Control system for work machine and control method for work machine

Abstract

This control system for a work machine comprises a controller. The controller comprises: a restart position setting unit that sets a restart position of the work machine performing travel work according to a target travel route; and an operation control unit that, when an error occurs in the travel work, causes the work machine to move to the restart position, and then causes the work machine to return to the travel work.

Description

Work machine control system and work machine control method

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

[0002] BACKGROUND ART In the technical field of work machines, an automatic excavator such as that disclosed in Patent Document 1 is known.

[0003] Japanese Patent Application Publication No. 10-088625

[0004] When the work machine is performing a traveling operation along a travel path, an error may occur in the traveling operation.

[0005] An object of the present disclosure is to enable a work machine to smoothly return to traveling operations when an error occurs during traveling operations of the work machine.

[0006] According to the present disclosure, there is provided a control system for a work machine including a controller. The controller includes a restart position setting unit that sets a restart position for the work machine traveling along a target travel path, and an operation control unit that, when an error occurs during traveling, moves the work machine to the restart position and then returns the work machine to traveling.

[0007] According to the present disclosure, when an error occurs during the traveling operation of a work machine, the work machine can be smoothly returned to traveling operation.

[0008] FIG. 1 is a diagram schematically showing a work site management system according to a first embodiment. FIG. 2 is a configuration diagram showing a work machine according to the first embodiment. FIG. 3 is a hardware configuration diagram of a controller according to the first embodiment. FIG. 4 is a functional block diagram showing a work machine control system according to the first embodiment. FIG. 5 is a diagram explaining cyclic work of a work machine according to the first embodiment. FIG. 6 is a flowchart showing a work machine control method according to the first embodiment. FIG. 7 is a diagram explaining a work machine control method according to the first embodiment. FIG. 8 is a diagram explaining a work machine control method according to the first embodiment. FIG. 9 is a diagram explaining a work machine control method according to the first embodiment. FIG. 10 is a diagram explaining a work machine control method according to a second embodiment. FIG. 11 is a diagram explaining a work machine control method according to a third embodiment. FIG. 12 is a diagram explaining a work machine control method according to the third embodiment.

[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] First Embodiment A first embodiment will be described.

[0011] <Management System> Fig. 1 is a diagram that schematically shows a work site management system 100 according to this embodiment. A work machine 1 operates at the work site. The work machine 1 is an unmanned work machine. An unmanned work machine is a work machine that operates unmanned without being operated by a driver. The work machine 1 is automatically controlled. In this embodiment, the work machine 1 is a wheel loader.

[0012] The management system 100 includes a management server 101. The management server 101 is located outside the work machine 1. The management server 101 includes a computer system. The management server 101 is able to communicate with the work machine 1 via a communication system 102. The communication system 102 includes an internet communication network. Note that the communication system 102 may include a mobile phone communication network, a satellite communication network, or a local area network (LAN).

[0013] <Work machine> Figure 2 is a configuration diagram showing a work machine 1 according to this embodiment. As shown in Figures 1 and 2, the work machine 1 comprises a body 2, an articulating device 3, a traveling device 5 including wheels 4, and a work implement 6. The work machine 1 travels around a work site using the traveling device 5. The work machine 1 performs work at the work site using the work implement 6. Examples of work that the work machine 1 can perform include excavation work, loading work, and transporting work.

[0014] The vehicle body 2 supports the work implement 6. The vehicle body 2 includes a front vehicle body section 2F and a rear vehicle body section 2R. The front vehicle body section 2F is located forward of the rear vehicle body section 2R. The front vehicle body section 2F and the rear vehicle body section 2R are connected by an articulation device 3. The articulation device 3 includes an articulation cylinder 7. The articulation cylinder 7 is a hydraulic cylinder. The articulation cylinder 7 connects the front vehicle body section 2F and the rear vehicle body section 2R. As the articulation cylinder 7 extends and retracts, the front vehicle body section 2F bends left and right relative to the rear vehicle body section 2R. As the front vehicle body section 2F bends relative to the rear vehicle body section 2R, the traveling direction of the work machine 1 is adjusted.

[0015] The traveling device 5 supports the vehicle body 2. The traveling device 5 includes wheels 4. The wheels 4 are attached to each of the front vehicle body 2F and the rear vehicle body 2R.

[0016] The work implement 6 is supported by the vehicle body 2. The work implement 6 is connected to the vehicle body front portion 2F. The work implement 6 has a boom 8, a bucket 9, a bell crank 10, a bucket link 11, a lift cylinder 12, and a bucket cylinder 13.

[0017] The base end of boom 8 is rotatably connected to the front vehicle body 2F. Bucket 9 is a working member that excavates an excavation target. The base end of bucket 9 is rotatably connected to the tip end of boom 8. The middle portion of bell crank 10 is rotatably connected to bracket 14 of boom 8. The lower end of bell crank 10 is rotatably connected to the base end of bucket link 11. The tip end of bucket link 11 is rotatably connected to bracket 15 of bucket 9. Bell crank 10 is connected to bucket 9 via bucket link 11.

