System and method for controlling work machine

Abstract

To easily set a target path in automatic control of a work machine.SOLUTION: A system for controlling a work machine comprises a sensor and a controller. The sensor detects a position of the work machine. The controller acquires target terrain data indicating target terrain composed of a plurality of surfaces. The controller selects, among the plurality of surfaces, a plurality of work surfaces to be worked on. The controller groups the plurality of work surfaces and sets the same as a target surface. The controller determines a target route along sides of the target surface. The controller acquires the position of the work machine. On the basis of the position of the work machine, the controller controls the work machine so that the work machine travels along the target route.SELECTED DRAWING: Figure 11

Description

[Technical field]

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

[0002] Conventionally, there is known a technique for automatically controlling a work machine to perform work such as excavation so that the terrain has a target shape (hereinafter referred to as target terrain). In such automatic control of a work machine, a controller controls the work machine so that the work machine travels along a target route. For example, in Patent Document 1, a controller determines a first work path for a first work machine. The first work path extends in a predetermined work direction in a first work area. The first work machine is automatically controlled so as to excavate the terrain with the work implement while traveling along the first work path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-097268 Summary of the Invention [Problem to be solved by the invention]

[0004] The target terrain created by work performed by a work machine is not limited to a simple linear shape as described above, but may have a complex curved shape. In such cases, it is not easy to set a target path for automatic control. An object of the present disclosure is to easily set a target path in automatic control of a work machine. [Means for solving the problem]

[0005] A system according to one aspect of the present disclosure is a system for controlling a work machine, and includes a sensor and a controller. The sensor detects a position of the work machine. The controller acquires target terrain data indicating a target terrain composed of multiple surfaces. The controller selects multiple work surfaces on which work will be performed from the multiple surfaces. The controller groups the multiple work surfaces and determines them as a target surface. The controller determines a target path to follow the edges of the target surface. The controller acquires the position of the work machine. The controller controls the work machine based on the position of the work machine so that the work machine travels along the target path.

[0006] A method according to another aspect of the present disclosure is a method for controlling a work machine, comprising obtaining target terrain data indicating a target terrain composed of a plurality of surfaces, selecting a plurality of work surfaces to be worked on from the plurality of surfaces, grouping the plurality of work surfaces to determine them as a target surface, determining a target route to follow the edges of the target surfaces, obtaining a position of the work machine, and controlling the work machine based on the position of the work machine so that the work machine travels along the target route. Effect of the Invention

[0007] According to the present disclosure, a plurality of work surfaces selected from a plurality of surfaces constituting a target terrain are grouped and determined as a target surface. Then, a target route is determined so as to follow the sides of the target surface. This makes it possible to easily set the target route. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a work machine according to an embodiment. [Diagram 2] 2 is a block diagram showing the configuration of a drive system and a control system of the work machine. FIG. [Diagram 3] 4 is a flowchart showing an automatic control process. [Figure 4] FIG. 4 is a diagram showing an example of a target terrain. [Diagram 5]FIG. 13 is a diagram showing an example of a setting screen for a target route. [Figure 6] FIG. 13 is a diagram showing an example of a setting screen for a target route. [Figure 7] FIG. 13 is a diagram showing an example of an input screen for an angle threshold value. [Figure 8] FIG. 13 is an enlarged view of the target terrain on the setting screen. [Figure 9] 11A and 11B are diagrams showing an example of a plurality of work planes and target planes selected on a setting screen. [Figure 10] 11A and 11B are diagrams showing an example of a plurality of work planes and target planes selected on a setting screen. [Figure 11] FIG. 11 is a diagram showing an example of a target route set on a setting screen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a work machine according to an embodiment will be described with reference to the drawings. Fig. 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 includes a vehicle body 11 and a work implement 12.

[0010] The vehicle body 11 includes a driver's cab 13, a drive source room 14, and a traveling device 15. A driver's seat (not shown) is arranged in the driver's cab 13. The drive source room 14 is arranged in front of the driver's 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 as the tracks 16 rotate.

[0011] The work machine 12 is attached to the vehicle body 11. The work machine 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 actuator 19 extends and retracts, causing the lift frame 17 to move up and down. The blade 18 moves up and down in conjunction with the up and down movement of the lift frame 17.

