EP4653624A1

EP4653624A1 - Work machine-including system, work machine controller, and work machine path generation method

Info

Publication number: EP4653624A1
Application number: EP24767071.4A
Authority: EP
Inventors: Takafumi MATSUYAMA
Original assignee: Komatsu Ltd
Current assignee: Komatsu Ltd
Priority date: 2023-03-08
Filing date: 2024-03-01
Publication date: 2025-11-26
Also published as: WO2024185703A1; JP2024126915A

Abstract

A direction in which a travel body is to travel when materials are stacked is appropriately determined. A work machine includes the travel body and works at a work site. A sensor detects objects at the work site. A controller provides an instruction for an operation of the work machine. The controller recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at the work site and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of the sensor. The controller determines a first direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.

Description

Technical Field

The present disclosure relates to a system including a work machine, a controller for a work machine, and a path generation method for a work machine.

Background Art

US 2021/0124359 A (Patent Literature 1) discloses that a surface of a mountain of material to be worked on by a wheel loader is detected by a sensor.

Citation List

Patent Literature

Patent Literature 1: US 2021/0124359 A

Summary of Invention

Technical Problem

The wheel loader performs work of stacking materials carried into a work site by a transport machine such as a dump truck. In order to efficiently perform this work, it is required to appropriately determine a path along which the wheel loader travels toward the material.
The present disclosure proposes a technique capable of appropriately determining a direction in which a travel body travels when stacking materials.

Solution to Problem

A system including a work machine according to a certain aspect of the present disclosure includes: a work machine that includes a travel body and works at a work site; a sensor that detects objects at the work site; and a controller that provides an instruction for an operation of the work machine. The controller recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at the work site and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of the sensor. The controller determines a first direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.
A controller for a work machine according to a certain aspect of the present disclosure recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at a work site where the work machine equipped with a travel body works and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of a sensor that detects objects at the work site. The controller determines a direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.
A path generation method for a work machine according to a certain aspect of the present disclosure includes the following steps. A first step is recognizing a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at a work site where the work machine equipped with a travel body works and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of a sensor that detects objects at the work site. A second step is determining a direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.

Advantageous Effects of Invention

According to the present disclosure, it is possible to appropriately determine a direction in which a travel body travels when stacking materials.

Brief Description of Drawings

Fig. 1 is a side view of a wheel loader as an example of a work machine.
Fig. 2 is a plan view of the wheel loader illustrated in Fig. 1.
Fig. 3 is a block diagram illustrating a schematic configuration of a control system for the wheel loader.
Fig. 4 is a block diagram illustrating a configuration of an automatic control system for the wheel loader.
Fig. 5 is a schematic diagram of an accumulated body of materials accumulated on the ground.
Fig. 6 is a schematic view illustrating work of stacking materials forming a second accumulated body on a first accumulated body.
Fig. 7 is a flowchart illustrating a flow of processing of generating a travel path for the wheel loader.
Fig. 8 is a schematic diagram illustrating a first example of a traveling direction of the wheel loader toward an accumulated body.
Fig. 9 is a schematic diagram illustrating a second example of a traveling direction of the wheel loader toward an accumulated body.
Fig. 10 is a flowchart illustrating another example of a flow of processing of generating a travel path of the wheel loader.
Fig. 11 is a schematic diagram illustrating an example of a traveling direction of the wheel loader toward a stockyard.

Description of Embodiments

Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the same parts and components will be denoted by the same reference signs. This also applies to their names and functions. Therefore, detailed descriptions thereof will not be repeated. It is also inherently intended that any configurations can be extracted from the embodiment and freely combined.

