Work machine, system including work machine, and method for controlling work machine

Abstract

The present invention avoids any decrease in efficiency in work performed by a work machine. In the present invention, a work machine includes a work implement, a sensor for detecting an excavation object excavated by the work implement, and a management controller for recognizing the state of the excavation object and determining the work of the work machine. The management controller determines, on the basis of the state of the excavation object, whether or not the work machine that executes excavation work for excavating the excavation object can appropriately continue the excavation work. The management controller stops the excavation work when it is determined that the excavation work cannot be continued properly.

Description

Work machine, system including work machine, and method for controlling work machine

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

[0002] U.S. Patent No. 10,041,229 (Patent Document 1) discloses a system for controlling the operation of a mobile machine such as a wheel loader. The system includes an imaging device and a controller in communication with the imaging device. The imaging device generates a signal indicative of the surrounding area of ​​the machine. The controller identifies a work aggregate within the surrounding area of ​​the machine. The controller recognizes the work implements of the machine and the work aggregate and performs an excavation operation.

[0003] U.S. Pat. No. 1,004,1229

[0004] When a wheel loader is used to excavate material in a stockyard and load the excavated material onto a dump truck or dump it into a hopper, work efficiency can decrease when excavation work is performed continuously.

[0005] The present disclosure proposes a work machine, a system including a work machine, and a method for controlling a work machine that can avoid a decrease in the efficiency of work performed by the work machine.

[0006] A work machine and a system including a work machine according to the present disclosure include a work implement, a sensor that detects an excavation target to be excavated by the work implement, and a management controller that recognizes the condition of the excavation target and determines the work to be performed by the work machine. The management controller determines whether the work machine performing excavation work to excavate the excavation target can continue the excavation work appropriately based on the condition of the excavation target. If the management controller determines that the excavation work cannot be continued appropriately, it stops the excavation work.

[0007] A control method for a work machine according to the present disclosure includes the following steps: a first step is to recognize the state of an excavation target; a second step is to determine, based on the state of the excavation target, whether a work machine performing excavation work to excavate the excavation target can continue the excavation work appropriately; and a third step is to stop the excavation work when it is determined that the excavation work cannot be continued appropriately.

[0008] According to the work machine, the system including the work machine, and the control method for the work machine of the present disclosure, it is possible to avoid a decrease in work efficiency.

[0009] 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 shown in FIG. 1. FIG. 3 is a block diagram showing the general configuration of a control system for the wheel loader. FIG. 4 is a block diagram showing the general configuration of an automatic control system for the wheel loader. FIG. 5 is a block diagram showing the general configuration of a communication system. FIG. 6 is a schematic diagram showing a travel path of a wheel loader performing excavation and loading work. FIG. 7 is a flowchart showing the flow of a process for generating a travel path of a wheel loader. FIG. 7 is a schematic diagram showing an example of an elevation model of an excavation target. FIG. 8 is a diagram explaining a process for calculating the remaining amount of material. FIG. 8 is a schematic diagram of a wheel loader moving forward empty. FIG. 9 is a schematic diagram showing a state in which the wheel loader has moved to an excavation position.

[0010] Hereinafter, the embodiments will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. It is also intended from the beginning that any configuration may be extracted from the embodiments and arbitrarily combined.

[0011] <Overall configuration of wheel loader 1> 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 shown in Fig. 1.

[0012] 1 and 2 , the wheel loader 1 mainly comprises a body frame 2, a work implement 3, a traveling device 4, and a cab 5. The body frame 2, the cab 5, etc. make up the body of the wheel loader 1. The work implement 3 and the traveling device 4 are attached to the body of the wheel loader 1. The main body of the wheel loader 1 (work machine main body) comprises the body and the traveling device 4.

[0013] The traveling device 4 includes traveling wheels 4a, 4b, which cause the body of the wheel loader 1 to travel. The wheel loader 1 is a wheeled vehicle that has traveling wheels 4a, 4b on both the left and right sides of the body as rotating bodies for traveling. The wheel loader 1 is self-propelled by driving the traveling wheels 4a, 4b to rotate, and can perform desired work using the work implement 3.

[0014] In this specification, the direction in which the wheel loader 1 travels straight ahead is referred to as the fore-and-aft direction of the wheel loader 1. In the fore-and-aft direction of the wheel loader 1, the side on which the work implement 3 is arranged relative to the body frame 2 is referred to as the front direction, and the side opposite the front direction is referred to as the rear direction. The left-and-right direction of the wheel loader 1 is the direction perpendicular to the fore-and-aft direction when the wheel loader 1 is viewed from above on flat ground. The right and left sides of the left-and-right direction when looking forward are the right direction and the left direction, respectively. The up-and-down direction of the wheel loader 1 is the direction perpendicular to the plane defined by the fore-and-aft direction and the left-and-right direction. In the up-and-down direction, the side with ground is the bottom side, and the side with sky is the top side.

[0015] The vehicle body frame 2 includes a front frame 2 a and a rear frame 2 b. The front frame 2 a is disposed in front of the rear frame 2 b. The front frame 2 a and the rear frame 2 b are attached to each other by a center pin 10 so as to be movable relative to each other in the left-right direction.

[0016] A pair of left and right steering cylinders 11 are attached across the front frame 2a and the rear frame 2b. The steering cylinders 11 are hydraulic cylinders. The steering cylinders 11 are extended and retracted by hydraulic oil from a steering pump (not shown), thereby changing the direction of travel of the wheel loader 1 to the left and right. The front frame 2a and the rear frame 2b make up a body frame 2 with an articulated structure. The wheel loader 1 is an articulated work machine in which the front frame 2a and the rear frame 2b are connected so that they can be flexibly moved.

[0017] A work implement 3 and a pair of running wheels (front wheels) 4a are attached to the front frame 2a. The work implement 3 is attached to the front of the body of the wheel loader 1. The work implement 3 is supported by the body of the wheel loader 1. Specifically, the work implement 3 is rotatably supported by the body frame 2, more particularly by the front frame 2a. The work implement 3 is disposed in front of the body frame 2.

[0018] The work implement 3 includes a boom 14. The base end 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 by a joining member extending in the left-right direction so as not to move relative to each other, forming the boom 14 of an integral structure. The boom pin 9 includes a pair of left and right boom pins, a left boom pin 9L and a right boom pin 9R. The boom 14 is rotatable relative to the front frame 2a around the left boom pin 9L and the right boom pin 9R as rotation centers. The left boom pin 9L and the right boom pin 9R support the work implement 3 rotatably relative to the body frame 2.