[0012] Fig. 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 Fig. 2, the drive system 2 includes a drive source 22, a hydraulic pump 23, and a power transmission device 24. The drive source 22 includes, for example, an internal combustion engine. The drive source 22 may include an electric motor. The hydraulic pump 23 is driven by the drive source 22 and discharges hydraulic oil. The hydraulic oil discharged from the hydraulic pump 23 is supplied to the lift actuator 19. Note that, although one hydraulic pump 23 is shown in Fig. 2, multiple hydraulic pumps may be provided.

[0013] 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.

[0014] 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 records programs and data for controlling the work machine 1.

[0015] The control valve 27 is a proportional control valve, and 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.

[0016] The control system 3 includes an input device 32 and a display 33. The input device 32 can be operated by an operator. The display 33 displays information related to the work machine 1. The input device 32 and the display 33 may be, for example, a touch panel. Alternatively, the input device 32 may include other devices such as a physical switch. The input device 32 may include a pointing device such as a joystick or a touchpad. The operator can use the input device 32 to set automatic control of the work machine 1. The automatic control of the work machine 1 will be described in detail later.

[0017] The control system 3 includes a position sensor 34, a vehicle body sensor 35, and a work equipment sensor 36. The position sensor 34 is attached to the vehicle body 11. The position sensor 34 includes, for example, a sensor based on a Global Navigation Satellite System (GNSS). The position sensor 34 detects the position and orientation of the vehicle body 11. The position sensor 34 outputs a detection signal indicating the position and orientation of the vehicle body 11.

[0018] The vehicle body sensor 35 is attached to the vehicle body 11. The vehicle body sensor 35 detects the attitude of the vehicle body 11. For example, the vehicle body sensor 35 detects the pitch angle and roll angle of the vehicle body 11. The work machine sensor 36 is attached to the work machine 12. The work machine sensor 36 detects the attitude of the work machine 12. For example, the work machine sensor 36 detects the pitch angle of the work machine 12.

[0019] The vehicle body sensor 35 and the work machine sensor 36 are, for example, an IMU (Inertial Measurement Unit). However, the work machine sensor 36 is not limited to an IMU, and may be another sensor such as an angle sensor or a cylinder stroke sensor. The vehicle body sensor 35 and the work machine sensor 36 each output a detection signal indicating the detected angle.

[0020] The controller 26 receives detection signals from the position sensor 34, the vehicle body sensor 35, and the work machine sensor 36. The controller 26 calculates the position and orientation of the work machine 1 based on the detection signals. The controller 26 performs automatic control to control the traveling direction of the work machine 1 based on the position and orientation of the work machine 1. In the automatic control, the controller 26 causes the work machine 1 to travel according to a target route. The automatic control of the work machine 1 will be described below.

[0021] Fig. 3 is a flowchart showing the automatic control process executed by the controller 26. As shown in Fig. 3, in step S101, the controller 26 acquires target terrain data. The target terrain data indicates a target terrain for work by the work machine 1. The target terrain data is stored in the storage device 28.

[0022] FIG. 4 is a diagram showing an example of the target terrain 40. As shown in FIG. 4, the target terrain 40 is expressed by a polygon mesh. The target terrain 40 is composed of a plurality of faces 51-54. The plurality of faces 51-54 have a triangular shape. The plurality of faces 51-54 is not limited to a triangle, and may be another polygonal shape. The target terrain data indicates the position of each of the plurality of faces 51-54. For example, the target terrain data includes the coordinates and altitude of each vertex of the plurality of faces 51-54.

[0023] In detail, the target terrain 40 includes a first flat surface 41, a first slope 42, a second slope 43, and a second flat surface 44. The first flat surface 41 and the second flat surface 44 are horizontal surfaces. However, the first flat surface 41 and the second flat surface 44 may be inclined with respect to a horizontal plane. The first slope 42 is inclined with respect to the first flat surface 41. A toe 45 is provided between the first slope 42 and the first flat surface 41. The second slope 43 is inclined with respect to the first flat surface 41. A shoulder 46 is provided between the second slope 43 and the first flat surface 41. The second slope 43 is inclined with respect to the second flat surface 44. A toe 47 is provided between the second slope 43 and the second flat surface 44.