In the embodiment, a wheel loader 1 will be described as an example of a work machine. Fig. 1 is a side view of the wheel loader 1 as an example of a work machine. Fig. 2 is a plan view of the wheel loader 1 illustrated in Fig. 1.
As illustrated in Figs. 1 and 2, the wheel loader 1 mainly includes a vehicle body frame 2, a work implement 3, a travel device 4, and a cab 5. The vehicle body frame 2, the cab 5, and the like form the vehicle body of the wheel loader 1. The work implement 3 and the travel device 4 are attached to the vehicle body of the wheel loader 1. The main body of the wheel loader 1 (work machine main body) includes the vehicle body and the travel device 4.
The travel device 4 causes the vehicle body of the wheel loader 1 to travel, and includes travel wheels 4a and 4b. The wheel loader 1 is a wheeled vehicle including the travel wheels 4a and 4b as traveling rotation bodies on both sides of the vehicle body in a left-right direction. The wheel loader 1 is self-propelled by rotationally driving the travel wheels 4a and 4b, and can perform desired work using the work implement 3. The travel device 4 corresponds to an example of a "travel body".
In the present specification, a direction in which the wheel loader 1 travels straight is referred to as a front-rear direction of the wheel loader 1. In the front-rear direction of the wheel loader 1, a side on which the work implement 3 is disposed with respect to the vehicle body frame 2 is defined as a forward direction, and a side opposite to the forward direction is defined as a rearward direction. The left-right direction of the wheel loader 1 is a direction orthogonal to the front-rear direction in a plan view of the wheel loader 1 on a flat ground. The right side and the left side in the left-right direction when facing the forward direction are the right direction and the left direction, respectively. The vertical direction of the wheel loader 1 is a direction orthogonal to a plane defined by the front-rear direction and the left-right direction. In the vertical direction, the side at the ground is the lower side, and the side toward the sky is the upper side.
The vehicle body frame 2 includes a front frame 2a and a rear frame 2b. The front frame 2a is disposed in front of the rear frame 2b. The front frame 2a and the rear frame 2b are attached to each other by a center pin 10 so as to be movable in the left-right direction.
A pair of left and right steering cylinders 11 is attached across the front frame 2a and the rear frame 2b. The steering cylinders 11 are hydraulic cylinders. By the steering cylinders 11 being expanded and contracted by hydraulic oil from a steering pump (not illustrated), the travel direction of the wheel loader 1 is changed to the left and right. The front frame 2a and the rear frame 2b form the vehicle body frame 2 including an articulated structure. The wheel loader 1 is an articulated work machine in which the front frame 2a and the rear frame 2b are coupled to each other so as to be bendable.
The work implement 3 and a pair of the travel wheels (front wheels) 4a are attached to the front frame 2a. The work implement 3 is attached to the front of the vehicle body of the wheel loader 1. The work implement 3 is supported by the vehicle body of the wheel loader 1. Specifically, the work implement 3 is rotatably supported by the vehicle body frame 2, more specifically, the front frame 2a. The work implement 3 is disposed in front of the vehicle body frame 2.
The work implement 3 includes a boom 14. A base end portion of the boom 14 is rotatably attached to the front frame 2a by a boom pin 9. The boom 14 includes a left boom member 14L and a right boom member 14R. The left boom member 14L and the right boom member 14R are joined to each other so as to be unable to relatively move by a joining member that extends in the left-right direction to form the boom 14 including an integrated structure. The boom pin 9 includes a pair of a left boom pin 9L and a right boom pin 9R. The boom 14 is rotatable with respect to the front frame 2a about the left boom pin 9L and the right boom pin 9R. The left boom pin 9L and the right boom pin 9R rotatably support the work implement 3 with respect to the vehicle body frame 2.
The work implement 3 includes a bucket 6. The bucket 6 is disposed at the distal end of the work implement 3. The bucket 6 is a work tool for excavation and loading. A blade edge 6a is a distal end portion of the bucket 6. A back surface 6b is a part of the outer surface of the bucket 6. The back surface 6b includes a flat surface. The back surface 6b extends rearward from the blade edge 6a. The bucket 6 is rotatably attached to the boom 14 by a bucket pin 17 located at a distal end of the boom 14. The bucket 6 includes a left boom attachment portion to which the left boom member 14L is attached and a right boom attachment portion to which the right boom member 14R is attached.
The work implement 3 further includes a bell crank 18 and a link 15. A substantially central portion of the bell crank 18 is rotatably supported by the boom 14 by a support pin 18a located substantially at the center of the boom 14 in the longitudinal direction. The link 15 is coupled to a coupling pin 18c included at the lower end portion (distal end portion) of the bell crank 18. The link 15 couples the bell crank 18 and the bucket 6. The bell crank 18 and the link 15 are disposed between the left boom member 14L and the right boom member 14R in the left-right direction.
The front frame 2a and the boom 14 are coupled by a pair of boom cylinders 16. The boom cylinders 16 are hydraulic cylinders. The boom cylinders 16 drive the boom 14 to rotate up and down about the boom pin 9. The base ends of the boom cylinders 16 are attached to the front frame 2a. The distal ends of the boom cylinders 16 are attached to the boom 14. The boom cylinders 16 are hydraulic actuators that move the boom 14 up and down with respect to the front frame 2a. As the boom 14 ascends and descends, the bucket 6 attached to the distal end of the boom 14 also ascends and descends.
A bucket cylinder 19 couples the bell crank 18 and the front frame 2a. The base end of the bucket cylinder 19 is attached to the front frame 2a. The distal end of the bucket cylinder 19 is attached to a coupling pin 18b included at the upper end portion (base end portion) of the bell crank 18. The bucket cylinder 19 is a hydraulic actuator that rotates the bucket 6 up and down with respect to the boom 14. The bucket cylinder 19 is a work tool cylinder that drives the bucket 6. The bucket cylinder 19 rotationally drives the bucket 6 around the bucket pin 17. The bucket 6 is formed to be operable with respect to the boom 14. The bucket 6 is formed to be operable with respect to the front frame 2a.
The boom cylinders 16 and the bucket cylinder 19 form a work implement actuator that drives the work implement 3.
The cab 5 on which an operator boards and the pair of travel wheels (rear wheels) 4b are attached to the rear frame 2b. The box-shaped cab 5 is disposed behind the boom 14. The cab 5 is mounted on the rear frame 2b. The cab 5 is placed on the vehicle body frame 2. In the cab 5, a seat on which the operator of the wheel loader 1 sits, an operation device 8 to be described below, and the like are disposed.
A perception device 111 is included on the cab 5. The perception device 111 is disposed, for example, on a ceiling of the cab 5. The perception device 111 is mounted on, for example, an upper surface of the cab 5. The perception device 111 is disposed, for example, on a front portion of the cab 5. The perception device 111 is attached to the cab 5 facing forward, for example, and can acquire information of the front of the cab 5. Details of the perception device 111 will be described below.
A length L9 illustrated in Fig. 2 is a length (bucket width) from the left end to the right end of the bucket 6 in the left-right direction. A width direction center 6c of the bucket 6 is a center point of the bucket 6 in the left-right direction. The length L9 is included in the dimension of the work implement 3. The length L9 is included in a specification value of the wheel loader 1. The specification value of the wheel loader 1 is a value unique to each individual of the wheel loader 1, and is stored in a vehicle body controller 50 to be described below.

Fig. 3 is a block diagram illustrating a schematic configuration of a control system that controls the wheel loader 1.
An engine 21 is a driving source that generates a driving force for driving the work implement 3 and the travel device 4, and is, for example, a diesel engine. As the driving source, instead of the engine 21, a motor driven by a power storage body may be used, 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.
The driving force generated by the engine 21 is transmitted to a transmission 23. The transmission 23 shifts the driving force to an appropriate torque and rotational speed. An axle 25 is connected to an output shaft of the transmission 23. The driving force shifted by the transmission 23 is transmitted to the axle 25. The driving force is transmitted from the axle 25 to the travel wheels 4a and 4b (Figs. 1 and 2). Thus, the wheel loader 1 travels. In the wheel loader 1 of the embodiment, both the travel wheels 4a and the travel wheels 4b form driving wheels that receive a driving force and cause the wheel loader 1 to travel.
A part of the driving force of the engine 21 is transmitted to a work implement pump 13. The work implement pump 13 is a hydraulic pump that is driven by the engine 21 and operates the work implement 3 by discharged hydraulic oil. The work implement 3 is driven by the hydraulic oil from the work implement pump 13. The hydraulic oil discharged from the work implement pump 13 is supplied to the boom cylinders 16 and the bucket cylinder 19 via a main valve 32. When the boom cylinders 16 expand and contract by receiving the supply of the hydraulic oil, the boom 14 moves up and down. When the bucket cylinder 19 receives the supply of the hydraulic oil and expands and contracts, the bucket 6 rotates up and down.
The wheel loader 1 includes the vehicle body controller 50. The vehicle body controller 50 includes an engine controller 60, a transmission controller 70, and a work implement controller 80.
The vehicle body controller 50 is generally implemented by reading various programs by a central processing unit (CPU). The vehicle body controller 50 includes a memory (not illustrated). The memory functions as a work memory and stores various programs for implementing the functions of the wheel loader 1.
The operation device 8 is included in the cab 5. The operation device 8 is operated by the operator. The operation device 8 includes a plurality of types of operation members operated by the operator to operate the wheel loader 1. The operation device 8 includes an accelerator pedal 41 and a work implement operation lever 42. The operation device 8 may include a steering wheel, a shift lever, and the like (not illustrated).
The accelerator pedal 41 is operated to set a target rotation speed of the engine 21. The engine controller 60 controls the output of the engine 21 on the basis of the operation amount of the accelerator pedal 41. When the operation amount (depression amount) of the accelerator pedal 41 is increased, the output of the engine 21 is increased. When the operation amount of the accelerator pedal 41 is reduced, the output of the engine 21 is reduced. The transmission controller 70 controls the transmission 23 on the basis of the operation amount of the accelerator pedal 41.
The work implement operation lever 42 is operated to operate the work implement 3. The work implement controller 80 controls electromagnetic proportional control valves 35 and 36 on the basis of the operation amount of the work implement operation lever 42.
The electromagnetic proportional control valve 35 contracts the bucket cylinder 19 to switch the main valve 32 such that the bucket 6 moves in the dumping direction (direction in which the blade edge of the bucket 6 is lowered). Furthermore, the electromagnetic proportional control valve 35 extends the bucket cylinder 19 to switch the main valve 32 such that the bucket 6 moves in the tilting direction (direction in which the blade edge of the bucket 6 is raised). The electromagnetic proportional control valve 36 contracts the boom cylinders 16 to switch the main valve 32 such that the boom 14 is lowered. Furthermore, the electromagnetic proportional control valve 36 extends the boom cylinders 16 to switch the main valve 32 such that the boom 14 is raised.
A machine monitor 51 receives an input of an instruction signal from the vehicle body controller 50 and displays various types of information. The various types of information displayed on the machine monitor 51 may be, for example, information regarding work executed by the wheel loader 1, vehicle body information such as a remaining amount of fuel, a cooling water temperature, and a hydraulic oil temperature, a peripheral image obtained by imaging the periphery of the wheel loader 1, and the like. The machine monitor 51 may be a touch panel, and in this case, a signal generated by the operator touching a part of the machine monitor 51 is output from the machine monitor 51 to the vehicle body controller 50.