[0019] The work implement 3 includes a bucket 6. The bucket 6 is disposed at the tip of the work implement 3. The bucket 6 is a work tool for excavating and loading. The cutting edge 6a is the tip of the bucket 6. The back surface 6b is part of the outer surface of the bucket 6. The back surface 6b is formed as a flat surface. The back surface 6b extends rearward from the cutting edge 6a. The bucket 6 is rotatably attached to the boom 14 by a bucket pin 17 located at the tip of the boom 14. The bucket 6 has 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.

[0020] The work implement 3 further includes a bell crank 18 and a link 15. The bell crank 18 is rotatably supported at its approximate center on the boom 14 by a support pin 18a located approximately in the longitudinal center of the boom 14. The link 15 is connected to a connecting pin 18c provided at the lower end (tip) of the bell crank 18. The link 15 connects 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.

[0021] The front frame 2a and the boom 14 are connected by a pair of boom cylinders 16. The boom cylinders 16 are hydraulic cylinders. The boom cylinders 16 rotate the boom 14 up and down around the boom pin 9. The base end of the boom cylinder 16 is attached to the front frame 2a. The tip of the boom cylinder 16 is attached to the boom 14. The boom cylinder 16 is a hydraulic actuator that moves the boom 14 up and down relative to the front frame 2a. As the boom 14 moves up and down, the bucket 6 attached to the tip of the boom 14 also moves up and down.

[0022] The bucket cylinder 19 connects 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 tip of the bucket cylinder 19 is attached to a connecting pin 18b provided at the upper end (base end) of the bell crank 18. The bucket cylinder 19 is a hydraulic actuator that rotates the bucket 6 up and down relative to the boom 14. The bucket cylinder 19 is an implement cylinder that drives the bucket 6. The bucket cylinder 19 drives the bucket 6 to rotate around the bucket pin 17. The bucket 6 is configured to be movable relative to the boom 14. The bucket 6 is configured to be movable relative to the front frame 2a.

[0023] The boom cylinder 16 and the bucket cylinder 19 constitute a work implement actuator that drives the work implement 3 .

[0024] A cab 5 in which the operator sits, and a pair of running wheels (rear wheels) 4b are attached to the rear frame 2b. The box-shaped cab 5 is located behind the boom 14. The cab 5 is mounted on the rear frame 2b. The cab 5 is placed on the body frame 2. Inside the cab 5, a seat in which the operator of the wheel loader 1 sits, an operating device 8 (described later), and the like are arranged.

[0025] The cab 5 is provided with a perception device 111. The perception device 111 is disposed, for example, on the ceiling of the cab 5. The perception device 111 is mounted, for example, on the top surface of the cab 5. The perception device 111 is disposed, for example, in the front of the cab 5. The perception device 111 is attached to the cab 5 facing forward, for example, and is capable of acquiring information about the area in front of the cab 5. Details of the perception device 111 will be described later.

[0026] Length L9 shown in Figure 2 is the length from the left end to the right end of the bucket 6 in the left-right direction (bucket width). The widthwise center 6c of the bucket 6 is the center point of the bucket 6 in the left-right direction. Length L9 is included in the dimensions of the work implement 3. Length L9 is included in the specification values ​​of the wheel loader 1. The specification values ​​of the wheel loader 1 are values ​​unique to each individual wheel loader 1, and are stored in the vehicle body controller 50, which will be described later.

[0027] <System Configuration> FIG. 3 is a block diagram showing the schematic configuration of a control system that controls the wheel loader 1.

[0028] The engine 21 is a drive source, such as a diesel engine, that generates drive power for driving the work implement 3 and the traveling device 4. Instead of the engine 21, a motor driven by an electricity storage device may be used as the drive source, 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.

[0029] The driving force generated by the engine 21 is transmitted to the transmission 23. The transmission 23 changes the driving force to an appropriate torque and rotational speed. An axle 25 is connected to the output shaft of the transmission 23. The driving force changed by the transmission 23 is transmitted to the axle 25. The driving force is transmitted from the axle 25 to the running wheels 4a, 4b (FIGS. 1 and 2). This causes the wheel loader 1 to travel. In the wheel loader 1 of this embodiment, both the running wheels 4a and 4b constitute driving wheels that receive the driving force and cause the wheel loader 1 to travel.

[0030] A portion of the driving force of the engine 21 is transmitted to the 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 the hydraulic oil that it discharges. 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 cylinder 16 and the bucket cylinder 19 via a main valve 32. The boom cylinder 16 receives the supply of hydraulic oil and extends and contracts, thereby raising and lowering the boom 14. The bucket cylinder 19 receives the supply of hydraulic oil and extends and contracts, thereby rotating the bucket 6 up and down.

[0031] The wheel loader 1 is equipped with a vehicle body controller 50. The vehicle body controller 50 includes an engine controller 60, a transmission controller 70, and a work machine controller 80.

[0032] The vehicle body controller 50 is generally implemented by reading various programs using a CPU (Central Processing Unit). The vehicle body controller 50 has a memory (not shown). The memory functions as a work memory and stores various programs for implementing the functions of the wheel loader 1.

[0033] The operating device 8 is provided in the cab 5. The operating device 8 is operated by an operator. The operating device 8 is equipped with a plurality of types of operating members that the operator operates to operate the wheel loader 1. The operating device 8 includes an accelerator pedal 41 and a work implement operating lever 42. The operating device 8 may also include a steering handle, a shift lever, etc., which are not shown.

[0034] 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 based on the amount of operation of the accelerator pedal 41. When the amount of operation (depression amount) of the accelerator pedal 41 is increased, the output of the engine 21 increases. When the amount of operation of the accelerator pedal 41 is decreased, the output of the engine 21 decreases. The transmission controller 70 controls the transmission 23 based on the amount of operation of the accelerator pedal 41.

[0035] The work machine control lever 42 is operated to operate the work machine 3. The work machine controller 80 controls the electromagnetic proportional control valves 35, 36 based on the amount of operation of the work machine control lever 42. The work machine controller 80, or the vehicle controller 50 including the work machine controller 80, corresponds to an example of a "machine controller" that controls the work machine.

[0036] The electromagnetic proportional control valve 35 switches the main valve 32 so that the bucket cylinder 19 retracts and the bucket 6 moves in the dump direction (the direction in which the cutting edge of the bucket 6 moves down). The electromagnetic proportional control valve 35 also switches the main valve 32 so that the bucket cylinder 19 extends and the bucket 6 moves in the tilt direction (the direction in which the cutting edge of the bucket 6 moves up). The electromagnetic proportional control valve 36 switches the main valve 32 so that the boom cylinder 16 retracts and the boom 14 moves down. The electromagnetic proportional control valve 36 also switches the main valve 32 so that the boom cylinder 16 extends and the boom 14 moves up.