[0018] The boom 8 is operated by a lift cylinder 12. The lift cylinder 12 is a hydraulic cylinder. The base end of the lift cylinder 12 is connected to the front vehicle body 2F. The tip end of the lift cylinder 12 is connected to the boom 8. The bucket 9 is operated by a bucket cylinder 13. The bucket cylinder 13 is a hydraulic cylinder. The base end of the bucket cylinder 13 is connected to the front vehicle body 2F. The tip end of the bucket cylinder 13 is connected to the upper end of the bell crank 10.

[0019] In this embodiment, the work machine 6 is a front-loading type work machine in which the opening of the bucket 9 faces forward during excavation work. The boom 8 is raised or lowered by extending or contracting the lift cylinder 12. The bucket cylinder 13 is extended or contracted by extending or contracting the bucket 9, causing the bucket 9 to tilt or dump.

[0020] 2 , the work machine 1 includes an engine 16, a power take-off (PTO) 17, a power transmission device 18, wheels 4, a brake device 19, a steering pump 20, a steering control valve 21, an articulate cylinder 7, a work implement pump 22, a work implement control valve 23, a lift cylinder 12, a bucket cylinder 13, a position sensor 24, a direction sensor 25, a speed sensor 26, an object sensor 27, and a controller 28. The traveling device 5 includes the power transmission device 18, the brake device 19, and wheels 4.

[0021] The engine 16 is a drive source for the work machine 1. The engine 16 is supported by the vehicle body 2. An example of the engine 16 is a diesel engine. A power take-off 17 distributes the drive force of the engine 16 to a power transmission device 18, a steering pump 20, and a work implement pump 22.

[0022] The power transmission device 18 transmits the driving force of the engine 16 to the wheels 4. The power transmission device 18 controls the traveling speed and direction of travel of the work machine 1. The traveling direction of the work machine 1 includes forward and reverse. The power transmission device 18 may be a transmission having a torque converter, or may be a transmission having a plurality of speed-changing gears. The brake device 19 slows down or stops the working machine 1 while it is traveling.

[0023] The steering pump 20 is a hydraulic pump that is operated by the driving force generated by the engine 16. The hydraulic oil discharged from the steering pump 20 is supplied to the articulate cylinder 7 via a steering control valve 21. The steering control valve 21 controls the flow rate and direction of the hydraulic oil supplied from the steering pump 20 to the articulate cylinder 7. The articulate device 3 is operated by the hydraulic oil from the steering pump 20.

[0024] The work implement pump 22 is a hydraulic pump that operates using driving force generated by the engine 16. The hydraulic oil discharged from the work implement pump 22 is supplied to each of the lift cylinder 12 and the bucket cylinder 13 via a work implement control valve 23. The work implement control valve 23 controls the flow rate and direction of the hydraulic oil supplied from the work implement pump 22 to each of the lift cylinder 12 and the bucket cylinder 13. The work implement 6 operates using the hydraulic oil from the work implement pump 22. The work implement 6 operates using the hydraulic oil from the work implement pump 22.

[0025] The position sensor 24 detects the position of the work machine 1. The position of the work machine 1 is detected using a global navigation satellite system (GNSS). The global navigation satellite system includes a global positioning system (GPS). The global navigation satellite system detects the position of a global coordinate system defined by coordinate data of latitude, longitude, and altitude. The global coordinate system is a coordinate system fixed to the Earth. The position sensor 24 includes a GNSS receiver, and detects the absolute position of the work machine 1, which indicates the position of the work machine 1 in the global coordinate system.

[0026] The orientation sensor 25 detects the orientation of the work machine 1. An example of the orientation sensor 25 is an inertial measurement unit (IMU). The orientation sensor 25 may include a calculator that calculates the orientation from position data detected by two GNSS antennas provided on the work machine 1. The calculator can calculate the orientation from a vector connecting the two GNSS antennas.

[0027] The speed sensor 26 detects the traveling speed of the work machine 1. An example of the speed sensor 26 is a magnetic sensor that detects the rotation speed of a drive shaft connected to the wheel 4.

[0028] The object sensor 27 detects objects in the vicinity of the work machine 1. Objects in the vicinity of the work machine 1 include obstacles. The object sensor 27 detects objects in a non-contact manner. An example of the object sensor 27 is a radar sensor (RADAR: Radio Detection and Ranging) that detects objects by emitting radio waves. Note that the object sensor 27 may include a laser sensor (LiDAR: Light Detection and Ranging) that detects objects by emitting laser light, or may include a camera.

[0029] FIG. 3 is a hardware configuration diagram of the controller 28 according to this embodiment. The controller 28 includes a computer system. The controller 28 has a processor 29 such as a CPU (Central Processing Unit), a main memory 30 including a nonvolatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory), a storage 31, and an interface 32 including an input / output circuit. The functions of the controller 28 are stored in the storage 31 as a computer program. The processor 29 reads the computer program from the storage 31, loads it into the main memory 30, and executes processing in accordance with the computer program. The computer program may be distributed to the controller 28 via a network. The management server 101 also includes a computer system such as that shown in FIG. 3.

[0030] <Control System> Figure 4 is a functional block diagram showing a control system 200 for the work machine 1 according to this embodiment. The control system 200 includes a management server 101 and a controller 28. Detection data from the position sensor 24, direction sensor 25, speed sensor 26, and object sensor 27 is sent to the controller 28. The controller 28 sends control commands to each of the articulating device 3, traveling device 5, and work implement 6.

