System, controller for work machine, and method for deciding material positioning

Abstract

A position at which a transport machine is to unload materials at a work site is appropriately determined. The transport machine transports the materials at the work site. A sensor detects an accumulated body of the materials accumulated on the ground at the work site. A controller provides a command for an operation of the transport machine. The controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body.

Description

Technical Field

[0001] The present disclosure relates to a system, a controller for a work machine, and a method of determining disposition of materials.Background Art

[0002] US 2020 / 0190775 A (Patent Literature 1) discloses that a transport machine moves materials from a loading position to a dumping position and unloads the materials at the dumping position.Citation ListPatent Literature

[0003] Patent Literature 1: US 2020 / 0190775 ASummary of InventionTechnical Problem

[0004] 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 the work, appropriately disposing the materials transported by the transport machine at the work site is required.

[0005] The present disclosure proposes a technique capable of appropriately determining a position at which a transport machine is to unload materials at a work site.Solution to Problem

[0006] A system according to a certain aspect of the present disclosure includes: a transport machine that transports materials at a work site; a sensor that detects an accumulated body of the materials accumulated on ground at the work site; and a controller that provides a command for an operation of the transport machine. The controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body.

[0007] A system according to a certain aspect of the present disclosure includes: a sensor that detects an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and a controller. The controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which an amount of the accumulated materials in the accumulated body is a minimum on the basis of information regarding the accumulated body.

[0008] A controller for a work machine according to a certain aspect of the present disclosure recognizes an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site. The controller determines a position at which a transport machine transporting the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.

[0009] A method of determining disposition of materials according to a certain aspect of the present disclosure includes the following steps. A first step is recognizing an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site. A second step is determining a position at which a transport machine carrying the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.Advantageous Effects of Invention

[0010] According to the present disclosure, it is possible to appropriately determine the position at which a transport machine is to unload materials at a work site.Brief Description of Drawings

[0011] 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 determining a position at which a transport machine is to unload materials. Fig. 8 is a schematic diagram illustrating an example of an altitude model of an accumulated body of the materials. Fig. 9 is a schematic diagram illustrating a first example of disposition of a bucket with respect to the accumulated body illustrated in Fig. 8. Fig. 10 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 8. Fig. 11 is a schematic diagram illustrating another example of the accumulated body of the materials and a first example of disposition of the bucket. Fig. 12 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 11. Fig. 13 is a flowchart illustrating a flow of processing of the transport machine unloading the materials. Fig. 14 is a schematic diagram illustrating a first example of disposition of materials forming a second accumulated body. Fig. 15 is a schematic diagram illustrating a second example of disposition of the materials forming the second accumulated body. Description of Embodiments

[0012] 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.<Overall Configuration of Wheel Loader 1>

[0013] 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.

[0014] 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.

[0015] 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".

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The boom cylinders 16 and the bucket cylinder 19 form a work implement actuator that drives the work implement 3.

[0026] 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.

[0027] 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.

[0028] 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.<System Configuration>

[0029] Fig. 3 is a block diagram illustrating a schematic configuration of a control system that controls the wheel loader 1.

[0030] 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.

[0031] 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.

[0032] Apart 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.

[0033] 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.

[0034] 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.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.<Automatic Control System of Wheel Loader 1>

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The automation controller 100 includes a position estimation unit 101, a path planning unit 102, and a path follow-up control unit 103.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.<Stacking Work of Materials>

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.<Flow for determining disposition of materials>

[0074] In order for the wheel loader 1 to efficiently perform the work of stacking the materials, appropriately disposing the materials to be transported by the transport machine at the work site is required. Fig. 7 is a flowchart illustrating a flow of processing of determining the position at which the transport machine is to unload the materials. Control to automatically determine the disposition of the materials that the transport machine is to unload on the ground will be described with reference to Fig. 7 and subsequent Figs. 8 to 12 as needed.

[0075] As illustrated in Fig. 7, the perception device 111 mounted on the wheel loader 1 detects 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.

[0076] 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 an example of an altitude model of the first accumulated body 200, which is an accumulated body of materials. The first accumulated body 200 illustrated in Fig. 8 and subsequent Figs. 9 and 10 is accumulated at a stockyard 220, which is an example of a material accumulation place. Fig. 8 illustrates a schematic view of the stockyard 220 and the first accumulated body 200 accumulated at the stockyard 220 in a plan view.

[0077] 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 orthogonally 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. 8. 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.

[0078] In the first accumulated body 200 illustrated in Fig. 8, the first accumulated body top portion 201 is a part with the highest mountain height. The skirt 202 is schematically illustrated linearly. In the vicinity of the skirt 202, the first accumulated body 200 includes a low mountain region 203 in which the amount of accumulated materials is small and the mountain height is low and an accumulation region 204 in which the amount of accumulated materials is larger than that in the low mountain region 203 and the mountain height is higher than that in the low mountain region 203.

[0079] The direction in which the left side wall 221 and the right side wall 222 extend (the up-down direction in Fig. 8) is the direction in which the wheel loader 1 travels straight toward the first accumulated body 200 when the wheel loader 1 stacks the materials on the first accumulated body 200. In the direction orthogonal to the traveling direction (the left-right direction in Fig. 8; hereinafter, referred to as an orthogonal direction in the specification), the back wall 223 extends. The first accumulated body 200 has a non-uniform mountain height in the orthogonal direction.

[0080] Returning to Fig. 7, the path planning unit 102 of the automation controller 100 calculates the amount of accumulated materials in a section obtained by virtually sectioning the first accumulated body 200 in units of the dimension of the width of the bucket 6 in the orthogonal direction in Step S3.

[0081] Fig. 9 is a schematic diagram illustrating a first example of disposition of the bucket 6 with respect to the first accumulated body 200 illustrated in Fig. 8. Fig. 9 and subsequent Fig. 10 schematically illustrate the bucket 6 of the wheel loader 1. As illustrated in Fig. 2, the length L9 is the dimension of the width of the bucket 6. The length L9 is an example of the dimension of the work implement 3. The rectangles illustrated by the two-dotted chain lines in Figs. 9 and 10 indicate sections obtained by sectioning the first accumulated body 200 by the dimension of the width of the bucket 6 in the orthogonal direction.

[0082] Fig. 9 illustrates disposition with the left end of the bucket 6 aligned with the left side wall 221 of the stockyard 220. In Fig. 9, a large amount of low mountain region 203 illustrated by the rough hatching in the drawing is included in the section surrounded by the two-dotted chain line. Therefore, the amount of accumulated materials in the section surrounded by the two-dotted chain line is small.

