System including work machine, controller for work machine, and control method for work machine

Abstract

The purpose of the present invention is to achieve automation of loading operations into containers of various shapes. A controller of a work machine stores a trajectory of the work machine and a reference point of a container when the work machine performs an operation for loading a cargo loaded on the work machine into the container, and changes the trajectory in accordance with the changed reference point when the position of the reference point is changed.

Description

Technical Field

[0001] The present disclosure relates to a system including a working machine, a controller of the working machine, and a control method of the working machine. Background Art

[0002] A conventional wheel loader is disclosed in, for example, International Publication No. 2020 / 224768 (Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2020 / 224768 Summary of the invention

[0006] Problems to be solved by the invention

[0007] A wheel loader repeatedly performs excavation and loading operations. When automating the loading operation, it is required to be able to cope with loading into containers of various shapes.

[0008] In the present disclosure, a system including a working machine, a controller of the working machine, and a control method of the working machine are proposed, which can realize automation of loading work into containers of various shapes.

[0009] Means for solving problems

[0010] According to one embodiment of the present disclosure, a system including a working machine is provided, which includes a working machine body; a working device, which is mounted on the working machine body and has a bucket; a working device posture sensor, which detects the posture of the working device; an object sensor, which detects objects around the working machine body; and a controller, which communicates with the working device posture sensor and the object sensor. The controller stores the trajectory of the working device and the reference point of the container when the working machine performs an operation for loading the cargo in the bucket into the container. When the position of the reference point is changed, the controller changes the trajectory according to the changed reference point.

[0011] According to one embodiment of the present disclosure, a controller of a working machine is provided. The controller stores the trajectory of the working device and the reference point of the container when the working machine performs an operation for loading cargo loaded on the working device into the container. When the position of the reference point is changed, the controller moves the reference point according to the changed reference point trajectory.

[0012] According to one embodiment of the present disclosure, a control method for a working machine is provided. The control method includes: the working machine stores a trajectory of a working device and a reference point of a container when an operation for loading a cargo loaded on the working device into a container is performed; and when the position of the reference point is changed, the trajectory is changed according to the changed reference point.

[0013] Effects of the Invention

[0014] According to the system including the working machine, the controller of the working machine, and the control method of the working machine disclosed herein, it is possible to automate the loading operation into containers of various shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side view of a wheel loader as an example of a working machine.

[0016] Figure 2 This is a block diagram showing a schematic configuration of a control system of a wheel loader.

[0017] Figure 3 It is a top view of a wheel loader performing excavation and loading operations.

[0018] Figure 4 This is a block diagram showing the structure of an automatic control system of a wheel loader.

[0019] Figure 5 This is a flowchart showing the flow of a process of controlling the working machine when a skilled operator records loading into a container.

[0020] Figure 6 This is a diagram showing the trajectory of the working device when a skilled operator loads the workpiece into a container.

[0021] Figure 7 This is a flowchart showing the flow of processing for editing recorded parameters.

[0022] Figure 8 This is a graph showing changes in cylinder length during loading work.

[0023] Fig. 9 The figure schematically shows the posture of the wheel loader when the unloading operation of the bucket is started.

[0024] Fig.10 The figure schematically shows the posture of the wheel loader when the blade edge reaches the deepest position.

[0025] Fig.11 The figure schematically shows the posture of the wheel loader when the unloading operation of the bucket is stopped.

[0026] Fig.12The figure schematically shows the posture of the wheel loader when the lifting operation of the boom is stopped.

[0027] Fig.13 The figure schematically shows the posture of the wheel loader when the bucket tilting operation is started.

[0028] Fig.14 It is a diagram schematically showing the posture of the wheel loader when the tilting operation of the bucket is stopped.

[0029] Fig.15 : is a flowchart showing the flow of the second process of editing parameters.

[0030] Fig.16 It is a schematic diagram showing characteristic points corresponding to the truck bodies of different vehicle specifications.

[0031] Fig.17 This is a schematic diagram showing reference points when changing the loading position of the dump truck.

[0032] Fig.18 This is a flowchart showing the flow of a process of loading a load loaded on a bucket into a container by automatic control. DETAILED DESCRIPTION

[0033] Hereinafter, the implementation mode will be described based on the accompanying drawings. In the following description, the same reference numerals are used for the same components and constituent elements. Their names and functions are also the same. Therefore, their detailed description will not be repeated. It is also predetermined from the beginning that any structure can be extracted from the implementation mode and combined arbitrarily.

[0034] <Overall structure of wheel loader 1>

[0035] In the embodiment, a wheel loader 1 will be described as an example of a working machine. Figure 1 It is a side view of a wheel loader 1 as an example of a working machine.

[0036] like Figure 1 As shown, the wheel loader 1 includes a body frame 2, a working device 3, a traveling device 4, and a cab 5. The body frame 2, the cab 5, etc. constitute the body of the wheel loader 1. The working device 3 and the traveling device 4 are mounted on the body of the wheel loader 1. The main body of the wheel loader 1 includes the body and the traveling device 4.

[0037] The travel device 4 is a device for driving the body of the wheel loader 1, and includes travel wheels 4a, 4b. The wheel loader 1 is a wheeled vehicle having travel wheels 4a, 4b as travel rotating bodies on both sides of the body in the left and right directions. The wheel loader 1 can move by itself by driving the travel wheels 4a, 4b to rotate, and can perform desired work using the work device 3. The travel device 4 corresponds to an example of a travel body.

[0038] In this specification, the direction in which the wheel loader 1 travels straight is referred to as the front-rear direction of the wheel loader 1. In the front-rear direction of the wheel loader 1, the side on which the working device 3 is arranged relative to the vehicle body frame 2 is set as the front direction, and the side opposite to the front direction is set as the rear direction. The left-right direction of the wheel loader 1 is a direction perpendicular to the front-rear direction when looking down at the wheel loader 1 on a flat ground. The right side and the left side of the left-right direction when observing the front direction are the right direction and the left direction, respectively. The up-down direction of the wheel loader 1 refers to a direction perpendicular to a plane defined by the front-rear direction and the left-right direction. In the up-down direction, the side where the ground is located is the lower side, and the side where the sky is located is the upper side.

[0039] The vehicle body frame 2 includes a front frame 2a and a rear frame 2b. The front frame 2a is arranged in front of the rear frame 2b. The front frame 2a and the rear frame 2b are mounted so as to be movable in the left-right direction relative to each other.

[0040] A pair of steering cylinders 11 are installed across the front frame 2a and the rear frame 2b. The steering cylinders 11 are hydraulic cylinders. The steering cylinders 11 are extended and retracted by the hydraulic oil from the steering pump, thereby changing the travel direction of the wheel loader 1 to the left and right. The vehicle body frame 2 of the articulated structure is formed by the front frame 2a and the rear frame 2b. The wheel loader 1 is an articulated working machine in which the front frame 2a and the rear frame 2b are connected in a manner that allows bending.

[0041] The front frame 2a is provided with a working device 3 and a pair of travel wheels (front wheels) 4a. The working device 3 is installed in front of the main body of the wheel loader 1. The working device 3 is supported by the body of the wheel loader 1. The working device 3 includes a boom 14 and a bucket 6. The bucket 6 is arranged at the front end of the working device 3. The bucket 6 is a working tool for digging / loading. The tip 6a is the front end of the bucket 6. The back surface 6b is a part of the outer surface of the bucket 6. The back surface 6b is formed by a plane. The back surface 6b extends rearward from the tip 6a.

[0042] The base end of the boom 14 is rotatably mounted to the front frame 2a via a boom pin 9. The bucket 6 is rotatably mounted to the boom 14 via a bucket pin 17 located at the front end of the boom 14. The boom pin 9 and the bucket pin 17 correspond to a plurality of joints of the working device 3.

[0043] The working device 3 further includes a bell crank 18 and a connecting rod 15. The bell crank 18 is rotatably supported by the boom 14 via a supporting pin 18a located substantially in the center of the boom 14. The connecting rod 15 is connected to a connecting pin 18c provided at the front end of the bell crank 18. The connecting rod 15 connects the bell crank 18 and the bucket 6.

[0044] The front frame 2a and the boom 14 are connected by a pair of boom cylinders 16. The boom cylinder 16 is a hydraulic cylinder. The boom cylinder 16 drives the boom 14 to rotate up and down around the boom pin 9. The base end of the boom cylinder 16 is mounted on the front frame 2a. The front end of the boom cylinder 16 is mounted on the boom 14. The boom cylinder 16 is a hydraulic actuator that moves the boom 14 up and down relative to the front frame 2a. As the boom 14 rises and falls, the bucket 6 mounted on the front end of the boom 14 also rises and falls.

[0045] The bucket cylinder 19 connects the bell crank 18 to the front frame 2a. The base end of the bucket cylinder 19 is mounted on the front frame 2a. The front end of the bucket cylinder 19 is mounted on the connecting pin 18b provided at the base end of the bell crank 18. The bucket cylinder 19 is a hydraulic actuator that rotates the bucket 6 up and down relative to the boom 14. The bucket cylinder 19 is a working tool cylinder that drives the bucket 6. The bucket cylinder 19 drives the bucket 6 to rotate around the bucket pin 17. The bucket 6 is configured to be able to move relative to the boom 14. The bucket 6 is configured to be able to move relative to the front frame 2a.