[0031] 4, the management server 101 has a task data generation unit 33 and a restart position setting unit 34. The controller 28 has an operation control unit 35. Each of the task data generation unit 33, the restart position setting unit 34, and the operation control unit 35 is realized by the computer system (controller) described above.

[0032] The work data generation unit 33 generates work data that indicates the work conditions of the work machine 1. The work conditions include the operating conditions of the articulating unit 3 and the traveling unit 5, and the operating conditions of the work implement 6. The operating conditions of the articulating unit 3 and the traveling unit 5 are the traveling conditions of the work machine 1. The work data includes traveling data that indicates the traveling conditions of the work machine 1, and work implement data that indicates the operating conditions of the work implement 6. The work data generation unit 33 transmits the work data to the work machine 1 via the communication system 102.

[0033] The travel data indicating the travel conditions of the work machine 1 includes a target travel path 36, a target position, a target orientation, and a target travel speed of the work machine 1. In the following description, travel by the work machine 1 based on the travel data will be referred to as "traveling work" as appropriate. Traveling work includes at least one of excavation work, loading work, and transporting work. Transporting work includes traveling work in which the work machine 6 travels with an excavated material held in the bucket 9. Note that traveling work may also include simple traveling work (empty traveling work) in which the work machine 6 travels without an excavated material held in the bucket 9.

[0034] The travel data only needs to include at least one of the target travel path 36 and the target position. As long as at least one of the target travel path 36 and the target position is specified, the controller 28 can cause the work machine 1 to perform travel work. Furthermore, travel work may be a state in which both the travel device 5 and the work implement 6 are controlled, or a state in which the travel device 5 is controlled without controlling the work implement 6.

[0035] The restart position setting unit 34 sets a restart position 41 for the work machine 1 performing traveling work based on the traveling data. The restart position 41 is a position at which the operation of the work machine 1 can be switched. Switching the operation of the work machine 1 includes at least one of causing a forward moving work machine 1 to move in reverse, causing a reverse moving work machine 1 to move forward, causing a traveling work machine 1 to stop, and causing a stopped work machine 1 to travel.

[0036] The operation control unit 35 outputs control commands to control each of the articulating unit 3, the traveling unit 5, and the work machine 6 based on the work data transmitted from the management server 101. The operation control unit 35 outputs control commands to each of the articulating unit 3 and the traveling unit 5 so that the work machine 1 travels based on the traveling data transmitted from the management server 101. The operation control unit 35 outputs control commands to the work machine 6 so that the work machine 6 operates based on the work machine data transmitted from the management server 101.

[0037] <Work machine cyclical work> Figure 5 is a diagram illustrating cyclical work of the work machine 1 according to this embodiment. The work data generation unit 33 generates work data including a target travel route so that the work machine 1 performs a plurality of preset travel tasks. In this embodiment, the work data generation unit 33 generates work data so that the work machine 1 performs a cyclical work in which a series of travel tasks are repeated as the plurality of travel tasks. A cyclical work is made up of a plurality of travel tasks that are interrelated. A travel task includes at least travel by the travel device 5. A travel task includes operation of the work implement 6.

[0038] In this embodiment, the cycle work is made up of a series of six traveling operations, including an empty load forward operation M1, an excavation operation M2, a loaded load backward operation M3, a loaded load forward operation M4, a loading operation M5, and an empty load backward operation M6.

[0039] The order of the series of traveling operations is fixed. After the unladen forward operation M1 is performed, the digging operation M2 is performed. After the digging operation M2 is performed, the loaded reverse operation M3 is performed. After the loaded reverse operation M3 is performed, the loaded forward operation M4 is performed. After the loaded forward operation M4 is performed, the loading operation M5 is performed. After the loading operation M5 is performed, the unladen reverse operation M6 is performed.

[0040] The work machine 1 performs a cycle of work in which a series of traveling operations are repeated multiple times. After a first empty backward movement operation M6 is performed, a second empty forward movement operation M1 is performed.

[0041] In cyclical work, the work machine 1 operates based on work data generated by the work data generation unit 33. As described above, the work data includes travel data indicating the travel conditions of the work machine 1 and work implement data indicating the operating conditions of the work implement 6. The travel data includes the target travel path 36, target position, target orientation, and target travel speed of the work machine 1.

[0042] The target travel path 36 is defined in a global coordinate system. The target travel path 36 is defined by a trajectory that passes through a plurality of travel points. The travel points define the target position of the work machine 1. A target heading and a target travel speed for the work machine 1 are set for each of the plurality of travel points. The plurality of travel points are set at intervals. The intervals between the travel points may be uniform or uneven. The target travel path 36 is a virtual line connecting the plurality of travel points. The operation control unit 35 controls the articulating device 3 and the traveling device 5 so that the work machine 1 travels according to the target travel path 36. The operation control unit 35 causes the work machine 1 to travel so that, for example, the center of the rear body 2R of the work machine 1 coincides with the target travel path 36 in the vehicle width direction of the work machine 1.

[0043] The target position refers to the target position of the work machine 1 when it passes through a travel point. The target position of the work machine 1 is defined in a global coordinate system. The target heading of the work machine 1 refers to the target heading of the work machine 1 when it passes through a travel point. The target traveling speed of the work machine 1 refers to the target traveling speed of the work machine 1 when it passes through a travel point.