[0083] Fig. 10 is a schematic diagram illustrating a second example of disposition of the bucket 6 with respect to the first accumulated body 200 illustrated in Fig. 8. Fig. 10 illustrates disposition with the left end of the bucket 6 spaced apart from the left side wall 221 of the stockyard 220 achieved by causing the bucket 6 illustrated in Fig. 9 to move in the orthogonal direction. In Fig. 10, the amount of low mountain region 203 included in the section surrounded by the two-dotted chain line is small, and a region that is higher than the mountain height indicated by fine hatching in the drawing is included in the section. A part of the first accumulated body top portion 201 is included in the section surrounded by the two-dotted chain line in Fig. 10. The amount of accumulated materials in the section surrounded by the two-dotted chain line in Fig. 10 is larger than the amount of accumulated materials in the section illustrated in Fig. 9.

[0084] The amount of movement of the bucket 6 from the position of the bucket 6 illustrated in Fig. 9 to the position thereof illustrated in Fig. 10 is regarded as a unit amount of movement of the bucket 6 when the amount of accumulated materials is calculated in units of the width of the bucket. The unit amount of movement of the bucket 6 may be set with reference to the bucket width (length L9) or may be set with reference to the dimension of the stockyard 220. The path planning unit 102 causes the bucket 6 to move rightward by the unit amount of movement from the state in which the left end of the bucket 6 is aligned with the left side wall 221 of the stockyard 220 as illustrated in Fig. 9 and calculates the amount of accumulated materials in each section. The path planning unit 102 continues the calculation until disposition in which the right end of the bucket 6 is aligned with the right side wall 222 of the stockyard 220 is achieved.

[0085] Distribution of the amount of accumulated materials in the orthogonal in the first accumulated body 200 is calculated by completing the calculation of the amount of accumulated materials in units of the bucket width. Returning to Fig. 7, the path planning unit 102 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200 on the basis of the dimension of the work implement 3 and the shape of the first accumulated body 200 next in Step S4. The path planning unit 102 compares the amount of accumulated materials calculated for each section obtained by sectioning the first accumulated body 200 by the dimension of the width of the bucket 6, and determines the minimum amount of accumulation. The path planning unit 102 obtains the section corresponding to the minimum amount of accumulation and obtains the position of the bucket 6 when the section is sectioned. The path planning unit 102 obtains a position at which the least amount of materials are accumulated in the orthogonal direction in the first accumulated body 200.

[0086] In the exemplary case of the first accumulated body 200 illustrated in Figs. 8 to 10, the first accumulated body top portion 201 is located at a position closer to the right side wall 222 than to the left side wall 221 of the stockyard 220, and the low mountain region 203 extends along the left side wall 221 of the stockyard 220. In the exemplary case of the first accumulated body 200 illustrated in Figs. 8 to 10, the amount of accumulated materials in the section in the case where the left end of the bucket 6 is aligned with the left side wall 221 of the stockyard 220 as illustrated in Fig. 9 is a minimum. The path planning unit 102 obtains the position of the bucket 6 in the orthogonal direction that minimizes the amount of accumulated materials on the basis of the bucket width and the shape of the first accumulated body 200.

[0087] In Step S5, the path planning unit 102 determines the position obtained in Step S4 as the position at which the transport machine is to unload the materials. In this manner, the position at which the transport machine is to unload the materials with respect to the first accumulated body 200 accumulated in the stockyard 220 is determined ("end" in Fig. 7).

[0088] Fig. 11 is a schematic diagram illustrating another example of the accumulated body of the materials and a first example of disposition of the bucket 6. The first accumulated body 200 illustrated in Fig. 11 and subsequent Fig. 12 is a mountain of materials formed in a vacant place. 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. The materials dropped on the flat ground are ideally accumulated in a right circular cone shape. The angle formed by the conical surface of the right circular cone and the ground is an angle of repose of the materials. Two one-dotted chain lines illustrated in Figs. 11 and 12 extend in the radial direction of the circle formed by the skirt 202 and are orthogonal to each other. Therefore, the one-dotted chain lines pass the first accumulated body top portion 201 at the center of the circle.

[0089] An altitude model of the first accumulated body 200 is created from the point cloud of the first accumulated body 200 detected by the LiDAR, which is the perception device 111. The bucket 6 is disposed in the circumferential direction of the circle formed by the skirt 202 with respect to the first accumulated body 200 with the conical shape illustrated in Figs. 11 and 12. The path planning unit 102 of the automation controller 100 assumes a fan-shaped section surrounded by an arc corresponding to the bucket width and two radii of the circle, and calculates the amount of accumulated materials in the section.

[0090] Fig. 12 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 11. The bucket 6 is caused to move by a unit angle in the counterclockwise direction in the circumferential direction of the circle. The unit angle is an angle obtained by equally dividing the circumferential angle of 360°. The unit angle may be 1°. The path planning unit 102 causes the bucket 6 to move by a unit angle and calculates the amount of loaded materials in each section. The path planning unit 102 continues the calculation until the bucket 6 moves by 360° in the circumferential direction of the circle.

[0091] Once the calculation of the amount of accumulated materials in units of bucket width is completed, the path planning unit 102 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200. The path planning unit 102 compares the amount of accumulated materials calculated for each section and determines the minimum amount of accumulation. The path planning unit 102 obtains the section corresponding to the minimum amount of accumulation and obtains the position of the bucket 6 when the section is sectioned.

[0092] Although the first accumulated body 200 of the materials ideally has a conical shape as described above, the particle diameters of the materials are not constant in practice, the shape of the skirt 202 is thus not a perfect circle, and the shape of the first accumulated body 200 may not be a right circular cone. In addition, the shape of the first accumulated body 200 becomes a shape that is not a right circular cone after a part of the materials in the first accumulated body 200 is excavated.

[0093] In a case where the bucket 6 is caused to move by 360° in the circumferential direction of the circle centered on the first accumulated body top portion 201, the amount of accumulated materials in the section defined by the two radii and the arc therebetween may not be constant, and the amount of accumulated materials in each section may vary. The path planning unit 102 determines the section in which the amount of accumulated materials is a minimum and obtains the position of the bucket 6 corresponding to the section. The path planning unit 102 determines the position as the position at which the transport machine is to unload the materials.<Flow of unloading materials>

[0094] Fig. 13 is a flowchart illustrating a flow of processing of the transport machine unloading the materials. As illustrated in Fig. 13, the transport machine transports the materials that are targets to be worked on by the wheel loader 1 in Step S11. The transport machine is, for example, a dump truck. The dump truck includes a vessel. The dump truck transports the materials by the dump track traveling in a state where the materials are loaded in the vessel.