[0046] The boom cylinder 16 and the bucket cylinder 19 correspond to an example of a work implement actuator that drives the work implement 3 .

[0047] A cab 5 for an operator to sit on and a pair of travel wheels (rear wheels) 4b are mounted on the rear frame 2b. The box-shaped cab 5 is arranged behind the boom 14. The cab 5 is mounted on the vehicle body frame 2. A seat for the operator of the wheel loader 1 to sit on and an operating device 8 described later are arranged in the cab 5.

[0048] The cab 5 is provided with a sensing device 111. The sensing device 111 is, for example, disposed on the top plate portion of the cab 5. The sensing device 111 is, for example, mounted on the upper surface of the cab 5. The sensing device 111 is, for example, disposed at the front portion of the cab 5. The sensing device 111 is, for example, mounted on the cab 5 facing forward and can acquire information in front of the cab 5. The details of the sensing device 111 will be described later.

[0049] <System Structure>

[0050] Figure 2 This is a block diagram showing a schematic configuration of a control system for controlling the wheel loader 1 .

[0051] The engine 21 is a driving source that generates driving force for driving the working device 3 and the travel device 4, and is, for example, a diesel engine. As a driving source, a motor driven by an electric storage body may be used instead of the engine 21, or both the engine and the motor may be used. The output of the engine 21 is controlled by adjusting the amount of fuel injected into the cylinder of the engine 21.

[0052] The driving force generated by the engine 21 is transmitted to the transmission 23. The transmission 23 changes the driving force to an appropriate torque and rotation speed. The output shaft of the transmission 23 is connected to the axle 25. The driving force after the speed change by the transmission 23 is transmitted to the axle 25. From the axle 25 to the running wheels 4a, 4b ( Figure 1 ) transmits driving force. As a result, the wheel loader 1 travels. In the wheel loader 1 of the embodiment, both the traveling wheel 4a and the traveling wheel 4b constitute driving wheels that receive driving force to make the wheel loader 1 travel.

[0053] A part of the driving force of the engine 21 is transmitted to the working device pump 13. The working device pump 13 is a hydraulic pump driven by the engine 21 and uses the discharged working oil to operate the working device 3. The working device 3 is driven by the working oil from the working device pump 13. The working oil discharged from the working device pump 13 is supplied to the boom cylinder 16 and the bucket cylinder 19 through the main valve 32. The boom cylinder 16 is extended and retracted by the supply of working oil, thereby the boom 14 is raised and lowered. The bucket cylinder 19 is extended and retracted by the supply of working oil, thereby the bucket 6 is rotated up and down.

[0054] The wheel loader 1 includes a vehicle body controller 50 . The vehicle body controller 50 includes an engine controller 60 , a transmission controller 70 , and a work implement controller 80 .

[0055] The vehicle body controller 50 is generally realized by a CPU (Central Processing Unit) reading various programs. The vehicle body controller 50 includes a memory (not shown). The memory functions as a working memory and stores various programs for realizing the functions of the wheel loader 1 .

[0056] The operating device 8 is provided in the cab 5. The operating device 8 is operated by the operator. The operating device 8 includes a plurality of operating members that the operator operates to operate the wheel loader 1. The operating device 8 includes an accelerator pedal 41 and a working device operating lever 42. The operating device 8 may also include a steering wheel, a shift lever, etc., which are not shown.

[0057] The accelerator pedal 41 is operated to set a target speed of the engine 21. The engine controller 60 controls the output of the engine 21 based on the operation amount of the accelerator pedal 41. If the operation amount (depression amount) of the accelerator pedal 41 is increased, the output of the engine 21 increases. If the operation amount of the accelerator pedal 41 is reduced, the output of the engine 21 decreases. The transmission controller 70 controls the transmission 23 based on the operation amount of the accelerator pedal 41.

[0058] The work implement operating lever 42 is operated to operate the work implement 3 . The work implement controller 80 controls the electromagnetic proportional control valves 35 and 36 based on the operation amount of the work implement operating lever 42 .

[0059] The electromagnetic proportional control valve 35 switches the main valve 32 so that the bucket cylinder 19 contracts and the bucket 6 moves in the unloading direction (the direction in which the blade tip of the bucket 6 is lowered). In addition, the electromagnetic proportional control valve 35 switches the main valve 32 so that the bucket cylinder 19 extends and the bucket 6 moves in the tilting direction (the direction in which the blade tip of the bucket 6 is raised). The electromagnetic proportional control valve 36 switches the main valve 32 so that the boom cylinder 16 contracts and the boom 14 is lowered. In addition, the electromagnetic proportional control valve 36 switches the main valve 32 so that the boom cylinder 16 extends and the boom 14 is raised.

[0060] The machine monitor 51 receives input of a command signal from the vehicle body controller 50 and displays various information. The various information displayed on the machine monitor 51 may be, for example, information related to the work performed by the wheel loader 1, vehicle body information such as the remaining fuel level, cooling water temperature, and operating oil temperature, and a peripheral image obtained by photographing the periphery of the wheel loader 1. The machine monitor 51 may also be a touch panel, in which case a signal generated by an operator touching a part of the machine monitor 51 is output from the machine monitor 51 to the vehicle body controller 50.

[0061] <Excavation and loading work>

[0062] The wheel loader 1 of the present embodiment performs an excavation and loading operation of excavating an excavation object such as soil and earth and loading the excavation object into a loading object such as a dump truck. Figure 3 FIG. 1 is a top view of the wheel loader 1 performing excavation and loading operations. Figure 3 2 shows a wheel loader 1 that performs so-called V-shaped operation.

[0063] exist Figure 3(A) shows a wheel loader 1 that is performing so-called no-load forward movement. The wheel loader 1 moves forward along an excavation path R1 toward an excavation object 310 such as sand. The wheel loader 1 digs the bucket 6 into the excavation object 310 and stops moving forward. The bucket 6 is raised while the blade tip 6a of the bucket 6 is sunk into the excavation object 310, thereby performing an excavation operation to dig the excavation object 310 into the bucket 6.

[0064] exist Figure 3 (B) shows the wheel loader 1 in so-called load-carrying reverse travel. The bucket 6 is loaded with an excavation object 310. The wheel loader 1 is traveling reversely along the excavation path R1 to a position where the excavation object 310 is located. Figure 3 The position where forward travel begins in (A).

[0065] exist Figure 3 (C) shows a wheel loader 1 that is performing so-called cargo forward movement. The wheel loader 1 is moving forward toward the bucket 301 of the dump truck 300 with the excavation object 310 loaded in the bucket 6. The wheel loader 1 is moving forward from Figure 3 The wheel loader 1 moves forward along the loading path R2 toward the dump truck 300 from the position where the forward travel starts in (A). When the wheel loader 1 approaches the dump truck 300 and reaches a predetermined position, the wheel loader 1 loads the excavation object 310 in the bucket 6 into the truck bed 301. The truck bed 301 corresponds to an example of a "container" for loading the cargo loaded in the working device 3.

[0066] exist Figure 3 (D) shows the wheel loader 1 in so-called no-load reverse travel. In a state where the excavated object 310 in the bucket 6 is completely discharged into the bucket 301 of the dump truck 300 and the bucket 6 is empty, the wheel loader 1 reverses along the loading path R2 to Figure 3 (C) The position where forward travel begins.

[0067] In this way, the wheel loader 1 can repeatedly perform a series of operations including excavation, backing up, unloading and approaching, soil discharge, and backing up.

[0068] <Automatic control system of wheel loader 1>

[0069] When automating the loading operation into the dump truck 300 by the wheel loader 1 , it is desirable to reproduce the operation of the work implement 3 by an experienced operator by automatic control in order to ensure the workload and perform the loading operation more quickly without causing the bucket 6 to come into contact with the truck bed 301 . Figure 4 It is a block diagram showing the configuration of an automatic control system of the wheel loader 1 .

[0070] The automation controller 100 is configured to be able to Figure 2The automatic controller 100 is also configured to be able to transmit and receive signals with an external information acquisition unit 110. The external information acquisition unit 110 includes a sensing device 111 and a position information acquisition device 112. The sensing device 111 and the position information acquisition device 112 are mounted on the wheel loader 1.

[0071] The sensing device 111 acquires information about the surroundings of the wheel loader 1. The sensing device 111 is attached to, for example, the front portion of the upper surface of the cab 5. The sensing device 111 is an example of an "object sensor" that detects an object around the main body of the wheel loader 1.

[0072] The sensing device 111 detects the direction of an object outside the wheel loader 1 and the distance to the object in a non-contact manner. The sensing device 111 is, for example, a LiDAR (Light Detection and Ranging) that emits laser light to obtain information about the object. The sensing device 111 may also be a visual sensor including a camera. The sensing device 111 may also be a Radar (Radio Detection and Ranging) that obtains information about the object by emitting radio waves. The sensing device 111 may also be an infrared sensor.

[0073] The position information acquisition device 112 acquires information about the current position of the wheel loader 1. The position information acquisition device 112 acquires the position information of the wheel loader 1 in a global coordinate system based on the earth using, for example, a satellite positioning system. The position information acquisition device 112 uses, for example, a GNSS (Global Navigation Satellite Systems) and has a GNSS receiver. The satellite positioning system calculates the position of the antenna of the GNSS receiver based on the positioning signal received by the GNSS receiver from the satellite, and calculates the position of the wheel loader 1.