[0044] The operation control unit 35 controls the articulating unit 3 and the traveling units 5 based on the detection data from the position sensor 24 and the detection data from the orientation sensor 25 so that the work machine 1 travels along the target travel path 36. In other words, the operation control unit 35 controls the articulating unit 3 and the traveling units 5 so that the deviation between the detected position of the work machine 1 detected by the position sensor 24 when passing a travel point and the target position of the work machine 1 set for the travel point is reduced. The operation control unit 35 also controls the articulating unit 3 and the traveling units 5 so that the deviation between the detected orientation of the work machine 1 detected by the orientation sensor 25 when passing a travel point is reduced and the target orientation of the work machine 1 set for the travel point is reduced. The operation control unit 35 also controls the traveling units 5 based on the detection data from the speed sensor 26 so that the work machine 1 travels at the target travel speed. In other words, the operation control unit 35 controls the traveling units 5 so that the deviation between the detected travel speed of the work machine 1 detected by the speed sensor 26 when passing a travel point is reduced and the target travel speed of the work machine 1 set for the travel point is reduced.

[0045] Empty-load forward movement work M1 is work of moving forward to approach the excavation target. In this embodiment, the excavation target is a mound of natural ground 37 placed on the ground. The mound of natural ground 37 refers to a pile of earth and sand. In empty-load forward movement work M1, the movement control unit 35 moves the work machine 1 forward based on the traveling data so that the work machine 1 approaches the mound of natural ground 37. When moving the work machine 1 forward, the movement control unit 35 controls the attitude of the work machine 6 based on the work machine data so that the bucket 9 excavates the mound of natural ground 37. The movement control unit 35 controls the attitude of the work machine 6 so that the cutting edge of the bucket 9 approaches the ground. When the work machine 1 moves forward with the cutting edge of the bucket 9 approaching the ground, the cutting edge of the bucket 9 is inserted into the lower end of the mound of natural ground 37.

[0046] Excavation work M2 is work to excavate an excavation target with the bucket 9 of the work machine 6. The operation control unit 35 tilts the bucket 9 after the cutting edge of the bucket 9 is inserted into the natural ground 37 based on the work machine data. This causes the bucket 9 to excavate the natural ground 37. The bucket 9 scoops up the excavated material. The excavated material is held in the bucket 9.

[0047] The load reversing work M3 is work in which the work machine 6 moves backward so as to move away from the excavation target with the excavated material held in the bucket 9 of the work machine 6. In the load reversing work M3, the operation control unit 35 reverses the work machine 1 so that the work machine 1 moves away from the natural ground 37, based on the traveling data. The operation control unit 35 also controls the attitude of the work machine 6 so that the excavated material does not spill from the bucket 9.

[0048] Load forward operation M4 is an operation in which the work machine 1 moves forward to approach the loading target. In load reverse operation M3, the work machine 1 moves backward toward switchback point 36P defined on the target travel path 36. After switching back at switchback point 36P, the work machine 1 transitions to load forward operation M4. Switchback point 36P refers to the position at which the work machine 1 switches back. Switchback refers to the operation in which the work machine 1, while moving backward, changes direction of travel at an acute angle and moves forward.

[0049] In this embodiment, the loading target is a dump body 39 of a transport vehicle 38 that is capable of traveling on the ground. An example of the transport vehicle 38 is a dump truck. After completing the load reversing operation M3, the work machine 1 moves forward while turning so as to approach the transport vehicle 38. In the load advancing operation M4, the operation control unit 35 moves the work machine 1 forward so as to approach the transport vehicle 38 based on the traveling data.

[0050] The loading operation M5 is an operation of loading the excavated material held in the bucket 9 of the work implement 6 onto a loading target. Based on the work implement data, the operation control unit 35 controls the attitude of the work implement 6 so that the excavated material held in the bucket 9 is loaded into the dump body 39 of the transport vehicle 38. Based on the work implement data, the operation control unit 35 controls the attitude of the work implement 6 so that the excavated material does not spill out of the bucket 9 and so that the bucket 9 is positioned above the upper end of the dump body 39.

[0051] The empty reverse operation M6 is an operation of moving the work machine 1 in reverse so as to move away from the loading target. After the loading operation M5 is completed, the operation control unit 35 moves the work machine 1 in reverse so as to move away from the transport vehicle 38 based on the travel data.

[0052] The work machine 1 repeats a cycle of operations including an empty forward operation M1, an excavation operation M2, a loaded reverse operation M3, a loaded forward operation M4, a loading operation M5, and an empty reverse operation M6 until the excavated material is loaded onto the transport vehicle 38 at the target load amount.

[0053] <Control Method> Figure 6 is a flowchart showing a control method for the work machine 1 according to this embodiment. Figures 7, 8, and 9 are each diagrams for explaining the control method for the work machine 1 according to this embodiment.

[0054] The work data generation unit 33 generates travel data and work machine data, including a target travel path 36. The work data generation unit 33 generates the target travel path 36 so that the work machine 1 performs the cycle work. The operation control unit 35 starts the cycle work based on the work data, including the travel data and work machine data.

[0055] During cyclical work, the operation control unit 35 causes the work machine 1 to travel under the predetermined travel conditions generated by the work data generation unit 33. During cyclical work, the operation control unit 35 controls each of the articulating unit 3 and the traveling unit 5 based on travel data that indicates the travel conditions of the work machine 1. The operation control unit 35 controls each of the articulating unit 3 and the traveling unit 5 so that the work machine 1 travels according to a target travel path 36.