[0024] The first flat surface 41 is composed of a plurality of first surfaces 51. The first slope 42 is composed of a plurality of second surfaces 52. The second slope 43 is composed of a plurality of third surfaces 53. The second flat surface 44 is composed of a plurality of fourth surfaces 54. In the drawings, only a portion of the plurality of first surfaces 51, the plurality of second surfaces 52, the plurality of third surfaces 53, and the plurality of fourth surfaces 54 are labeled with reference numerals 51-54, and the reference numerals of the other first surfaces 51, the second surfaces 52, the third surfaces 53, and the fourth surfaces 54 are omitted.

[0025] The plurality of first surfaces 51 may be planar or may be angled relative to one another. Similarly, the plurality of second surfaces 52 may be planar or may be angled relative to one another. The plurality of third surfaces 53 may be planar or may be angled relative to one another. The plurality of fourth surfaces 54 may be planar or may be angled relative to one another.

[0026] However, the angle between the multiple first surfaces 51 and the angle between the multiple second surfaces 52 are each smaller than the inclination angle of the first slope 42 with respect to the first flat surface 41. The angle between the multiple first surfaces 51 and the angle between the multiple third surfaces 53 are each smaller than the inclination angle of the second slope 43 with respect to the first flat surface 41. The angle between the multiple third surfaces 53 and the angle between the multiple fourth surfaces 54 are each smaller than the inclination angle of the second slope 43 with respect to the second flat surface 44.

[0027] In step S102, the controller 26 displays the target terrain 40 on the display 33. Fig. 5 is a diagram showing an example of a target route setting screen 60. As shown in Fig. 5, the setting screen 60 includes the target terrain 40 in a top view and an icon 61 indicating the position of the work machine 1.

[0028] In step S103, the controller 26 selects a reference plane. The operator operates the input device 32 to specify one of the multiple planes 51-54 as the reference plane. For example, as shown in FIG. 6, the operator specifies the reference plane 55 by touching one of the multiple planes 51-54 on the setting screen 60. The controller 26 acquires the reference plane 55 specified by the operator based on a signal from the input device 32.

[0029] The operator designates a surface included in the portion of the target terrain 40 that is the target of work by the work machine 1 as the reference surface 55. In the example shown in Fig. 6, the operator designates one of the multiple first surfaces 51 of the first flat surface 41 as the reference surface 55 in order to form the toe 45 between the first flat surface 41 and the first slope 42.

[0030] In step S104, the controller 26 acquires an angle threshold. As shown in Fig. 7, when the reference surface 55 is selected, the controller 26 displays an input screen 62 for the angle threshold on the display 33. The operator operates the input device 32 to input the angle threshold. The angle threshold is the upper limit of the angle of the inflection point at which multiple surfaces are recognized as one target surface.

[0031] In step S105, the controller 26 selects a plurality of work surfaces to be the target of the work. The controller 26 sequentially selects, from among the plurality of surfaces 51-54, surfaces whose adjacent surfaces have angles with respect to the reference surface 55 as the starting point that are equal to or smaller than the angle threshold value, as the plurality of work surfaces.

[0032] For example, as shown in Fig. 8, when the angle between the first surface 51A adjacent to the reference surface 55 and the reference surface 55 is equal to or less than the angle threshold, the controller 26 selects the first surface 51A as the work surface. When the angle between the first surface 51B adjacent to the reference surface 55 and the reference surface 55 is equal to or less than the angle threshold, the controller 26 selects the first surface 51B as the work surface. When the angle between the first surface 51C adjacent to the first surface 51B and the first surface 51B is equal to or less than the angle threshold, the controller 26 selects the first surface 51C as the work surface.

[0033] On the other hand, if the angle between the second surface 52A adjacent to the first surface 51A and the first surface 51A is greater than the angle threshold, the controller 26 does not select the second surface 52A as the work surface. If the angle between the third surface 53A adjacent to the first surface 51C and the first surface 51C is greater than the angle threshold, the controller 26 does not select the third surface 52A as the work surface. Thereafter, similarly, for all of the multiple surfaces 51-54 of the target terrain 40, surfaces whose angles between adjacent surfaces are equal to or less than the angle threshold are selected as work surfaces.