[0037] The machine monitor 51 displays various types of information upon receiving command signals as input from the vehicle body controller 50. The various types of information displayed on the machine monitor 51 may be, for example, information relating to the work performed by the wheel loader 1, vehicle body information such as the remaining fuel amount, coolant temperature, and hydraulic oil temperature, and peripheral images captured of the area around the wheel loader 1. The machine monitor 51 may be a touch panel, and in this case, a signal generated when the operator touches a part of the machine monitor 51 is output from the machine monitor 51 to the vehicle body controller 50.

[0038] <Automatic Control System of Wheel Loader 1> When automating the work of the wheel loader 1, it is desirable to reproduce the operations of a skilled operator through automatic control. Figure 4 is a block diagram showing the configuration of the automatic control system of the wheel loader 1.

[0039] The automation controller 100 is configured to be able to send and receive signals to and from the vehicle body controller 50 described with reference to Fig. 3. The automation controller 100 is also configured to be able to send and receive signals to and from an external environment information acquisition unit 110. The external environment information acquisition unit 110 has a 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.

[0040] The perception device 111 acquires information about the surroundings of the wheel loader 1. As shown in Fig. 1 , the perception device 111 is attached, for example, to the front part of the top surface of the cab 5. The perception device 111 detects objects at the work site where the wheel loader 1 is working, for example objects around (in front of) the main body of the wheel loader 1 (work machine main body), specifically, the excavation target to be excavated by the work implement 3. The perception device 111 corresponds to an example of a "sensor".

[0041] The perception device 111 detects the direction of an object outside the wheel loader 1 and the distance to the object in a non-contact manner. The perception device 111 is, for example, a LiDAR (Light Detection and Ranging) device that emits laser light to acquire information about the object. The perception device 111 may also be a visual sensor including a camera. The perception device 111 may also be a Radar (Radio Detection and Ranging) device that acquires information about the object by emitting radio waves. The perception device 111 may also be an infrared sensor.

[0042] The position information acquisition device 112 acquires information about the current position of the wheel loader 1. For example, the position information acquisition device 112 uses a satellite positioning system to acquire position information of the wheel loader 1 in a global coordinate system based on the Earth. The position information acquisition device 112 uses, for example, GNSS (Global Navigation Satellite Systems) and has a GNSS receiver. The satellite positioning system calculates the position of the GNSS receiver antenna using positioning signals received by the GNSS receiver from satellites, thereby calculating the position of the wheel loader 1.

[0043] The external environment information of the wheel loader 1 obtained by the perception device 111 and the position information of the wheel loader 1 obtained by the position information acquisition device 112 are input to the automation controller 100 .

[0044] The vehicle body controller 50 is configured to be able to send and receive signals to and from the vehicle information acquisition unit 120, and receives input of information about the wheel loader 1 acquired by the vehicle information acquisition unit 120. The vehicle information acquisition unit 120 is made up of various sensors mounted on the wheel loader 1. The vehicle information acquisition unit 120 has 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.

[0045] The articulation angle sensor 121 detects the articulation angle, which is the angle between the front frame 2 a and the rear frame 2 b, and generates a signal of the detected articulation angle. The articulation angle sensor 121 outputs the signal of the articulation angle to the vehicle body controller 50.

[0046] The vehicle speed sensor 122 detects the travel speed of the wheel loader 1 caused by the traveling device 4, for example, by detecting the rotational 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 vehicle speed signal to the vehicle body controller 50. The vehicle speed sensor 122 corresponds to an example of a travel sensor that detects the progress of the traveling device 4 (traveling body).

[0047] The boom angle sensor 123 is configured, for example, by a rotary encoder provided on the boom pin 9, which is the attachment portion of the boom 14 to the body frame 2. The boom angle sensor 123 detects the angle (boom angle) of the boom 14 with respect to the horizontal direction, and generates a signal of the detected angle of the boom 14. The boom angle sensor 123 outputs the signal of the angle of the boom 14 to the body controller 50.

[0048] Bucket angle sensor 124 is configured, for example, by a rotary encoder provided on support pin 18a, which is the rotation axis of bell crank 18. Bucket angle sensor 124 detects the angle of bell crank 18 relative to boom 14 (bell crank angle) and generates a signal of the detected angle of bell crank 18. Vehicle information acquisition unit 120 or vehicle body controller 50 calculates the angle of bucket 6 relative to boom 14 (bucket angle) from the detected angle of bell crank 18.

[0049] The boom angle sensor 123 and the bucket angle sensor 124 correspond to an example of a work implement attitude sensor that detects the attitude of the work implement 3. The boom angle sensor 123 may be a stroke sensor arranged in 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 arranged in the bucket cylinder 19.

[0050] Boom cylinder pressure sensor 125 detects the pressure on the bottom side of boom cylinder 16 (boom bottom pressure) and generates a signal of the detected boom bottom pressure. The boom bottom pressure increases when bucket 6 is loaded and decreases when bucket 6 is empty. Boom cylinder pressure sensor 125 outputs the boom bottom pressure signal to vehicle body controller 50.

[0051] The vehicle body controller 50 outputs the information input from the vehicle information acquisition unit 120 to the automation controller 100. The automation controller 100 inputs the detection values ​​of the vehicle speed sensor 122, the boom angle sensor 123, and the bucket angle sensor 124 via the vehicle body controller 50.

[0052] The actuator 140 is configured to be able to send and receive signals to and from the vehicle body controller 50. The actuator 140 is driven in response to a command signal from the vehicle body controller 50. The actuator 140 includes a brake EPC (electromagnetic proportional control valve) 141 for actuating the brakes of the traveling 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 an HMT (hydraulic mechanical transmission) 144.

[0053] The electromagnetic proportional control valves 35, 36 shown in Fig. 3 constitute a work machine EPC 143. The transmission 23 shown in Fig. 3 is realized as an HMT 144 that utilizes electronic control. The transmission 23 may be a hydrostatic transmission (HST). The power transmission device that transmits power from the engine 21 to the running wheels 4a, 4b may include an electric drive device such as a diesel-electric system, or may include any combination of an HMT, an HST, and an electric drive device.

[0054] The transmission controller 70 has a brake control unit 71 and an accelerator control unit 72. The brake control unit 71 outputs a command signal to the brake EPC 141 to control the operation of the brakes. The accelerator control unit 72 outputs a command signal to the HMT 144 to control the vehicle speed.

[0055] The work machine controller 80 has a steering control section 81 and a work machine control section 82. The steering control section 81 outputs a command signal to the steering EPC 142 to control the traveling direction of the wheel loader 1. The work machine control section 82 outputs a command signal to the work machine EPC 143 to control the operation of the work machine 3.