[0074] The external information of the wheel loader 1 by the sensing device 111 and the position information of the wheel loader 1 by the position information acquiring device 112 are input to the automation controller 100 .

[0075] The vehicle body controller 50 is configured to be able to transmit and receive signals with the vehicle information acquisition unit 120, and receives input of information of the wheel loader 1 acquired by the vehicle information acquisition unit 120. The vehicle information acquisition unit 120 is configured by various sensors mounted on the wheel loader 1. The vehicle information acquisition unit 120 includes an articulation angle sensor 121, a vehicle speed sensor 122, a boom angle sensor 123, a bucket angle sensor 124, and a boom cylinder pressure sensor 125.

[0076] The articulation angle sensor 121 detects the articulation angle, which is the angle between the front frame 2 a and the rear frame 2 b , and generates a signal of the detected articulation angle. The articulation angle sensor 121 outputs the signal of the articulation angle to the vehicle body controller 50 .

[0077] The vehicle speed sensor 122 detects the moving speed of the wheel loader 1 based on the travel device 4 by detecting the rotation speed of the output shaft of the transmission 23, for example, and generates a signal of the detected vehicle speed. The vehicle speed sensor 122 outputs the vehicle speed signal to the vehicle body controller 50. The vehicle speed sensor 122 corresponds to an example of a travel sensor that detects the travel condition of the travel device 4 (travel body).

[0078] The boom angle sensor 123 is composed of, for example, a rotary encoder provided on the boom pin 9 as a mounting portion of the boom 14 with respect to the vehicle body frame 2. The boom angle sensor 123 detects the angle of the boom 14 with respect to the horizontal direction and generates a signal of the detected angle of the boom 14. The boom angle sensor 123 outputs the signal of the angle of the boom 14 to the vehicle body controller 50.

[0079] The bucket angle sensor 124 is composed of, for example, a rotary encoder provided on the support pin 18a, which is the rotating shaft of the bell crank 18. The bucket angle sensor 124 detects the angle of the bucket 6 relative to the boom 14 and generates a signal of the detected angle of the bucket 6. The bucket angle sensor 124 outputs the signal of the angle of the bucket 6 to the vehicle body controller 50.

[0080] The boom angle sensor 123 and the bucket angle sensor 124 correspond to an example of a “work machine posture sensor” that detects the posture of the work machine 3 .

[0081] The boom cylinder pressure sensor 125 detects the pressure on the bottom side of the boom cylinder 16 (boom bottom pressure) and generates a signal of the detected boom bottom pressure. The boom bottom pressure becomes high when the bucket 6 is loaded with cargo and becomes low when it is empty. The boom cylinder pressure sensor 125 outputs the signal of the boom bottom pressure to the vehicle body controller 50.

[0082] The vehicle body controller 50 outputs the information input from the vehicle information acquisition unit 120 to the automation controller 100 . The automation controller 100 receives the detection values ​​of the vehicle speed sensor 122 , the boom angle sensor 123 , and the bucket angle sensor 124 via the vehicle body controller 50 .

[0083] The actuator 140 is configured to be able to transmit and receive signals with the vehicle body controller 50. The actuator 140 is driven by receiving a command signal from the vehicle body controller 50. The actuator 140 includes a brake EPC (electromagnetic proportional control valve) 141 for operating the brake of the travel device 4, a steering EPC 142 for adjusting the travel direction of the wheel loader 1, a work device EPC 143 for operating the work device 3, and an HMT (Hydraulic Mechanical Transmission) 144.

[0084] Figure 2 The electromagnetic proportional control valves 35 and 36 shown constitute the working device EPC143. Figure 2 The transmission 23 shown is realized as an HMT 144 that effectively utilizes electronic control. The transmission 23 may also be an HST (Hydro-Static Transmission). The power transmission device that transmits power from the engine 21 to the running wheels 4a, 4b may include an electric drive device such as a diesel / electric method, or may include any combination of HMT, HST, and electric drive devices.

[0085] The transmission controller 70 includes a brake control unit 71 and an accelerator control unit 72. The brake control unit 71 outputs a command signal for controlling the operation of the brake to the brake EPC 141. The accelerator control unit 72 outputs a command signal for controlling the vehicle speed to the HMT 144.

[0086] The work implement controller 80 includes a steering control unit 81 and a work implement control unit 82. The steering control unit 81 outputs a command signal for controlling the travel direction of the wheel loader 1 to the steering EPC 142. The work implement control unit 82 outputs a command signal for controlling the operation of the work implement 3 to the work implement EPC 143.

[0087] The automation controller 100 includes a position estimating unit 101 , a path planning unit 102 , and a path following control unit 103 .

[0088] The position estimating unit 101 estimates the position of the wheel loader 1 based on the position information acquired by the position information acquiring device 112. In addition, the position estimating unit 101 recognizes the target position based on the external information acquired by the sensing device 111. The target position is, for example, Figure 3 The position of the excavation object 310 or the dump truck 300 shown. The position estimation unit 101 can obtain a predetermined reference point of the dump truck 300, such as the position of the upper end of the side of the truck bed 301. The sensing device 111 can identify the target position and input it to the automation controller 100, and the position estimation unit 101 can also identify the target position based on the detection result detected by the sensing device 111.

[0089] The path planning unit 102 generates an optimal path for the wheel loader 1 when the wheel loader 1 is automatically controlled. The optimal path includes the path for the travel of the travel device 4 and the path for the operation of the work device 3. For example, the path planning unit 102 generates an optimal path for the wheel loader 1 to move forward toward the dump truck 300 with a load during the loading operation into the dump truck 300, and an optimal path for the wheel loader 1 to move backward without a load and leave the dump truck 300. The path planning unit 102 also generates an optimal path that connects the current position of the wheel loader 1 with the target position to which the wheel loader 1 will move next during the loading operation into the dump truck 300.

[0090] The travel route of the travel device 4 included in the optimal route may be generated based on actual travel history based on the operator's operation. Alternatively, the travel route may be a travel route obtained by calculation.

[0091] The path following control unit 103 controls the accelerator, brake, and steering so that the wheel loader 1 travels along the optimal path generated by the path planning unit 102. The path following control unit 103 outputs a command signal for causing the wheel loader 1 to travel along the optimal path to the brake control unit 71, the accelerator control unit 72, and the steering control unit 81. The path following control unit 103 controls the boom cylinder 16 and the bucket cylinder 19 so that the working device 3 moves along the optimal path generated by the path planning unit 102. The path following control unit 103 outputs a command signal for causing the working device 3 to move along the optimal path to the working device control unit 82.

[0092] The interface 130 is configured to be able to transmit and receive signals with the vehicle body controller 50. The interface 130 includes a mode selection operation unit 131, an engine emergency stop switch 132, and a mode lamp 133.

[0093] The mode selection operation unit 131 is operated by an operator. The operator selects a driving mode of the wheel loader 1 by operating the mode selection operation unit 131. The driving modes of the wheel loader 1 include a manual mode in which the wheel loader 1 is manually operated and an automatic mode in which the wheel loader 1 is automatically controlled. In addition, the driving modes include a record & edit mode in which actual work based on the operator's operation is recorded and parameters recorded in the work are edited in order to generate an optimal path when the wheel loader 1 is automatically controlled.

[0094] If the manual mode is selected, the operation is performed by the operator's operation. If the automatic mode is selected, the operation is performed by automatically controlling the wheel loader 1. In the state where the record & edit mode is selected, when the operator operates the wheel loader 1 to perform the operation, the operation is recorded, the feature points in the trajectory of the working device 3 in the operation are extracted, and the position and posture of the working device 3 at each feature point are determined. A path that sequentially tracks each feature point is generated, and the generated path is used as the path of the action of the working device 3 when the wheel loader 1 is automatically controlled.

[0095] The engine emergency stop switch 132 is operated by an operator. When a phenomenon requiring emergency stop of the engine 21 occurs, the operator operates the engine emergency stop switch 132. Operation signals of the mode selection operation unit 131 and the engine emergency stop switch 132 are input to the vehicle body controller 50.

[0096] The mode lamp 133 indicates whether the wheel loader 1 is currently in a manual mode in which the operator is manually operating, an automatic mode in which the wheel loader 1 is automatically controlled, or a recording & editing mode. A command signal for controlling lighting of the lamp is output from the vehicle body controller 50 to the mode lamp 133 .

[0097] <Work records of skilled operators (records)>

[0098] Figure 5 This is a flowchart showing the flow of a process for recording the work machine control when a skilled operator performs a loading operation of loading the cargo in the bucket 6 into the vessel 301 of the dump truck 300 .

[0099] First, as a preliminary preparation, before starting the loading operation, in step S100, the operator selects a driving mode of the wheel loader 1. The operator operates the mode selection operation unit 131 to select the recording & editing mode. The operation of the mode selection operation unit 131 may be a button operation or a monitor operation.

[0100] In step S101, the shape of the dump truck 301, which is a container for loading cargo, is recognized. For example, the shape of the dump truck 300 is acquired by LiDAR as the sensing device 111. Laser is irradiated from the LiDAR to the dump truck 300, and point group data representing the three-dimensional coordinate values ​​of the measurement points on the dump truck 300 is acquired. The dump truck 300 can be detected from the front, rear, right, and left, and the shape of the dump truck 301 can be recognized based on the information of the point group. The recognized shape of the dump truck 301 is input to the automation controller 100.