In automating work of the wheel loader 1, an operation of a skilled operator is desirably reproduced by automatic control. Fig. 4 is a block diagram illustrating a configuration of an automatic control system of the wheel loader 1.
An automation controller 100 is formed to be able to transmit and receive signals to and from the vehicle body controller 50 described with reference to Fig. 3. The automation controller 100 is also formed to be able to transmit and receive signals to and from an external information acquisition unit 110. The external information acquisition unit 110 includes the perception device 111 and a position information acquisition device 112. The perception device 111 and the position information acquisition device 112 are mounted on the wheel loader 1.
The perception device 111 acquires information of the surroundings of the wheel loader 1. The perception device 111 is attached to a front portion of the upper surface of the cab 5, for example, as illustrated in Fig. 1. The perception device 111 corresponds to an example of an "object sensor" that detects an object at a work site where the wheel loader 1 works, specifically, an object around (in front of) the main body of the wheel loader 1 (work machine main body).
The perception device 111 detects a direction of an object outside the wheel loader 1 and a distance to the object in a non-contact manner. The perception device 111 is, for example, a light detection and ranging (LiDAR) that emits laser light and acquires information of an object. The perception device 111 may be a visual sensor including a camera. The perception device 111 may be a radio detection and ranging (Radar) that acquires information of an object by emitting radio waves. The perception device 111 may be an infrared sensor.
The position information acquisition device 112 acquires information of the current position of the wheel loader 1. The position information acquisition device 112 acquires position information of the wheel loader 1 in a global coordinate system with reference to the earth using, for example, a satellite positioning system. The position information acquisition device 112 uses, for example, global navigation satellite systems (GNSS), and includes a GNSS receiver. The satellite positioning system calculates the position of the antenna of the GNSS receiver from a positioning signal received by the GNSS receiver from a satellite to calculate the position of the wheel loader 1.
External information of the wheel loader 1 acquired by the perception device 111 and the position information of the wheel loader 1 acquired by the position information acquisition device 112 are input to the automation controller 100.
The vehicle body controller 50 is formed to be able to transmit and receive signals to and from a vehicle information acquisition unit 120, and receives an input of information of the wheel loader 1 acquired by the vehicle information acquisition unit 120. The vehicle information acquisition unit 120 includes 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.
The articulation angle sensor 121 detects an articulation angle that is an angle formed by the front frame 2a and the rear frame 2b, 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.
The vehicle speed sensor 122 detects the moving speed of the wheel loader 1 by the travel device 4, for example, by detecting the rotation speed of the output shaft of the transmission 23, and generates a signal of the detected vehicle speed. The vehicle speed sensor 122 outputs the signal of the vehicle speed to the vehicle body controller 50. The vehicle speed sensor 122 corresponds to an example of a travel sensor that detects a traveling status of the travel device 4 (travel body).
The boom angle sensor 123 includes, for example, a rotary encoder included in the boom pin 9 that is an attachment portion of the boom 14 to the vehicle body frame 2. The boom angle sensor 123 detects an angle of the boom 14 with respect to the horizontal direction (boom angle), and generates a signal indicating 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.
The bucket angle sensor 124 includes, for example, a rotary encoder included in the support pin 18a that is a rotation shaft of the bell crank 18. The bucket angle sensor 124 detects an angle of the bell crank 18 with respect to the boom 14 (bell crank angle), and generates a signal of the detected angle of the bell crank 18. The vehicle information acquisition unit 120 or the vehicle body controller 50 calculates an angle of the bucket 6 with respect to the boom 14 (bucket angle) from the detected angle of the bell crank 18.
The boom angle sensor 123 and the bucket angle sensor 124 correspond to an example of a work implement posture sensor that detects the posture of the work implement 3. The boom angle sensor 123 may be a stroke sensor disposed on the boom cylinder 16. The bucket angle sensor 124 may be a potentiometer or a proximity switch attached to the bucket pin 17, or may be a stroke sensor disposed on the bucket cylinder 19.
The boom cylinder pressure sensor 125 detects pressure on the bottom side (boom bottom pressure) of the boom cylinder 16, and generates a signal of the detected boom bottom pressure. The boom bottom pressure increases in a case where a load is loaded on the bucket 6, and decreases in a case where the load is empty. The boom cylinder pressure sensor 125 outputs the signal of the boom bottom pressure to the vehicle body controller 50.
The vehicle body controller 50 outputs information input from the vehicle information acquisition unit 120 to the automation controller 100. The automation controller 100 receives inputs of 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.
An actuator 140 is formed to be able to transmit and receive signals to and from the vehicle body controller 50. The actuator 140 is driven upon receiving an instruction signal from the vehicle body controller 50. The actuator 140 includes a brake electromagnetic proportional control valve (EPC) 141 for operating the brake of the travel device 4, a steering EPC 142 for adjusting the traveling direction of the wheel loader 1, a work implement EPC 143 for operating the work implement 3, and a hydraulic mechanical transmission (HMT) 144.
The electromagnetic proportional control valves 35 and 36 illustrated in Fig. 3 form the work implement EPC 143. The transmission 23 illustrated in Fig. 3 is implemented as the HMT 144 utilizing electronic control. The transmission 23 may be a hydro-static transmission (HST). A power transmission device that transmits power from the engine 21 to the travel wheels 4a and 4b may include an electric drive device of a diesel electric type or the like, or may include any combination of the HMT, the HST, and the electric drive device.
The transmission controller 70 includes a brake control unit 71 and an accelerator control unit 72. The brake control unit 71 outputs an instruction signal for controlling the operation of the brake to the brake EPC 141. The accelerator control unit 72 outputs an instruction signal for controlling the vehicle speed to the HMT 144.
The work implement controller 80 includes a steering control unit 81 and a work implement control unit 82. The steering control unit 81 outputs an instruction signal for controlling the traveling direction of the wheel loader 1 to the steering EPC 142. The work implement control unit 82 outputs an instruction signal for controlling the operation of the work implement 3 to the work implement EPC 143.
The automation controller 100 includes a position estimation unit 101, a path planning unit 102, and a path follow-up control unit 103.
The position estimation unit 101 estimates the self-position of the wheel loader 1 on the basis of the position information acquired by the position information acquisition device 112. Furthermore, the position estimation unit 101 recognizes a target position on the basis of the external information acquired by the perception device 111. The target position is, for example, the position of an accumulated body (first accumulated body) in which materials to be worked on by the wheel loader 1 are accumulated on the ground at the work site. Alternatively, the target position is, for example, the position of an accumulated body (second accumulated body) in which materials to be accumulated on the first accumulated body are accumulated on the ground at the work site. The perception device 111 may recognize the target position and input the target position to the automation controller 100, or the position estimation unit 101 may recognize the target position on the basis of the result of the detection by the perception device 111.
As the position of the accumulated body, the top portion of the accumulated body may be regarded as the position of the accumulated body. In another example, the center of gravity of the accumulated body may be calculated from the shape of the accumulated body, and the position of the center of gravity may be regarded as the position of the accumulated body.
The path planning unit 102 generates an optimum path of the wheel loader 1 in a case where the wheel loader 1 is automatically controlled. The optimum path includes a path of traveling by the travel device 4 and a path of operation of the work implement 3. The path planning unit 102 generates an optimum path that connects the current self-position of the wheel loader 1 and the target position to which the wheel loader 1 is heading. For example, the path planning unit 102 generates optimum paths for the path of traveling by the travel device 4 and the path of the operation of the work implement 3 when the materials forming the second accumulated body are stacked on the first accumulated body.
The path follow-up control unit 103 gives instructions of operations of the travel device 4 and the work implement 3. The path follow-up control unit 103 controls the accelerator, the brake, and the steering such that the wheel loader 1 travels following the optimum path generated by the path planning unit 102. An instruction signal for causing the wheel loader 1 to travel along the optimum path is output from the path follow-up control unit 103 to the brake control unit 71, the accelerator control unit 72, and the steering control unit 81. The path follow-up control unit 103 controls the boom cylinders 16 and the bucket cylinder 19 such that the work implement 3 operates along the optimum path generated by the path planning unit 102. An instruction signal for moving the work implement 3 along the optimum path is output from the path follow-up control unit 103 to the work implement control unit 82.
An interface 130 is formed to be able to transmit and receive signals to and from the vehicle body controller 50. The interface 130 includes an automation switching switch 131, an engine emergency stop switch 132, and a mode lamp 133.
The automation switching switch 131 is operated by the operator. The operator operates the automation switching switch 131 to switch between manually operating the wheel loader 1 and automatically controlling the wheel loader 1. The engine emergency stop switch 132 is operated by the operator. In a case where an event that requires emergency stop of the engine 21 occurs, the operator operates the engine emergency stop switch 132. Operation signals of the automation switching switch 131 and the engine emergency stop switch 132 are input to the vehicle body controller 50.
The mode lamp 133 displays whether the wheel loader 1 is currently in a mode of being manually operated by the operator or in a mode of being automatically controlled. An instruction signal for controlling lighting of the lamp is output from the vehicle body controller 50 to the mode lamp 133.
The automation controller 100 is also formed to be able to transmit and receive signals to and from a communication device 150. The automatic control system of the wheel loader 1 is formed to be able to give an instruction of information held by the automation controller 100 to a transport machine such as a dump truck via the communication device 150. The path follow-up control unit 103 of the automation controller 100 gives an instruction for the operation of the transport machine via the communication device 150.