[0056] The automation controller 100 corresponds to an example of a "management controller" that recognizes the state of the excavation target to be excavated by the work machine 3 and determines the work to be performed by the work machine. The automation controller 100 has a position estimation unit 101, a path planning unit 102, and a path following control unit 103.

[0057] The position estimation unit 101 estimates the self-position of the wheel loader 1 based on position information acquired by the position information acquisition device 112. The position estimation unit 101 also recognizes a target position based on external environment information acquired by the perception device 111. The target position is, for example, an excavation position in an excavation target where the wheel loader 1 excavates the excavation target with the bucket 6. Another example of the target position is a loading position in a loading target, which is the relative position of the work implement 3 (bucket 6) with respect to the loading target when loading material into the loading target. The perception device 111 may recognize the target position and input it to the automation controller 100, or the position estimation unit 101 may recognize the target position based on the detection results detected by the perception device 111.

[0058] The path planning unit 102 generates an optimal route for the wheel loader 1 when automatically controlling the wheel loader 1. The optimal route includes a route for travel by the traveling devices 4 and a route for operation of the work implement 3. The path planning unit 102 generates an optimal route that connects the current position of the wheel loader 1 with a target position to which the wheel loader 1 is heading.

[0059] For example, the path planning unit 102 generates a travel path for the wheel loader 1 moving forward empty toward the excavation target while performing excavation and loading work. The path planning unit 102 generates a path for the movement of the work implement 3 during excavation work. The path planning unit 102 generates a travel path for the wheel loader 1 moving backward with the load away from the excavation target, and a path for the movement of the work implement 3 while moving backward with the load. The path planning unit 102 generates a travel path for the wheel loader 1 moving forward with the load toward the loading target, and a path for the movement of the work implement 3 while moving forward with the load. The path planning unit 102 generates a path for the movement of the work implement 3 that unloads material scooped into the bucket 6 onto the loading target. The path planning unit 102 generates a travel path for the wheel loader 1 moving backward empty away from the loading target, and a path for the movement of the work implement 3 while moving backward with the load.

[0060] The path following control unit 103 commands the operation of the traveling device 4 and the work implement 3. The path following control unit 103 controls the accelerator, brake, and steering so that the wheel loader 1 travels following the optimal path generated by the path planning unit 102. The path following control unit 103 outputs a command signal to the brake control unit 71, accelerator control unit 72, and steering control unit 81 to cause the wheel loader 1 to travel along the optimal path. The path following control unit 103 controls the boom cylinder 16 and bucket cylinder 19 so that the work implement 3 operates along the optimal path generated by the path planning unit 102. The path following control unit 103 outputs a command signal to the work implement control unit 82 to cause the work implement 3 to move along the optimal path.

[0061] The interface 130 is configured to be able to send and receive signals to and from the vehicle body controller 50. The interface 130 has an automation changeover switch 131, an engine emergency stop switch 132, and a mode lamp 133.

[0062] The automation selector switch 131 is operated by an operator. By operating the automation selector switch 131, the operator switches 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. When an event occurs that requires an emergency stop of the engine 21, the operator operates the engine emergency stop switch 132. Signals indicating the operation of the automation selector switch 131 and the engine emergency stop switch 132 are input to the vehicle body controller 50.

[0063] The mode lamp 133 indicates whether the wheel loader 1 is currently in a mode where it is manually operated by an operator, or in a mode where it is automatically controlled. A command signal is output from the vehicle body controller 50 to the mode lamp 133 to control the lighting of the lamp.

[0064] The automation controller 100 is also configured to be able to send and receive signals to and from the communication device 150. The automatic control system of the wheel loader 1 is configured to be able to transmit information held by the automation controller 100 to the outside via the communication device 150.

[0065] Fig. 5 is a block diagram showing a schematic configuration of the communication system. The automation controller 100 shown in Fig. 4 transmits information to an external controller 400 via a communication device 150. The external controller 400 is provided outside the wheel loader 1. The external controller 400 transmits a command signal to a communication device 350 of the transport machine 300 based on the information received from the automation controller 100. The transport machine 300 is a machine that transports material, such as a dump truck or a belt conveyor.

[0066] The external controller 400 issues commands to operate the transport machine 300 via the communication device 350. The external controller 400 transmits a command to the transport machine 300 to replenish material at a material accumulation site such as a stockyard where the remaining amount of material is low and the material needs to be replenished.

[0067] The external controller 400 may be located at the work site of the wheel loader 1, or may be located in a remote location away from the work site of the wheel loader 1. The external controller 400 may be a portable device. The external controller 400 may be a portable device that can be carried and used by an operator, such as a laptop computer, a tablet computer, or a smartphone.

[0068] <Travel Path During Excavation and Loading Operation> The wheel loader 1 of this embodiment performs excavation and loading operation by scooping material into the bucket 6 and loading the material in the bucket 6 into a loading target such as a dump truck. The material is soil, rocks, ore, wood chips, or the like, that has been excavated at the work site or transported to the work site by a transport machine such as a dump truck or a ship.

[0069] Figure 6 is a schematic diagram showing the travel path of a wheel loader 1 performing excavation and loading work. The excavation target 200 shown in Figure 6 is a pile of material that is excavated and scooped up by the bucket 6 of the work implement 3 of the wheel loader 1. The work site shown in Figure 6 has multiple (two) stockyards 220A, 220B. The excavation target 200 is accumulated in stockyard 220A and stockyard 220B. The same type of material is accumulated in stockyard 220A and stockyard 220B.

[0070] Excavation position PA is the position to which the widthwise center 6c (FIG. 2) of the bucket 6 should head when the wheel loader 1 excavates material in stockyard 220A. Excavation position PB is the position to which the widthwise center 6c of the bucket 6 should head when the wheel loader 1 excavates material in stockyard 220B. The wheel loader 1 excavating the excavation target 200 can select, as excavation positions PA and PB, positions that minimize the forward travel distance toward the excavation target 200 in order to scoop material into the bucket 6 and load a certain amount of material onto the work implement 3, typically to fully load the bucket 6 with material.

[0071] The loading target 500 is a container into which the material loaded on the work machine 3 (bucket 6) is loaded. Examples of the loading target 500 include the vessel of a dump truck and a hopper disposed above a belt conveyor. The loading target 500 has a structure capable of receiving the material. The loading position PD is the position to which the widthwise center 6c of the bucket 6 should be directed when loading the material into the loading target 500.

