Work machine control system, work machine, work machine remote operation system, and work machine control method

Abstract

To suppress deterioration of a work machine.SOLUTION: A work machine control system comprises a controller. The controller includes: a posture determination unit that determines whether or not the height of an implement is equal to or higher than a prescribed height; an operation determination unit that when it is determined that the height of the implement is equal to or higher than the prescribed height, determines existence of a prescribed operation in which a bucket of the implement repeats tilting operation and dumping operation; and an implement control unit that when it is determined that the prescribed operation exists and an operation speed of the prescribed operation exceeds a threshold, outputs a control command so that the operation speed becomes equal to or lower than the threshold.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a work machine control system, a work machine, a work machine remote operation system, and a work machine control method. [Background technology]

[0002] In the technical field related to work machines, a remote control system for a wheel loader is known, as disclosed in Patent Document 1. In Patent Document 1, the wheel loader has a camera and an antenna. An on-board controller of the wheel loader receives a remote signal from an off-board controller via the antenna. The off-board controller receives a camera image from the camera and displays it on a display. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent Application Publication No. 3926107 Summary of the Invention [Problem to be solved by the invention]

[0004] A work machine has a working implement. When the work implement operates based on an operation signal from an operating device operated by an operator, violent operation of the operating device causes the work implement to operate violently. Violent operation of the work implement may cause early deterioration of the work machine.

[0005] The present disclosure aims to suppress deterioration of a work machine. [Means for solving the problem]

[0006] According to the present disclosure, there is provided a control system for a work machine including a controller. The controller has an attitude determination unit that determines whether the height of a work implement provided in the work machine is equal to or greater than a predetermined height, an operation determination unit that, if it is determined that the height of the work implement is equal to or greater than the predetermined height, determines whether or not a predetermined operation in which the bucket of the work implement repeats tilting and dumping operations, and a work implement control unit that, if it is determined that the predetermined operation has occurred and that the operation speed of the predetermined operation has exceeded a threshold, outputs a control command to reduce the operation speed to equal to or less than the threshold. [Effects of the Invention]

[0007] According to the present disclosure, deterioration of the work machine is suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a remote control system for a work machine according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram showing a work machine and an operating device according to the embodiment. [Figure 3] FIG. 3 is a hardware configuration diagram showing the in-vehicle controller according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating the operation of the work machine according to the embodiment. [Figure 5] FIG. 5 is a functional block diagram showing a control system for a work machine according to an embodiment. [Figure 6] FIG. 6 is a flowchart showing a control method for a work machine according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating the attitude of the work machine according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of an operation signal from a bucket lever according to the embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of an operation signal from a bucket lever according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] [Remote Control System] 1 is a diagram showing a remote operation system 200 for a work machine 1 according to an embodiment. The remote operation system 200 remotely operates a work machine 1 located at a work site 201. At least a part of the remote operation system 200 is disposed in a remote operation room 202 provided outside the work machine 1. The remote operation system 200 comprises an operation device 7, a display device 8, and a remote controller 9.

[0011] The operation device 7 is arranged in the remote control room 202. The operation device 7 is operated by an operator in the remote control room 202. The operator can operate the operation device 7 while seated in the pilot seat 10. The operator may also operate a portable operation device 700. The operation device 700 may also be operated outside the remote control room 202.

[0012] The display device 8 is disposed in the remote control room 202. An example of the display device 8 is a flat panel display such as a liquid crystal display or an organic EL display. The display device 8 displays at least an image of the work site 201. The display device 8 may also output audio of the work site 201.

[0013] The operator operates the operation device 7 while checking an image of the work site 201 displayed on the display device 8. The work machine 1 is remotely controlled by the operation device 7.

[0014] The remote controller 9 is placed in a remote operation room 202. The remote controller 9 and the work machine 1 communicate with each other via a communication system 203. Examples of the communication system 203 include the internet, a local area network (LAN), a mobile phone communication network, and a satellite communication network.

[0015] [Work machinery] In the embodiment, the work machine 1 is a wheel loader. As shown in Fig. 1, the work machine 1 includes a body 2, an articulating mechanism 3, a cab 4, wheels 5, a work implement 6, and a camera 29. The work machine 1 travels on the wheels 5 at a work site 201. The work machine 1 performs work using the work implement 6 at the work site 201. Examples of work that the work machine 1 can perform include excavation work, loading work, transporting work, and snow removal work.

[0016] The vehicle body 2 supports the work machine 6. The vehicle body 2 includes a front frame 2F and a rear frame 2R. The front frame 2F is located forward of the rear frame 2R. The front frame 2F and the rear frame 2R are connected by an articulation mechanism 3. The articulation mechanism 3 includes an articulation cylinder 11. The articulation cylinder 11 is a hydraulic cylinder. The articulation cylinder 11 connects the front frame 2F and the rear frame 2R. When the articulation cylinder 11 extends and retracts, the front frame 2F bends left and right relative to the rear frame 2R. When the front frame 2F bends relative to the rear frame 2R, the traveling direction of the work machine 1 is adjusted. The cab 4 is located on top of the rear frame 2R.

[0017] The wheels 5 support the vehicle body 2. The wheels 5 include tires. The wheels 5 come into contact with the ground at the work site. The wheels 5 include front wheels 5F attached to the front frame 2F and rear wheels 5R attached to the rear frame 2R. The front wheels 5F rotate about a rotation axis CXf. The rear wheels 5R rotate about a rotation axis CXr. When the work machine 1 travels in a straight line, the rotation axis CXf of the front wheels 5F and the rotation axis CXr of the rear wheels 5R are parallel. The rotation of the wheels 5 causes the work machine 1 to travel on the ground at the work site 201.

[0018] The work implement 6 is supported by the vehicle body 2. The work implement 6 is connected to the front frame 2F. The work implement 6 has a boom 12, a bucket 13, a bell crank 14, and a bucket link 15.

[0019] A base end of the boom 12 is rotatably connected to the front frame 2F. The boom 12 rotates about a rotation axis AXa relative to the front frame 2F. A bracket 16 is fixed to the middle of the boom 12.

[0020] The bucket 13 is a working member that excavates an excavation target. The bucket 13 holds the excavated material. The bucket 13 has a cutting edge 13A, an opening 13B, and a bottom surface 13C.