[0056] The operation control unit 35 determines whether an error has occurred during the traveling operation (step S1).

[0057] Traveling work errors include deviation of the work machine 1 from the target travel path 36. Traveling work errors include interruption of travelling work. Traveling work errors include stopping of the work machine 1 that is not specified in the travelling data indicating the travelling conditions generated by the work data generation unit 33.

[0058] For example, due to road surface conditions at the work site, there is a possibility that the work machine 1 performing traveling work may deviate from the target traveling path 36. The operation control unit 35 determines that the work machine 1 has deviated from the target traveling path 36 when it determines that the deviation amount ΔD, which indicates the difference between the detected position of the work machine 1 detected by the position sensor 24 and the target position of the work machine 1 set at the traveling point, is equal to or greater than a predetermined specified value. Note that the operation control unit 35 may also determine that the work machine 1 has deviated from the target traveling path 36 when it determines that the difference between the detected heading of the work machine 1 detected by the heading sensor 25 and the target heading of the work machine 1 set at the traveling point is equal to or greater than a predetermined specified value. When it is determined that the work machine 1 has deviated from the target traveling path 36, the operation control unit 35 stops the work machine 1. Furthermore, an obstacle 44 present in the traveling direction of the work machine 1 is detected by the object sensor 27. When the object sensor 27 detects an obstacle 44, the operation control unit 35 interrupts traveling work. When an obstacle 44 is detected by the object sensor 27, the operation control section 35 causes the work machine 1 to stop.

[0059] In step S1, if it is determined that no error has occurred in the driving operation (step S1: No), the operation control unit 35 continues the driving operation.

[0060] If it is determined in step S1 that an error has occurred in the traveling operation (step S1: Yes), the restart position setting unit 34 sets the restart position 41 of the work machine 1 (step S2).

[0061] 7 shows an example in which the work machine 1 deviates from the target travel path 36 during a load forward movement operation M4. When the work machine 1 deviates from the target travel path 36, the operation control unit 35 causes the work machine 1 to stop.

[0062] If the work machine 1 deviates from the target travel path 36, the restart position setting unit 34 sets a restart position 41 for the work machine 1. The restart position 41 is a position different from the error position 40 where an error in the travel operation occurred. In the example shown in Figure 7, the error position 40 is the position where the work machine 1, having deviated from the target travel path 36, stopped.

[0063] 7, the restart position 41 is a position away from the target travel route 36. The restart position setting unit 34 does not set the restart position 41 on the target travel route 36, but sets it to a position away from the target travel route 36.

[0064] In cargo forward movement work M4, the work machine 1 travels forward. If an error occurs while the work machine 1 is traveling forward, the restart position setting unit 34 sets a restart position 41 behind the error position 40 where the error occurred.

[0065] 8, after the restart position 41 has been set, the operation control unit 35 moves the work machine 1 to the restart position 41. The operation control unit 35 moves the work machine 1 to the restart position 41 so that the work machine 1 moves backward along a restart path 42 connecting the error position 40 and the restart position 41 (step S3).

[0066] The restart path 42 may be generated by the restart position setting unit 34, or may be generated by the operation control unit 35. Note that the operation control unit 35 may cause the work machine 1 to move backward from the error position 40 to the restart position 41 in a state in which the restart path 42 is not set.

[0067] As shown in FIG. 9, the operation control unit 35 moves the work machine 1 backward to the restart position 41, and then moves the work machine 1 forward from the restart position 41 to the target travel route 36 (step S4).

[0068] The operation control unit 35 stops the work machine 1 at the restart position 41, and then moves the work machine 1 forward from the restart position 41 toward the target travel path 36. Note that the operation control unit 35 does not have to stop the work machine 1 at the restart position 41.

[0069] 9 , the operation control unit 35 moves the work machine 1 to the target travel path 36 so that the work machine 1 moves forward along a return path 43 that connects the restart position 41 and the target travel path 36. The operation control unit 35 moves the work machine 1 forward from the restart position 41 to return to traveling work.

[0070] The return path 43 may be generated by the restart position setting unit 34, or may be generated by the operation control unit 35. Note that the operation control unit 35 may cause the work machine 1 to move forward from the restart position 41 to the target travel path 36 in a state where the return path 43 is not set.

[0071] The operation control unit 35 causes the work machine 1 to return to traveling work by moving the work machine 1 from the restart position 41 to the target traveling path 36. In this embodiment, the operation control unit 35 causes the work machine 1 to move backward to the restart position 41, and then moves the work machine 1 forward from the restart position 41 to return to traveling work (step S5).

[0072] The operation control unit 35 causes the work machine 1 to enter the target travel path 36 in the vicinity of the error position 40. The operation control unit 35 causes the work machine 1 to enter the target travel path 36 from the position on the target travel path 36 where the travel operation error occurred.

[0073] Returning the work machine 1 to traveling work includes returning it to cyclic work. The operation control unit 35 controls the work machine 1 so that the work machine 1 returns to the interrupted part of the cyclic work. In the examples shown in Figures 7, 8, and 9, an error in traveling work occurs during load advancing work M4 of the work machine 1. The cyclic work of the work machine 1 is interrupted during load advancing work M4. The operation control unit 35 causes the work machine 1 to enter the target travel path 36 so that the work machine 1 returns to load advancing work M4.

