual operation by the steering operation device 33B. Also, as shown in Fig. 6, when the traveling reference point P2 is located outside the control execution region 43, the controller 24 does not display the control execution region 43 on the guide screen 40.

[0048] If the traveling reference point P2 is located within the control execution area 43, the process proceeds to step S105. In step S105, the controller 24 executes traveling alignment control. As shown in Figs. 7 and 8, the controller 24 automatically steers the work machine 1 while the work machine 1 is traveling so that the traveling reference point P2 is aligned with the target line 42. That is, the controller 24 automatically steers the work machine 1 so that the arc of the traveling assist image 52 is tangent to the target line 42 at the traveling reference point P2. Thereby, the controller 24 causes the work machine 1 to travel in response to manual operation by the traveling operation device 33A, and automatically steers the work machine 1 so that the traveling reference point P2 is aligned with the target line 42.

[0049] As shown in FIG. 8, when the driving reference point P2 coincides with the target line 42, the controller 24 displays the driving assist image 52 in a manner different from when the driving reference point P2 does not coincide with the target line 42.

[0050] Note that even if the traveling reference point P2 is located within the control execution region 43, when manual operation is performed by the steering operation device 33B, the controller 24 prioritizes the manual operation by the steering operation device 33B over the traveling alignment control. In other words, even if the traveling reference point P2 is located within the control execution region 43, when manual operation is performed by the steering operation device 33B, the controller 24 stops the traveling alignment control and steers the work machine 1 in accordance with the manual operation by the steering operation device 33B.

[0051] As shown in Figures 7 and 8, while the traveling alignment control is being executed, the controller 24 displays the control icon IC1 in a different manner than when the traveling alignment control is stopped. For example, while the traveling alignment control is being executed, the controller 24 displays the control icon IC1 in a different color than when the traveling alignment control is stopped. As shown in Figure 9, even if the traveling reference point P2 is located within the control execution area 43, while the traveling alignment control is stopped, the controller 24 does not display the control execution area 43 on the display 35. Even when the operator is not operating the traveling operation device 33A and the traveling of the work machine 1 is stopped, the controller 24 displays the control icon IC1 in the same manner as when the traveling alignment control is stopped.

[0052] When the driving operation by the driving operation device 33A ends, the controller 24 stops the driving alignment control. However, since the driving alignment control is in a valid state, when the driving operation by the driving operation device 33A is resumed, the controller 24 continues to execute the driving alignment control.

[0053] Next, the turning alignment control will be described. Fig. 10 is a flowchart showing the processing of the turning alignment control. As shown in Fig. 10, in step S201, the controller 24 acquires the design line 41. The controller 24 acquires the design line 41 in the same manner as in the traveling alignment control described above.

[0054] In step S202, the controller 24 determines whether the turning alignment control is enabled. For example, when the turning alignment control is set to on and the operator touches the design line 41 on the guide screen 40, the controller 24 determines that the turning alignment control is enabled. The turning alignment control is set to on / off by, for example, the input device 34. If the turning alignment control is enabled, the process proceeds to step S203.

[0055] In step S203, the controller 24 determines the target line 42. The controller 24 determines the target line 42 in the same manner as in the processing of the traveling alignment control. FIG. 11 is a diagram showing the guide screen 40 during the turning alignment control. As in the traveling alignment control, the controller 24 displays the target line 42 on the guide screen 40 in a manner different from that of the design line 41. For example, the controller 24 displays the target line 42 on the guide screen 40 in a color different from that of the design line 41. In addition, the controller 24 displays a control icon IC2 on the guide screen 40, which indicates that the turning alignment control has started.

[0056] After the target line 42 is determined, the operator operates the turning operation device 33C to turn the turning body 4. In FIG. 11, the work reference point P1 is located at a position outside the target line 42, for example, at a dumping position. The operator operates the turning operation device 33C to turn the turning body 4 so that the work reference point P1 approaches the target line 42.