[0021] A base end of the bucket 13 is rotatably connected to the tip end of the boom 12. The bucket 13 rotates around a rotation axis AXb relative to the boom 12. The bucket 13 is disposed forward of the front wheels 5F. A bracket 17 is fixed to a part of the bucket 13.

[0022] An intermediate portion of the bell crank 14 is rotatably connected to a bracket 16 of the boom 12. The bell crank 14 rotates about a rotation axis AXc relative to the bracket 16 of the boom 12. A lower end portion of the bell crank 14 is rotatably connected to a base end portion of a bucket link 15.

[0023] The tip end of the bucket link 15 is rotatably connected to a bracket 17 of the bucket 13. The bucket link 15 rotates about a rotation axis AXd relative to the bracket 17 of the bucket 13. The bell crank 14 is connected to the bucket 13 via the bucket link 15.

[0024] The boom 12 is operated by a boom cylinder 18. The boom cylinder 18 is a hydraulic cylinder. A base end of the boom cylinder 18 is connected to the front frame 2F. A tip end of the boom cylinder 18 is connected to the boom 12. The boom 12 rotates relative to the boom cylinder 18 about a rotation axis AXe.

[0025] The bucket 13 is operated by a bucket cylinder 19. The bucket cylinder 19 is a hydraulic cylinder. A base end of the bucket cylinder 19 is connected to the front frame 2F. A tip end of the bucket cylinder 19 is connected to an upper end of a bell crank 14. The bell crank 14 rotates relative to the bucket cylinder 19 about a rotation axis AXf.

[0026] The pivot axis AXa, the pivot axis AXb, the pivot axis AXc, the pivot axis AXd, the pivot axis AXe, the pivot axis AXf, and the rotation axis CXf of the front wheel 5F are parallel to each other. When the work machine 1 travels in a straight line, the pivot axis AXa of the work implement 6 and the rotation axis CXr of the rear wheel 5R are parallel to each other.

[0027] The camera 29 captures an image of the work site 201. The camera 29 captures an image of at least the work site 201 in front of the work machine 1. The camera 29 captures an image of at least a portion of the work implement 6. In this embodiment, the camera 29 is arranged in the cab 4.

[0028] [Configuration of work machine and operating device] Fig. 2 is a configuration diagram showing a work machine 1 and an operating device 7 according to the embodiment. As shown in Fig. 2, the work machine 1 is equipped with an engine 20, a power take-off (PTO) 21, a power transmission device 22, a brake device 23, a steering pump 24, a steering control valve 37, an articulate cylinder 11, a work implement pump 26, a boom control valve 38, a bucket control valve 39, a boom cylinder 18, a bucket cylinder 19, a work implement attitude sensor 28, a camera 29, and an on-board controller 30.

[0029] The engine 20 is a drive source for the work machine 1. The engine 20 is supported by the vehicle body 2. An example of the engine 20 is a diesel engine. A power take-off 21 distributes the drive force of the engine 20 to a power transmission device 22, a steering pump 24, and a work implement pump 26.

[0030] The power transmission device 22 transmits the driving force of the engine 20 to the wheels 5. The power transmission device 22 controls the speed range and traveling direction of the work machine 1. The power transmission device 22 may be a transmission having a torque converter, or may be a transmission having multiple speed change gears. The brake device 23 reduces the traveling speed of the work machine 1.

[0031] The steering pump 24 is a hydraulic pump that is operated by the driving force generated by the engine 20. The hydraulic oil discharged from the steering pump 24 is supplied to the articulate cylinder 11 via a steering control valve 37. The steering control valve 37 controls the flow rate and direction of the hydraulic oil supplied from the steering pump 24 to the articulate cylinder 11. The articulate mechanism 3 is operated by the hydraulic oil from the steering pump 24.

[0032] The work implement pump 26 is a hydraulic pump that is operated by the driving force generated by the engine 20. The hydraulic oil discharged from the work implement pump 26 is supplied to the boom cylinder 18 via a boom control valve 38. The hydraulic oil discharged from the work implement pump 26 is supplied to the bucket cylinder 19 via a bucket control valve 39. The boom control valve 38 controls the flow rate and direction of the hydraulic oil supplied from the work implement pump 26 to the boom cylinder 18. The bucket control valve 39 controls the flow rate and direction of the hydraulic oil supplied from the work implement pump 26 to the bucket cylinder 19. The work implement 6 is operated by the hydraulic oil from the work implement pump 26.

[0033] The work implement attitude sensor 28 detects the attitude of the work implement 6. The attitude of the work implement 6 includes the angle of the work implement 6. The work implement attitude sensor 28 includes a boom angle sensor 28A that detects the attitude of the boom 12, and a bucket angle sensor 28B that detects the attitude of the bucket 13. The attitude of the boom 12 includes the angle of the boom 12. The attitude of the bucket 13 includes the angle of the bucket 13.

[0034] The boom angle sensor 28A detects a boom angle that indicates the angle of the boom 12. The boom angle refers to the angle of the boom 12 relative to the vehicle body 2 in the local coordinate system. In the embodiment, the boom angle is the angle between a line connecting the rotation axis AXa and the rotation axis AXb and a line connecting the rotation axis CXf and the rotation axis CXr when the work machine 1 is traveling in a straight line. An example of the boom angle sensor 28A is an angle sensor that is arranged at the connection between the front frame 2F and the boom 12.

[0035] The bucket angle sensor 28B detects a bucket angle indicating the angle of the bucket 13. The bucket angle refers to the angle of the bucket 13 with respect to the boom 12 in a local coordinate system. In this embodiment, the bucket angle is the angle between a line connecting the rotation axis AXb and the cutting edge 13A and a line connecting the rotation axis AXa and the rotation axis AXb. An example of the bucket angle sensor 28B is an angle sensor disposed at the connection between the boom 12 and the bell crank 14. In this embodiment, the bucket angle sensor 28B detects a bell crank angle indicating the angle of the bell crank 14 with respect to the boom 12 in the local coordinate system. The bell crank angle is the angle between a line connecting the rotation axis AXc and the rotation axis AXf and a line connecting the rotation axis AXa and the rotation axis AXb. The bucket angle and the bell crank angle correspond one-to-one. The bucket angle sensor 28B detects the bell crank angle. The bucket angle is calculated based on the detection data of the bell crank angle and the detection data of the boom angle.