[0074] The load advancing operation M4 includes the work machine 1 advancing from the switchback point 36P toward the transport vehicle 38 according to the target travel route 36 between the switchback point 36P and the transport vehicle 38. The operation control unit 35 causes the work machine 1 to enter the target travel route 36 between the switchback point 36P and the transport vehicle 38, and then causes the work machine 1 to advance toward the transport vehicle 38. Having entered the target travel route 36, the work machine 1 returns to the load advancing operation M4. Having returned to the load advancing operation M4, the work machine 1 resumes the cycle work.

[0075] <Effects> As described above, in this embodiment, the control system 200 of the work machine 1 comprises the restart position setting unit 34 that sets the restart position 41 of the work machine 1 that is performing traveling work in accordance with the target traveling path 36, and the operation control unit 35 that, when an error occurs during traveling work, moves the work machine 1 to the restart position 41 and then causes the work machine 1 to return to traveling work.

[0076] According to this embodiment, because the restart position 41 is set, if an error occurs in the traveling operation of the work machine 1, the work machine 1 can be smoothly returned to traveling operation. For example, if an error in traveling operation occurs near the transport vehicle 38 during load forwarding operation M4, it may be difficult to resume load forwarding operation M4 from the position where the error occurred and move on to loading operation M5. If an error in traveling operation occurs near the transport vehicle 38 and the work machine 1 stops, it may be difficult to adjust the orientation and posture of the work machine 1 so that the load can be smoothly loaded into the dump body 39. According to this embodiment, if an error in traveling operation occurs near the transport vehicle 38 and the work machine 1 stops, the restart position 41 is set at a position away from the transport vehicle 38. The operation control unit 35 moves the work machine 1 to the restart position 41 and then returns it to traveling operation. Because the distance from the restart position 41 to the transport vehicle 38 is long, the operation control unit 35 can adjust the direction and attitude of the work machine 1 so that the load can be smoothly loaded into the dump body 39 .

[0077] Second Embodiment A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0078] Figure 10 is a diagram illustrating a control method for the work machine 1 according to this embodiment. Figure 10 shows an example in which the work machine 1 deviates from the target travel path 36 during a load forward movement operation M4. Travel operation errors include the amount of deviation ΔD of the work machine 1 from the target travel path 36 being equal to or greater than a predetermined specified amount. If the amount of deviation ΔD is equal to or greater than a predetermined specified value, the operation control unit 35 stops the work machine 1 and then moves it to the restart position 41.

[0079] If the deviation amount ΔD falls below the specified amount, the operation control unit 35 controls the work machine 1 so as to reduce the deviation amount ΔD without moving the work machine 1 to the restart position 41. If the deviation amount ΔD falls below the specified amount, the operation control unit 35 controls the articulating unit 3 and the traveling unit 5 so as to reduce the deviation amount ΔD without stopping the work machine 1. If the deviation amount ΔD falls below the specified amount, the operation control unit 35 controls the articulating unit 3 and the traveling unit 5 so as to reduce the difference between the detected position of the work machine 1 detected by the position sensor 24 and the target position of the work machine 1 set at the traveling point, without interrupting the traveling operation.

[0080] As explained above, in this embodiment, when the deviation amount ΔD falls below the specified amount, traveling work is not interrupted, and therefore a decrease in the work efficiency of the work machine 1 is suppressed.

[0081] Third Embodiment A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0082] Figures 11 and 12 are diagrams illustrating a control method for the work machine 1 according to this embodiment. Figure 11 shows an example in which the work machine 1 has stopped during an empty forward movement operation M1 due to the presence of an obstacle 44. Figure 12 shows an example in which the work machine 1 has stopped during a loaded backward movement operation M3 due to the presence of an obstacle 44. When an obstacle 44 is detected by the object sensor 27, the operation control unit 35 causes the work machine 1 to stop.

[0083] As shown in FIG. 11 , if an error occurs during traveling while the work machine 1 is traveling forward, a restart position 41 is set behind the error position 40 where the error occurred. The error position 40 is the position where the object sensor 27 detects an obstacle 44 ahead of the work machine 1 and the work machine 1 stops. The operation control unit 35 causes the work machine 1 to move backward from the error position 40 to the restart position 41. After the obstacle 44 is removed, the operation control unit 35 causes the work machine 1 to move forward from the restart position 41 and return to traveling. The operation control unit 35 causes the work machine 1 to enter the target traveling path 36 between the switchback point 36P and the natural ground 37, and then moves forward toward the natural ground 37. Once the work machine 1 has entered the target traveling path 36, it returns to unladen forward operation M1. Once the work machine 1 has returned to unladen forward operation M1, it resumes cyclic work.