[0095] In Step S12, the transport machine with the materials loaded thereon arrives at the work site where the wheel loader 1 is to work.

[0096] In Step S13, the transport machine receives the position at which the materials are to be unloaded. The transport machine includes a communication device, which is not illustrated, and is configured to be able to wirelessly communicate with the outside. As described above with reference to Fig. 4, for example, the path follow-up control unit 103 of the automation controller 100 can transmit, to the transport machine, a signal indicating the position where the materials are to be unloaded, which has been determined in the flow illustrated in Fig. 7, via the communication device 150 and provide an instruction for the unloading position to the transport machine. Alternatively, a signal indicating the unloading position may be transmitted from the automation controller 100 to control, and the signal may be transmitted from the control to the transport machine to provide the instruction for the unloading position to the transport machine.

[0097] In Step S14, the transport machine unloads the loaded materials at the position, at which the materials are to be unloaded, which has been received in previous Step S13.

[0098] Fig. 14 is a schematic diagram illustrating a first example of disposition of materials forming the second accumulated body 210. A transport machine 300 illustrated in Figs. 14 and 15 is a dump truck and includes a vessel 301. The transport machine 300 transports the materials at the work site by the transport machine 300 traveling in the work site in a state where the materials are loaded in the vessel 301. The transport machine 300 approaches the first accumulated body 200. As described above, the second accumulated body 210 is an accumulated body in which the materials that are to be stacked on the first accumulated body 200 are accumulated on the ground at the work site. The first accumulated body 200 illustrated in Figs. 14 and 15 has a substantially conical shape similarly to Figs. 11 and 12. The position of the one-dotted chain line passing through the first accumulated body top portion 201 is the position at which the amount of accumulated materials is a minimum and the transport machine 300 is to unload the materials. When the wheel loader 1 stacks the materials forming the second accumulated body 210 on the first accumulated body 200, the travel device 4 travels straight along the one-dotted chain line.

[0099] The transport machine 300 travels along a path that does not interfere with the first accumulated body 200 and reaches the position at which the materials are to be unloaded. The transport machine 300 unloads the materials at the position passing through the one-dotted chain line in the circumferential direction centered on the first accumulated body top portion 201. The transport machine 300 unloads the materials at the 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.

[0100] 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.

[0101] Fig. 15 is a schematic diagram illustrating a second example of disposition of the materials forming the second accumulated body 210. Fig. 15 illustrates an exemplary case in which the amount of materials transported by the transport machine 300 is larger than the capacity of the bucket 6 of the wheel loader 1. The position of the one-dotted chain line passing through the first accumulated body top portion 201 is determined as the center of the position at which the amount of accumulated materials is a minimum and the transport machine 300 is to unload the materials. The direction in which the one-dotted chain line passing through the first accumulated body top portion 201 is one path along which the travel device 4 travels when the wheel loader 1 stacks the materials forming the second accumulated body 210 on the first accumulated body 200.

[0102] An instruction for the operation of the transport machine 300 is provided such that the transport machine 300 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. The transport machine 300 unloads the materials loaded in the vessel 301 on the ground while slightly traveling forward along the one-dotted chain line that is orthogonal to the one-dotted chain line passing through the first accumulated body top portion 201 and extends in the tangential direction of the circle centered on the first accumulated body top portion 201. The skirt of the second accumulated body 210 is formed into an elliptical shape in a plan view through the unloading work. The length in which the second accumulated body 210 extends in the tangential direction of the circle centered on the first accumulated body top portion 201 is larger than the width (the length L9; Fig. 2) of the bucket 6 of the wheel loader 1. Fig. 2) of the bucket 6 of the wheel loader 1.

[0103] The materials forming the second accumulated body 210 is stacked on the first accumulated body 200 by the wheel loader 1 operating as described above with reference to Fig. 6. The position at which the transport machine 300 is to unload the materials is determined to form the second accumulated body 210 at the position at which the amount of accumulated materials is a minimum in the first accumulated body 200. In the first accumulated body 200 after the second accumulated body 210 is stacked thereon, variations in the amount of accumulated materials are reduced, and uniformity of the shape is improved. The first accumulated body 200 after the second accumulated body 210 is stacked thereon has a more uniform shape.<Actions and Effects>

[0104] 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.

[0105] The perception device 111 detects the first accumulated body 200 in which the materials that are targets to be worked on by the wheel loader 1 are accumulated on the ground at the work site. As illustrated in Figs. 7 and 8 to 12, the path planning unit 102 of the automation controller 100 determines the position at which the transport machine 300 is to unload the materials at the work site on the basis of the information regarding the first accumulated body 200. 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).

[0106] The path planning unit 102 can determine an appropriate position at which the transport machine 300 is to unload the materials at the work site on the basis of the information regarding the first accumulated body 200. The path planning unit 102 can determine, as the position at which the materials are to be unloaded, the position at which the wheel loader 1 can efficiently perform the work of stacking the materials on the first accumulated body 200. The wheel loader 1 can efficiently perform the work of stacking the unloaded materials on the first accumulated body 200 by the transport machine 300 unloading the materials at the determined position.

[0107] As illustrated in Figs. 1 and 2, the wheel loader 1 includes the work implement 3. 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 300 by using the work implement 3. The path planning unit 102 may determine the position at which the transport machine 300 is to unload the materials at the work site on the basis of the dimension of the work implement 3 of the wheel loader 1 and the information regarding the first accumulated body 200. The wheel loader 1 can efficiently perform the work of stacking the unloaded materials on the first accumulated body 200 by determining the appropriate position at which the transport machine 300 is to unload the materials at the work site 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 by the transport machine 300 unloading the materials at the determined position.

[0108] As illustrated in Figs. 1 and 2, the work implement 3 includes the bucket 6 at the distal end. As illustrated in Figs. 9 to 12, the path planning unit 102 may determine the position at which the transport machine 300 is to unload the materials at the work site on the basis of the width of the bucket 6 and the information regarding the first accumulated body 200. The wheel loader 1 performs an operation of scooping the materials into the bucket 6 while traveling forward, and stacking the scooped materials. The dimension of the width of the bucket 6 corresponds to a range in which the stacking operation can be performed by one forward traveling operation of the wheel loader 1, and it is possible to state that the dimension is a reference dimension for the work of the wheel loader 1. It is possible to appropriately determine the position at which the materials are to be unloaded such that the wheel loader 1 can efficiently perform the work of stacking the materials, on the basis of the width of the bucket 6.