[0057] In step S204, the controller 24 determines whether the rotation operation amount of the rotating body 4 is greater than the target rotation speed. When the rotation speed according to the operation of the rotation operation device 33C of the rotating body 4 is greater than the target rotation speed, the controller 24 determines that the rotation operation amount of the rotating body 4 is greater than the target rotation speed. When the rotation operation amount of the rotating body 4 is greater than the target rotation speed, the process proceeds to step S205.

[0058] In step S205, the controller 24 decelerates the rotating body 4. The controller 24 decelerates the rotating body 4 until the working reference point P1 reaches the target line 42, and automatically stops the rotation of the rotating body 4 when it reaches the target line 42. As a result, as shown in FIG. 12, the rotating body 4 stops with the working reference point P1 coinciding with the target line 42. In this state, the operator can excavate the terrain on the target line 42 by operating the work machine operation device 33D. Note that in step S204, if the rotation operation amount of the rotating body 4 is equal to or less than the target rotation speed, the rotating body 4 does not decelerate or automatically stop, but continues to rotate in response to the operation of the rotation operation device 33C.

[0059] When the task reference point P1 coincides with the target line 42, the controller 24 displays the task assist image 51 in a manner different from that when the task reference point P1 deviates from the target line 42. For example, when the task reference point P1 coincides with the target line 42, the controller 24 displays the task assist image 51 in a color different from that when the task reference point P1 deviates from the target line 42.

[0060] Furthermore, while the rotating body 4 is automatically stopped, the controller 24 displays the control icon IC2 in a manner different from when the rotating body 4 is not automatically stopped. For example, while the rotating body 4 is automatically stopped, the controller 24 displays the control icon IC2 in a color different from when the rotating body 4 is not automatically stopped.

[0061] After the rotating body 4 automatically stops, when the operator returns the rotation operation device 33C to the neutral position, the controller 24 displays the control invalid area 44 on the guide screen 40 as shown in FIG. 13. The control invalid area 44 is an area from the target line 42 to a position that is separated by an allowable width in both directions to the left and right of the target line 42. The allowable width can be set, for example, by the input device 34. The control invalid area 44 is separated by two straight lines L3 and L4 that are separated by two directions to the left and right of the target line 42 and extend in a direction parallel to the target line 42. After the operator returns the rotation operation device 33C to the neutral position, the controller 24 rotates the rotating body 4 in response to the operation of the rotation operation device 33C.

[0062] In step S206, the controller 24 determines whether the working reference point P1 is located within the control invalid area 44. If the working reference point P1 is located within the control invalid area 44, in step S207, the controller 24 disables the automatic stop of the rotating body 4. That is, even if the operator rotates the rotating body 4 by manual operation after the automatic stop of the rotating body 4 and the working reference point P1 reaches the target line 42, if the working reference point P1 is located within the control invalid area 44, the controller 24 does not automatically stop the rotating body 4. This allows the operator to easily excavate the terrain near the target line 42 by manually rotating the working reference point P1 within the control invalid area 44.

[0063] When the operator manually rotates the rotating body 4 so that the work reference point P1 goes outside the control invalid area 44, the controller 24 erases the control invalid area 44 from the guide screen 40, as shown in Fig. 11. For example, after the operator excavates the terrain on the target line 42 with the work implement 3, the operator rotates the rotating body 4 to dump earth and sand from the bucket 13 to a position off the target line 42. This causes the control invalid area 44 to be erased from the guide screen 40.

[0064] Furthermore, when the working reference point P1 moves out of the control invalid area 44, the controller 24 re-enables the automatic stop of the rotating unit 4. As a result, as described above, when the rotation speed of the rotating unit 4 is slower than the rotation operation, the rotation of the rotating unit 4 is decelerated, and when the working reference point P1 reaches the target line 42, the controller 24 automatically stops the rotating unit 4. By repeating such operations of the work machine 1, a groove is formed in the topography on the target line 42.