[0101] In step S102, the reference point P of the dump truck 301 is recognized by the sensing device 111. The dump truck 300 is detected by the LiDAR as the sensing device 111. The automation controller 100 compares the point group detected by the sensing device 111 with the main point group representing the shape of the dump truck 301, and recognizes the position of the dump truck 301. The automation controller 100 sets the upper end of the side of the dump truck 301 recognized by the LiDAR as the sensing device 111 as the reference point P.

[0102] When the travel route is generated based on the actual travel history according to the operator's operation, the reference point P is determined based on the position when loading is performed. In this case, the sensing device 111 detects the loading position at the position of the bucket 301 during the loading operation and obtains the reference point P based on the loading position.

[0103] After the processing of steps S101 and S102 is completed, in step S103, the operator on the wheel loader 1 performs an operation for loading the cargo in the bucket 6 into the truck bed 301. Figure 3 As described in (C) and (D) of FIG. 1 , the operator causes the wheel loader 1 with the cargo loaded on the working device 3 (bucket 6) to travel forward toward the bucket 301. The operator causes the working device 3 (boom 14, bucket 6) to operate at an appropriate timing, and switches the travel direction of the wheel loader 1 from forward to reverse at an appropriate timing. Thus, the operator loads the cargo loaded on the working device 3 (bucket 6) into the bucket 301.

[0104] Figure 6 3 is a diagram showing the trajectory of the working device 3 when a skilled operator loads the vehicle into the bucket 301. Figure 6 and subsequent Figures 9 to 14 , a dump truck 300 viewed from the front and rear directions is schematically shown, and a portion of the front side of the wheel loader 1 approaching the dump truck 300 from the left or right side is schematically shown. The wheel loader 1 travels on a flat ground G. The ground G on which the wheel loader 1 travels is horizontal.

[0105] Figure 6 The trajectory TR shown is a trajectory traced by the blade tip 6 a of the bucket 6 from the time when the wheel loader 1 starts to travel forward (approach unloading) toward the dump truck 300 for loading the load in the bucket 6 into the bucket 301 until the wheel loader 1 leaves the dump truck 300 after discharging the load in the bucket 6 into the bucket 301 .

[0106] like Figure 6As shown, an xy coordinate system is set with the reference point P as the origin. The x-axis is the left-right direction of the dump truck 300 passing through the reference point P. The direction away from the truck bed 301 based on the reference point P is the +x direction. The y-axis is the up-down direction passing through the reference point P. The upward direction from the reference point P is the +y direction.

[0107] Figure 6 The bucket angle θ shown is an angle formed between the ground and the back surface 6b of the bucket 6. The bucket angle θ may be an angle formed between the back surface 6b of the bucket 6 and a horizontal plane based on the vehicle body.

[0108] In step S104, the automation controller 100 recognizes the current position of the blade tip 6a of the bucket 6. The current position of the vehicle body of the wheel loader 1 is acquired by the position information acquisition device 112, and the posture of the working device relative to the vehicle body is acquired by the boom angle sensor 123 and the bucket angle sensor 124, thereby being able to recognize the current position of the blade tip 6a of the bucket 6 in the global coordinate system. Based on the current positions of the wheel loader 1 and the working device 3 and the current position of the dump truck 300 in the global coordinate system, the relative position of the blade tip 6a of the bucket 6 relative to the bucket 301 of the dump truck 300 can be calculated.

[0109] Alternatively, the sensing device 111 may be used to obtain the direction and distance of the reference point P of the dump truck 301 relative to the configuration position of the sensing device 111, thereby calculating the current relative position of the shovel tip 6a of the bucket 6 relative to the reference point P and identifying the relative position as the current position.

[0110] In step S105, the path planning unit 102 of the automation controller 100 records parameters during the operator's loading operation into the bucket 301. The recorded parameters include the horizontal and vertical positions of the blade tip 6a of the bucket 6 with reference to the reference point P, that is, the x-coordinate and the y-coordinate. The parameters also include the bucket angle θ. The path planning unit 102 can calculate the bucket angle θ based on the detection results of the boom angle sensor 123 and the bucket angle sensor 124 installed on the work device 3.

[0111] The current position of blade edge 6a of bucket 6 and bucket angle θ are recorded while the operator is loading into bucket 301. The posture of work implement 3 while the operator is loading into bucket 301 is recorded based on the current position of blade edge 6a of bucket 6 and bucket angle θ.

[0112] In step S106, the automation controller 100 determines whether the loading operation is completed. For example, it can be recognized that the goods in the bucket 6 are all discharged into the bucket 301 and the bucket 6 is empty based on the detection result of the boom cylinder pressure sensor 125. When the bucket 6 is empty, if it is recognized that the current position of the blade tip 6a of the bucket 6 has moved to a position away from the dump truck 300, it can be determined that the loading operation is completed.

[0113] If it is determined in step S106 that the loading operation has not been completed (NO in step S106 ), the process returns to step S104 and the recognition of the current position of blade edge 6a of bucket 6 and the recording of parameters are repeated while the operator is performing the loading operation into bucket 301 .

[0114] In the judgment of step S106, if it is judged that the loading operation has been completed (yes in step S106), the operation record of the skilled operator is terminated ( Figure 5 "End of Record").

[0115] The recognition of the current position of the blade tip 6a in step S104 and the recording of the parameters at the current position in step S105 are repeated until the skilled operator starts the operation of loading the cargo loaded on the working device 3 (bucket 6) into the bucket 301 in step S103 and ends in step S106. By plotting the horizontal and vertical positions of the blade tip 6a of the bucket 6 with reference to the reference point P, i.e., the x-coordinate and the y-coordinate, the Figure 6 The trajectory TR of the blade edge 6a is shown. The path planning unit 102 stores the acquired trajectory TR. The path planning unit 102 also stores the reference point P of the bucket 301 acquired in step S102.

[0116] <Editing recorded parameters>

[0117] Figure 7 It means that it will be Figure 5 The parameter recorded in step S105 shown is edited as a flowchart of the process flow used in the automatic control of the loading work.

[0118] In step S201, the path planning unit 102 Figure 6 The feature points constituting the trajectory TR of the work machine 3 (the blade edge 6a of the bucket 6) during the loading operation shown are extracted. In the present embodiment, the feature points a, b, c, d, f, and g described in detail below are extracted.

[0119] Figure 8 This is a graph showing changes in cylinder length during loading work. Figure 8 The horizontal axis of represents the passage of time, and auxiliary lines are drawn when the blade edge 6a passes through the characteristic points a, b, c, d, f, and g. Figure 8 The vertical axis represents the lengths of the boom cylinder 16 and the bucket cylinder 19 .

[0120] While the wheel loader 1 is traveling forward toward the dump truck 300 , the position of the blade edge 6 a of the bucket 6 when the bucket 6 starts to move in the unloading direction to load the load in the bucket 6 into the truck bed 301 is extracted as a feature point a. Fig. 9 1 is a diagram schematically showing the posture of the wheel loader 1 when the unloading operation of the bucket 6 is started. The characteristic point a is a position where the blade tip 6a of the bucket 6 passes when the wheel loader 1 is moving forward toward the dump truck 300. The characteristic point a is farther from the bucket 301 than the reference point P. The characteristic point a is located in front of the reference point P of the bucket 301. The characteristic point a is located at a position higher than the reference point P of the bucket 301.

[0121] like Figure 8 and Figure 6 , 9 As shown, before the blade tip 6a reaches the characteristic point a, the wheel loader 1 is traveling forward. The length of the boom cylinder 16 increases, so the boom 14 rises. The length of the bucket cylinder 19 is constant, so the posture of the bucket 6 is constant. The bucket 6 is in a state of being loaded with an excavation object and tilted. The bucket 6 takes a posture that can stably carry the load in the bucket 6.

[0122] The wheel loader 1 moves forward and approaches the bucket 301, and the blade tip 6a of the bucket 6 moves to the deepest side (at Figure 9~Figure 14 The position of the blade tip 6a of the bucket 6 when the bucket 6 moves (the left side in the figure) is extracted as a feature point b. Fig.10 1 is a diagram schematically showing the posture of wheel loader 1 when blade edge 6a reaches the deepest position. Feature point b is the position where blade edge 6a of bucket 6 passes after passing feature point a and crossing reference point P. Feature point b is located above bucket 301 .

[0123] like Figure 8 and Fig. 9 , 10 As shown, the wheel loader 1 continues to move forward after the shovel tip 6a passes the characteristic point a until it reaches the characteristic point b. The boom cylinder 16 continues to increase in length, so the boom 14 continues to rise. The bucket 6 starts to move in the unloading direction when the shovel tip 6a reaches the characteristic point a, and the bucket 6 continues to move in the unloading direction until it reaches the characteristic point b. The length of the bucket cylinder 19 continues to decrease. In the movement of the shovel tip 6a from the characteristic point a to the characteristic point b, the unloading action of the bucket 6 has a greater impact on the position of the shovel tip 6a than the rise of the boom 14. Therefore, the height position of the characteristic point b is lower than that of the characteristic point a. The value of the y coordinate of the characteristic point b is smaller than the value of the y coordinate of the characteristic point a.