[0109] As illustrated in Figs. 9 to 12, the section that is obtained by sectioning the first accumulated body 200 by the length L9 which is the dimension of the width of the bucket 6 and that includes a minimum amount of accumulated materials in the direction orthogonal to the direction in which the travel device 4 travels toward the first accumulated body 200 when the wheel loader 1 stacks the materials on the first accumulated body 200 may be regarded as the position at which the transport machine 300 is to unload the materials. The distribution of the amount of accumulated materials is calculated in units of the width of the bucket 6 with which the wheel loader 1 performs the work of stacking the materials, and setting is performed such that the materials are to be unloaded at the position of the minimum amount of accumulation. The shape of the first accumulated body 200 after the stacking work can be adjusted by the wheel loader 1 performing the work of stacking the unloaded materials on the first accumulated body 200.

[0110] An illustrated in Figs. 14 and 15, the path follow-up control unit 103 of the automation controller 100 may provide an instruction for an operation of the transport machine 300 to unload 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 on the first accumulated body 200. Since the direction in which the material is unloaded is determined, it is possible to suppress interference between the transport machine 300 that performs the work of unloading the materials and the first accumulated body 200. In addition, it is possible to form the materials to be unloaded from the transport machine 300 into a shape with which the wheel loader 1 can easily perform the stacking operation. It is thus possible to improve workability.

[0111] As illustrated in Fig. 15, the amount of materials to be transported by the transport machine 300 may be larger than the capacity of the bucket 6. The materials, the amount of which is larger than the capacity of the bucket 6, are unloaded 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 on the first accumulated body 200. It is thus possible to form the materials to be unloaded from the transport machine 300 into a shape with which the wheel loader 1 can easily perform the stacking work and to thereby improve workability.

[0112] As illustrated in Figs. 4 and 13, the path follow-up control unit 103 of the automation controller 100 may transmit the position, at which the materials are to be unloaded, which has been determined by the path planning unit 102, to the transport machine 300. The transport machine 300 unloads the materials at the received position. The materials are unloaded at the appropriate position determined on the basis of the dimension of the work implement 3 and the information regarding the first accumulated body 200. The wheel loader 1 can efficiently stack the unloaded materials on the first accumulated body 200.

[0113] As illustrated in Figs. 7 and 8 to 10, the path planning unit 102 of the automation controller 100 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200 on the basis of the information regarding the first accumulated body 200. The transport machine 300 can unload the materials at the position at which the amount of accumulated materials is a minimum, the wheel loader 1 can stack the unloaded materials on the first accumulated body 200, and it is thus possible to adjust the shape of the first accumulated body 200 after the stacking work.

[0114] 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. The 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 an external controller, and the external controller that has received a signal may determine the position at which the transport machine 300 is to unload the materials.

[0115] 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.

[0116] 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.

[0117] 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.<Supplement>

[0118] The above description includes the following features.(Supplement 1)

[0119] A system including: a transport machine that transports materials at a work site; a sensor that detects an accumulated body of the materials accumulated on ground at the work site; and a controller that provides an instruction for an operation of the transport machine, in which the controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body. (Supplement 2)

[0120] The system according to Supplement 1, in which the work machine working at the work site includes a work implement, and the controller determines the position at which the transport machine is to unload the materials on the basis of a dimension of the work implement as well. (Supplement 3)

[0121] The system according to Supplement 2, in which the work implement includes a bucket at a distal end, and the dimension of the work implement includes a width of the bucket. (Supplement 4)

[0122] The system according to Supplement 3, in which the work machine includes a travel body, and the controller regards, as the position at which the transport machine is to unload the materials, a section that is obtained by sectioning the accumulated body by a dimension of the width of the bucket and that includes a minimum amount of accumulated materials, in an orthogonal direction with respect to a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body. (Supplement 5)

[0123] The system according to any one of Supplements 1 to 4, in which a work machine working at the work site includes a travel body, and the controller provides an instruction for an operation of the transport machine to unload the materials in a direction intersecting a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body. (Supplement 6)

[0124] The system according to Supplement 5, in which the work machine includes a work implement with a bucket provided at a distal end, and an amount of materials transported by the transport machine is larger than a capacity of the bucket. (Supplement 7)

[0125] The system according to any one of Supplements 1 to 6, in which the controller transmits the position at which the materials are to be unloaded to the transport machine.(Supplement 8)

[0126] A system including: a sensor that detects an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and a controller, in which the controller recognizes the accumulated body on the basis of a detection result of the sensor and obtains a position at which an amount of accumulated materials in the accumulated body is a minimum on the basis of information regarding the accumulated body. (Supplement 9)

[0127] The system according to Supplement 8, in which the work machine includes a work implement, and the controller obtains the position at which the amount of accumulation is a minimum on the basis of a dimension of the work implement as well. (Supplement 10)

[0128] The system according to Supplement 9, in which the work implement includes a bucket at a distal end, and the dimension of the work implement includes a width of the bucket.

[0129] 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

[0130] 1Wheel loader 2Vehicle body frame 2aFront frame 2bRear frame 3Work implement 4Travel device 4aFront wheel 4bRear wheel 6Bucket 6aBlade edge 6cWidth direction center 14Boom 50Vehicle body controller 60Engine controller 70Transmission controller 80Work implement controller 100Automation controller 101Position estimation unit 102Path planning unit 103Path follow-up control unit 110External information acquisition unit 111Perception device 120Vehicle information acquisition unit 150Communication device 200First accumulated body 201First accumulated body top portion 202Skirt 203Low mountain region 204Accumulation region 205Slope 210Second accumulated body 220Stockyard 221Left side wall 222Right side wall 223Back wall 300Transport machine 301Vessel.

Examples

Embodiment Construction

[0012]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.

[0013]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.

[0014]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. Th...

Technical Field

[0001] The present disclosure relates to a system, a controller for a work machine, and a method of determining disposition of materials.Background Art

[0002] US 2020 / 0190775 A (Patent Literature 1) discloses that a transport machine moves materials from a loading position to a dumping position and unloads the materials at the dumping position.Citation ListPatent Literature

[0003] Patent Literature 1: US 2020 / 0190775 ASummary of InventionTechnical Problem

[0004] 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 the work, appropriately disposing the materials transported by the transport machine at the work site is required.

[0005] The present disclosure proposes a technique capable of appropriately determining a position at which a transport machine is to unload materials at a work site.Solution to Problem

[0006] A system according to a certain aspect of the present disclosure includes: a transport machine that transports materials at a work site; a sensor that detects an accumulated body of the materials accumulated on ground at the work site; and a controller that provides a command for an operation of the transport machine. The controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body.

[0007] A system according to a certain aspect of the present disclosure includes: a sensor that detects an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and a controller. The controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which an amount of the accumulated materials in the accumulated body is a minimum on the basis of information regarding the accumulated body.