[0036] The boom angle and bucket angle are each angles in the operating plane of the work implement 6 that is perpendicular to the rotation axis AXa. The line connecting the rotation axis AXa and the rotation axis AXb, the line connecting the rotation axis AXc and the rotation axis AXf, the line connecting the rotation axis AXb and the cutting edge 13A, and the line connecting the rotation axis CXf and the rotation axis CXr when the work machine 1 is traveling in a straight line are each lines in the operating plane of the work implement 6.

[0037] The camera 29 captures an image of the work site 201. The camera 29 captures an image of at least a portion of the work machine 6. Image data captured by the camera 29 is transmitted to the remote controller 9 via the on-board controller 30 and the communication system 203. The remote controller 9 displays the image data captured by the camera 29 on the display device 8.

[0038] The operation device 7 is operated by an operator. When operated by the operator, the operation device 7 generates an operation signal for operating the work machine 1. The operation signal generated by the operation device 7 is transmitted to the on-vehicle controller 30 via the remote controller 9 and the communication system 203. The on-vehicle controller 30 outputs a control command for operating the work machine 1 based on the operation signal transmitted from the remote controller 9. The operation device 7 includes a traveling system operation device 7A and a work implement operation device 7B.

[0039] The traveling system operating device 7A generates an operation signal for operating at least one of the engine 20, the power transmission device 22, and the brake device 23. The traveling system operating device 7A includes an accelerator pedal 71, a brake pedal 72, a steering wheel 73, and a forward / reverse selector lever 74. The accelerator pedal 71 is operated to increase the traveling speed of the work machine 1. The brake pedal 72 is operated to decrease the traveling speed of the work machine 1 or to stop the traveling of the work machine 1. The steering wheel 73 is operated to change the traveling direction of the work machine 1. The forward / reverse selector lever 74 is operated to switch the work machine 1 between forward and reverse traveling.

[0040] The work implement operating device 7B generates an operation signal for operating the work implement 6. The work implement operating device 7B includes a boom lever 75 and a bucket lever 76. The boom lever 75 is operated to operate the boom 12. The bucket lever 76 is operated to operate the bucket 13. The boom lever 75 and the bucket lever 76 are each operated to a neutral position, a first operating position on one side of the neutral position, and a second operating position rearward of the neutral position.

[0041] When the boom lever 75 is positioned in the neutral position of the boom lever 75, the spool of the boom control valve 38 is positioned in a neutral position where hydraulic oil does not circulate. When the boom lever 75 is operated to one side from the neutral position of the boom lever 75, the spool of the boom control valve 38 is positioned in a bottom position where hydraulic oil discharged from the work implement pump 26 is supplied to the bottom chamber of the boom cylinder 18. When the spool of the boom control valve 38 is positioned in the bottom position, the boom cylinder 18 extends. When the boom lever 75 is operated to the other side from the neutral position of the boom lever 75, the spool of the boom control valve 38 is positioned in a rod position where hydraulic oil discharged from the work implement pump 26 is supplied to the rod chamber of the boom cylinder 18. When the spool of the boom control valve 38 is positioned in the rod position, the boom cylinder 18 retracts.

[0042] When the bucket lever 76 is positioned in its neutral position, the spool of the bucket control valve 39 is positioned in a neutral position that does not allow hydraulic oil to flow. When the bucket lever 76 is operated to one side from the neutral position of the bucket lever 76, the spool of the bucket control valve 39 is positioned in a bottom position where hydraulic oil discharged from the work implement pump 26 is supplied to the bottom chamber of the bucket cylinder 19. When the spool of the bucket control valve 39 is positioned in the bottom position, the bucket cylinder 19 extends. When the bucket lever 76 is operated to the other side from the neutral position of the bucket lever 76, the spool of the bucket control valve 39 is positioned in a rod position where hydraulic oil discharged from the work implement pump 26 is supplied to the rod chamber of the bucket cylinder 19. When the spool of the bucket control valve 39 is positioned in the rod position, the bucket cylinder 19 retracts.

[0043] [In-vehicle controller] FIG. 3 is a hardware configuration diagram showing an in-vehicle controller 30 according to an embodiment. The in-vehicle controller 30 includes a computer system. The in-vehicle controller 30 includes a processor 31 such as a central processing unit (CPU), a main memory 32 including a non-volatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 33, an input / output interface 34 including an input / output circuit, and a communication interface 35 including a communication circuit. The functions of the in-vehicle controller 30 are stored in the storage 33 as a computer program. The processor 31 reads the computer program from the storage 33, loads it into the main memory 32, and executes processing in accordance with the computer program. The computer program may be distributed to the in-vehicle controller 30 via a network.

[0044] The remote controller 9 also includes a computer system. Like the in-vehicle controller 30, the remote controller 9 has a processor, a main memory, a storage, an input / output interface, and a communication interface.

[0045] [Work machine operation] 4 is a diagram illustrating the operation of the work machine 1 according to the embodiment. In the embodiment, the work implement 6 is a front-loading type work implement in which the opening 13B of the bucket 13 faces forward during excavation work. The boom cylinder 18 extends and retracts to cause the boom 12 to perform a raising or lowering operation. The bucket cylinder 19 extends and retracts to cause the bucket 13 to perform a tilting or dumping operation.

[0046] The raising operation of the boom 12 refers to the operation of the boom 12 rotating about the rotation axis AXa so that the tip of the boom 12 moves away from the ground. The lowering operation of the boom 12 refers to the operation of the boom 12 rotating about the rotation axis AXa so that the tip of the boom 12 moves closer to the ground.

[0047] The boom lever 75 is operated to one side from the neutral position of the boom lever 75 to extend the boom cylinder 18, thereby raising the boom 12. The boom lever 75 is operated to the other side from the neutral position of the boom lever 75 to retract the boom cylinder 18, thereby lowering the boom 12.