Fig. 5 is a schematic diagram of an accumulated body of materials, which are to be worked on by the wheel loader 1, accumulated on the ground at the work site. The materials are earth, sand, rock, ore, or the like excavated at the work site or carried into the work site by the transport machine such as a dump truck.
A first accumulated body 200 is a mountain of materials accumulated in a material accumulation place such as a stockyard, or a mountain of materials formed in a vacant place. The first accumulated body 200 includes a first accumulated body top portion 201 with the highest height, a closer side (a side on which the wheel loader 1 traveling toward the first accumulated body 200 reaches the first accumulated body 200; the right side in Figs. 5 and 6) skirt 202, and a slope 205 connecting the first accumulated body top portion 201 and the skirt 202. The mountain height of the first accumulated body 200 is not uniform, and the mountain height gradually decreases from the first accumulated body top portion 201 toward the skirt 202.
A second accumulated body 210 is a mountain of materials to be stacked on the first accumulated body 200. The material forming the second accumulated body 210 is carried into the work site by a transport machine such as a dump truck. The second accumulated body 210 is formed, for example, by the transport machine unloading the materials at an appropriate position on the ground in the vicinity of the skirt 202 at the work site. The shape of the second accumulated body 210 illustrated in Fig. 5 is a shape immediately after the second accumulated body 210 is unloaded from the transport machine. The second accumulated body 210 has a second accumulated body top portion 211 with the highest height. An angle θ illustrated in Fig. 5 is the angle of repose of the materials. Specifically, the angle θ of repose of the materials differs depending on ingredients and a state of the materials.
Fig. 6 is a schematic diagram illustrating work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200. In Fig. 6, only the front frame 2a, the rear frame 2b, the front wheels 4a, the rear wheels 4b, the bucket 6, and the boom 14 in the configurations of the wheel loader 1 illustrated in Figs. 1 and 2 are representatively illustrated.
The wheel loader 1 linearly travels forward toward the first accumulated body 200 in a posture in which the distal end of the boom 14 is at a low position and the back surface 6b of the bucket 6 faces horizontally, and causes the blade edge 6a of the bucket 6 to bite into the materials forming the second accumulated body 210. The wheel loader 1 further travels forward in that state. When the blade edge 6a reaches just before the skirt 202 of the first accumulated body 200, the boom 14 rises and the bucket 6 tilts back. Through this operation, the materials forming the second accumulated body 210 are scooped into the bucket 6.
The wheel loader 1 discharges the materials in the bucket 6 to the vicinity of the first accumulated body top portion 201 of the first accumulated body 200, and stacks the materials on the slope 205 of the first accumulated body 200. In this manner, the work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200 is executed.
When the wheel loader 1 executes the work of stacking the materials as illustrated in Fig. 6, the wheel loader 1 is in a straight traveling posture in which the front frame 2a and the rear frame 2b are not bent. The wheel loader 1 may stack the materials on the first accumulated body 200 by stopping the forward traveling before the front wheels 4a reach the skirt 202 of the first accumulated body 200 and causing the work implement 3 to operate. Alternatively, the wheel loader 1 may continue the forward traveling and stack the materials on the first accumulated body 200 in a posture in which the front wheels 4a ride on the slope 205 of the first accumulated body 200.