[0084] As shown in FIG. 12 , if an error occurs during traveling while the work machine 1 is performing a traveling operation such that it is moving backward, a restart position 41 is set behind the error position 40 where the error occurred. The error position 40 is the position where an obstacle 44 present behind the work machine 1 is detected by the object sensor 27 and the work machine 1 stops. As shown in FIG. 12 , the restart position 41 may also be set on the target traveling route 36. In the example shown in FIG. 12 , the restart position 41 is set at a switchback point 36P. After the obstacle 44 is removed, the operation control unit 35 causes the work machine 1 to move backward from the error position 40 to the restart position 41. The operation control unit 35 moves the work machine 1 forward from the restart position 41 to return to traveling operations. The operation control unit 35 causes the work machine 1 to enter the target traveling route 36 between the switchback point 36P and the haulage vehicle 38, and then moves the work machine 1 forward toward the haulage vehicle 38. Having entered the target traveling route 36, the work machine 1 returns to the load forwarding operation M4. After returning to the load advancing operation M4, the work machine 1 resumes the cycle work.

[0085] As shown in Figure 11, if an error occurs when the work machine 1 is traveling forward, the restart position 41 is set a first distance L1 behind the error position 40 where the error occurred. As shown in Figure 12, if an error occurs when the work machine 1 is traveling backward, the restart position 41 is set a second distance L2 behind the error position 40 where the error occurred. The second distance L2 may be shorter than the first distance L1.

[0086] [Other Embodiments] In the above-described embodiment, the functions of the management server 101 may be provided in the controller 28. For example, the controller 28 may have the functions of the restart position setting unit 34 and the operation control unit 35, or may have the functions of the task data generation unit 33, the restart position setting unit 34, and the operation control unit 35.

[0087] In the above-described embodiment, the restart position 41 may be set after an error occurs in the traveling operation, or may be set before the error occurs in the traveling operation. The restart position 41 may be set based on the error position 40. The restart position 41 may also be a position that is fixed in advance at the work site.

[0088] In the above embodiment, the restart position 41 may be set before the error position 40 .

[0089] In the above-described embodiment, the work data generation unit 33 generates a target travel path so that the work machine 1 performs cyclical work as a plurality of preset travel operations. The plurality of travel operations do not have to be cyclical works. If the travel operations include excavation work, loading work, transport work (traveling work with a load), and simple traveling work (traveling work with no load), a target travel path may be generated so that the work machine 1 performs a travel operation that combines at least two of the excavation work, loading work, transport work (traveling work with a load), and simple traveling work (traveling work with no load).

[0090] In the above-described embodiment, a driver may ride on the work machine 1. In the above-described embodiment, each of the articulating device 3, the traveling device 5, and the work implement 6 may be automatically controlled. The articulating device 3 and the traveling device 5 may be automatically controlled, and the work implement 6 may operate based on the operation of a work lever by the driver.

[0091] In the above-described embodiment, a driver does not have to ride on the work machine 1. The work machine 1 may be operated based on an operation signal from a remote control device provided outside the work machine 1. In other words, the work machine 1 may be remotely controlled.

[0092] [Supplementary Notes] The present disclosure may also adopt the following configurations. (Supplementary Note 1) A work machine control system comprising a controller, the controller comprising: a restart position setting unit that sets a restart position for a work machine traveling along a target travel path; and an operation control unit that, when an error occurs in the traveling operation, moves the work machine to the restart position and then returns to the traveling operation. (Supplementary Note 2) The work machine control system described in (Supplementary Note 1), wherein the restart position is a position different from the error position where the error occurred. (Supplementary Note 3) The work machine control system described in (Supplementary Note 1) or (Supplementary Note 2), wherein the restart position is a position away from the target traveling path. (Supplementary Note 4) The work machine control system described in (Supplementary Note 3), wherein the operation control unit moves the work machine to the restart position, and then moves the work machine from the restart position to the target traveling path and returns to the traveling operation. (Supplementary Note 5) The work machine control system described in any one of (Supplementary Note 1) to (Supplementary Note 4), wherein the operation control unit stops the work machine at the restart position and then returns it to the traveling operation. (Supplementary Note 6) The work machine control system described in any one of (Supplementary Note 1) to (Supplementary Note 5), wherein the operation control unit moves the work machine backward to the restart position and then moves it forward from the restart position and returns it to the traveling operation. (Supplementary Note 7) The work machine control system described in any one of (Supplementary Note 1) to (Supplementary Note 6), wherein the work machine has a traveling device and a work implement, and the traveling operation includes excavation work and loading work. (Supplementary Note 8) The work machine control system according to any one of (Supplementary Note 1) to (Supplementary Note 7), wherein the controller further comprises a work data generation unit that generates the target travel path, the work data generation unit generates the target travel path so that the work machine performs a plurality of preset travel tasks, and returning to the travel task includes returning to the travel task. (Supplementary Note 9) The work machine control system according to any one of (Supplementary Note 1) to (Supplementary Note 8), wherein the error includes deviation of the work machine from the target travel path.(Supplementary Note 10) A work machine control system as set forth in any one of (Supplementary Note 1) to (Supplementary Note 9), wherein the error includes the amount of deviation of the work machine from the target travel path being equal to or greater than a predetermined specified amount, and wherein the operation control unit controls the work machine to reduce the amount of deviation if the amount of deviation is below the specified amount, without moving the work machine to the restart position. (Supplementary Note 11) A work machine control system as set forth in any one of (Supplementary Note 1) to (Supplementary Note 10), wherein the operation control unit causes the work machine to perform a travel operation under predetermined travel conditions, and wherein the error includes an interruption of the travel operation. (Supplementary Note 12) A work machine control system as set forth in (Supplementary Note 11), wherein the error includes a stop of the work machine that is not specified in the travel conditions. (Supplementary Note 13) A work machine control system as set forth in any one of (Supplementary Note 1) to (Supplementary Note 12), wherein the error includes a stop of the work machine that is not specified in the travel conditions. (Supplementary Note 14) A work machine control system as set forth in any one of (Supplementary Note 1) to (Supplementary Note 13), wherein if the error occurs when the work machine is traveling in reverse, the restart position is set behind the error position where the error occurred. (Supplementary Note 15) A work machine control system as set forth in any one of (Supplementary Note 1) to (Supplementary Note 13), wherein if the error occurs when the work machine is traveling in forward, the restart position is set behind the error position where the error occurred by a first distance, and if the error occurs when the work machine is traveling in reverse, the restart position is set behind the error position where the error occurred by a second distance, the second distance being shorter than the first distance. (Supplementary Note 16) A work machine control method, wherein a controller sets a restart position for a work machine traveling in accordance with a target travel path, and when an error occurs in the traveling operation, moves the work machine to the restart position and then returns to the traveling operation.