[0072] As shown in Figure 6, a travel route for the wheel loader 1 performing excavation and loading work is generated so that the wheel loader 1 performs V-shaped travel. V-shaped travel is a typical travel route when the wheel loader 1 performs excavation and loading work, and the travel route of the wheel loader 1 forms a V shape. When the wheel loader 1 performs excavation and loading work by traveling in a V shape, the travel distance of the wheel loader 1 is minimized, and therefore this is considered to be an efficient travel route.

[0073] The switching position PC is a position where the wheel loader 1 switches its traveling direction from reverse to forward. After excavating the excavation target 200, the wheel loader 1 moves backward, switches its traveling direction at the switching position PC, and moves forward toward the loading target 500. After loading the material into the loading target 500, the wheel loader 1 moves backward, switches its traveling direction at the switching position PC, and moves forward toward the stockyards 220A, 220B.

[0074] An excavation and loading operation using V-shape traveling will now be described. The wheel loader 1 moves forward empty along path 250A toward excavation position PA in stockyard 220A. Alternatively, the wheel loader 1 moves forward empty along path 250B toward excavation position PB in stockyard 220B. During the empty forward movement, the boom cylinder 16 and bucket cylinder 19 operate to place the work implement 3 in an excavation position with the tip of the boom 14 in a low position and the bucket 6 facing horizontally.

[0075] The wheel loader 1 plunges the cutting edge 6a of the bucket 6 into the excavation target 200 and stops forward travel. This digging (plunging) operation causes the cutting edge 6a of the bucket 6 to dig into the excavation target 200. In this state, the boom 14 and the bucket 6 are raised and the bucket 6 tilts back. This excavation (scooping) operation scoops the excavation target 200 into the bucket 6. In this way, the wheel loader 1 performs the excavation operation.

[0076] The wheel loader 1 performs loaded reverse travel, in which the wheel loader 1 moves backward with the excavation target 200 loaded in the bucket 6. The wheel loader 1 moves backward from an excavation position PA to a turning point PC along the path 250A. Alternatively, the wheel loader 1 moves backward from an excavation position PB to a turning point PC along the path 250B. The wheel loader 1 may raise the bucket 6 while moving backward.

[0077] The wheel loader 1 switches its traveling direction from reverse to forward at the switching position PC and moves forward with the excavation target 200 loaded in the bucket 6, carrying the load forward. The wheel loader 1 travels forward along the route 550 from the switching position PC to the loading position PD. The wheel loader 1 travels forward toward the loading target 500 while raising the bucket 6 or while maintaining the bucket 6 in a raised state. The wheel loader 1 approaches the loading target 500 until the bucket 6 reaches a predetermined position located almost directly above the bed of the loading target 500.

[0078] When the wheel loader 1 approaches the loading target 500 and reaches a predetermined position, it dumps the bucket 6 and loads the material in the bucket 6 onto the loading target 500. The wheel loader 1 then moves backward along the path 550 to the turning position PC, while lowering the boom 14 to return the work implement 3 to the excavation position.

[0079] The above is a typical operation that constitutes one cycle of excavation and loading work. The wheel loader 1 repeats the above-described operations in sequence to excavate the excavation target 200 and load the excavated material into the loading target 500.

[0080] When the wheel loader 1 excavates the excavation target 200, the front frame 2a and the rear frame 2b are in a straight-advance position without bending relative to each other. When the wheel loader 1 loads material in the bucket 6 onto the loading target 500, the front frame 2a and the rear frame 2b are in a straight-advance position without bending relative to each other.

[0081] <Travel Path Generation Processing> The following describes processing for generating a travel path for the wheel loader 1 when automatically controlling the excavation and loading work described with reference to Figure 6. Figure 7 is a flowchart showing the flow of processing for generating a travel path for the wheel loader 1. In the example described below, it is assumed that at the time of "start" in Figure 7, the wheel loader 1 is excavating the excavation target 200 accumulated in stockyard 220A of stockyards 220A and 220B shown in Figure 6. Stockyard 220A corresponds to an example of a "first stockyard".

[0082] In step S1, the perception device 111 mounted on the wheel loader 1 detects a pile of material in the stockyard 220A, which is the excavation target 200. The perception device 111 is, for example, a LiDAR, and inputs a point cloud indicating the detection result of the excavation target 200 to the position estimation unit 101 of the automation controller 100. The position estimation unit 101 creates an elevation model of the excavation target 200 in the stockyard 220A from the point cloud detected by the LiDAR.

[0083] Fig. 8 is a schematic diagram showing an example of an elevation model of an excavation target 200, which is a material accumulation body. The excavation target 200 shown in Fig. 8 is accumulated in a stockyard 220, which is an example of a material accumulation site. Fig. 8 shows a schematic diagram of the stockyard 220 and the excavation target 200 accumulated in the stockyard 220, viewed from above.

[0084] The stockyard 220 has a left side wall 221, a right side wall 222, and a rear wall 223. The left side wall 221, the right side wall 222, and the rear wall 223 are flat walls. The left side wall 221 and the right side wall 222 are arranged parallel to each other. The left side wall 221 and the right side wall 222 extend perpendicular to the rear wall 223. The left side wall 221 is connected to one end of the rear wall 223, and the right side wall 222 is connected to the other end of the rear wall 223. The stockyard 220 has a three-sided frame shape in a plan view. The stockyard 220 is open on the bottom side in FIG. 8 . Through this opening, the wheel loader 1 can load materials into the stockyard 220 and excavate the excavation target 200 within the stockyard 220.

[0085] 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 towards the excavation target 200 when excavating the excavation target 200. The back wall 223 extends in a direction perpendicular to that traveling direction (the left-right direction in FIG. 8 ; hereinafter referred to as the perpendicular direction).

[0086] The point cloud data acquired by the LiDAR includes three-dimensional position information of each reflection point where the laser light is reflected. The elevation model shown in FIG. 8 is generated using height information at each point within the stockyard 220 viewed in plan view as shown in FIG. 8. The position estimation unit 101 recognizes the position and shape of the excavation target 200 based on the elevation model. The position and shape of the excavation target 200 are included in the appearance characteristics of the excavation target 200. The appearance characteristics of the excavation target 200 are included in the state of the excavation target 200.

[0087] The excavation target 200 has a peak 201, which has the highest peak height, and a base 202 on the near side (the side where the wheel loader 1 excavates the excavation target 200; the lower side in FIG. 8 ). The peak height of the excavation target 200 is not uniform, but gradually decreases from the peak 201 to the base 202. The base 202 is schematically illustrated as a straight line. Near the base 202, the excavation target 200 has a low-peak region 203 where the amount of accumulated material is small and the peak height is low, and an accumulation region 204 where the amount of accumulated material is greater than in the low-peak region 203 and the peak height is higher than in the low-peak region 203.