[0034] Fig. 9 is a diagram showing an example of a plurality of work surfaces 56 selected on the setting screen 60. Note that in Fig. 9, only some of the plurality of work surfaces 56 are labeled with the reference numerals 56, and the reference numerals of the other work surfaces 56 are omitted. In Fig. 9, the plurality of work surfaces 56 are hatched.

[0035] In step S106, the controller 26 determines a target plane 57. The controller 26 groups the multiple work planes 56 selected in step S105 and determines them as one target plane 57. The controller 26 displays the target plane 57 on the setting screen 60 in a color different from the other planes.

[0036] If the angle threshold is too small, as shown in Fig. 10, the operator may not be able to select the entire part that he or she wishes to select as the target of the work (for example, the entire first flat surface 41) as the target surface 57. In such a case, the operator can increase the angle threshold on the angle threshold input screen 62 described above, thereby selecting the entire part that he or she wishes to select as the target of the work as the target surface 57, as shown in Fig. 9.

[0037] In step S107, the controller 26 determines a target path. The controller 26 determines the target path so as to follow the side of the target surface 57. FIG. 11 is a diagram showing an example of a target path 58 set on the setting screen 60. The target surface 57 includes a first side 59A and a second side 59B located opposite to the first side 59A. The first side 59A is a set of sides of the multiple first surfaces 51 aligned along one side edge of the target surface 57. The second side 59B is a set of sides of the multiple first surfaces 51 aligned along the other side edge of the target surface 57.

[0038] The controller 26 determines the target path 58 to follow either the first side 59A or the second side 59B, whichever is closer to the reference plane 55. Alternatively, the controller 26 may determine the target path 58 to follow either the first side 59A or the second side 59B, whichever is closer to the work machine 1. Alternatively, the controller 26 may determine the target path 58 to follow either the first side 59A or the second side 59B, whichever is selected by the operator. The controller 26 displays the target path 58 on the setting screen 60 in a color different from the target plane 57 and other planes.

[0039] In the example shown in FIG. 11, the first side 59A indicates the toe 45 between the first flat surface 41 and the first slope 42. The second side 59B indicates the shoulder 46 between the first flat surface 41 and the second slope 43. As described above, the target path 58 is determined to follow the first side 59A, and thus the target path 58 is determined to follow the toe 45. In step S108, the controller 26 acquires the position of the work machine 1. The controller 26 acquires the position of the work machine 1 based on the detection signals from the sensors 34-36 described above. In detail, the controller 26 acquires the position of a reference point 63 included in the work machine 1. The reference point 63 is, for example, the left end or the right end of the blade 18. For example, the controller 26 determines, as the reference point 63, the left end or the right end of the blade 18, whichever is closer to the target route 58. Alternatively, the controller 26 may determine, as the reference point 63, the left end or the right end of the blade 18, whichever is selected by the operator. In the example shown in FIG. 11, the controller 26 determines the right end of the blade 18 as the reference point 63.

[0040] In step S109, the controller 26 controls the work machine 1 according to the target route 58, based on the position of the work machine 1. As shown in Fig. 11, the controller 26 causes the work machine 1 to travel so that a reference point 63 of the work machine 1 moves along the target route 58. In addition, the controller 26 operates the work implement 12 so that the reference point 63 moves along the target route 58.

[0041] According to the control system for the work machine 1 according to this embodiment described above, a plurality of work surfaces 56 selected from the plurality of surfaces 51-54 constituting the target terrain 40 are grouped and determined as a target surface 57. Then, a target route 58 is determined so as to follow the sides of the target surface 57. This makes it possible to easily set the target route 58 even if the target terrain 40 has a complex shape.

[0042] 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.

[0043] The work machine 1 is not limited to a bulldozer, and may be other vehicles such as a wheel loader, a motor grader, etc. The work machine 1 may be operable remotely. In that case, the input device 32 and the display 33 may be disposed outside the work machine 1.

[0044] 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. The position sensor 34 may be attached to the work implement 12. The controller 26 may calculate the position of the reference point 63 of the blade 18 based on a detection signal from the position sensor 34.

[0045] The automatic control process by the controller 26 is not limited to that of the above embodiment and may be modified. For example, the angle threshold may be automatically determined by the controller 26. The controller 26 may select the working plane 56 using other parameters, not limited to the angle between adjacent faces. For example, the controller 26 may select the working plane 56 using the slope or height of each of the multiple faces 51-54.