[0048] The tilting operation of bucket 13 refers to the operation of bucket 13 rotating about pivot axis AXb so that opening 13B of bucket 13 faces upward and blade tip 13A moves away from the ground. The dumping operation of bucket 13 refers to the operation of bucket 13 rotating about pivot axis AXb so that opening 13B of bucket 13 faces downward and blade tip 13A moves closer to the ground.

[0049] When the bucket lever 76 is operated to one side from the neutral position of the bucket lever 76 and the bucket cylinder 19 extends, the bell crank 14 rotates so that the upper end of the bell crank 14 moves forward and the lower end of the bell crank 14 moves rearward. When the lower end of the bell crank 14 moves rearward, the bucket 13 is pulled rearward by the bucket link 15, performing a tilt operation. When the bucket lever 76 is operated to the other side from the neutral position of the bucket lever 76 and the bucket cylinder 19 retracts, the bell crank 14 rotates so that the upper end of the bell crank 14 moves rearward and the lower end of the bell crank 14 moves forward. When the lower end of the bell crank 14 moves forward, the bucket 13 is pushed forward by the bucket link 15, performing a dumping operation.

[0050] When the bucket 13 performs a tilting operation, the excavated material is scooped up by the bucket 13 and held in the bucket 13. When the bucket 13 performs a dumping operation, the excavated material held in the bucket 13 is discharged from the bucket 13.

[0051] As shown in Fig. 4, the work machine 1 can perform loading work to load excavated material into the dump body of the dump truck 300. The operator operates the work implement operating device 7B to control the attitude of the work implement 6 so that the excavated material held in the bucket 13 is loaded into the dump body of the dump truck 300. The operator controls the attitude of the work implement 6 so that the excavated material does not spill out of the bucket 13 and so that the bucket 13 is positioned higher than the upper end of the dump body.

[0052] In order to load excavated material into the dump body of the dump truck 300, the operator may perform a dump operation with the bucket 13 while raising the front end of the boom 12, and then operate the bucket 13 so that the excavated material adhering to the bucket 13 is shaken off from the bucket 13. When shaking off the excavated material adhering to the bucket 13 from the bucket 13, the operator operates the bucket lever 76 to move back and forth between one side and the other side of the neutral position. As the bucket lever 76 is operated back and forth, the bucket 13 repeatedly performs a tilt operation and a dump operation. As the bucket 13 repeatedly performs a tilt operation and a dump operation, the excavated material adhering to the bucket 13 is shaken off from the bucket 13. In the following description, the operation of the bucket 13 to repeat the excavation operation and the dump operation will be referred to as a predetermined operation, as appropriate.

[0053] [Control System] 5 is a functional block diagram showing a control system 100 of a work machine 1 according to an embodiment. The control system 100 has an operation device 7, a remote controller 9, an on-board controller 30, a work machine attitude sensor 28, and a camera 29.

[0054] The on-vehicle controller 30 has a sensor data acquisition unit 101, an operation signal acquisition unit 102, an attitude determination unit 103, an operation determination unit 104, a travel control unit 105, a work machine control unit 106, and a transmission unit 107.

[0055] The sensor data acquisition unit 101 acquires detection data from the work machine attitude sensor 28. The detection data from the work machine attitude sensor 28 includes detection data from a boom angle sensor 28A that indicates the boom angle, and detection data from a bucket angle sensor 28B that indicates the bucket angle.

[0056] The operation signal acquisition unit 102 acquires operation signals from the operation device 7. The operation signals from the operation device 7 include an operation signal from the boom lever 75 that is operated to operate the boom 12, and an operation signal from the bucket lever 76 that is operated to operate the bucket 13.

[0057] The attitude determination unit 103 determines whether the attitude of the work implement 6 satisfies a predetermined attitude condition based on detection data from the work implement attitude sensor 28. Satisfying the attitude condition includes the work implement 6 being in a predetermined attitude where the height of the work implement 6 is equal to or greater than a predetermined height. The attitude determination unit 103 determines whether the height of the work implement 6 is equal to or greater than a predetermined height. The attitude determination unit 103 determines whether the height of the work implement 6 is equal to or greater than a predetermined height based on detection data from the work implement attitude sensor 28 that detects the attitude of the work implement 6.

[0058] In the embodiment, the work implement 6 being in a predetermined posture includes the bottom surface 13C of the bucket 13 being inclined downward toward the front. The posture determination unit 103 determines whether the bottom surface 13C of the bucket 13 is in a predetermined posture in which it is inclined downward toward the front.

[0059] The operation determination unit 104 determines whether or not the operation of the bucket 13 satisfies predetermined operation conditions based on the operation signal from the bucket lever 76. Satisfying the operation conditions includes causing the bucket 13 to perform a predetermined operation of repeating tilting and dumping. The operation determination unit 104 determines whether or not the bucket 13 has performed the predetermined operation of repeating tilting and dumping.

[0060] The traveling control unit 105 controls the traveling of the work machine 1 based on operation signals from the traveling system operation device 7A. Based on operation signals from the traveling system operation device 7A, the traveling control unit 105 adjusts the traveling speed of the work machine 1, adjusts the traveling direction of the work machine 1, and switches the work machine 1 between forward and reverse traveling.

[0061] The work implement control unit 106 controls the work implement 6 based on an operation signal from the work implement operating device 7B. The work implement control unit 106 controls the boom control valve 38 based on an operation signal from the boom lever 75. By controlling the boom control valve 38, the boom cylinder 18 extends and retracts, and the boom 12 performs a raising and lowering operation. The work implement control unit 106 controls the bucket control valve 39 based on an operation signal from the bucket lever 76. By controlling the bucket control valve 39, the bucket cylinder 19 extends and retracts, and the bucket 13 performs a tilting operation and a dumping operation.

[0062] The work implement control unit 106 also performs intervention control of the bucket 13. Intervention control of the bucket 13 refers to controlling the bucket control valve 39 so that the bucket control valve 39 is driven under predetermined conditions while the bucket lever 76 is being operated. In other words, intervention control of the bucket 13 refers to outputting a control command from the work implement control unit 106 so that the bucket 13 operates under predetermined conditions while an operation signal from the bucket lever 76 is being acquired by the operation signal acquisition unit 102.