[0088] The position estimation unit 101 calculates the remaining amount of material in the stockyard 220A. The remaining amount of material (excavation target 200) is included in the state of the excavation target 200. The remaining amount of material is calculated from an elevation model. Figure 9 is a diagram illustrating the process of calculating the remaining amount of material.

[0089] As shown in Fig. 9, the position estimation unit 101 virtually divides the elevation model of the excavation target 200 in the stockyard 220A into equal intervals in the traveling direction and the perpendicular direction. The position estimation unit 101 calculates the height of each divided section. The height of the section may be the height of the center point of the section. The height of the section may also be the average value of the heights of each point included in the section.

[0090] The position estimation unit 101 calculates the volume of material in a section based on the area of ​​the section when the stockyard 220A is viewed from above and the height of the section. The position estimation unit 101 calculates the remaining amount of material in the stockyard 220A by adding up the volume values ​​of material in all sections.

[0091] 7 , in step S2, the path planning unit 102 of the automation controller 100 determines whether the remaining amount of material in the stockyard 220A is less than a specified value. The specified value may be, for example, the capacity of the bucket 6 of the wheel loader 1. The capacity of the bucket 6 is included in the specifications of the work machine 3.

[0092] The default value for the remaining amount of material is stored in the memory of the automation controller 100 or in another storage device. The path planning unit 102 reads out the default value for the remaining amount of material and compares the remaining amount of material calculated in step S1 with the default value to determine whether the remaining amount of material in the stockyard 220A is less than the specified value.

[0093] If the remaining amount of material in the stockyard 220A is equal to or greater than a specified value (NO in step S2), the wheel loader 1 excavating the excavation target 200 in the stockyard 220A can fill the bucket 6 with material in one excavation operation, and can continue the excavation operation properly. In this case, one excavation operation refers to the operation of the wheel loader 1 traveling forward toward the excavation target 200, excavating the excavation target 200, and starting to move backward. In step S3, the excavation operation in the stockyard 220A continues. The process returns to step S1.

[0094] Figure 10 is a schematic diagram of a wheel loader 1 moving forward empty toward an excavation target 200 in a stockyard 220. Figure 10(A) shows a state in which the remaining amount of material (excavation target 200) in the stockyard 220 is sufficiently greater than a specified value. In the state shown in Figure 10(A), it is easy to scoop up the excavation target 200 that is equal to or greater than the specified value into the bucket 6 of the wheel loader 1 and fill the bucket 6 with material.

[0095] If the remaining amount of material in the stockyard 220A is less than the specified value (YES in step S2), the wheel loader 1 excavating the excavation target 200 in the stockyard 220A will not be able to load the bucket 6 with material in one excavation operation, and it is therefore determined that the excavation operation cannot be continued properly. Determining whether the remaining amount of material is less than the specified value corresponds to an example of determining "whether the excavation operation can be continued properly." The determination of whether the excavation operation can be continued properly is made based on the remaining amount of material and the capacity of the bucket 6.

[0096] 10(B) shows a state in which the remaining amount of material (excavation target 200) in the stockyard 220 has fallen below a specified value. When the remaining amount of material in the stockyard 220 decreases as shown in FIG. 10(B), it becomes difficult to fully fill the bucket 6 with material when the wheel loader 1 performs excavation work, and the filling rate of material in the bucket 6 decreases. If excavation work is performed with a low filling rate, the amount of work cannot be ensured, and work efficiency decreases. Therefore, when the path planning unit 102 determines that the remaining amount of material has decreased to the point where the bucket 6 cannot scoop up more than the specified amount of material (excavation target 200) in one excavation operation, it determines that excavation work cannot be continued appropriately.

[0097] If the dimension of the stockyard 220 in the orthogonal direction is greater than the width of the bucket 6 (length L9 shown in FIG. 2), the path planning unit 102 determines whether the remaining amount of material in the stockyard 220 is less than a specified value in units of the width of the bucket 6. Even if the remaining amount of material in the stockyard 220 as a whole is equal to or greater than the specified value, if the remaining amount of material in a section that is a virtual division of the stockyard 220 in the orthogonal direction in units of the width of the bucket 6 is less than the specified value, the bucket 6 cannot scoop up more than the specified amount of material in one excavation operation. Therefore, in this case, the path planning unit 102 determines that the excavation operation cannot be continued properly.

[0098] In step S4, the path planning unit 102 stops the excavation work in the stockyard 220A. A command signal is sent from the path following control unit 103 of the automation controller 100 to the vehicle body controller 50. Upon receiving the signal, the vehicle body controller 50 controls the actuator 140 to stop the excavation work in the stockyard 220A.

[0099] In step S5, the automation controller 100 transmits information to the external controller 400 (FIG. 5) via the communication device 150. The external controller 400 is a computer accessible by a manager who manages the work site, or a computer that constitutes a control system for the work site.

[0100] The information transmitted by the wheel loader 1 to the external controller 400 includes location information of the stockyard 220 currently being worked on. In other words, it includes information indicating where within the work site the stockyard 220 in which the wheel loader 1 is performing excavation work is located. Typically, it includes information indicating in which of the stockyards 220A and 220B shown in Fig. 6 the wheel loader 1 is performing excavation work.

[0101] The information transmitted by the wheel loader 1 to the external controller 400 includes the remaining amount of material in the currently operating stockyard 220. In other words, the information includes information indicating how much material remains in the stockyard 220 where the wheel loader 1 is performing excavation work.

[0102] The information sent by the wheel loader 1 to the external controller 400 includes a report that the remaining amount of material in the stockyard 220 where work is currently being performed has fallen below a specified value. In other words, a report is issued that the remaining amount of material in the stockyard 220 where excavation work is currently being performed is low, and therefore sufficient excavation cannot be performed.

[0103] In step S6, the work site manager or the control system instructs the wheel loader 1 from the external controller 400 via the communication device 150 to move from the stockyard 220A where excavation work has been performed to the stockyard 220B. The stockyard 220B corresponds to an example of a "second stockyard." The excavation targets 200 accumulated in the stockyard 220B correspond to an example of an "other excavation target."

[0104] In step S7, the wheel loader 1 moves to the stockyard 220B and starts excavating the excavation target 200 accumulated in the stockyard 220B. A command signal is sent from the path following control unit 103 of the automation controller 100 to the vehicle body controller 50. Upon receiving the signal, the vehicle body controller 50 performs excavation work in the stockyard 220B and controls the actuator 140 to load the excavated material into the loading target 500.

[0105] In step S8, the manager or control system of the work site issues a command from the external controller 400 via the communication device 350 (FIG. 5) to the transport machine 300 to replenish the material to the original stockyard 220 (stockyard 220A in this example).