Processing of generating a travel path for the wheel loader 1 will be described below. Fig. 7 is a flowchart illustrating a flow of the processing of generating a travel path for the wheel loader 1. Processing of determining a direction in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200 in a case where the first accumulated body 200 is a mountain of materials formed in a vacant place will be described with reference to Fig. 7 and subsequent Figs. 8 and 9.
As illustrated in Fig. 7, the perception device 111 mounted on the wheel loader 1 recognizes the first accumulated body 200, which is a mountain of materials accumulated on the ground at the work site, first in Step S1. The objects at the work site detected by the perception device 111 include the first accumulated body 200. The perception device 111 is, for example, LiDAR, and inputs a point cloud indicating a detection result of the first accumulated body 200 to the position estimation unit 101 of the automation controller 100. The position estimation unit 101 recognizes the position and the shape of the first accumulated body 200 on the basis of the detection result of the perception device 111. The position of the first accumulated body 200 and the shape of the first accumulated body 200 are included in appearance features of the first accumulated body 200. The appearance features of the first accumulated body 200 are included in information regarding the first accumulated body 200.
In Step S2, the position estimation unit 101 of the automation controller 100 creates an altitude model of the first accumulated body 200 from the point cloud detected by the LiDAR. Fig. 8 is a schematic diagram illustrating a first example of arrangement of the accumulated body and the traveling direction of the wheel loader 1. The first accumulated body 200 illustrated in Fig. 8 and subsequent Fig. 9 is a mountain of materials formed in a vacant place. Figs. 8 and 9 illustrate schematic diagrams of the first accumulated body 200, the second accumulated body 210 in the vicinity of the skirt 202 of the first accumulated body 200, and the wheel loader 1 stacking the materials forming the second accumulated body 210 on the first accumulated body 200 in a plan view.
The materials dropped on the flat ground are ideally accumulated in a right circular cone shape. An angle formed by the conical surface of the right circular cone and the ground is the angle θ of repose (Fig. 5) of the materials. The position estimation unit 101 creates an altitude model of the first accumulated body 200 with the right circular cone shape.
In Step S3, the position estimation unit 101 of the automation controller 100 recognizes the mountaintop portion of the first accumulated body 200. The first accumulated body 200 has a non-uniform mountain height. A part of the first accumulated body 200 with the highest height is the first accumulated body top portion 201 illustrated in Fig. 8. The skirt 202 of the first accumulated body 200 has a circular shape in a plan view, and the center of the circle is the first accumulated body top portion 201.
In Step S4, the perception device 111 mounted on the wheel loader 1 recognizes the second accumulated body 210 in which the materials to be stacked on the first accumulated body 200 are accumulated on the ground at the work site. The objects at the work site detected by the perception device 111 include the second accumulated body 210. The perception device 111 is, for example, LiDAR, and inputs a point cloud indicating a detection result of the second accumulated body 210 to the position estimation unit 101 of the automation controller 100. The position estimation unit 101 recognizes the position and the shape of the second accumulated body 210 on the basis of the detection result of the perception device 111. The position of the second accumulated body 210 and the shape of the second accumulated body 210 are included in appearance features of the second accumulated body 210. The appearance features of the second accumulated body 210 are included in information regarding the second accumulated body 210.
The second accumulated body 210 is a mountain of materials carried by the transport machine such as a dump truck to the work site and unloaded on the ground at the work site. The transport machine travels along a path that does not interfere with the first accumulated body 200 and reaches the position where the materials are to be unloaded. The transport machine unloads the materials at a position on the radially outer side of the circle centered on the first accumulated body top portion 201 with respect to the skirt 202 of the first accumulated body 200. The unloaded materials form the second accumulated body 210.
The arrangement of the second accumulated body 210 in the radial direction of the circle centered on the first accumulated body top portion 201 may be determined in consideration of the angle of repose of the materials. It is desirable that the arrangement of the second accumulated body 210 with respect to the skirt 202 of the first accumulated body 200 be determined such that the skirt of the second accumulated body 210 is disposed close to the skirt 202 of the first accumulated body 200. As illustrated in Fig. 5, it is desirable that the skirt of the second accumulated body 210 and the skirt 202 of the first accumulated body 200 coincide with each other.
In Step S5, the position estimation unit 101 of the automation controller 100 creates an altitude model of the second accumulated body 210 from the point cloud detected by the LiDAR. In the example illustrated in Fig. 8, the position estimation unit 101 creates an altitude model of the second accumulated body 210 with a right circular cone shape.
In Step S6, the position estimation unit 101 of the automation controller 100 recognizes the mountaintop portion of the second accumulated body 210. The second accumulated body 210 has a non-uniform mountain height. A part of the second accumulated body 210 with the highest mountain height is the second accumulated body top portion 211 illustrated in Fig. 8. The skirt of the second accumulated body 210 has a circular shape in a plan view, and the center of the circle is the second accumulated body top portion 211.
The processing in Steps S4 to S6 may not necessarily be executed after the processing in Steps S1 to S3. The processing in Steps S1 to S3 and the processing in Steps S4 to S6 may be executed in parallel. The processing in Steps S1 to S3 may be executed after the processing in Steps S4 to S6.
In Step S7, the path planning unit 102 of the automation controller 100 creates a straight line passing through the mountaintop portions of the first accumulated body 200 and the second accumulated body 210 on the basis of the shape of the first accumulated body 200 and the shape of the second accumulated body 210. As illustrated in Fig. 8, the path planning unit 102 creates a straight line Lc passing through the first accumulated body top portion 201 and the second accumulated body top portion 211. As will be described later, the extending direction of the straight line Lc is one direction in which the travel device 4 of the wheel loader 1 travels when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200.
In Step S8, the path planning unit 102 calculates the length of extension of the second accumulated body 210 in the direction orthogonal to the extending direction of the straight line Lc passing through the first accumulated body top portion 201 and the second accumulated body top portion 211.
In Step S9, the path planning unit 102 compares the length of extension of the second accumulated body 210 calculated in previous Step S8 with the width of the bucket 6 (the length L9 illustrated in Fig. 2). The path planning unit 102 determines whether or not the length of extension of the second accumulated body 210 is longer than the width of the bucket 6.
In the example illustrated in Fig. 8, the diameter of the circle formed by the skirt of the second accumulated body 210 is shorter than the width of the bucket 6. The length of extension of the second accumulated body 210 in the direction orthogonal to the extending direction of the straight line Lc is determined to be equal to or less than the width of the bucket 6 (NO in Step S9), and the processing proceeds to Step S12. In Step S12, the path planning unit 102 determines the extending direction of the straight line Lc, which has been created in Step S7 and is an extended line connecting the first accumulated body top portion 201 and the second accumulated body top portion 211, as a direction DR in which the travel device 4 of the wheel loader 1 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200.
Fig. 9 is a schematic diagram illustrating a second example of a traveling direction of the wheel loader 1 toward an accumulated body. Fig. 9 illustrates an exemplary case where the length of extension of the second accumulated body 210 in the direction orthogonal to the straight line Lc passing through the first accumulated body top portion 201 and the second accumulated body top portion 211 is longer than the width of the bucket 6. The skirt of the second accumulated body 210 illustrated in Fig. 9 has an elliptical shape in a plan view. The center of the ellipse is the second accumulated body top portion 211. The direction in which the straight line Lc extends is the short axis direction of the ellipse. The long axis direction of the ellipse is the direction orthogonal to the straight line Lc. In the long axis direction of the ellipse, the length of extension of the second accumulated body 210 is greater than the width (the length L9; Fig. 2) of the bucket 6 of the wheel loader 1.
The direction orthogonal to the extending direction of the straight line Lc is a tangential direction of the circle centered on the first accumulated body top portion 201. The second accumulated body 210 illustrated in Fig. 9 is formed by unloading the loaded materials on the ground while the transport machine is traveling forward at a very low speed in the direction. An instruction for the operation of the transport machine is provided such that the transport machine unloads the materials in the direction intersecting the direction in which the travel device 4 travels toward the first accumulated body 200 when the wheel loader 1 stacks the materials forming the second accumulated body 210 on the first accumulated body 200.