[0093] REFERENCE SIGNS LIST 1...work machine, 2...body, 2F...front body, 2R...rear body, 3...articulation device, 4...wheel, 5...traveling device, 6...work implement, 7...articulation cylinder, 8...boom, 9...bucket, 10...bell crank, 11...bucket link, 12...lift cylinder, 13...bucket cylinder, 14...bracket, 15...bracket, 16...engine, 17...power take-off, 18...power transmission device, 19...brake device, 20...steering pump, 21...steering control valve, 22...work implement pump, 23...work implement control valve, 24...position sensor, 25...direction sensor, 26...speed sensor, 27...object sensor, 28...controller , 29...processor, 30...main memory, 31...storage, 32...interface, 33...work data generation unit, 34...restart position setting unit, 35...operation control unit, 36...target driving route, 36P...switchback point, 37...ground, 38...transport vehicle, 39...dump body, 40...error position, 41...restart position, 42...restart route, 43...return route, 44...obstacle, 100...management system, 101...management server, 102...communication system, 200...control system, L1...first distance, L2...second distance, M1...empty load forward operation, M2...excavation operation, M3...loaded load backward operation, M4...loaded load forward operation, M5...loading operation, M6...empty load backward operation.

Claims

1. A control system for a work machine, comprising a controller, the controller including a restart position setting unit configured to set a restart position for the work machine that performs a traveling operation according to a target traveling route, and an operation control unit configured to, when an error occurs during the traveling operation, move the work machine to the restart position and then cause the work machine to resume the traveling operation.

2. The control system for a work machine according to claim 1, wherein the restart position is a position different from the error position where the error occurred.

3. The control system for a work machine according to claim 2, wherein the restart position is a position away from the target traveling route.

4. The control system for a work machine according to claim 3, wherein the operation control unit moves the work machine to the restart position and then moves the work machine from the restart position to the target traveling route to cause the work machine to resume the traveling operation.

5. The control system for a work machine according to claim 1, wherein the operation control unit stops the work machine at the restart position and then causes the work machine to resume the traveling operation.

6. The control system for a work machine according to claim 1, wherein the operation control unit reverses the work machine to the restart position and then moves the work machine forward from the restart position to cause the work machine to resume the traveling operation.

7. The work machine has a traveling device and a work implement, and the traveling operation includes at least one of an excavation operation and a loading operation. The control system for a work machine according to claim 1.

8. The controller further includes a work data generation unit configured to generate the target traveling route. The work data generation unit generates the target traveling route so that the work machine performs a plurality of preset traveling operations. Causing the work machine to resume the traveling operation includes causing the work machine to resume the traveling operation. The control system for a work machine according to claim 7.

9. The error includes deviation of the work machine from the target traveling route. The control system for a work machine according to claim 1.

10. The error includes that the deviation amount of the work machine from the target traveling route is equal to or greater than a predetermined specified amount. When the deviation amount is less than the specified amount, the operation control unit controls the work machine so that the deviation amount becomes smaller without moving the work machine to the restart position. The control system for a work machine according to claim 1.

11. The operation control unit causes the work machine to perform a traveling operation under a predetermined traveling condition, and the error includes interruption of the traveling operation. The control system for a work machine according to claim 1.

12. The error includes stopping of the work machine not defined in the traveling condition. The control system for a work machine according to claim 11.

13. When the error occurs while the work machine is performing a traveling operation in a forward direction, the restart position is set behind the error position where the error occurred. The control system for a work machine according to claim 1.

14. When the error occurs while the work machine is performing a traveling operation in a reverse direction, the restart position is set behind the error position where the error occurred. The control system for a work machine according to claim 1.

15. When the error occurs while the work machine is performing a traveling operation in a forward direction, the restart position is set behind the error position where the error occurred by a first distance. When the error occurs while the work machine is performing a traveling operation in a reverse direction, the restart position is set behind the error position where the error occurred by a second distance. The second distance is shorter than the first distance. The control system for a work machine according to claim 1.

16. A controller executes setting a restart position of a work machine that performs a traveling operation according to a target traveling route, and after moving the work machine to the restart position when an error occurs in the traveling operation, causing the work machine to resume the traveling operation. A control method for a work machine.

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