[0063] The transmission unit 107 transmits image data captured by the camera 29 to the remote controller 9. The transmission unit 107 may also transmit detection data of the work machine attitude sensor 28 to the remote controller 9.

[0064] [Work machine control method] 6 is a flowchart showing a method for controlling the work machine 1 according to the embodiment. The operation signal acquisition unit 102 acquires an operation signal from the operation device 7. The traveling control unit 105 controls the traveling of the work machine 1 based on an operation signal from the traveling system operation device 7A. The work implement control unit 106 controls the work implement 6 based on an operation signal from the work implement operation device 7B. The sensor data acquisition unit 101 acquires detection data from the work implement attitude sensor 28 (step S1).

[0065] The attitude determination unit 103 determines whether or not the work implement 6 is in a predetermined attitude based on detection data from the work implement attitude sensor 28 that detects the attitude of the work implement 6 (step S2).

[0066] 7 is a diagram illustrating the posture of the work machine 6 according to the embodiment. The bucket 13 has a cutting edge 13A, an opening 13B, and a bottom surface 13C. The opening 13B is provided in the front of the bucket 13. The cutting edge 13A is provided at the lower end of the opening 13B. The bottom surface 13C is provided so as to extend rearward from the cutting edge 13A. The bottom surface 13C is substantially flat.

[0067] The work implement 6 being in a predetermined posture includes the work implement 6 being at a height equal to or greater than a predetermined height. When the boom 12 and the bucket 13 are connected via a rotation axis AXb, the height of the work implement 6 includes the height of the rotation axis AXb from the ground. If a line connecting the rotation axis CXf of the front wheels 5F and the rotation axis CXr of the rear wheels 5R is defined as a predetermined line RL, the predetermined height includes the height of the predetermined line RL from the ground. That is, in the embodiment, the work implement 6 being at a height equal to or greater than a predetermined height includes the work implement 6 being at a height higher than the predetermined line RL. Note that the work implement 6 being at a height equal to or greater than a predetermined height may also include the work implement 6 being at a height higher than the bottom surface of the vehicle body 2. Note that the height of the work implement 6 may also be the height of the bottom surface 13C of the bucket 13 from the ground. The height of the bottom surface 13C of the bucket 13 may change due to tilting or dumping of the bucket 13.

[0068] Furthermore, the work implement 6 being in a predetermined posture also includes the bottom surface 13C of the bucket 13 being inclined downward toward the front. In the embodiment, if the line connecting the rotation axis CXf of the front wheels 5F and the rotation axis CXr of the rear wheels 5R is defined as a predetermined line RL, the work implement 6 being in a predetermined posture also includes the bottom surface 13C of the bucket 13 being inclined downward toward the front with respect to the predetermined line RL. The posture determination unit 103 determines whether the bottom surface 13C of the bucket 13 is inclined downward toward the front with respect to the predetermined line RL. If the predetermined line RL is parallel to the horizontal plane, the work implement 6 being in a predetermined posture also includes the cutting edge 13A being positioned below the rear of the bottom surface 13C. The work implement 6 being in a predetermined posture also includes the work implement 6 being in a predetermined posture when the distance between the cutting edge 13A and the ground in the vertical direction is shorter than the distance between the rear of the bottom surface 13C and the ground.

[0069] Note that the work implement 6 being in a predetermined posture may also include the pivot axis AXb between the boom 12 and the bucket 13 being positioned higher than the pivot axis AXa between the front frame 2F and the boom 12. In other words, the work implement 6 being in a predetermined posture may also include the distance between the pivot axis AXb and the ground in the vertical direction being longer than the distance between the pivot axis AXa and the ground. The posture determination unit 103 may determine whether the pivot axis AXb is positioned higher than the pivot axis AXa.

[0070] 4, when excavated material is loaded onto the dump body of the dump truck 300, the bucket 13 performs a dumping operation with the front end of the boom 12 raised. The predetermined posture of the work implement 6 may be considered to be the posture of the work implement 6 immediately after the work implement 6 has loaded excavated material onto the dump body of the dump truck 300.

[0071] In step S2, if it is determined that the work implement 6 is in a predetermined posture (step S2: Yes), the operation determination unit 104 determines whether or not a predetermined operation in which the bucket 13 repeats tilting and dumping operations is occurring, based on an operation signal from the bucket lever 76 (step S3).

[0072] 8 and 9 are diagrams showing an example of an operation signal from the bucket lever 76 according to the embodiment. In the following description, the operation signal from the bucket lever 76 will be referred to as the bucket lever signal as appropriate. In FIGS. 8 and 9, the horizontal axis represents the time elapsed since it was determined that the work implement 6 is in a predetermined posture, and the vertical axis represents the bucket lever signal. A positive value of the bucket lever signal means that the bucket lever 76 has been operated to one side from the neutral position of the bucket lever 76, and a negative value of the bucket lever signal means that the bucket lever 76 has been operated to the other side from the neutral position of the bucket lever 76. In other words, a positive value of the bucket lever signal means that the bucket 13 has performed a tilt operation, and a negative value of the bucket lever signal means that the bucket 13 has performed a dump operation.

[0073] The bucket lever signal includes the amount of operation of the bucket lever 76. The larger the absolute value of the bucket lever signal, the larger the amount of operation of the reciprocating bucket lever 76. The larger the absolute value of the bucket lever signal, the higher the operating speed of the bucket 13, which repeats tilting and dumping operations.

[0074] As described above, after loading excavated material into the dump body of the dump truck 300, the operator may perform a predetermined operation of the bucket 13 so that the excavated material adhering to the bucket 13 is shaken off from the bucket 13. When performing a predetermined operation of the bucket 13, the operator operates the bucket lever 76 to reciprocate to one side and the other side of the neutral position of the bucket lever 76. As shown in FIG. 8 , the bucket lever 76 is operated to reciprocate, causing the bucket lever signal to alternate between a positive value and a negative value.

[0075] The operation determination unit 104 determines that a predetermined operation of the bucket 13 has occurred when it determines that the number of times the bucket lever 76 has been operated back and forth to one side and the other side of the neutral position is equal to or greater than a predetermined number of times within a predetermined time Tm. The number of times the bucket lever 76 has been operated back and forth is the number of times the bucket lever signal has changed from one of a positive value state and a negative value state to the other state. For example, when the bucket lever signal changes from a positive value state to a negative value state and then changes back to a positive value state, the operation determination unit 104 determines that the number of times the bucket lever 76 has been operated back and forth is one.