[0065] Next, the operator reverses the work machine 1. At this time, the work machine 1 is automatically steered by the above-mentioned traveling alignment control so that the traveling reference point P2 moves along the target line 42. Then, excavation and soil removal by the rotation of the rotating body 4 are repeated again, forming a trench in the terrain on the target line 42. By repeating such operations of the work machine 1, a long trench is formed in the terrain along the target line 42.

[0066] In addition, similarly to the traveling alignment control, the turning alignment control may also be terminated when a control termination operation is performed.

[0067] In the work machine 1 according to the present embodiment described above, the work machine 1 is automatically steered by the traveling alignment control so that the traveling reference point P2 of the vehicle body 2 is aligned with the target line 42. This makes it easier to perform operations for aligning the vehicle body 2.

[0068] Furthermore, the work machine 1 is automatically steered not along the design line 41, but along a target line 42 which is a linear extension of the design line 41. If the work machine 1 is automatically steered along the design line 41, the work implement 3 may deviate from the design line 41 if the design line 41 includes a straight portion 41A and a curved portion 41B as described above.

[0069] For example, Fig. 14 is a top view showing the operation of a work machine according to a comparative example. In the comparative example shown in Fig. 14, traveling alignment control is performed with the design line 41 itself as the target line. As shown in Fig. 14, when the work machine 1 moves backward and the traveling reference point P2 moves from the straight portion 41A to the curved portion 41B, the orientation of the vehicle body 2 changes, and the orientation of the work implement 3 also changes. As a result, the working reference point P1 of the work implement 3 deviates from the straight portion 41A. However, in the work machine 1 according to this embodiment, the work machine 1 is automatically steered so as to follow not the design line 41, but the target line 42 which is a linear extension of the design line 41. As a result, the work implement 3 is prevented from deviating from the design line 41.

[0070] 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.

[0071] The work machine 1 may be equipped with wheels instead of the tracks 7. The work machine 1 may be remotely operable. The operation device 33, the input device 34, and the display 35 may be disposed outside the work machine 1. Part of the automatic control processing described above may be executed by a controller external to the work machine 1. The automatic control processing may be distributed and executed among multiple controllers.

[0072] The work of the work machine 1 under automatic control is not limited to the work of forming a trench, but may be other work. For example, automatic control may be applied to the work of filling a trench with soil. The automatic control process is not limited to that of the above embodiment, but may be modified. For example, the start of the travel alignment control or the turning alignment control is not limited to touching the design line 41, but may be other operations. The turning alignment control may be omitted.

[0073] The guide screen 40 is not limited to that of the above embodiment, and may be modified. For example, the task assist image 51 is not limited to a crosshair, and may be other shapes such as a dot. The driving assist image 52 is not limited to a crosshair and an arc, and may be other shapes such as a dot. The orientation assist image 53 is not limited to a triangle, and may be other shapes such as an arrow. The "different aspects" in the display of the guide screen 40 described above are not limited to different colors, and may be different shapes. The shape of the control invalid area 44 is not limited to that of the above embodiment, and may be modified. For example, the control invalid area 44 may have a trapezoid or a sector shape.

[0074] (Appendix 1) A system for controlling a work machine including a vehicle body and a work implement attached to the vehicle body, A controller is provided. The controller: Obtaining a design line extending on the terrain to be constructed; A line obtained by linearly extending the design line is determined as a target line; executing a traveling alignment control for automatically steering the work machine while the work machine is traveling so that a traveling reference point included in the vehicle body is aligned with the target line; system.

[0075] (Appendix 2) Further equipped with a display, The controller causes the display to display the work machine, the target line, and the traveling reference point. 2. The system of claim 1.

[0076] (Appendix 3) The work machine further includes a steering operation device operable by an operator to manually operate the steering of the work machine, The controller: When the travel reference point is located outside a predetermined area, the work machine is steered in response to a manual operation by the steering operation device; When the travel reference point is located within a predetermined area, the work machine is automatically steered. 10. The system of claim 1 or claim 1.