[0008] A controller for a work machine according to a certain aspect of the present disclosure recognizes an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site. The controller determines a position at which a transport machine transporting the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.

[0009] A method of determining disposition of materials according to a certain aspect of the present disclosure includes the following steps. A first step is recognizing an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site. A second step is determining a position at which a transport machine carrying the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.Advantageous Effects of Invention

[0010] According to the present disclosure, it is possible to appropriately determine the position at which a transport machine is to unload materials at a work site.Brief Description of Drawings

[0011] 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 determining a position at which a transport machine is to unload materials. Fig. 8 is a schematic diagram illustrating an example of an altitude model of an accumulated body of the materials. Fig. 9 is a schematic diagram illustrating a first example of disposition of a bucket with respect to the accumulated body illustrated in Fig. 8. Fig. 10 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 8. Fig. 11 is a schematic diagram illustrating another example of the accumulated body of the materials and a first example of disposition of the bucket. Fig. 12 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 11. Fig. 13 is a flowchart illustrating a flow of processing of the transport machine unloading the materials. Fig. 14 is a schematic diagram illustrating a first example of disposition of materials forming a second accumulated body. Fig. 15 is a schematic diagram illustrating a second example of disposition of the materials forming the second accumulated body. Description of Embodiments

[0012] 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.<Overall Configuration of Wheel Loader 1>

[0013] 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.

[0014] 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.

[0015] 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".

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The boom cylinders 16 and the bucket cylinder 19 form a work implement actuator that drives the work implement 3.

[0026] 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.

[0027] 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.

[0028] 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.<System Configuration>

[0029] Fig. 3 is a block diagram illustrating a schematic configuration of a control system that controls the wheel loader 1.

[0030] 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.

[0031] 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.

[0032] Apart 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.

[0033] 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.

[0034] 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.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.<Automatic Control System of Wheel Loader 1>

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The automation controller 100 includes a position estimation unit 101, a path planning unit 102, and a path follow-up control unit 103.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.<Stacking Work of Materials>

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.<Flow for determining disposition of materials>

[0074] In order for the wheel loader 1 to efficiently perform the work of stacking the materials, appropriately disposing the materials to be transported by the transport machine at the work site is required. Fig. 7 is a flowchart illustrating a flow of processing of determining the position at which the transport machine is to unload the materials. Control to automatically determine the disposition of the materials that the transport machine is to unload on the ground will be described with reference to Fig. 7 and subsequent Figs. 8 to 12 as needed.

[0075] As illustrated in Fig. 7, the perception device 111 mounted on the wheel loader 1 detects 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.

[0076] 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 an example of an altitude model of the first accumulated body 200, which is an accumulated body of materials. The first accumulated body 200 illustrated in Fig. 8 and subsequent Figs. 9 and 10 is accumulated at a stockyard 220, which is an example of a material accumulation place. Fig. 8 illustrates a schematic view of the stockyard 220 and the first accumulated body 200 accumulated at the stockyard 220 in a plan view.

[0077] 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 orthogonally 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. 8. 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.

[0078] In the first accumulated body 200 illustrated in Fig. 8, the first accumulated body top portion 201 is a part with the highest mountain height. The skirt 202 is schematically illustrated linearly. In the vicinity of the skirt 202, the first accumulated body 200 includes a low mountain region 203 in which the amount of accumulated materials is small and the mountain height is low and an accumulation region 204 in which the amount of accumulated materials is larger than that in the low mountain region 203 and the mountain height is higher than that in the low mountain region 203.

[0079] The direction in which the left side wall 221 and the right side wall 222 extend (the up-down direction in Fig. 8) is the direction in which the wheel loader 1 travels straight toward the first accumulated body 200 when the wheel loader 1 stacks the materials on the first accumulated body 200. In the direction orthogonal to the traveling direction (the left-right direction in Fig. 8; hereinafter, referred to as an orthogonal direction in the specification), the back wall 223 extends. The first accumulated body 200 has a non-uniform mountain height in the orthogonal direction.

[0080] Returning to Fig. 7, the path planning unit 102 of the automation controller 100 calculates the amount of accumulated materials in a section obtained by virtually sectioning the first accumulated body 200 in units of the dimension of the width of the bucket 6 in the orthogonal direction in Step S3.

[0081] Fig. 9 is a schematic diagram illustrating a first example of disposition of the bucket 6 with respect to the first accumulated body 200 illustrated in Fig. 8. Fig. 9 and subsequent Fig. 10 schematically illustrate the bucket 6 of the wheel loader 1. As illustrated in Fig. 2, the length L9 is the dimension of the width of the bucket 6. The length L9 is an example of the dimension of the work implement 3. The rectangles illustrated by the two-dotted chain lines in Figs. 9 and 10 indicate sections obtained by sectioning the first accumulated body 200 by the dimension of the width of the bucket 6 in the orthogonal direction.

[0082] Fig. 9 illustrates disposition with the left end of the bucket 6 aligned with the left side wall 221 of the stockyard 220. In Fig. 9, a large amount of low mountain region 203 illustrated by the rough hatching in the drawing is included in the section surrounded by the two-dotted chain line. Therefore, the amount of accumulated materials in the section surrounded by the two-dotted chain line is small.

[0083] Fig. 10 is a schematic diagram illustrating a second example of disposition of the bucket 6 with respect to the first accumulated body 200 illustrated in Fig. 8. Fig. 10 illustrates disposition with the left end of the bucket 6 spaced apart from the left side wall 221 of the stockyard 220 achieved by causing the bucket 6 illustrated in Fig. 9 to move in the orthogonal direction. In Fig. 10, the amount of low mountain region 203 included in the section surrounded by the two-dotted chain line is small, and a region that is higher than the mountain height indicated by fine hatching in the drawing is included in the section. A part of the first accumulated body top portion 201 is included in the section surrounded by the two-dotted chain line in Fig. 10. The amount of accumulated materials in the section surrounded by the two-dotted chain line in Fig. 10 is larger than the amount of accumulated materials in the section illustrated in Fig. 9.

[0084] The amount of movement of the bucket 6 from the position of the bucket 6 illustrated in Fig. 9 to the position thereof illustrated in Fig. 10 is regarded as a unit amount of movement of the bucket 6 when the amount of accumulated materials is calculated in units of the width of the bucket. The unit amount of movement of the bucket 6 may be set with reference to the bucket width (length L9) or may be set with reference to the dimension of the stockyard 220. The path planning unit 102 causes the bucket 6 to move rightward by the unit amount of movement from the state in which the left end of the bucket 6 is aligned with the left side wall 221 of the stockyard 220 as illustrated in Fig. 9 and calculates the amount of accumulated materials in each section. The path planning unit 102 continues the calculation until disposition in which the right end of the bucket 6 is aligned with the right side wall 222 of the stockyard 220 is achieved.