[0076] The predetermined time Tm is a time from the point in time when it is determined that the work implement 6 is in a predetermined posture, and is a predetermined time. The predetermined number of times is a predetermined number of times. As an example, the predetermined time Tm is one second, and the predetermined number of times is two.

[0077] In step S3, if it is determined that a predetermined operation of the bucket 13 has occurred (step S3: Yes), the work machine control unit 106 determines whether or not to start intervention control of the bucket 13 based on the operation speed of the predetermined operation (step S4).

[0078] There is a one-to-one correspondence between the amplitude of the bucket lever signal when the bucket lever 76 is operated back and forth and the operating speed of the bucket 13 that repeats tilting and dumping operations. The larger the amplitude of the bucket lever signal, the higher the operating speed of the bucket 13 that performs the predetermined operation. The bucket lever signal includes the operation amount of the bucket lever 76. A large amplitude of the bucket lever signal means that the absolute value of the operation amount of the bucket lever 76 that is operated back and forth is large. A large amplitude of the bucket lever signal means that the operating speed of the bucket 13 that performs the predetermined operation is high. The operation determination unit 104 determines whether the operating speed of the predetermined operation of the bucket 13 exceeds a threshold value based on the amplitude of the bucket lever signal. The threshold value is a predetermined value.

[0079] The work implement control unit 106 compares the amplitude of the bucket lever signal at a time when a predetermined time Tm has elapsed since the time when it was determined that the work implement 6 was in a predetermined posture with a threshold value Sh related to the bucket lever signal. That is, the work implement control unit 106 compares the absolute value of the operation amount of the bucket lever 76 at the time when the predetermined time Tm has elapsed with the threshold value Sh. The threshold value Sh is a predetermined value. If the work implement control unit 106 determines that the amplitude of the bucket lever signal (absolute value of the operation amount) at the time when the predetermined time Tm has elapsed is equal to or less than the threshold value Sh, it determines that the operating speed of the predetermined operation of the bucket 13 does not exceed the threshold value. If the work implement control unit 106 determines that the amplitude of the bucket lever signal (absolute value of the operation amount) at the time when the predetermined time Tm has elapsed has exceeded the threshold value Sh, it determines that the operating speed of the predetermined operation of the bucket 13 has exceeded the threshold value.

[0080] In the example shown in Fig. 8, as indicated by the symbol PK, the amplitude of the bucket lever signal at the time when the predetermined time Tm has elapsed does not exceed the threshold value Sh. In the example shown in Fig. 9, as indicated by the symbol PK, the amplitude of the bucket lever signal at the time when the predetermined time Tm has elapsed exceeds the threshold value Sh. In the case of the amplitude of the bucket lever signal shown in Fig. 8, the work implement control unit 106 determines that the operating speed of the predetermined operation of the bucket 13 does not exceed the threshold value. In the case of the amplitude of the bucket lever signal shown in Fig. 9, the work implement control unit 106 determines that the operating speed of the predetermined operation of the bucket 13 has exceeded the threshold value.

[0081] If the work machine control unit 106 determines that the operating speed of the predetermined operation of the bucket 13 does not exceed the threshold value, it determines not to start intervention control of the bucket 13. If the work machine control unit 106 determines that the operating speed of the predetermined operation of the bucket 13 has exceeded the threshold value, it determines to start intervention control of the bucket 13.

[0082] If it is determined in step S4 that intervention control of the bucket 13 is to be started (step S4: Yes), the work machine control unit 106 outputs a control command so that the operating speed of the predetermined operation of the bucket 13 becomes equal to or less than a threshold. In the embodiment, the intervention control of the bucket 13 includes performing a limiting process to reduce the amplitude of the bucket lever signal while the bucket lever signal is being acquired by the operation signal acquisition unit 102. While the bucket lever signal is being acquired by the operation signal acquisition unit 102, the work machine control unit 106 performs the limiting process to reduce the amplitude of the bucket lever signal (step S5).

[0083] As shown in FIG. 9 , the work implement control unit 106 performs limiting processing on the bucket lever signal acquired by the operation signal acquisition unit 102 to generate a bucket lever signal with a small amplitude. The limiting processing reduces the amplitude of the bucket lever signal after a predetermined time Tm has elapsed. The limiting processing suppresses the amplitude of the bucket lever signal to a value equal to or less than the threshold value Sh. The work implement control unit 106 outputs a control command to control the bucket control valve 39 based on the bucket lever signal that has been limited. The bucket control valve 39 is driven based on the bucket lever signal that has been limited (step S6).

[0084] In the embodiment, the work machine control unit 106 changes the amplitude so as to reduce the amplitude (absolute value of the operation amount) of the bucket lever signal acquired by the operation signal acquisition unit 102. The work machine control unit 106 does not change the timing at which the bucket lever signal acquired by the operation signal acquisition unit 102 switches from one of a positive value state and a negative value state to the other state. In other words, when the bucket lever 76 is operated to one side and the other side of the neutral position at regular time intervals, the work machine control unit 106 does not change the cycle of the bucket lever signal acquired by the operation signal acquisition unit 102.

[0085] As the amplitude of the bucket lever signal decreases, the operating speed of the predetermined operation of the bucket 13 decreases.

[0086] The work machine control unit 106 determines whether or not to end the intervention control based on the bucket lever signal acquired by the operation signal acquisition unit 102 (step S7).

[0087] When it is determined that the amplitude of the bucket lever signal acquired by the operation signal acquisition unit 102 is equal to or less than the threshold value Sh, the work machine control unit 106 determines to end the intervention control. For example, when the operator reduces the amount of operation of the bucket lever 76 or stops operating the bucket lever 76, it is determined to end the intervention control.

[0088] In step S7, if it is determined not to end the intervention control (step S7: No), the work machine control unit 106 returns to the processing of step S5. In step S7, if it is determined to end the intervention control (step S7: Yes), the work machine control unit 106 returns to the processing of step S1.