In the case of the example illustrated in Fig. 9, determination of YES is made in Step S9 for comparing the length of extension of the second accumulated body 210 with the width of the bucket 6, and the processing proceeds to Step S10. In Step S10, the path planning unit 102 equally divides the second accumulated body 210 in the direction orthogonal to the straight line Lc.
The division lines Ld1 and Ld2 indicated by two-dot chain lines in Fig. 9 are straight lines that divide the second accumulated body 210 into three equal parts. The straight line Lc and the division lines Ld1 and Ld2 extend in parallel to each other. Double-headed arrows illustrated in Fig. 9 indicate a length of each accumulated body obtained by dividing the second accumulated body 210 into the three equal parts in the direction orthogonal to the straight line Lc and the division lines Ld1 and Ld2, in the direction orthogonal to the straight line Lc and the division lines Ld1 and Ld2. Each of the divided accumulated bodies has a division length b as illustrated in Fig. 9. A midpoint 216 illustrated in Fig. 9 is a midpoint of the division length b.
It is more desirable that the number of divided parts from the second accumulated body 210 be smaller. This is because it is necessary to perform work of stacking the divided accumulated bodies on the first accumulated body 200 by the number of divided parts. On the other hand, in order to stack the accumulated body of the materials on the first accumulated body 200 in one stacking operation, it is necessary for the amount of accumulated materials included in the accumulated body to be smaller than the capacity of the bucket 6. Therefore, it is desirable that the second accumulated body 210 be equally divided by the minimum number of divisions from among the numbers of divisions by which it is possible to set the amount of accumulated materials included in each of the divided accumulated bodies to be smaller than the capacity of the bucket 6. It is desirable that the second accumulated body 210 be equally divided by the minimum number of divisions among the number of divisions that can make the division length b in the direction orthogonal to the straight line Lc smaller than the length L9 that is the width of the bucket 6.
In Step S11, the path planning unit 102 creates a plurality of straight lines passing through the first accumulated body top portion 201 and the midpoint 216 of the division length b of each equally divided part of the second accumulated body 210. In the example illustrated in Fig. 9, the second accumulated body 210 is equally divided into an odd number of accumulated bodies, and the second accumulated body top portion 211 coincides with one of the three midpoints 216. The straight line Lc is one of the straight lines passing through the first accumulated body top portion 201 and the midpoints 216. Straight lines Lc1 and Lc2 illustrated in Fig. 9 are straight lines passing through the midpoints 216 of the other two accumulated bodies obtained by dividing the second accumulated body 210 into three equal parts and the first accumulated body top portion 201.
Subsequently, in Step S12, the path planning unit 102 determines the extending direction of the straight line Lc as a first direction DR in which the travel device 4 of the wheel loader 1 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. The path planning unit 102 determines the extending direction of the straight line Lc1 as a second direction in which the travel device 4 of the wheel loader 1 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. The path planning unit 102 determines the extending direction of the straight line Lc2 as a third direction in which the travel device 4 of the wheel loader 1 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200.
In this manner, a series of processing for generating a path for the wheel loader 1 is ended ("end" in Fig. 7).
Fig. 10 is a flowchart illustrating another example of a flow of processing of generating a travel path for the wheel loader 1. Processing of determining a direction in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200 in a case where the first accumulated body 200 is a mountain of materials accumulated in a stockyard, which is an example of a material accumulation place, will be described with reference to Fig. 10 and subsequent Fig. 11.
As illustrated in Fig. 10, the perception device 111 mounted on the wheel loader 1 recognizes the stockyard first in Step S21. Objects at the work site detected by the perception device 111 include the stockyard. Fig. 11 is a schematic diagram illustrating an example of a traveling direction of the wheel loader 1 toward a stockyard 220. Fig. 11 illustrates a schematic view of the stockyard 220, the first accumulated body 200 accumulated in the stockyard 220, the second accumulated body 210 in the vicinity of the skirt of the first accumulated body 200, and the wheel loader 1 that stacks the materials forming the second accumulated body 210 on the first accumulated body 200 in a plan view.
The stockyard 220 includes a left side wall 221, a right side wall 222, and a back wall 223. The left side wall 221, the right side wall 222, and the back wall 223 are flat walls. The left side wall 221 and the right side wall 222 are disposed in parallel to each other. The left side wall 221 and the right side wall 222 extend orthogonal to the back wall 223. The left side wall 221 is coupled to one end of the back wall 223, and the right side wall 222 is coupled to the other end of the back wall 223. The stockyard 220 has a three-way frame shape in a plan view. The stockyard 220 is open on the lower side in Fig. 11. Through the opening, the wheel loader 1 can load materials on the stockyard 220 or excavate the first accumulated body 200 in the stockyard 220.
The perception device 111 is, for example, LiDAR, and inputs a point cloud indicating a detection result of the stockyard 220 to the position estimation unit 101 of the automation controller 100. The position estimation unit 101 recognizes the position and the shape of the stockyard 220 on the basis of the detection result of the perception device 111.
In Step S22, the perception device 111 recognizes the second accumulated body 210 in which the materials to be stacked on the first accumulated body 200 are accumulated on the ground at the work site. The objects at the work site detected by the perception device 111 include the second accumulated body 210. The perception device 111 is, for example, LiDAR, and inputs a point cloud indicating a detection result of the second accumulated body 210 to the position estimation unit 101 of the automation controller 100. The position estimation unit 101 recognizes the position and the shape of the second accumulated body 210 on the basis of the detection result of the perception device 111.
The second accumulated body 210 is a mountain of materials carried by the transport machine such as a dump truck to the work site and unloaded on the ground at the work site. The transport machine travels along a path that does not interfere with the first accumulated body 200 and reaches the position where the materials are to be unloaded. The transport machine unloads the materials at a position in the vicinity of the skirt of the first accumulated body 200. The unloaded materials form the second accumulated body 210.
The arrangement of the second accumulated body 210 with respect to the first accumulated body 200 may be determined in consideration of the angle of repose of the materials. It is desirable that the arrangement of the second accumulated body 210 with respect to the skirt of the first accumulated body 200 be determined such that the skirt of the second accumulated body 210 is arranged near the skirt of the first accumulated body 200. As illustrated in Fig. 5, it is desirable that the skirt of the second accumulated body 210 and the skirt of the first accumulated body 200 coincide with each other.
In Step S23, the position estimation unit 101 of the automation controller 100 creates an altitude model of the second accumulated body 210 from the point cloud detected by the LiDAR. In the example illustrated in Fig. 11, the position estimation unit 101 creates an altitude model of the second accumulated body 210 with a right circular cone shape.
In Step S24, the position estimation unit 101 of the automation controller 100 recognizes the mountaintop portion of the second accumulated body 210. The second accumulated body 210 has a non-uniform mountain height. A part of the second accumulated body 210 with the highest mountain height is the second accumulated body top portion 211 illustrated in Fig. 11. The skirt of the second accumulated body 210 has a circular shape in a plan view, and the center of the circle is the second accumulated body top portion 211.
In Step S25, the path planning unit 102 of the automation controller 100 creates a straight line Lc that passes through the second accumulated body top portion 211, which is the mountaintop portion of the second accumulated body 210, and is parallel to the left side wall 221 and the right side wall 222 of the stockyard 220.
In Step S26, the path planning unit 102 determines the extending direction of the straight line Lc created in Step S25 as a direction DR in which the travel device 4 of the wheel loader 1 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. In this manner, a series of processing of generating a travel path for the wheel loader 1 is ended ("end" in Fig. 10).
The wheel loader 1 can stack the materials forming the second accumulated body 210 on the first accumulated body 200 as described above with reference to Fig. 6 by the wheel loader 1 traveling straight along the straight line Lc (Lc1, Lc2) created in the example described above with reference to Figs. 7 to 9 or Figs. 10 and 11.