[0124] like Figure 8As shown, after the blade tip 6a reaches the characteristic point a, the rising speed of the boom 14 decreases. The lifting action of the boom 14 becomes slow. Before the blade tip 6a reaches the characteristic point b, the rising speed of the boom 14 increases again.

[0125] The position of the blade edge 6a of the bucket 6 when the movement of the bucket 6 in the unloading direction is stopped above the bucket 301 is extracted as a feature point c. Fig.11 1 is a diagram schematically showing the posture of the wheel loader 1 when the unloading action of the bucket 6 is stopped. The characteristic point c is the position where the blade tip 6a of the bucket 6 passes after passing the characteristic point b. The action of the bucket 6 in the unloading direction continues from the time when the blade tip 6a of the bucket 6 passes the characteristic point a to the time when it reaches the characteristic point c. When the blade tip 6a of the bucket 6 is located at the characteristic point c, the bucket 6 is in the full unloading state. When the blade tip 6a of the bucket 6 is located at the characteristic point c, the length of the bucket cylinder 19 is the smallest. The characteristic point c is located closer to the reference point P than the characteristic point b.

[0126] like Figure 8 and Fig.10 , 11 As shown, the wheel loader 1 continues to move forward after the shovel tip 6a passes the characteristic point b until it reaches the characteristic point c. The boom cylinder 16 continues to increase in length, so the boom 14 continues to rise. The bucket cylinder 19 continues to reduce in length, so the bucket 6 continues to move in the unloading direction. At the moment when the shovel tip 6a reaches the characteristic point c, the bucket 6 is in a full unloading posture, and the unloading action of the bucket 6 stops. At the moment when the shovel tip 6a reaches the characteristic point c, the length of the bucket cylinder 19 is the smallest. In the movement of the shovel tip 6a from the characteristic point b to the characteristic point c, the unloading action of the bucket 6 has a greater impact on the position of the shovel tip 6a than the rise of the boom 14. Therefore, the height position of the characteristic point c is lower than that of the characteristic point b. The value of the y coordinate of the characteristic point c is smaller than the value of the y coordinate of the characteristic point b.

[0127] The boom 14 continues to rise during the unloading operation of the bucket 6. The boom 14 continues to rise when soil is discharged from the bucket 6. The boom 14 continues to rise during the process of loading the cargo into the dump truck 300. During the unloading operation of the bucket 6, the wheel loader 1 moves forward toward the bucket 301 of the dump truck 300, so the forward travel also continues.

[0128] The position of the blade edge 6a of the bucket 6 when the operation of raising the boom 14 above the bucket 301 is stopped is extracted as a feature point d. Fig.12: is a diagram schematically showing the posture of the wheel loader 1 when the lifting action of the boom 14 is stopped. Feature point d is the position where the blade tip 6a of the bucket 6 passes after passing the feature point c. In order to avoid interference with the bucket 301 of the working device 3, the wheel loader 1, which is moving forward toward the dump truck 300, performs the action of lifting the boom 14. The lifting action of the boom 14 is continued from the time when the wheel loader 1 starts unloading and approaches until the blade tip 6a of the bucket 6 reaches the feature point d. When the blade tip 6a of the bucket 6 is located at the feature point d, the height position of the boom 14 is the highest. When the blade tip 6a of the bucket 6 is located at the feature point d, the length of the boom cylinder 16 is the largest. The feature point d is located closer to the reference point P than the feature point c.

[0129] like Figure 8 and Fig.11 , 12 As shown, when the blade tip 6a passes through the characteristic point c, the wheel loader 1 moves forward, and when the blade tip 6a passes through the characteristic point d, the wheel loader 1 moves backward. While the blade tip 6a moves between the characteristic point c and the characteristic point d, the travel direction of the wheel loader 1 is switched from forward to backward. The boom cylinder 16 continues to increase in length, so the boom 14 continues to rise. The length of the bucket cylinder 19 is constant, so the posture of the bucket 6 relative to the vehicle body is constant. The characteristic point c is the position where the movement of the bucket 6 in the unloading direction is stopped, and while the blade tip 6a moves from the characteristic point c to the characteristic point d, the bucket 6 maintains a full unloading posture.

[0130] When the boom 14 stops rising, the cargo in the bucket 6 has been loaded into the bucket 301, and the bucket 6 is empty. The weight of the cargo in the bucket 6 is reduced, so the influence of inertia when the boom 14 is stopped is small. Therefore, the vibration of the vehicle body is unlikely to occur when the action of raising the boom 14 is stopped at the characteristic point d.

[0131] When the travel direction of the wheel loader 1 is switched from forward to reverse, the center of gravity changes in the forward direction. When the rise of the boom 14 is reduced, the center of gravity of the load in the bucket 6 moves. Thus, by smoothly moving the load in the bucket 6 to the truck bed 301, the time required for the loading operation can be shortened, and the cycle time of the loading operation can be shortened.

[0132] The position of the blade edge 6a of the bucket 6 when the bucket 6 starts to move in the tilting direction above the bucket 301 is extracted as a feature point f. Fig.131 is a diagram schematically showing the posture of the wheel loader 1 when the tilting action of the bucket 6 is started. The characteristic point f is the position where the blade tip 6a of the bucket 6 passes after passing the characteristic point d. From the time when the blade tip 6a of the bucket 6 passes the characteristic point c to the time when it reaches the characteristic point f, the bucket 6 maintains the full discharge state. The characteristic point f is set closer to the reference point P than the characteristic point d. From the time when the blade tip 6a of the bucket 6 passes the characteristic point d to the time when it reaches the characteristic point f, the length of the boom cylinder 16 is constant, and the boom 14 is maintained at the uppermost position.

[0133] like Figure 8 and Fig.12 , 13 As shown, the wheel loader 1 continues to move backward after the blade tip 6a passes the characteristic point d until it reaches the characteristic point f. The length of the boom cylinder 16 is constant, so the posture of the boom 14 relative to the vehicle body is constant. At this time, the height position of the boom 14 is the highest. When the boom 14 stops rising, the cargo in the bucket 6 has been loaded into the bucket 301, and the bucket 6 is in an empty state. The length of the bucket cylinder 19 is constant, so the posture of the bucket 6 relative to the vehicle body is constant. During the period when the blade tip 6a moves from the characteristic point d to the characteristic point f, the wheel loader 1 moves backward while maintaining the full unloading state of the bucket 6.

[0134] The position of the blade edge 6a of the bucket 6 when the movement of the bucket 6 in the tilting direction is stopped is extracted as a feature point g. Fig.14 1 is a diagram schematically showing the posture of the wheel loader 1 when the tilting action of the bucket 6 is stopped. The characteristic point g is the position where the blade tip 6a of the bucket 6 passes after passing the characteristic point f. The action of the bucket 6 in the tilting direction continues from the time when the blade tip 6a of the bucket 6 passes the characteristic point f to the time when the blade tip 6a of the bucket 6 reaches the characteristic point g. The characteristic point g is located above the reference point P. From the time when the blade tip 6a of the bucket 6 passes the characteristic point d to the time when the blade tip 6a of the bucket 6 reaches the characteristic point g, the boom 14 is maintained at the uppermost position.

[0135] like Figure 8 and Fig.13 , 14As shown, after the blade tip 6a passes through the characteristic point f, the wheel loader 1 continues to move backward until it reaches the characteristic point g. The length of the boom cylinder 16 is constant, so the posture of the boom 14 relative to the vehicle body is constant. The movement of the bucket 6 in the tilting direction starts when the blade tip 6a reaches the characteristic point f, and the bucket 6 continues to move in the tilting direction until it reaches the characteristic point g. The length of the bucket cylinder 19 continues to increase. When the blade tip 6a reaches the characteristic point g, the movement of the bucket 6 in the tilting direction stops. The characteristic point f is the position where the tilting movement of the bucket 6 starts. The characteristic point g is the position where the tilting movement of the bucket 6 stops. While the blade tip 6a moves from the characteristic point f to the characteristic point g, the wheel loader 1 moves backward while tilting the bucket 6. After the wheel loader 1 performs the loading operation into the dump truck 300, the bucket 6 is tilted while retreating to leave the dump truck 300.

[0136] During the tilting operation of the bucket 6, the posture of the boom 14 is kept constant. After the discharge of the load from the bucket 6 is completed, the boom 14 is held to tilt the bucket 6. During the tilting operation of the bucket 6, the wheel loader 1 continues to travel backward and travels in a direction away from the bucket 301 of the dump truck 300.

[0137] like Figure 8 As shown, after the blade tip 6a passes the characteristic point g, the wheel loader 1 continues to travel backward. The length of the boom cylinder 16 is reduced, so the boom 14 is lowered. The length of the bucket cylinder 19 is constant, so the posture of the bucket 6 relative to the vehicle body is constant.

[0138] return Figure 7 In step S202, the path planning unit 102 determines the position and posture of the working device 3 relative to the reference point P based on the parameters recorded in the extracted feature points a, b, c, d, f, and g. The path planning unit 102 stores the position of the blade tip 6a of the bucket 6 along the trajectory TR, in the horizontal direction and the vertical direction, that is, the x-coordinate and the y-coordinate and the bucket angle θ, based on the reference point P of the blade tip 6a of the bucket 6. The path planning unit 102 stores the posture of the working device 3 when the blade tip 6a of the bucket 6 is located at each point on the trajectory TR.