[0089] If it is determined in step S2 that the work implement 6 is not in the predetermined posture (step S2: No), if it is determined in step S3 that the bucket 13 has performed the predetermined operation (step S3: No), or if it is determined in step S4 that intervention control of the bucket 13 will not be started (step S4: No), the work implement control unit 106 does not perform limiting processing on the bucket lever signal, and outputs a control command to control the bucket control valve 39 based on the operation signal acquired by the operation signal acquisition unit 102. The bucket control valve 39 is driven based on the bucket lever signal that has not been limited (step S8).

[0090] [effect] As described above, according to the embodiment, the on-board controller 30 includes an attitude determination unit 103 that determines whether the height of the work implement 6 possessed by the work machine 1 is equal to or greater than a predetermined height; an operation determination unit 104 that, when it is determined that the height of the work implement 6 is equal to or greater than the predetermined height, determines whether the bucket 13 has performed a predetermined operation in which it repeats tilting and dumping operations; and a work implement control unit 106 that, when it is determined that the bucket 13 has performed the predetermined operation and that the operation speed of the predetermined operation has exceeded a threshold, outputs a control command so that the operation speed becomes equal to or less than the threshold.

[0091] According to the embodiment, when the bucket lever 76 is violently operated by the operator, for example, so that excavated material adhering to the bucket 13 is shaken off from the bucket 13, intervention control is implemented so that the tilting and dumping operations of the bucket 13 do not accelerate deterioration of the work implement 6. Therefore, deterioration of the work machine 1 is suppressed.

[0092] When the work machine 1 is remotely operated, even if the operator in the remote control room 202 operates the bucket lever 76 violently, it is difficult for the operator in the remote control room 202 to feel that the bucket 13 is moving violently. Therefore, there is a possibility that the operator in the remote control room 202 will unconsciously operate the bucket lever 76 violently. According to the embodiment, when the bucket lever 76 is operated violently, intervention control is implemented to prevent violent tilting and dumping of the bucket 13. Therefore, deterioration of the work machine 6 is suppressed.

[0093] [Other embodiments] In the above-described embodiment, the operation determination unit 104 determines whether or not the bucket 13 has performed a predetermined operation based on the bucket lever signal. Furthermore, the work implement control unit 106 determines whether or not the operating speed of the bucket 13 performing a predetermined operation has exceeded a threshold value based on the amplitude of the bucket lever signal. The operation determination unit 104 may determine whether or not the bucket 13 has performed a predetermined operation based on detection data from the work implement attitude sensor 28 (bucket angle sensor 28B). The work implement control unit 106 may determine whether or not the operating speed of the bucket 13 performing a predetermined operation has exceeded a threshold value based on detection data from the work implement attitude sensor 28 (bucket angle sensor 28B). If a pressure sensor that detects the pressure of the hydraulic oil in the bucket cylinder 19 (the bottom pressure of the bucket cylinder 19) is provided, the operation determination unit 104 may determine whether or not the bucket 13 has performed a predetermined operation based on detection data from the pressure sensor. The work implement control unit 106 may determine whether or not the operating speed of the bucket 13 performing a predetermined operation has exceeded a threshold value based on detection data from the pressure sensor.

[0094] Furthermore, when camera 29 captures an image of work implement 6, operation determination unit 104 may determine whether or not bucket 13 has performed a predetermined operation based on image data of work implement 6 captured by camera 29. Work implement control unit 106 may determine whether or not the amplitude of bucket 13 performing a predetermined operation has exceeded a threshold value based on image data of work implement 6 captured by camera 29.

[0095] In the above-described embodiment, when intervention control is started, notification data indicating that intervention control has been started may be output from the display device 8.

[0096] In the above-described embodiment, some or all of the functions of the in-vehicle controller 30 may be provided in the remote controller 9. For example, the attitude determination unit 103 and the movement determination unit 104 may be provided in the remote controller 9.

[0097] In the above-described embodiment, the work machine 1 does not have to be remotely controlled. An operator may operate the work machine 1 by getting into the cab 4 of the work machine 1.

[0098] In the above-described embodiment, the work machine 1 is a wheel loader. However, the work machine 1 may also be a hydraulic excavator having a work implement.

[0099] [Note] The present disclosure may also have the following configurations. (Appendix 1) Equipped with a controller, The controller an attitude determination unit that determines whether the height of a work implement of the work machine is equal to or greater than a predetermined height; an operation determination unit that determines, when it is determined that the height of the work implement is equal to or greater than a predetermined height, whether or not a predetermined operation in which a bucket of the work implement repeats a tilt operation and a dump operation; and a work machine control unit that, when it is determined that the predetermined operation has occurred and that the operation speed of the predetermined operation has exceeded a threshold, outputs a control command so that the operation speed becomes equal to or less than the threshold. Work machine control systems. (Appendix 2) The attitude determination unit determines whether the height of the work machine is equal to or greater than a predetermined height based on detection data from a work machine attitude sensor that detects the attitude of the work machine. A control system for a work machine as described in (Appendix 1). (Appendix 3) The attitude determination unit determines whether or not the bottom surface of the bucket is inclined downward toward the front. A control system for a work machine according to (Appendix 1) or (Appendix 2). (Appendix 4) The work machine has front and rear wheels, When the line connecting the rotation axis of the front wheel and the rotation axis of the rear wheel is defined as the prescribed line, the attitude determination unit determines whether or not the bottom surface of the bucket is inclined downward toward the front with respect to the specified line. (Appendix 3) A control system for a work machine. (Appendix 5) the work implement has a boom that is rotatably connected to a vehicle body of the work machine around a first rotation axis, and the bucket is rotatably connected to the boom around a second rotation axis, the attitude determination unit determines whether the second rotation axis is disposed above the first rotation axis. (Appendix 4) A control system for a work machine. (Appendix 6) The operation determination unit determines whether or not the predetermined operation has occurred based on an operation signal from a bucket lever that is operated to operate the bucket. A control system for a work machine according to any one of (Appendix 1) to (Appendix 5). (Appendix 7) When the bucket lever is operated to one side from a neutral position of the bucket lever, the bucket performs a tilt operation, and when the bucket lever is operated to the other side from the neutral position, the bucket performs a dump operation, the operation determination unit determines that the predetermined operation is occurring when it determines that the number of times the bucket lever has been reciprocated from the neutral position to one side and the other side is equal to or greater than a predetermined number of times within a predetermined time period. (Appendix 6) A control system for a work machine. (Appendix 8) the operation determination unit determines whether or not the operation speed of the predetermined operation exceeds the threshold value based on the amplitude of the operation signal. (Appendix 7) A control system for a work machine. (Appendix 9) the work machine control unit outputs the control command in a state in which an operation signal from the bucket lever is acquired so as to reduce the amplitude of the operation signal. (Appendix 8) A control system for a work machine. (Appendix 10) A work machine control system according to any one of (Appendix 1) to (Appendix 9), Work machinery. (Appendix 11) A work machine control system according to any one of (Appendix 1) to (Appendix 9), Remote control system for work machines. (Appendix 12) The controller determining whether or not the height of the working implement of the working machine is at a predetermined height or higher and in a predetermined posture; When it is determined that the bucket is in the predetermined posture, it is determined whether or not a predetermined operation in which the bucket of the work machine repeats a tilt operation and a dump operation is performed; and when it is determined that the predetermined motion has been performed and that the motion speed of the predetermined motion has exceeded a threshold, outputting a control command so that the motion speed becomes equal to or less than the threshold. A method for controlling a work machine. [Explanation of symbols]