Although there is a description partially overlapping with the above description, the characteristic configurations and actions and effects of the present embodiment will be collectively described as follows.
As illustrated in Figs. 7 to 11, the position estimation unit 101 of the automation controller 100 recognizes the first accumulated body 200 in which materials that are targets to be worked on by the wheel loader 1 are accumulated on the ground at the work site and the second accumulated body 210 in which the materials to be stacked on the first accumulated body 200 are accumulated on the ground at the work site on the basis of the detection result of the perception device 111. The path planning unit 102 of the automation controller 100 determines the first direction DR in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200 on the basis of the information regarding the first accumulated body 200 and the information regarding the second accumulated body 210.
The information regarding the first accumulated body 200 includes appearance features of the first accumulated body 200. The appearance features of the first accumulated body 200 include the shape of the first accumulated body 200 and the position of the first accumulated body 200 (the position of the top portion or the center of gravity of the first accumulated body 200 as described above). The information regarding the second accumulated body 210 includes appearance features of the second accumulated body 210. The appearance features of the second accumulated body 210 include the shape of the second accumulated body 210 and the position of the second accumulated body 210 (the position of the top portion or the center of gravity of the second accumulated body 210 as described above).
The path planning unit 102 can determine the first direction DR in which the travel device 4 is to travel on the basis of the information regarding the first accumulated body 200 and the information regarding the second accumulated body 210. The path planning unit 102 determines traveling direction in which the wheel loader 1 can efficiently perform work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200 as the first direction DR. The wheel loader 1 can efficiently perform the work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200 by traveling along the determined path.
As illustrated in Figs. 7 to 11, the path planning unit 102 may regard the extending direction of the straight line Lc passing through the second accumulated body top portion 211 with the highest mountain height in the second accumulated body 210 as the first direction DR in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. The bucket 6 passes through the second accumulated body top portion 211 when the bucket 6 scoops the materials forming the second accumulated body 210 by the wheel loader 1 traveling along the thus determined path. Since it is possible to load a large amount of materials forming the second accumulated body 210 on the bucket 6, the wheel loader 1 can efficiently perform the work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200.
As illustrated in Figs. 7 to 9, the path planning unit 102 may regard the extending direction of the straight line Lc passing through the first accumulated body top portion 201 with the highest mountain height in the first accumulated body 200 as the first direction DR in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. The materials forming the second accumulated body 210 are stacked toward the first accumulated body top portion 201 of the first accumulated body 200 by the wheel loader 1 traveling along the thus determined path. It is thus possible to adjust the shape of the first accumulated body 200 after the stacking work.
As illustrated in Figs. 1 and 2, the wheel loader 1 includes the work implement 3. The work implement 3 includes the bucket 6 at the distal end. As illustrated in Fig. 6, the wheel loader 1 performs the work of stacking the materials transported into the work site by the transport machine by using the work implement 3. As illustrated in Figs. 7 to 9, the path planning unit 102 may determine the second direction in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200 in a case where the length of extension of the second accumulated body 210 in the direction orthogonal to the first direction DR is longer than the width of the bucket 6.
In a case where the wheel loader 1 cannot stack the materials forming the second accumulated body 210 on the first accumulated body 200 in one operation and it is necessary to travel a plurality of times to stack the materials forming the second accumulated body 210 on the first accumulated body 200, it is possible to determine a plurality of appropriate directions in which the travel device 4 is to travel when the materials are stacked on the basis of the dimension of the work implement 3, which is a work tool, and the information regarding the first accumulated body 200 and the second accumulated body 210. The wheel loader 1 can efficiently perform the work of stacking the materials forming the second accumulated body 210 on the first accumulated body 200 by the wheel loader 1 traveling toward the materials along the thus determined path.
As illustrated in Figs. 7 to 9, the path planning unit 102 may determine the extending direction of the straight line Lc1 passing through the midpoint 216 of the division length b obtained by equally dividing the length of extension of the second accumulated body 210 in the direction orthogonal to the first direction DR as the second direction in which the travel device 4 is to travel when the materials forming the second accumulated body 210 are stacked on the first accumulated body 200. It is possible to stack the materials forming the second accumulated body 210 on the first accumulated body 200 without any of them left, by the wheel loader 1 traveling along the thus determined path.
The automation controller 100 that forms the automatic control system of the wheel loader 1 described in the above embodiment is not necessarily mounted on the wheel loader 1. A controller outside the wheel loader 1 may construct a system included in the automation controller 100. A controller mounted on the wheel loader 1 may perform processing of transmitting information acquired by the external information acquisition unit 110, the vehicle information acquisition unit 120, and the like to the external controller, and the external controller having received a signal may determine the direction in which the travel device 4 is to travel.
The external controller may be disposed at the work site of the wheel loader 1, or may be disposed at a remote place away from the work site of the wheel loader 1. The external controller may be a portable device. The external controller may be a portable device that can be carried and used by a worker, such as a notebook computer, a tablet computer, or a smartphone.
In the embodiment, the example in which the perception device 111 mounted on the wheel loader 1 detects the first accumulated body 200 has been described. The object sensor that detects objects at the work site where the wheel loader 1 works may not necessarily be mounted on the wheel loader 1. The object sensor may be disposed outside the work machine. For example, the object sensor may be disposed at a predetermined point of the work site, may be mounted on another work machine, or may be mounted on an unmanned aerial vehicle such as a drone.
In the embodiment, the example in which the wheel loader 1 includes the cab 5 and is a manned vehicle in which the operator boards the cab 5 has been described. The wheel loader 1 may be an unmanned vehicle. The wheel loader 1 may not include the cab 5 for the operator to board and operate. The wheel loader 1 may not include a manipulation function by a boarding operator. The wheel loader 1 may be a work machine dedicated to remote manipulation. The manipulation of the wheel loader 1 may be performed by a radio signal from a remote manipulation device.