[0077] (Appendix 4) the controller, when the driving reference point is located within a predetermined area and a manual operation is performed using the steering operation device, prioritizes the manual operation using the steering operation device; 4. The system of claim 3.

[0078] (Appendix 5) The working machine further includes a travel operation device operable by an operator to manually operate forward and / or reverse travel of the working machine, When the travel reference point is located within a predetermined area, the controller causes the work machine to travel in response to manual operation by the travel operation device, and automatically steers the work machine so that the travel reference point is aligned with the target line. 5. The system of claim 3 or 4.

[0079] (Appendix 6) Further equipped with a display, the controller causes the display to display the work machine, the target line, the traveling reference point, and the specified area. 6. The system of claim 3, (Appendix 7) The predetermined area is a range from the target line to a position separated by an allowable width. 7. The system of claim 3.

[0080] (Appendix 8) The vehicle body includes a rotating body that is capable of rotating around a rotation center, the travel reference point is a point of contact between a work machine plane and an arc having the turning center as a center when viewed from above the work machine, the work machine plane passes through a work reference point included in the work machine and extends in the fore-and-aft direction of the work machine in a state in which the work machine is disposed along the fore-and-aft direction of the work machine in a top view of the work machine, the controller automatically steers the work machine in the traveling alignment control so that the arc is tangent to the target line at the traveling reference point. 8. The system of claim 1.

[0081] (Appendix 9) A method for controlling a work machine including a vehicle body and a work implement attached to the vehicle body, comprising: Obtaining a design line extending over the terrain to be constructed; determining a line obtained by linearly extending the design line as a target line; executing a traveling alignment control for automatically steering the work machine while the work machine is traveling so that a traveling reference point included in the vehicle body is aligned with the target line; A method for providing the above.

[0082] (Appendix 10) Displaying the work machine, the target line, and the traveling reference point on a display. 10. The method according to claim 9.

[0083] (Appendix 11) receiving an operation signal from a steering operation device operable by an operator to manually operate the steering of the work machine; When the travel reference point is located outside a predetermined area, steering the work machine in response to a manual operation by the steering operation device; automatically steering the work machine when the travel reference point is located within a predetermined area; 11. The method of claim 9 or 10, comprising:

[0084] (Appendix 12) and when the driving reference point is located within a predetermined area and a manual operation is performed by the steering operation device, the manual operation by the steering operation device is given priority. 12. The method according to claim 11.

[0085] (Appendix 13) Receiving an operation signal from a travel operation device operable by an operator to manually operate forward and / or reverse travel of the work machine. when the travel reference point is located within a predetermined area, traveling the work machine in response to manual operation by the travel operation device, and automatically steering the work machine so that the travel reference point is along the target line; 13. The method according to claim 11 or 12, comprising:

[0086] (Appendix 14) displaying the work machine, the target line, the traveling reference point, and the specified area on a display. 14. The method according to any one of claims 11 to 13.

[0087] (Appendix 15) The predetermined area is a range from the target line to a position separated by an allowable width. 15. The system of any one of claims 11 to 14.

[0088] (Appendix 16) The vehicle body includes a rotating body that is capable of rotating around a rotation center, the travel reference point is a point of contact between a work machine plane and an arc having the turning center as a center when viewed from above the work machine, the work machine plane passes through a work reference point included in the work machine and extends in the fore-and-aft direction of the work machine in a state in which the work machine is disposed along the fore-and-aft direction of the work machine in a top view of the work machine, the driving alignment control includes automatically steering the work machine so that the arc is tangent to the target line at the driving reference point, 16. The method according to any one of claims 9 to 15. [Industrial Applicability]

[0089] To facilitate an operation for aligning a body of a work machine. [Explanation of symbols]

[0090] 1: Work machine 3: Work equipment 4: Rotating body 24: Controller 33A: Driving operation device 33B: Steering device 35: Display 41: Design line 42: Target line C1: Center of rotation P2: Driving reference point PL1: Work machine plane

Claims

1. A system for controlling a work machine including a vehicle body and a work implement attached to the vehicle body, A controller is provided. The controller: Obtaining a design line extending on the terrain to be constructed; A line obtained by linearly extending the design line is determined as a target line; executing a traveling alignment control for automatically steering the work machine while the work machine is traveling so that a traveling reference point included in the vehicle body is aligned with the target line; system.