[0100] 1...work machine, 2...body, 2F...front frame, 2R...rear frame, 3...articulation mechanism, 4...cab, 5...wheel, 5F...front wheels, 5R...rear wheels, 6...work implement, 7...operation device, 7A...traveling system operation device, 7B...work implement operation device, 8...display device, 9...remote controller, 10...operator seat, 11...articulation cylinder, 12...boom, 13...bucket, 13A...blade tip, 13B...opening, 13C...bottom, 14... Bell crank, 15...bucket link, 16...bracket, 17...bracket, 18...boom cylinder, 19...bucket cylinder, 20...engine, 21...power take-off, 22...power transmission device, 23...brake device, 24...steering pump, 26...work implement pump, 28...work implement attitude sensor, 28A...boom angle sensor, 28B...bucket angle sensor, 29...camera, 30...on-board controller, 31...processor, 32...main memory, 33...storage, 34...input / output interface, 35...communication interface, 37...steering control valve, 38...boom control valve, 39...bucket control valve, 71...accelerator pedal, 72...brake pedal, 73...steering wheel, 74...forward / reverse selector lever, 75...boom lever, 76...bucket lever, 100...control system, 101...sensor data acquisition unit, 102...operation signal acquisition unit, 103...attitude determination determination unit, 104...operation determination unit, 105...travel control unit, 106...work machine control unit, 107...transmission unit, 200...remote operation system, 201...work site, 202...remote operation room, 203...communication system, 300...dump truck, 700...operation device, AXa...rotating axis (first rotating axis), AXb...rotating axis (second rotating axis), AXc...rotating axis, AXd...rotating axis, AXe...rotating axis, AXf...rotating axis, CXf...rotating axis, CXr...rotating axis, RL...specified line.

Claims

1. Equipped with a controller, The controller an attitude determination unit that determines whether the height of a work implement of the work machine is equal to or greater than a predetermined height; an operation determination unit that determines, when it is determined that the height of the work implement is equal to or greater than a predetermined height, whether or not a predetermined operation in which a bucket of the work implement repeats a tilt operation and a dump operation; and a work machine control unit that, when it is determined that the predetermined operation has occurred and that the operation speed of the predetermined operation has exceeded a threshold, outputs a control command so that the operation speed becomes equal to or less than the threshold. Work machine control systems.

2. The attitude determination unit determines whether the height of the work machine is equal to or greater than a predetermined height based on detection data from a work machine attitude sensor that detects the attitude of the work machine.

2. A control system for a work machine according to claim 1.

3. The attitude determination unit determines whether or not the bottom surface of the bucket is inclined downward toward the front.

2. A control system for a work machine according to claim 1.

4. The work machine has front and rear wheels, When the line connecting the rotation axis of the front wheel and the rotation axis of the rear wheel is defined as the prescribed line, the attitude determination unit determines whether or not the bottom surface of the bucket is inclined downward toward the front with respect to the specified line.

4. A control system for a work machine according to claim 3.

5. the work implement has a boom connected to a vehicle body of the work machine so as to be rotatable about a first rotation axis, and the bucket is connected to the boom so as to be rotatable about a second rotation axis, the attitude determination unit determines whether the second rotation axis is disposed above the first rotation axis.

5. A control system for a work machine according to claim 4.

6. The operation determination unit determines whether or not the predetermined operation has occurred based on an operation signal from a bucket lever that is operated to operate the bucket.

2. A control system for a work machine according to claim 1.

7. When the bucket lever is operated to one side from a neutral position of the bucket lever, the bucket performs a tilt operation, and when the bucket lever is operated to the other side from the neutral position, the bucket performs a dump operation, the operation determination unit determines that the predetermined operation is occurring when it determines that the number of times the bucket lever has been reciprocated from the neutral position to one side and the other side is equal to or greater than a predetermined number of times within a predetermined time period.

7. A control system for a work machine according to claim 6.

8. the operation determination unit determines whether or not the operation speed of the predetermined operation exceeds the threshold value based on the amplitude of the operation signal.

8. A work machine control system according to claim 7.

9. the work machine control unit outputs the control command in a state in which an operation signal from the bucket lever is acquired so as to reduce the amplitude of the operation signal.

9. A work machine control system according to claim 8.

10. A work machine control system comprising: a control system for controlling a work machine according to claim 1; Work machinery.

11. A work machine control system comprising: a control system for controlling a work machine according to claim 1; Remote control system for work machines.

12. The controller determining whether or not the height of a work implement of the work machine is equal to or greater than a predetermined height; When it is determined that the height of the work implement is equal to or greater than a predetermined height, it is determined whether or not a predetermined operation in which a bucket of the work implement repeats a tilt operation and a dump operation; and when it is determined that the predetermined motion has been performed and that the motion speed of the predetermined motion has exceeded a threshold, outputting a control command so that the motion speed becomes equal to or less than the threshold. A method for controlling a work machine.

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