[0085] Distribution of the amount of accumulated materials in the orthogonal in the first accumulated body 200 is calculated by completing the calculation of the amount of accumulated materials in units of the bucket width. Returning to Fig. 7, the path planning unit 102 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200 on the basis of the dimension of the work implement 3 and the shape of the first accumulated body 200 next in Step S4. The path planning unit 102 compares the amount of accumulated materials calculated for each section obtained by sectioning the first accumulated body 200 by the dimension of the width of the bucket 6, and determines the minimum amount of accumulation. The path planning unit 102 obtains the section corresponding to the minimum amount of accumulation and obtains the position of the bucket 6 when the section is sectioned. The path planning unit 102 obtains a position at which the least amount of materials are accumulated in the orthogonal direction in the first accumulated body 200.

[0086] In the exemplary case of the first accumulated body 200 illustrated in Figs. 8 to 10, the first accumulated body top portion 201 is located at a position closer to the right side wall 222 than to the left side wall 221 of the stockyard 220, and the low mountain region 203 extends along the left side wall 221 of the stockyard 220. In the exemplary case of the first accumulated body 200 illustrated in Figs. 8 to 10, the amount of accumulated materials in the section in the case where the left end of the bucket 6 is aligned with the left side wall 221 of the stockyard 220 as illustrated in Fig. 9 is a minimum. The path planning unit 102 obtains the position of the bucket 6 in the orthogonal direction that minimizes the amount of accumulated materials on the basis of the bucket width and the shape of the first accumulated body 200.

[0087] In Step S5, the path planning unit 102 determines the position obtained in Step S4 as the position at which the transport machine is to unload the materials. In this manner, the position at which the transport machine is to unload the materials with respect to the first accumulated body 200 accumulated in the stockyard 220 is determined ("end" in Fig. 7).

[0088] Fig. 11 is a schematic diagram illustrating another example of the accumulated body of the materials and a first example of disposition of the bucket 6. The first accumulated body 200 illustrated in Fig. 11 and subsequent Fig. 12 is a mountain of materials formed in a vacant place. 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. The materials dropped on the flat ground are ideally accumulated in a right circular cone shape. The angle formed by the conical surface of the right circular cone and the ground is an angle of repose of the materials. Two one-dotted chain lines illustrated in Figs. 11 and 12 extend in the radial direction of the circle formed by the skirt 202 and are orthogonal to each other. Therefore, the one-dotted chain lines pass the first accumulated body top portion 201 at the center of the circle.

[0089] An altitude model of the first accumulated body 200 is created from the point cloud of the first accumulated body 200 detected by the LiDAR, which is the perception device 111. The bucket 6 is disposed in the circumferential direction of the circle formed by the skirt 202 with respect to the first accumulated body 200 with the conical shape illustrated in Figs. 11 and 12. The path planning unit 102 of the automation controller 100 assumes a fan-shaped section surrounded by an arc corresponding to the bucket width and two radii of the circle, and calculates the amount of accumulated materials in the section.

[0090] Fig. 12 is a schematic diagram illustrating a second example of disposition of the bucket with respect to the accumulated body illustrated in Fig. 11. The bucket 6 is caused to move by a unit angle in the counterclockwise direction in the circumferential direction of the circle. The unit angle is an angle obtained by equally dividing the circumferential angle of 360°. The unit angle may be 1°. The path planning unit 102 causes the bucket 6 to move by a unit angle and calculates the amount of loaded materials in each section. The path planning unit 102 continues the calculation until the bucket 6 moves by 360° in the circumferential direction of the circle.

[0091] Once the calculation of the amount of accumulated materials in units of bucket width is completed, the path planning unit 102 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200. The path planning unit 102 compares the amount of accumulated materials calculated for each section and determines the minimum amount of accumulation. The path planning unit 102 obtains the section corresponding to the minimum amount of accumulation and obtains the position of the bucket 6 when the section is sectioned.

[0092] Although the first accumulated body 200 of the materials ideally has a conical shape as described above, the particle diameters of the materials are not constant in practice, the shape of the skirt 202 is thus not a perfect circle, and the shape of the first accumulated body 200 may not be a right circular cone. In addition, the shape of the first accumulated body 200 becomes a shape that is not a right circular cone after a part of the materials in the first accumulated body 200 is excavated.

[0093] In a case where the bucket 6 is caused to move by 360° in the circumferential direction of the circle centered on the first accumulated body top portion 201, the amount of accumulated materials in the section defined by the two radii and the arc therebetween may not be constant, and the amount of accumulated materials in each section may vary. The path planning unit 102 determines the section in which the amount of accumulated materials is a minimum and obtains the position of the bucket 6 corresponding to the section. The path planning unit 102 determines the position as the position at which the transport machine is to unload the materials.<Flow of unloading materials>

[0094] Fig. 13 is a flowchart illustrating a flow of processing of the transport machine unloading the materials. As illustrated in Fig. 13, the transport machine transports the materials that are targets to be worked on by the wheel loader 1 in Step S11. The transport machine is, for example, a dump truck. The dump truck includes a vessel. The dump truck transports the materials by the dump track traveling in a state where the materials are loaded in the vessel.

[0095] In Step S12, the transport machine with the materials loaded thereon arrives at the work site where the wheel loader 1 is to work.

[0096] In Step S13, the transport machine receives the position at which the materials are to be unloaded. The transport machine includes a communication device, which is not illustrated, and is configured to be able to wirelessly communicate with the outside. As described above with reference to Fig. 4, for example, the path follow-up control unit 103 of the automation controller 100 can transmit, to the transport machine, a signal indicating the position where the materials are to be unloaded, which has been determined in the flow illustrated in Fig. 7, via the communication device 150 and provide an instruction for the unloading position to the transport machine. Alternatively, a signal indicating the unloading position may be transmitted from the automation controller 100 to control, and the signal may be transmitted from the control to the transport machine to provide the instruction for the unloading position to the transport machine.

[0097] In Step S14, the transport machine unloads the loaded materials at the position, at which the materials are to be unloaded, which has been received in previous Step S13.