[0139] The position of the working device 3 at each feature point a, b, c, d, f, g is determined by assigning the x-coordinate and y-coordinate of the blade tip 6a of the bucket 6. The posture of the working device 3 when the blade tip 6a of the bucket 6 is at each feature point a, b, c, d, f, g is determined based on the x-coordinate and y-coordinate of each feature point a, b, c, d, f, g and the bucket angle θ at each feature point a, b, c, d, f, g.

[0140] The characteristic point a is located at the position where the height of the blade tip 6a is the highest (the y coordinate is the maximum value) during the loading operation. The characteristic point c is located at the position where the height of the blade tip 6a is the lowest (the y coordinate is the minimum value) during the discharge of the cargo in the bucket 6. The y coordinate of the characteristic point a is a positive value. The y coordinate of the characteristic point c is a negative value. The y coordinates of the characteristic points d, f, and g are positive values.

[0141] The x-coordinate of feature point a is positive. The x-coordinates of feature points b, c, d, and f are negative. Feature point b is located at a position where the x-coordinate is the minimum value in the discharge of the cargo in bucket 6. The x-coordinate of feature point g is zero. Feature point g is located directly above reference point P.

[0142] Then, end the process ( Figure 7 End of editing).

[0143] <Editing parameters corresponding to the change of the reference point (Edit 2)>

[0144] When automating loading work into containers of various shapes, it is necessary to set parameters that define the relative position of the wheel loader 1 and the posture of the work implement 3 according to the shape of the container, and a function that can easily set the parameters for each container is required. Fig.15 1 is a flowchart showing the flow of the second process of editing parameters based on the reference point P of the container.

[0145] In step S211, the shape of the actual container of the cargo that the wheel loader 1 loads into the bucket 6 by automatic control is recognized. As in step S101, the shape of the dump truck 300 that actually loads the cargo is obtained by, for example, LiDAR as the sensing device 111. Laser is irradiated from the LiDAR toward the dump truck 300 to obtain point group data representing the three-dimensional coordinate values ​​of the measurement points on the dump truck 300. The dump truck 300 can be detected from the front, rear, right, and left directions, and the shape of the bucket 301 can be recognized based on the information of the point group. The recognized shape of the bucket 301 is input to the automation controller 100.

[0146] In step S212, the reference point P' of the actual container of the cargo loaded into the bucket 6 by the wheel loader 1 through automatic control is identified. The dump truck 300 actually loaded with cargo is detected by the LiDAR as the sensing device 111. The automated controller 100 compares the point group detected by the sensing device 111 with the main point group representing the shape of the bucket 301, and identifies the position of the bucket 301. The automated controller 100 sets the upper end of the side of the bucket 301 of the dump truck 300 identified by the LiDAR as the sensing device 111 as the reference point P'.

[0147] In step S213 , the path planning unit 102 determines the positions of the characteristic points a′, b′, c′, d′, f′, and g′ relative to the reference point P′ of the actual container of the load that the wheel loader 1 automatically controls and loads into the bucket 6 .

[0148] Fig.16 This is a schematic diagram showing characteristic points a', b', c', d', f', and g' corresponding to the tank 301 of a dump truck 300 having different vehicle specifications. By the process of step S212, a reference point P' is set at the upper end of the side of the tank 301. Fig.16 The dump truck 300 with a truck bed 301 is shown with Figure 6 The vehicle size is smaller than the dump truck 300 in which a skilled operator has previously performed a loading operation. Fig.16 The distance from the ground G to the bucket 301, that is, the height (height above the ground) H of the bucket 301 shown is greater than Figure 6 The vehicle body 301 is shown to be small.

[0149] When the container for loading the cargo in the bucket 6 is changed, the changed container is detected and it is determined whether to change the position of the reference point. Even if the dump truck 300 that actually loads the cargo by automatic control is a different vehicle from the dump truck 300 that the skilled operator performed the loading operation, the position of the reference point will not change as long as the vehicle specifications are the same and the shape of the bucket 301 is the same. When the shape of the bucket 301 is different, the reference point is changed and the feature point corresponding to the changed reference point is changed.

[0150] Fig.17 It is a schematic diagram showing the reference point P′ when the loading position of the dump truck 300 is changed. Fig.17 The dump truck 300 shown has a truck bed 301 whose height varies from the front to the rear. When a skilled operator performs loading work, the cargo is loaded at the front of the truck bed 301, and a reference point P at the upper end of the side of the truck bed 301 is set at this time. When the cargo is actually loaded by automatic control, the cargo is loaded at the rear of the truck bed 301. At this time, the height position of the reference point P' at the upper end of the side of the truck bed 301 is different from the reference point P. The reference point P' is located at a position lower than the reference point P.

[0151] When the position of the loaded cargo in the container is changed, it is determined whether to change the position of the reference point. Even if the position of the cargo actually loaded in the bucket 301 by automatic control is different from the position of the cargo loaded by the loading operation of a skilled operator, for example, if the upper end of the side of the bucket 301 of the dump truck 300 is horizontal and the height position of the reference point is the same, the position of the reference point is not changed. In the case where the upper end of the side of the bucket 301 is inclined relative to the horizontal and the height position of the reference point is different, the feature point is changed according to the reference point with the different height position.

[0152] Each characteristic point is a characteristic point extracted from the trajectory TR of the tooth edge 6a of the bucket 6, so changing the characteristic point can be said to be changing the trajectory of the tooth edge 6a.

[0153] According to the change of the reference point P to the reference point P', the characteristic points a, b, c, d, f, g are parallel moved to determine the positions of the new characteristic points a', b', c', d', f', g' changed according to the changed reference point P'.

[0154] The x-coordinate and y-coordinate of the feature point a' in the xy-coordinate system with the reference point P' as the origin are the same as the x-coordinate and y-coordinate of the feature point a in the xy-coordinate system with the reference point P as the origin. The x-coordinate and y-coordinate of the feature points b', c', d', f', g' in the xy-coordinate system with the reference point P' as the origin are the same as the x-coordinate and y-coordinate of the feature points b, c, d, f, g in the xy-coordinate system with the reference point P as the origin.

[0155] In step S214, the path planning unit 102 determines the position and posture of the working device 3 at each of the changed feature points a', b', c', d', f', and g' relative to the reference point P'. The path planning unit 102 stores the bucket angle θ when the blade tip 6a of the bucket 6 is along the trajectory TR. The path planning unit 102 stores the posture of the working device 3 when the blade tip 6a of the bucket 6 is located at each point on the trajectory TR. The position of the working device 3 at each of the feature points a', b', c', d', f', and g' is determined by assigning the x-coordinate and y-coordinate of the blade tip 6a of the bucket 6. Based on the x-coordinate and y-coordinate of each of the feature points a', b', c', d', f', and g' and the stored bucket angle θ of each of the feature points a', b', c', d', f', and g', the posture of the working device 3 when the blade tip 6a of the bucket 6 is located at each of the feature points a', b', c', d', f', and g' is determined.

[0156] In step S215, the path planning unit 102 defines the posture of the working device 3 at each feature point a', b', c', d', f', g' by the length of the boom cylinder 16 and the bucket cylinder 19. The lengths of the boom cylinder 16 and the bucket cylinder 19 are uniquely determined according to the x-coordinate and y-coordinate of the feature point and the bucket angle θ. The path planning unit 102 determines the length of the boom cylinder 16 and the length of the bucket cylinder 19 when the blade tip 6a of the bucket 6 is at each feature point a', b', c', d', f', g'. The path planning unit 102 generates a path in which the blade tip 6a of the bucket 6 sequentially tracks the feature point a', feature point b', feature point c', feature point d', feature point f' and feature point g', and uses it as the path of the action of the working device 3 included in the optimal path. Then, the processing ends ( Fig.15 "End of Edit 2").

[0157] <Automatic control of loading operation (play)>

[0158] Fig.18 The flowchart shows the process of loading the cargo loaded in the bucket 6 into the truck bed 301 by automatic control. Hereinafter, the process of automatically controlling the wheel loader 1 according to the changed trajectory when the reference point of the container is changed and the trajectory of the working device and the characteristic points on the trajectory are changed according to the change of the reference point will be described.

[0159] In step S301, the automation controller 100 recognizes the current positions of the wheel loader 1 and the working device 3. The current position of the body of the wheel loader 1 is obtained by the position information acquisition device 112, and the posture of the working device relative to the body is obtained by the boom angle sensor 123 and the bucket angle sensor 124, thereby being able to recognize the current positions of the wheel loader 1 and the working device 3 in the global coordinate system. Based on the current positions of the wheel loader 1 and the working device 3 and the current position of the dump truck 300 in the global coordinate system, the relative position of the blade tip 6a of the bucket 6 relative to the bucket 301 of the dump truck 300 can be calculated.

[0160] Alternatively, the sensing device 111 may be used to obtain the direction and distance of the reference point P of the bucket 301 of the dump truck 300 relative to the configuration position of the sensing device 111, thereby calculating the current relative position of the blade edge 6a of the bucket 6 relative to the reference point P.