The above description includes the following features.

(Supplement 1)

A system including:

a work machine that includes a travel body and works at a work site;
a sensor that detects objects at the work site; and
a controller that provides an instruction for an operation of the work machine,
in which the controller recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at the work site and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of the sensor, and determines a first direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.

(Supplement 2)

The system according to Supplement 1,

in which the second accumulated body includes a second accumulated body top portion with the highest height, and
the controller regards a direction in which a straight line passing through the second accumulated body top portion extends as the first direction.

(Supplement 3)

The system according to Supplement 1 or 2,

in which the first accumulated body includes a first accumulated body top portion with the highest height, and
the controller regards a direction in which a straight line passing through the first accumulated body top portion extends as the first direction.

(Supplement 4)

The system according to any one of Supplements 1 to 3,

in which the work machine includes a work implement with a bucket provided at a distal end, and
the controller determines a second direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body in a case where a length of extension of the second accumulated body in an orthogonal direction with respect to the first direction is greater than a width of the bucket.

(Supplement 5)

The system according to Supplement 4,
in which the controller regards a direction in which a straight line passing through a midpoint of a division length obtained by equally dividing a length of extension of the second accumulated body in the orthogonal direction extends as the second direction.
It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

Reference Signs List

1: Wheel loader
2: Vehicle body frame
2a: Front frame
2b: Rear frame
3: Work implement
4: Travel device
4a: Front wheel
4b: Rear wheel
6: Bucket
6a: Blade edge
6c: Width direction center
14: Boom
50: Vehicle body controller
60: Engine controller
70: Transmission controller
80: Work implement controller
100: Automation controller
101: Position estimation unit
102: Path planning unit
103: Path follow-up control unit
110: External information acquisition unit
111: Perception device
120: Vehicle information acquisition unit
150: Communication device
200: First accumulated body
201: First accumulated body top portion
202: Skirt
205: Slope
210: Second accumulated body
211: Second accumulated body top portion
216: Midpoint
220: Stockyard
221: Left side wall
222: Right side wall
223: Back wall
Lc, Lc1, Lc2: Straight line
Ld1, Ld2: Division line.

Claims

A system comprising:
a work machine that includes a travel body and works at a work site;

a sensor that detects objects at the work site; and

a controller that provides an instruction for an operation of the work machine,

wherein the controller recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at the work site and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of the sensor, and determines a first direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.
The system according to claim 1,
wherein the second accumulated body includes a second accumulated body top portion with the highest height, and

the controller regards a direction in which a straight line passing through the second accumulated body top portion extends as the first direction.
The system according to claim 1 or 2,
wherein the first accumulated body includes a first accumulated body top portion with the highest height, and

the controller regards a direction in which a straight line passing through the first accumulated body top portion extends as the first direction.
The system according to claim 1 or 2,
wherein the work machine includes a work implement with a bucket provided at a distal end, and

the controller determines a second direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body in a case where a length of extension of the second accumulated body in an orthogonal direction with respect to the first direction is greater than a width of the bucket.
The system according to claim 4,
wherein the controller regards a direction in which a straight line passing through a midpoint of a division length obtained by equally dividing a length of extension of the second accumulated body in the orthogonal direction extends as the second direction.
A controller for a work machine which
recognizes a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at a work site where the work machine equipped with a travel body works and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of a sensor that detects objects at the work site, and

determines a direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.
A path generation method for a work machine comprising:
recognizing a first accumulated body in which targets to be worked on by the work machine are accumulated on a ground at a work site where the work machine equipped with a travel body works and a second accumulated body in which materials to be stacked on the first accumulated body are accumulated on the ground at the work site on the basis of a detection result of a sensor that detects objects at the work site; and

determining a direction in which the travel body is to travel when the materials forming the second accumulated body are stacked on the first accumulated body on the basis of information regarding the first accumulated body and information regarding the second accumulated body.