[0098] Fig. 14 is a schematic diagram illustrating a first example of disposition of materials forming the second accumulated body 210. A transport machine 300 illustrated in Figs. 14 and 15 is a dump truck and includes a vessel 301. The transport machine 300 transports the materials at the work site by the transport machine 300 traveling in the work site in a state where the materials are loaded in the vessel 301. The transport machine 300 approaches the first accumulated body 200. As described above, the second accumulated body 210 is an accumulated body in which the materials that are to be stacked on the first accumulated body 200 are accumulated on the ground at the work site. The first accumulated body 200 illustrated in Figs. 14 and 15 has a substantially conical shape similarly to Figs. 11 and 12. The position of the one-dotted chain line passing through the first accumulated body top portion 201 is the position at which the amount of accumulated materials is a minimum and the transport machine 300 is to unload the materials. When the wheel loader 1 stacks the materials forming the second accumulated body 210 on the first accumulated body 200, the travel device 4 travels straight along the one-dotted chain line.

[0099] The transport machine 300 travels along a path that does not interfere with the first accumulated body 200 and reaches the position at which the materials are to be unloaded. The transport machine 300 unloads the materials at the position passing through the one-dotted chain line in the circumferential direction centered on the first accumulated body top portion 201. The transport machine 300 unloads the materials at the 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.

[0100] 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.

[0101] Fig. 15 is a schematic diagram illustrating a second example of disposition of the materials forming the second accumulated body 210. Fig. 15 illustrates an exemplary case in which the amount of materials transported by the transport machine 300 is larger than the capacity of the bucket 6 of the wheel loader 1. The position of the one-dotted chain line passing through the first accumulated body top portion 201 is determined as the center of the position at which the amount of accumulated materials is a minimum and the transport machine 300 is to unload the materials. The direction in which the one-dotted chain line passing through the first accumulated body top portion 201 is one path along which the travel device 4 travels when the wheel loader 1 stacks the materials forming the second accumulated body 210 on the first accumulated body 200.

[0102] An instruction for the operation of the transport machine 300 is provided such that the transport machine 300 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. The transport machine 300 unloads the materials loaded in the vessel 301 on the ground while slightly traveling forward along the one-dotted chain line that is orthogonal to the one-dotted chain line passing through the first accumulated body top portion 201 and extends in the tangential direction of the circle centered on the first accumulated body top portion 201. The skirt of the second accumulated body 210 is formed into an elliptical shape in a plan view through the unloading work. The length in which the second accumulated body 210 extends in the tangential direction of the circle centered on the first accumulated body top portion 201 is larger than the width (the length L9; Fig. 2) of the bucket 6 of the wheel loader 1. Fig. 2) of the bucket 6 of the wheel loader 1.

[0103] The materials forming the second accumulated body 210 is stacked on the first accumulated body 200 by the wheel loader 1 operating as described above with reference to Fig. 6. The position at which the transport machine 300 is to unload the materials is determined to form the second accumulated body 210 at the position at which the amount of accumulated materials is a minimum in the first accumulated body 200. In the first accumulated body 200 after the second accumulated body 210 is stacked thereon, variations in the amount of accumulated materials are reduced, and uniformity of the shape is improved. The first accumulated body 200 after the second accumulated body 210 is stacked thereon has a more uniform shape.<Actions and Effects>

[0104] 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.

[0105] The perception device 111 detects the first accumulated body 200 in which the materials that are targets to be worked on by the wheel loader 1 are accumulated on the ground at the work site. As illustrated in Figs. 7 and 8 to 12, the path planning unit 102 of the automation controller 100 determines the position at which the transport machine 300 is to unload the materials at the work site on the basis of the information regarding the first accumulated body 200. 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).

[0106] The path planning unit 102 can determine an appropriate position at which the transport machine 300 is to unload the materials at the work site on the basis of the information regarding the first accumulated body 200. The path planning unit 102 can determine, as the position at which the materials are to be unloaded, the position at which the wheel loader 1 can efficiently perform the work of stacking the materials on the first accumulated body 200. The wheel loader 1 can efficiently perform the work of stacking the unloaded materials on the first accumulated body 200 by the transport machine 300 unloading the materials at the determined position.

[0107] As illustrated in Figs. 1 and 2, the wheel loader 1 includes the work implement 3. 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 300 by using the work implement 3. The path planning unit 102 may determine the position at which the transport machine 300 is to unload the materials at the work site on the basis of the dimension of the work implement 3 of the wheel loader 1 and the information regarding the first accumulated body 200. The wheel loader 1 can efficiently perform the work of stacking the unloaded materials on the first accumulated body 200 by determining the appropriate position at which the transport machine 300 is to unload the materials at the work site 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 by the transport machine 300 unloading the materials at the determined position.

[0108] As illustrated in Figs. 1 and 2, the work implement 3 includes the bucket 6 at the distal end. As illustrated in Figs. 9 to 12, the path planning unit 102 may determine the position at which the transport machine 300 is to unload the materials at the work site on the basis of the width of the bucket 6 and the information regarding the first accumulated body 200. The wheel loader 1 performs an operation of scooping the materials into the bucket 6 while traveling forward, and stacking the scooped materials. The dimension of the width of the bucket 6 corresponds to a range in which the stacking operation can be performed by one forward traveling operation of the wheel loader 1, and it is possible to state that the dimension is a reference dimension for the work of the wheel loader 1. It is possible to appropriately determine the position at which the materials are to be unloaded such that the wheel loader 1 can efficiently perform the work of stacking the materials, on the basis of the width of the bucket 6.

[0109] As illustrated in Figs. 9 to 12, the section that is obtained by sectioning the first accumulated body 200 by the length L9 which is the dimension of the width of the bucket 6 and that includes a minimum amount of accumulated materials in the direction orthogonal to the direction in which the travel device 4 travels toward the first accumulated body 200 when the wheel loader 1 stacks the materials on the first accumulated body 200 may be regarded as the position at which the transport machine 300 is to unload the materials. The distribution of the amount of accumulated materials is calculated in units of the width of the bucket 6 with which the wheel loader 1 performs the work of stacking the materials, and setting is performed such that the materials are to be unloaded at the position of the minimum amount of accumulation. The shape of the first accumulated body 200 after the stacking work can be adjusted by the wheel loader 1 performing the work of stacking the unloaded materials on the first accumulated body 200.

[0110] An illustrated in Figs. 14 and 15, the path follow-up control unit 103 of the automation controller 100 may provide an instruction for an operation of the transport machine 300 to unload 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 on the first accumulated body 200. Since the direction in which the material is unloaded is determined, it is possible to suppress interference between the transport machine 300 that performs the work of unloading the materials and the first accumulated body 200. In addition, it is possible to form the materials to be unloaded from the transport machine 300 into a shape with which the wheel loader 1 can easily perform the stacking operation. It is thus possible to improve workability.