[0161] Based on the current position of the working device 3, the position of the blade tip 6a of the bucket 6 relative to each characteristic point a', b', c', d', f', g' is identified. For example, it is identified that the blade tip 6a has not yet reached the characteristic point a', the blade tip 6a has passed the characteristic point a' and is between the characteristic point a' and the characteristic point b', the blade tip 6a has passed the characteristic point b' and is between the characteristic point b' and the characteristic point c', etc. Furthermore, the characteristic point to which the blade tip 6a will go next is identified as the target position. For example, if the blade tip 6a has not yet reached the characteristic point a', it is identified that the target position is the characteristic point a', and if the blade tip 6a is between the characteristic point a' and the characteristic point b', it is identified that the target position is the characteristic point b', etc.

[0162] In step S302, the automation controller 100 recognizes the length of the boom cylinder 16 and the length of the bucket cylinder 19 at the current position. The angle of the boom 14 is detected by the boom angle sensor 123. The angle of the bucket 6 is detected by the bucket angle sensor 124. The posture of the working device 3 is determined based on the angle of the boom 14 and the angle of the bucket 6. Based on the posture of the working device 3, the length of the boom cylinder 16 and the length of the bucket cylinder 19 at the current position are recognized.

[0163] An angle sensor for detecting the angle of the bell crank 18 and an angle sensor for detecting the angle of the connecting rod 15 may be provided in place of or in addition to the boom angle sensor 123 and the bucket angle sensor 124. A stroke sensor for detecting the cylinder stroke length may also be provided in the boom cylinder 16 and the bucket cylinder 19.

[0164] In step S303, the automation controller 100 calculates the difference between the length of the boom cylinder 16 and the length of the bucket cylinder 19 at the current position identified in step S302 and the length of the boom cylinder 16 and the length of the bucket cylinder 19 at the target position to which the blade tip 6a will next move (hereinafter referred to as the target cylinder length). The automation controller 100 calculates how much the cylinder should be moved before the blade tip 6a reaches the next target position.

[0165] In step S304, the automation controller 100 refers to the current vehicle speed and determines a target cylinder stroke speed that becomes a target cylinder length when the blade tip 6a reaches the next target position. When the blade tip 6a reaches the next target position, the automation controller 100 controls the boom cylinder 16 and the bucket cylinder 19 so that the working device 3 takes a posture corresponding to the target position. The current vehicle speed is obtained by the vehicle speed sensor 122. The time until the next target position can be calculated based on the current position of the blade tip 6a and the current vehicle speed. The target cylinder stroke speed can be determined by dividing the difference in cylinder length calculated in step S303 by the time until the next target position.

[0166] Alternatively, the cylinder stroke amount during which the wheel loader 1 travels a unit distance may be determined. The unit distance traveled by the wheel loader 1 may be obtained from the vehicle speed or may be detected by the sensing device 111.

[0167] In step S305, the automation controller 100 outputs a command current corresponding to the target cylinder stroke speed to the vehicle body controller 50. The automation controller 100 outputs a command to extend and retract the boom cylinder 16 and the bucket cylinder 19 at the target cylinder stroke speed to the work implement control unit 82 of the work implement controller 80. The command to extend and retract the boom cylinder 16 and the bucket cylinder 19 at the target cylinder stroke speed is output from the work implement control unit 82 to the work implement EPC 143.

[0168] In step S306, the working device EPC 143 that has received the command signal adjusts the opening degree, thereby supplying appropriate hydraulic oil to the boom cylinder 16 and the bucket cylinder 19. As a result, the boom cylinder 16 and the bucket cylinder 19 are actuated.

[0169] In step S307, the automation controller 100 recognizes the current lengths of the boom cylinder 16 and the bucket cylinder 19 in the same manner as in step S302. The automation controller 100 determines whether the current lengths of the boom cylinder 16 and the bucket cylinder 19 have reached the target cylinder lengths.

[0170] In the judgment of step S307 , if it is judged that the target cylinder length has been reached (Yes in step S307 ), the process proceeds to step S308 , and the automation controller 100 determines whether there is a next target position.

[0171] If it is determined in step S307 that the target cylinder length has not been reached (No in step S307), and if it is determined in step S308 that there is a next target position (Yes in step S308), the process returns to step S301, and the process of extending and retracting the boom cylinder 16 and the bucket cylinder 19 based on the current position of the work machine 3 is repeated. The cylinder speed is sequentially changed according to the current position of the blade tip 6a of the bucket 6. When the current position of the blade tip 6a deviates from the position based on the cylinder speed set in the previous process, the cylinder speed is adjusted.

[0172] In the judgment of step S308, if it is judged that there is no next target position (No in step S308), the loading operation is terminated ( Fig.18 In the present embodiment, this corresponds to not setting the next target position after the blade tip 6a passes through the feature point g'.

[0173] By moving the blade tip 6a of the bucket 6 so as to sequentially pass through the characteristic point a', the characteristic point b', the characteristic point c', the characteristic point d', the characteristic point f', and the characteristic point g', the cargo in the bucket 6 can be loaded into the bucket 301 without the bucket 6, the vehicle body, and the traveling wheel 4a coming into contact with the bucket 301. By applying such automatic control for moving the bucket 6 to the wheel loader 1, the operation of the working device 3 equivalent to the operation by the operation of a skilled operator can be realized.

[0174] <Function and Effect>

[0175] Although some descriptions overlap with the above descriptions, the characteristic configurations and effects of the present embodiment are summarized as follows.

[0176] like Figure 5 , Figure 6 As shown, the automation controller 100 stores the trajectory TR of the blade tip 6a of the bucket 6 and the reference point P of the bucket 301 when the wheel loader 1 performs an operation for loading the cargo loaded on the working device 3 on the bucket 301 of the dump truck 300. Figure 15~Figure 17 As shown, when the position of the reference point P is changed to the reference point P′, the automation controller 100 changes the trajectory TR of the blade edge 6a according to the changed reference point P′.

[0177] The trajectory TR of the working device 3 and the reference point P of the bucket 301 when the skilled operator performs loading operation on the wheel loader 1 are recorded. When the reference point is changed, the trajectory of the working device 3 when the working device is automatically controlled is set according to the changed reference point P'. It is possible to cope with the case of loading into containers of different shapes or when the conditions on the container side change slightly. Since loading can be performed regardless of the shape of the container, loading operations into containers of various shapes can be automated.

[0178] like Figure 7 to Figure 14 As shown, the automation controller 100 stores characteristic points a, b, c, d, f, and g, which constitute the trajectory TR of the blade tip 6a when loading the cargo loaded on the working device 3 on the bucket 301. Figure 15~Figure 17 As shown, the automation controller 100 changes the characteristic points a, b, c, d, f, g to characteristic points a', b', c', d', f', g' according to the changed reference point P'. The characteristic points a', b', c', d', f', g' corresponding to the changed reference point P' are determined, and the trajectory of the working device 3 when the working device 3 is automatically controlled according to the characteristic points a', b', c', d', f', g' is set, thereby appropriately setting the trajectory of the automatically controlled working device 3, and the operation performed by a skilled operator can be reproduced through automatic control.

[0179] like Figure 5~Figure 14 As shown, the automation controller 100 stores the postures of the working device 3 at the feature points a, b, c, d, f, and g. By automatically controlling the working device 3 according to the positions of the feature points a, b, c, d, f, and g and the postures of the working device 3 at the feature points a, b, c, d, f, and g, the operation performed by a skilled operator can be reproduced more faithfully.

[0180] like Fig.15 , Fig.16 As shown in the figure, when the bucket 301 to be loaded with goods is changed, the automation controller 100 detects the changed bucket 301 and determines whether to change the position of the reference point P. When the shape of the bucket 301 is changed, the reference point is changed, and the trajectory TR of the blade tip 6a is changed according to the changed reference point P'. For example, the height of the boom 14 can be adjusted in such a way that the y coordinate of the feature point based on the reference point is kept constant. If the height position of the reference point P' is lower than the reference point P, the boom 14 is adjusted to be lowered, and the trajectory TR of the blade tip 6a can be changed. In this way, the loading operation of loading goods into containers of different shapes can be performed by automatic control.

[0181] like Fig.15 , Fig.17As shown in FIG. 1 , when the position of the loading cargo in the bucket 301 is changed, the automation controller 100 determines whether to change the position of the reference point P. When the height position of the loading cargo position is changed, the reference point is changed, and the trajectory TR of the blade tip 6a is changed according to the changed reference point P'. Thus, even when the condition on the container side changes, the loading operation of loading cargo into the container can be performed by automatic control.

[0182] like Figure 8 , Fig. 9 As shown, the characteristic point a is the position of the blade tip 6a when the wheel loader 1 starts to move the bucket 6 in the unloading direction while moving forward toward the bucket 301. By automatically controlling the wheel loader 1 so that the blade tip 6a passes through the characteristic point a, the unloading action of the bucket 6 can be started at a time when the blade tip 6a has not reached the bucket 301. By simultaneously performing the forward movement of the wheel loader 1 toward the dump truck 300 and the unloading action of the bucket 6, and overlapping the multiple actions in time, the cycle time of the loading operation can be shortened.