[0106] FIG. 11 is a schematic diagram showing the state in which the wheel loader 1 has moved to an excavation position. The wheel loader 1 shown in FIG. 11 moves forward along the path 250B toward an excavation position PB in the stockyard 220B and scoops up the excavation target 200 in the stockyard 220B into the bucket 6. The wheel loader 1 moves backward along the path 250B and switches its traveling direction at a turning point PC. The wheel loader 1 moves forward along the path 550 toward a loading position PD of the loading target 500 and loads the material loaded in the bucket 6 into the loading target 500. The wheel loader 1 moves backward along the path 550 and switches its traveling direction at a turning point PC. In this way, the wheel loader 1 performs the work of excavating and loading materials in the stockyard 220B.

[0107] The transport machine 300 shown in FIG. 11 is a dump truck and has a vessel 301. The transport machine 300 transports materials at the work site by traveling around the work site with materials loaded in the vessel 301. The transport machine 300 approaches the stockyard 220A. The transport machine 300 travels along a path that does not interfere with the paths 250B, 550 of the wheel loader 1, and arrives at a position for unloading materials into the stockyard 220A. The transport machine 300 unloads the materials in the vessel 301 into the stockyard 220A. In this way, the transport machine 300 replenishes materials in the stockyard 220A.

[0108] In this way, the series of processes for generating the travel route of the wheel loader 1 is completed ("End" in FIG. 7).

[0109] <Functions and Effects> Although some of the description overlaps with the above description, the characteristic configuration and functions and effects of this embodiment can be summarized as follows.

[0110] 7 , the automation controller 100 determines whether the wheel loader 1 performing the excavation work can continue the excavation work properly based on the state of the excavation target 200. If the automation controller 100 determines that the excavation work cannot be continued properly, it stops excavating the excavation target 200.

[0111] When the wheel loader 1 performs continuous excavation work, work efficiency decreases if the excavation work cannot be continued appropriately. If it is determined that the excavation work of the excavation target 200 cannot be continued appropriately, the excavation of the excavation target 200 can be stopped, thereby avoiding a decrease in the efficiency of the excavation work by the wheel loader 1.

[0112] 7 and 11 , if the automation controller 100 determines that the excavation work cannot be continued appropriately, it may move the wheel loader 1 to another excavation target 200. If it determines that the excavation work of the excavation target 200 cannot be continued appropriately, the excavation of that excavation target 200 is stopped and another excavation target 200 is excavated, thereby allowing the excavation work by the wheel loader 1 to continue.

[0113] 6 and 11 , excavation targets 200 may be accumulated in stockyard 220A, and other excavation targets 200 may be accumulated in stockyard 220B. When it is determined that the excavation work of the excavation targets 200 accumulated in stockyard 220A cannot be continued appropriately, the excavation of the excavation targets 200 in stockyard 220A is stopped, and the other excavation targets 200 accumulated in stockyard 220B are excavated, thereby allowing the excavation work by the wheel loader 1 to continue.

[0114] 7 and 11 , if the automation controller 100 determines that the excavation work cannot be continued properly, it may issue a command to replenish the excavation target 200. The wheel loader 1 is moved to continue the excavation work on the other excavation target 200, while the original excavation target 200 is replenished with the excavation target 200. When the excavation work on the other excavation target 200 cannot be continued properly due to the continuous execution of the excavation work on the other excavation target 200, the excavation work on the other excavation target 200 can be stopped and the wheel loader 1 can be moved to excavate the replenished original excavation target 200. This allows the excavation work by the wheel loader 1 to continue.

[0115] 1 and 2 , the work implement 3 has a bucket at its tip, and the automation controller 100 determines whether the wheel loader 1 can continue excavation work appropriately based on the state of the excavation target 200 and the specifications of the work implement 3, and the specifications of the work implement 3 may include the capacity of the bucket 6. The automation controller 100 can determine whether the wheel loader 1 can continue excavation work appropriately based on the capacity of the bucket 6.

[0116] 8 and 9 , the automation controller 100 recognizes the shape of the excavation target 200 based on the detection results of the perception device 111, and the state of the excavation target 200 may include the remaining amount of the excavation target 200 calculated from the shape of the excavation target 200. The automation controller 100 can determine whether the wheel loader 1 can continue excavation work appropriately based on the remaining amount of the excavation target 200.

[0117] 7 and 10 , the automation controller 100 may determine that the excavation work cannot be continued properly if the bucket 6 is unable to scoop a specified amount of excavation targets 200 or more in one excavation operation. If the excavation work is performed when the filling rate of the bucket 6 with the excavation targets 200 is low, the amount of work cannot be secured, resulting in a decrease in work efficiency. In such a case, if it is determined that the excavation work cannot be continued properly and the excavation is stopped, a decrease in the efficiency of the excavation work can be avoided.

[0118] In the above embodiment, the automation controller 100 mounted on the wheel loader 1 recognizes the state of the excavation target 200 and determines the work of the wheel loader 1. Also, in the embodiment, the perception device 111 mounted on the wheel loader 1 detects the excavation target 200. This example is not limiting, and a system may be configured in which either or both of the sensor that detects the excavation target 200 and the management controller that determines the work of the work machine are provided outside the work machine.

[0119] An external controller 400 that is provided outside the wheel loader 1 and is capable of communicating with the wheel loader 1 may determine the work of the wheel loader 1. The external controller 400 may receive an input of the detection results of the excavation target 200 to recognize the state of the excavation target 200, read out the specifications of the work implement 3 of the wheel loader 1, and determine whether the excavation work can be continued appropriately based on the state of the excavation target 200 and the specifications of the work implement 3.

[0120] The sensor that detects the excavation target 200 excavated by the work machine 3 does not necessarily have to be mounted on the wheel loader 1. The sensor may be disposed outside the work machine. The sensor may be mounted on another work machine, or on an unmanned aerial vehicle such as a drone. The sensor may be disposed at a predetermined point on the work site. For example, a sensor may be disposed on the top of the wall of the stockyard 220 to detect the excavation target 200 within the stockyard 220.

[0121] The condition of the excavation target 200 that is used as a basis for determining whether excavation work can be continued appropriately is not limited to the remaining amount of the excavation target 200. For example, whether excavation work can be continued appropriately may be determined based on the shape of the excavation target 200. If it is determined that the shape of the excavation target 200 after continuous excavation has become such that the filling rate of the material in the bucket 6 would decrease if excavation work were to continue, it may be determined that excavation work cannot be continued appropriately.