[0111] As illustrated in Fig. 15, the amount of materials to be transported by the transport machine 300 may be larger than the capacity of the bucket 6. The materials, the amount of which is larger than the capacity of the bucket 6, are unloaded 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 on the first accumulated body 200. It is thus possible to form the materials to be unloaded from the transport machine 300 into a shape with which the wheel loader 1 can easily perform the stacking work and to thereby improve workability.

[0112] As illustrated in Figs. 4 and 13, the path follow-up control unit 103 of the automation controller 100 may transmit the position, at which the materials are to be unloaded, which has been determined by the path planning unit 102, to the transport machine 300. The transport machine 300 unloads the materials at the received position. The materials are unloaded at the appropriate position determined on the basis of the dimension of the work implement 3 and the information regarding the first accumulated body 200. The wheel loader 1 can efficiently stack the unloaded materials on the first accumulated body 200.

[0113] As illustrated in Figs. 7 and 8 to 10, the path planning unit 102 of the automation controller 100 obtains the position at which the amount of accumulated materials is a minimum in the first accumulated body 200 on the basis of the information regarding the first accumulated body 200. The transport machine 300 can unload the materials at the position at which the amount of accumulated materials is a minimum, the wheel loader 1 can stack the unloaded materials on the first accumulated body 200, and it is thus possible to adjust the shape of the first accumulated body 200 after the stacking work.

[0114] 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. The 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 an external controller, and the external controller that has received a signal may determine the position at which the transport machine 300 is to unload the materials.

[0115] 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.

[0116] 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.

[0117] 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.<Supplement>

[0118] The above description includes the following features.(Supplement 1)

[0119] A system including: a transport machine that transports materials at a work site; a sensor that detects an accumulated body of the materials accumulated on ground at the work site; and a controller that provides an instruction for an operation of the transport machine, in which the controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body. (Supplement 2)

[0120] The system according to Supplement 1, in which the work machine working at the work site includes a work implement, and the controller determines the position at which the transport machine is to unload the materials on the basis of a dimension of the work implement as well. (Supplement 3)

[0121] The system according to Supplement 2, in which the work implement includes a bucket at a distal end, and the dimension of the work implement includes a width of the bucket. (Supplement 4)

[0122] The system according to Supplement 3, in which the work machine includes a travel body, and the controller regards, as the position at which the transport machine is to unload the materials, a section that is obtained by sectioning the accumulated body by a dimension of the width of the bucket and that includes a minimum amount of accumulated materials, in an orthogonal direction with respect to a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body. (Supplement 5)

[0123] The system according to any one of Supplements 1 to 4, in which a work machine working at the work site includes a travel body, and the controller provides an instruction for an operation of the transport machine to unload the materials in a direction intersecting a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body. (Supplement 6)

[0124] The system according to Supplement 5, in which the work machine includes a work implement with a bucket provided at a distal end, and an amount of materials transported by the transport machine is larger than a capacity of the bucket. (Supplement 7)

[0125] The system according to any one of Supplements 1 to 6, in which the controller transmits the position at which the materials are to be unloaded to the transport machine.(Supplement 8)

[0126] A system including: a sensor that detects an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and a controller, in which the controller recognizes the accumulated body on the basis of a detection result of the sensor and obtains a position at which an amount of accumulated materials in the accumulated body is a minimum on the basis of information regarding the accumulated body. (Supplement 9)

[0127] The system according to Supplement 8, in which the work machine includes a work implement, and the controller obtains the position at which the amount of accumulation is a minimum on the basis of a dimension of the work implement as well. (Supplement 10)

[0128] The system according to Supplement 9, in which the work implement includes a bucket at a distal end, and the dimension of the work implement includes a width of the bucket.

[0129] 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

[0130] 1Wheel loader 2Vehicle body frame 2aFront frame 2bRear frame 3Work implement 4Travel device 4aFront wheel 4bRear wheel 6Bucket 6aBlade edge 6cWidth direction center 14Boom 50Vehicle body controller 60Engine controller 70Transmission controller 80Work implement controller 100Automation controller 101Position estimation unit 102Path planning unit 103Path follow-up control unit 110External information acquisition unit 111Perception device 120Vehicle information acquisition unit 150Communication device 200First accumulated body 201First accumulated body top portion 202Skirt 203Low mountain region 204Accumulation region 205Slope 210Second accumulated body 220Stockyard 221Left side wall 222Right side wall 223Back wall 300Transport machine 301Vessel.

Examples

Embodiment Construction

[0012]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.

[0013]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.

[0014]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. Th...

Claims

1. A system comprising: a transport machine that transports materials at a work site; a sensor that detects an accumulated body of the materials accumulated on ground at the work site; and a controller that provides an instruction for an operation of the transport machine, wherein the controller recognizes the accumulated body on the basis of a detection result of the sensor and determines a position at which the transport machine is to unload the materials at the work site on the basis of information regarding the accumulated body.

2. The system according to claim 1, wherein the work machine working at the work site includes a work implement, and the controller determines the position at which the transport machine is to unload the materials on the basis of a dimension of the work implement as well.

3. The system according to claim 2, wherein the work implement includes a bucket at a distal end, and the dimension of the work implement includes a width of the bucket.

4. The system according to claim 3, wherein the work machine includes a travel body, and the controller regards, as the position at which the transport machine is to unload the materials, a section that is obtained by sectioning the accumulated body by a dimension of the width of the bucket and that includes a minimum amount of accumulated materials, in an orthogonal direction with respect to a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body.

5. The system according to claim 1, wherein a work machine working at the work site includes a travel body, and the controller provides an instruction for an operation of the transport machine to unload the materials in a direction intersecting a direction in which the travel body travels toward the accumulated body when the work machine stacks the materials on the accumulated body.

6. The system according to claim 5, wherein the work machine includes a work implement with a bucket provided at a distal end, and an amount of materials transported by the transport machine is larger than a capacity of the bucket.

7. The system according to any one of claims 1 to 6, wherein the controller transmits the position at which the materials are to be unloaded to the transport machine.

8. A system comprising: a sensor that detects an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and a controller, wherein the controller recognizes the accumulated body on the basis of a detection result of the sensor and obtains a position at which an amount of accumulated materials in the accumulated body is a minimum on the basis of information regarding the accumulated body.

9. A controller for a work machine which recognizes an accumulated body in which materials that are targets to be worked on by the work machine are accumulated on ground at a work site, and determines a position at which a transport machine transporting the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.

10. A method of determining disposition of materials comprising: recognizing an accumulated body in which materials that are targets to be worked on by a work machine are accumulated on ground at a work site; and determining a position at which a transport machine transporting the materials is to unload the materials at the work site on the basis of information regarding the accumulated body.

Images