[0183] like Figure 8 , 11 As shown, characteristic point c is the position of blade edge 6a when bucket 6 stops moving in the unloading direction above bucket 301. By automatically controlling wheel loader 1 so that blade edge 6a passes characteristic point c, the cargo in bucket 6 can be reliably loaded into bucket 301.

[0184] like Figure 8 , 12 As shown, the characteristic point d is the position of the blade tip 6a when the action of raising the boom 14 stops above the bucket 301. By automatically controlling the wheel loader 1 so that the blade tip 6a passes through the characteristic point d, the loading operation can be performed without stopping the action of the working device 3, and the shaking of the vehicle caused by the inertia when the boom 14 stops can be suppressed.

[0185] like Figure 8 , Fig.13 As shown, feature point f is the position of blade tip 6a when bucket 6 starts to move in the tilting direction above bucket 301. By automatically controlling wheel loader 1 so that blade tip 6a passes feature point f, contact between blade tip 6a and back surface 6b of bucket 6 and bucket 301 can be avoided.

[0186] like Figure 8 , Fig.14As shown, the characteristic point g is the position of the blade tip 6a when the bucket 6 stops tilting. By automatically controlling the wheel loader 1 so that the blade tip 6a passes through the characteristic point g, it is possible to reliably avoid the bucket 6 from contacting the bucket 301. By not tilting the bucket 6 more than necessary and performing a tilting movement in which the bucket 6 can reliably avoid the bucket 301 and move, the bucket 6 can be quickly moved to a posture for the next excavation operation.

[0187] The automation controller 100 constituting the automatic control system of the wheel loader 1 described in the above-mentioned embodiment does not necessarily need to be mounted on the wheel loader 1. A controller external to the wheel loader 1 may also constitute the system constituting the automation controller 100. Alternatively, the vehicle body controller 50 mounted on the wheel loader 1 may perform a process of transmitting information acquired by the external information acquisition unit 110 and the vehicle information acquisition unit 120 to the external controller, and the external controller that receives the signal may extract the positions of the characteristic points a, b, c, d, f, and g constituting the trajectory TR of the blade tip 6a of the bucket 6 with reference to the reference point P.

[0188] The external controller may be arranged at the working site of the wheel loader 1 or may be arranged at a distance away from the working site of the wheel loader 1. The external controller may also be a mobile device. The external controller may also be a portable device such as a laptop computer, a tablet computer, or a smart phone that an operator can carry and use.

[0189] In the embodiment, the dump truck 300 bucket 301 is used as an example of a container, and the operation of loading the cargo loaded on the working device 3 (bucket 6) into the dump truck 301 is described. The container for loading the cargo loaded on the working device 3 is not limited to the dump truck 301, and may be, for example, a hopper.

[0190] In the embodiment, the wheel loader 1 is provided with a cab 5, and an example of a manned vehicle in which an operator rides in the cab 5 is described. The wheel loader 1 may also be an unmanned vehicle. The wheel loader 1 may not be provided with a cab 5 for an operator to ride in and operate. The wheel loader 1 may not be provided with a control function for an operator to ride in. The wheel loader 1 may also be a working machine dedicated to remote control. The wheel loader 1 may also be controlled by a wireless signal from a remote control device.

[0191] <Note>

[0192] The above description includes the following additional features.

[0193] (Note 1)

[0194] A system comprising a work machine, wherein:

[0195] The system has:

[0196] The main body of the operating machine;

[0197] A working device, which is mounted on the working machine body and has a bucket;

[0198] a working device posture sensor, which detects the posture of the working device;

[0199] an object sensor that detects an object around the working machine body; and

[0200] a controller that communicates with the working device posture sensor and the object sensor,

[0201] The controller stores the trajectory of the working device and the reference point of the container when the working machine performs an operation for loading the load in the bucket into the container, and changes the trajectory according to the changed reference point when the position of the reference point is changed.

[0202] (Note 2)

[0203] A system according to Appendix 1, wherein:

[0204] The system stores the positions of feature points constituting the trajectory,

[0205] The feature point is changed according to the changed reference point.

[0206] (Note 3)

[0207] A system according to Note 1 or Note 2, wherein:

[0208] The system obtains the posture of the working device at the feature point.

[0209] (Note 4)

[0210] A system according to any one of Notes 1 to 3, wherein:

[0211] When the container in which the cargo is loaded is changed, the changed container is detected to determine whether the position of the reference point is changed.

[0212] (Note 5)

[0213] A system according to any one of Notes 1 to 3, wherein:

[0214] When the position of the cargo in the container is changed, it is determined whether to change the position of the reference point.

[0215] (Note 6)

[0216] The system according to any one of Notes 1 to 5, wherein:

[0217] The characteristic point includes a position of the working device when the working machine starts moving the bucket in a discharge direction while traveling forward toward the container.

[0218] (Note 7)

[0219] A system according to any one of Notes 1 to 6, wherein:

[0220] The characteristic point includes a position of the working device when the movement of the bucket in the unloading direction is stopped above the container.

[0221] (Note 8)

[0222] A system according to any one of Notes 1 to 7, wherein:

[0223] The working device has a boom with the bucket mounted on the front end.

[0224] The characteristic point includes a position of the working device when the action of raising the boom is stopped above the container.

[0225] (Note 9)

[0226] A system according to any one of Notes 1 to 7, wherein:

[0227] The characteristic point includes a position of the working device when the bucket starts to move in a tilting direction above the container.

[0228] (Note 10)

[0229] A system according to Appendix 9, wherein:

[0230] The characteristic point includes a position of the working device when the movement of the bucket in the tilting direction is stopped.

[0231] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the technical claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the technical claims.

[0232] Description of reference numerals:

[0233] 1 Wheel loader; 2 Body frame; 2a Front frame; 2b Rear frame; 3 Work equipment; 4 Travel equipment; 4a, 4b Travel wheels; 5 Cab; 6 Bucket; 8 Operating device; 9 Boom pin; 11 Steering cylinder; 13 Work equipment pump; 14 Boom; 15 Connecting rod; 16 Boom cylinder; 17 Bucket pin; 18 Bell crank; 18a Support pin; 18b, 18c Connecting pin; 19 Bucket cylinder; 21 Engine; 23 Transmission; 25 Axle; 32 Main valve; 35, 36 Solenoid proportional control valve; 41 Accelerator pedal; 42 Work equipment operating lever; 50 Body controller; 51 Machine monitor; 60 Engine controller; 70 Transmission controller; 71 Brake control unit; 72 Accelerator control unit; 80 Work equipment controller; 81 Steering control unit; 82 Work equipment control unit; 100 Automation controller; 101 Position estimation unit; 102 Path planning unit; 103 Path following control unit; 110 External information acquisition unit; 111 Sensing device; 112 Position information acquisition device; 120 Vehicle body information acquisition unit; 121 Articulation angle sensor; 122 Vehicle speed sensor; 123 Boom angle sensor; 124 Bucket angle sensor; 125 Boom cylinder pressure sensor; 130 Interface; 131 Mode selection operation unit; 132 Engine emergency stop switch; 133 Mode lamp; 140 Actuator; 141 Brake EPC; 142 Steering EPC; 143 Work equipment EPC; 144 HMT.

Claims

1. A system comprising a working machine, wherein: The system has: The main body of the operating machine; A working device, which is mounted on the working machine body and has a bucket; a working device posture sensor, which detects the posture of the working device; an object sensor for detecting an object around the working machine body; as well as a controller that communicates with the working device posture sensor and the object sensor, The controller stores the trajectory of the working device and the reference point of the container when the working machine performs an operation for loading the load in the bucket into the container, and changes the trajectory according to the changed reference point when the position of the reference point is changed.

2. The system according to claim 1, wherein: The system stores the positions of feature points constituting the trajectory, The feature point is changed according to the changed reference point.

3. The system according to claim 2, wherein: The system stores the posture of the working device at the feature point.

4. The system according to any one of claims 1 to 3, wherein: When the container in which the cargo is loaded is changed, the changed container is detected to determine whether the position of the reference point is changed.

5. The system according to any one of claims 1 to 3, wherein: When the position of the cargo in the container is changed, it is determined whether to change the position of the reference point.

6. The system according to claim 2 or 3, wherein: The characteristic point includes a position of the working device when the working machine starts moving the bucket in a discharge direction while traveling forward toward the container.

7. The system according to claim 2 or 3, wherein: The characteristic point includes a position of the working device when the movement of the bucket in the unloading direction is stopped above the container.

8. The system according to claim 2 or 3, wherein: The working device has a boom with the bucket mounted at the front end. The characteristic point includes a position of the working device when the action of raising the boom is stopped above the container.

9. The system according to claim 2 or 3, wherein: The characteristic point includes a position of the working device when the bucket starts to move in a tilting direction above the container.

10. The system according to claim 9, wherein: The characteristic point includes a position of the working device when the movement of the bucket in the tilting direction is stopped.

11. A controller for a working machine, wherein: The working machine stores the trajectory of the working device and the reference point of the container when an operation for loading the cargo loaded on the working device into the container is performed, When the position of the reference point is changed, the trajectory is changed according to the changed reference point.

12. A method for controlling a working machine, wherein: The control method of the working machine comprises: The working machine stores a trajectory of the working device and a reference point of the container when an operation for loading the cargo loaded on the working device into the container is performed; and When the position of the reference point is changed, the trajectory is changed according to the changed reference point.

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