[0046] In the above embodiment, the right end of the blade 18 is determined as the reference point 63. However, the left end of the blade 18 may be determined as the reference point 63. Alternatively, the center of the cutting edge of the blade 18 in the left-right direction may be determined as the reference point 63. Alternatively, the reference point 63 may be included in the vehicle body 11.

[0047] In the above embodiment, the target route is determined so as to follow the first side 59A of the target surface 57. However, the target route may be determined so as to follow the second side 59B of the target surface 57. In the above embodiment, the first flat surface 41 is determined as the target surface 57. However, the first slope 42, the second slope 43, or the second flat surface 44 may be determined as the target surface 57. The target terrain 40 is not limited to that in the above embodiment, and may be changed. For example, the target terrain 40 may have a flat shape. [Industrial Applicability]

[0048] According to the present disclosure, a target route can be easily set. [Explanation of symbols]

[0049] 1: working machine, 26: controller, 32: input device, 34: position sensor, 40: target terrain, 51: first surface, 52: second surface, 55: reference surface, 56: working surface, 57: target surface, 58: target path

Claims

1. 1. A system for controlling a work machine, comprising: A sensor for detecting a position of the work machine; A controller; Equipped with The controller: acquiring target terrain data indicating a target terrain composed of a plurality of surfaces; Selecting a plurality of work surfaces to be the object of work from the plurality of surfaces; The plurality of working planes are grouped and determined as a target plane; determining a target path along an edge of the target surface; Obtaining the position of the work machine; controlling the work machine so that the work machine travels along the target route based on a position of the work machine; system.

2. The controller selects, from among the plurality of surfaces, surfaces whose adjacent surfaces have an angle equal to or smaller than a threshold value as the plurality of working surfaces. The system of claim 1 .

3. The controller: Selecting at least one of the plurality of surfaces as a reference surface; sequentially selecting, as at least one of the plurality of working surfaces, surfaces whose angle between adjacent surfaces starting from the reference surface is equal to or smaller than the threshold value; The system of claim 2.

4. a first input device operable to select the reference plane; The controller selects the reference surface based on an operation of the first input device. The system of claim 3.

5. the target surface includes a first side and a second side opposite the first side; the controller determines the target path to follow one of the first side and the second side, which is closer to the reference plane; The system of claim 3.

6. a second input device operable to set the threshold value; The controller sets the threshold value based on an operation of the second input device. The system of claim 2.

7. The work machine includes a work implement, the controller controls the work machine so that a left end or a right end of the work machine moves along the target path. The system of claim 1 .

8. The plurality of surfaces include a plurality of first surfaces constituting a horizontal surface and a plurality of second surfaces constituting a slope inclined relative to the horizontal surface. The system of claim 1 .

9. 1. A method for controlling a work machine, comprising: acquiring target terrain data indicative of a target terrain composed of a plurality of surfaces; selecting a plurality of work surfaces to be worked on from the plurality of surfaces; determining a target surface by grouping the plurality of working surfaces; determining a target path along an edge of the target surface; Obtaining a position of the work machine; Controlling the work machine so that the work machine travels along the target route based on a position of the work machine; A method for providing the above.

10. selecting, from among the plurality of faces, faces whose adjacent faces have an angle equal to or smaller than a threshold as the plurality of working faces; 10. The method of claim 9.

11. selecting at least one of the plurality of surfaces as a reference surface; sequentially selecting, as at least one of the plurality of working surfaces, surfaces whose angle between adjacent surfaces starting from the reference surface is equal to or smaller than the threshold value; The method of claim 10.

12. selecting the reference surface based on an operation of a first input device operable to select the reference surface. The method of claim 11.

13. the target surface includes a first side and a second side opposite the first side; determining the target path to follow one of the first side and the second side, which is closer to the reference surface; The method of claim 11.

14. setting the threshold value based on an operation of a second input device operable to set the threshold value. The method of claim 10.

15. The work machine includes a work implement, and controlling the work machine so that a left end or a right end of the work machine moves along the target path.

10. The method of claim 9.

16. The plurality of surfaces include a plurality of first surfaces constituting a horizontal surface and a plurality of second surfaces constituting a slope inclined relative to the horizontal surface.

10. The method of claim 9.

Images