[0122] The specifications of the work implement 3 that are used to determine whether excavation work can be continued appropriately are not limited to the capacity of the bucket 6. For example, whether excavation work can be continued appropriately may be determined based on the type of attachment attached to the tip of the work implement 3. If it is determined that the currently attached attachment is not an appropriate type of attachment for excavating the excavation target 200, it may be determined that excavation work cannot be continued appropriately.

[0123] The excavation target 200 described in the embodiment is accumulated in a stockyard 220 having a wall as shown in Fig. 8, but is not limited to this example. The excavation target 200 may also be a pile of material accumulated on the ground at a work site. The excavation target 200 may be formed by a transport machine unloading the material at an appropriate position at the work site and then shaping the material with a work machine such as a wheel loader or a shovel.

[0124] In the embodiment, a determination is made as to whether the work machine excavating the excavation target 200 can properly continue the work of excavating the excavation target 200. This example is not limiting, and if there are multiple piles of material at the work site and the work machine is about to start excavating one of the piles of material, a determination may be made as to which pile to excavate based on the state of the piles and the specifications of the work implement 3. For example, if the current shape of a certain pile is one that would be better adjusted by raking to make the excavation work easier, a determination may be made not to excavate that pile, and a determination may be made to excavate a pile that has already been raked.

[0125] In the embodiment, an example has been described in which the wheel loader 1 is equipped with a cab 5 and is a manned vehicle in which an operator rides in the cab 5. The wheel loader 1 may be an unmanned vehicle. The wheel loader 1 does not have to be equipped with a cab 5 for an operator to ride in and operate. The wheel loader 1 does not have to be equipped with a control function by an operator on board. The wheel loader 1 may be a work machine exclusively for remote control. The wheel loader 1 may be controlled by a radio signal from a remote control device.

[0126] <Additional Notes> The above description includes the following additional features.

[0127] (Supplementary Note 1) A work machine comprising: a work implement; a sensor that detects an excavation target to be excavated by the work implement; and a management controller that recognizes the state of the excavation target and determines the work of the work machine, wherein the management controller determines whether the work machine, which performs excavation work to excavate the excavation target, can properly continue the excavation work based on the state of the excavation target, and stops the excavation work when it determines that the excavation work cannot be properly continued.

[0128] (Supplementary Note 2) The work machine according to Supplementary Note 1, wherein the management controller moves the work machine to another excavation target when it determines that the excavation work cannot be continued appropriately.

[0129] (Supplementary Note 3) The work machine according to Supplementary Note 2, wherein the excavation targets are accumulated in a first stockyard, and the other excavation targets are accumulated in a second stockyard.

[0130] (Supplementary Note 4) The work machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the management controller issues a command to replenish the excavation target when it determines that the excavation work cannot be continued appropriately.

[0131] (Supplementary Note 5) The work machine according to any one of Supplementary Notes 1 to 4, wherein the work machine has a bucket at its tip, and the management controller determines whether the work machine can continue the excavation work appropriately based on the state of the excavation target and specifications of the work machine, and the specifications of the work machine include a capacity of the bucket.

[0132] (Supplementary Note 6) The work machine according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the management controller recognizes a shape of the excavation target based on a detection result of the sensor, and the state of the excavation target includes a remaining amount of the excavation target calculated from the shape of the excavation target.

[0133] (Supplementary Note 7) The work machine according to Supplementary Note 6, wherein the work implement has a bucket at its tip, the excavation work is work of scooping up the excavation target into the bucket, and the management controller determines that the excavation work cannot be continued properly if the bucket is unable to scoop up a specified amount or more of the excavation target in one excavation work.

[0134] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0135] 1 Wheel loader, 2 Body frame, 3 Work machine, 4 Traveling device, 6 Bucket, 6a Cutting edge, 6c Width direction center, 14 Boom, 50 Body controller, 60 Engine controller, 70 Transmission controller, 80 Work machine controller, 100 Automation controller, 101 Position estimation unit, 102 Path planning unit, 103 Path following control unit, 110 External information acquisition unit, 111 Perception device, 120 Vehicle information acquisition unit, 150, 350 Communication device, 200 Excavation target, 201 Mountain peak, 202 Foothills, 203 Low mountain area, 204 Accumulation area, 220, 220A, 220B Stockyard, 221 Left side wall, 222 Right side wall, 223 Back wall, 250A, 250B, 550 Route, 300 Transport machine, 301 Vessel, 400 external controller, 500 loading target, PA, PB digging position, PC turning position, PD loading position.

Claims

1. A work machine comprising: a working implement; a sensor that detects an excavation target to be excavated by the work machine; and a management controller that recognizes the condition of the excavation target and determines the work of the work machine, wherein the management controller judges whether the work machine performing excavation work to excavate the excavation target can properly continue the excavation work based on the condition of the excavation target, and stops the excavation work when it determines that the excavation work cannot be properly continued.

2. A work machine as set forth in claim 1, wherein said management controller moves said work machine to another excavation target when it determines that said excavation work cannot be continued properly.

3. The work machine according to claim 2, wherein the excavation targets are stored in a first stockyard, and the other excavation targets are stored in a second stockyard.

4. A work machine as claimed in any one of claims 1 to 3, wherein the management controller issues a command to replenish the excavation target when it determines that the excavation work cannot be continued properly.

5. A work machine as claimed in any one of claims 1 to 3, wherein the work machine has a bucket at its tip, and the management controller judges whether the work machine can continue the excavation work properly based on the state of the excavation target and the specifications of the work machine, and the specifications of the work machine include the capacity of the bucket.

6. A work machine as claimed in any one of claims 1 to 3, wherein the management controller recognizes the shape of the excavation target based on the detection results of the sensor, and the state of the excavation target includes a remaining amount of the excavation target calculated from the shape of the excavation target.

7. A work machine as described in claim 6, wherein the work implement has a bucket at its tip, the excavation work is a work of scooping up the excavation target into the bucket, and the management controller determines that the excavation work cannot be continued properly if the bucket is unable to scoop up a specified amount or more of the excavation target in one excavation work.

8. A system including a work machine comprising: a work machine; a sensor that detects an excavation target to be excavated by the work machine; and a management controller that recognizes the state of the excavation target and determines the work of the work machine, wherein the management controller judges whether the work machine performing excavation work to excavate the excavation target can properly continue the excavation work based on the state of the excavation target, and stops the excavation work when it determines that the excavation work cannot be properly continued.

9. A method for controlling a work machine comprising: recognizing a state of an excavation target; determining whether a work machine performing excavation work to excavate the excavation target can continue the excavation work properly based on the state of the excavation target; and stopping the excavation work when it is determined that the excavation work cannot be continued properly.

Images