2. Further equipped with a display, The controller causes the display to display the work machine, the target line, and the traveling reference point. The system of claim 1 .

3. The work machine further includes a steering operation device operable by an operator to manually operate the steering of the work machine, The controller: When the travel reference point is located outside a predetermined area, the work machine is steered in response to a manual operation by the steering operation device; When the travel reference point is located within a predetermined area, the work machine is automatically steered. The system of claim 1 .

4. the controller, when the driving reference point is located within a predetermined area and a manual operation is performed using the steering operation device, prioritizes the manual operation using the steering operation device; The system of claim 3.

5. Further comprising a travel operation device operable by an operator to manually operate the forward and / or reverse travel of the work machine; When the travel reference point is located within a predetermined area, the controller causes the work machine to travel in response to manual operation by the travel operation device, and automatically steers the work machine so that the travel reference point is aligned with the target line. The system of claim 3.

6. Further equipped with a display, the controller causes the display to display the work machine, the target line, the traveling reference point, and the specified area. The system of claim 3.

7. The predetermined area is a range from the target line to a position separated by an allowable width. The system of claim 3.

8. The vehicle body includes a rotating body that is capable of rotating around a rotation center, the travel reference point is a point of contact between a work machine plane and an arc having the turning center as a center when viewed from above the work machine, the work machine plane passes through a work reference point included in the work machine and extends in the fore-and-aft direction of the work machine in a state in which the work machine is disposed along the fore-and-aft direction of the work machine in a top view of the work machine, the controller automatically steers the work machine in the traveling alignment control so that the arc is tangent to the target line at the traveling reference point. The system of claim 1 .

9. A method for controlling a work machine including a vehicle body and a work implement attached to the vehicle body, comprising: Obtaining a design line extending over the terrain to be constructed; determining a line obtained by linearly extending the design line as a target line; executing a traveling alignment control for automatically steering the work machine while the work machine is traveling so that a traveling reference point included in the vehicle body is aligned with the target line; A method for providing the above.

10. Displaying the work machine, the target line, and the traveling reference point on a display.

10. The method of claim 9.

11. receiving an operation signal from a steering operation device operable by an operator to manually operate the steering of the work machine; When the travel reference point is located outside a predetermined area, steering the work machine in response to a manual operation by the steering operation device; automatically steering the work machine when the travel reference point is located within a predetermined area; The method of claim 9 comprising:

12. and when the driving reference point is located within a predetermined area and a manual operation is performed by the steering operation device, the manual operation by the steering operation device is given priority. The method of claim 11.

13. Receiving an operation signal from a travel operation device operable by an operator to manually operate forward and / or reverse travel of the work machine. when the travel reference point is located within a predetermined area, traveling the work machine in response to manual operation by the travel operation device, and automatically steering the work machine so that the travel reference point is along the target line; The method of claim 11 , comprising:

14. displaying the work machine, the target line, the traveling reference point, and the specified area on a display. The method of claim 11.

15. The predetermined area is a range from the target line to a position separated by an allowable width. The system of claim 11.

16. The vehicle body includes a rotating body that is capable of rotating around a rotation center, the travel reference point is a point of contact between a work machine plane and an arc having the turning center as a center when viewed from above the work machine, the work machine plane passes through a work reference point included in the work machine and extends in the fore-and-aft direction of the work machine in a state in which the work machine is disposed along the fore-and-aft direction of the work machine in a top view of the work machine, the driving alignment control includes automatically steering the work machine so that the arc is tangent to the target line at the driving reference point, 10. The method of claim 9.

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