Control system for a work machine, method for controlling a work machine, and work machine

Abstract

Set appropriate conditions for switching the work machine from manual to automatic operation. [Solution] The control system for controlling a wheel loader 1 capable of both automatic and manual operation includes an information acquisition device that acquires information about objects within the work area 600 where the wheel loader 1 performs its work, and a controller. The controller sets an automatic operation switching area within the work area 600 where the wheel loader 1 performs its work in automatic operation mode, using information from both the wheel loader 1 and the objects. When the wheel loader 1 reaches the automatic operation switching area in manual operation mode, the controller switches the wheel loader 1 from manual operation to automatic operation mode.

Description

Technical Field

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

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2024-62797 (Patent Document 1) discloses a construction machine capable of automatic operation and manual operation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=�4]] When performing work using a work machine capable of automatic operation and manual operation, it is required to appropriately set the conditions for switching from manual operation to automatic operation.

[0005] The present disclosure proposes a control system for a work machine, a control method for a work machine, and a work machine that can appropriately set the conditions for switching the work machine from manual operation to automatic operation.

Means for Solving the Problems

[0006] A control system for a work machine according to an aspect of the present disclosure is a control system that controls a work machine capable of automatic operation and manual operation, and includes an information acquisition device that acquires information on an object within a work area where the work machine performs work, and a controller. The controller sets an automatic operation switching area where the work machine performs work by automatic operation within the work area using both the information of the work machine and the information of the object. When the work machine reaches the automatic operation switching area by manual operation, the controller switches the work machine from manual operation to automatic operation.

[0007] A control method for a work machine relating to a certain aspect of this disclosure is a control method for a work machine that can be operated automatically and manually, and comprises the following steps: The first step is to acquire information about an object in a work area in which the work machine is performing work. The second step is to set an automatic operation switching area in which the work machine will perform work by automatic operation within the work area, using information about the work machine and information about the object. The third step is to switch the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area by manual operation.

[0008] A working machine relating to a certain aspect of this disclosure is a working machine capable of both automatic and manual operation, and comprises an information acquisition device that acquires information about objects within a work area in which the working machine performs work, and a controller. The controller sets an automatic operation switching area within the work area in which the working machine performs work in automatic operation, using information from both the working machine and the objects. When the working machine reaches the automatic operation switching area in manual operation, the controller switches the working machine from manual operation to automatic operation. [Effects of the Invention]

[0009] According to this disclosure, the conditions for switching a work machine from manual operation to automatic operation can be appropriately set. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of a wheel loader. [Figure 2] This is a plan view of a wheel loader. [Figure 3] This diagram illustrates excavation and loading operations using a wheel loader. [Figure 4] This is a block diagram illustrating the schematic configuration of a wheel loader control system. [Figure 5] This is a block diagram showing the configuration of an automatic control system for a wheel loader. [Figure 6]This is a schematic diagram showing the work area in a plan view. [Figure 7] This is a schematic diagram showing the setting of the width of the automatic excavation switching area. [Figure 8] This is a schematic diagram showing the setting of the width of the automatic loading and switching area. [Figure 9] This flowchart shows the automatic control method for a wheel loader. [Figure 10] This is a schematic diagram showing an example of the display screen of the display unit. [Modes for carrying out the invention]

[0011] The embodiments will be described below 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 of them will not be repeated. In the drawings, some configurations may be omitted or simplified for the sake of explanation. It is also intended from the outset that any configuration may be extracted from the embodiments and combined in any way.

[0012] <Overall configuration of wheel loader 1> In this embodiment, a wheel loader 1 will be described as an example of a work machine. Figure 1 is a side view of the wheel loader 1 as an example of a work machine. Figure 2 is a top view of the wheel loader 1 shown in Figure 1.

[0013] As shown in Figures 1 and 2, the wheel loader 1 mainly consists of a body frame 2, a work implement 3, a running gear 4, and a cab 5. The body of the wheel loader 1 is composed of the body frame 2, cab 5, etc. The work implement 3 and running gear 4 are attached to the body of the wheel loader 1. The main body of the wheel loader 1 has the body and the running gear 4.

[0014] The traveling device 4 is for driving the vehicle body of the wheel loader 1 and includes traveling wheels 4a and 4b. The wheel loader 1 is a wheeled vehicle equipped with the traveling wheels 4a and 4b as traveling rotors on both sides in the left - right direction of the vehicle body. The wheel loader 1 can self - travel when the traveling wheels 4a and 4b are rotationally driven, and can perform desired work using the working machine 3.

[0015] In this specification, the direction in which the wheel loader 1 travels straight is referred to as the front - rear direction of the wheel loader 1. In the front - rear direction of the wheel loader 1, the side where the working machine 3 is arranged with respect to the vehicle body frame 2 is defined as the front direction, and the side opposite to the front direction is defined as the rear direction. The left - right direction of the wheel loader 1 is the direction orthogonal to the front - rear direction when the wheel loader 1 on a flat ground is viewed in plan view. The right side and the left side in the left - right direction when looking in the front direction are the right direction and the left direction respectively. The up - down direction of the wheel loader 1 is the direction orthogonal to the plane defined by the front - rear direction and the left - right direction. The side with the ground in the up - down direction is the lower side, and the side with the air is the upper side.

[0016] The vehicle body frame 2 includes a front frame 2a and a rear frame 2b. The front frame 2a is arranged in front of the rear frame 2b. The front frame 2a and the rear frame 2b are attached to each other so as to be operable in the left - right direction by a center pin 10.

[0017] A pair of left - right steering cylinders 11 are attached across the front frame 2a and the rear frame 2b. The steering cylinder 11 is a hydraulic cylinder. When the steering cylinder 11 expands and contracts by hydraulic oil from a steering pump not shown, the traveling direction of the wheel loader 1 is changed left and right. The front frame 2a and the rear frame 2b constitute the vehicle body frame 2 having an articulated structure. The wheel loader 1 is an articulated working machine in which the front frame 2a and the rear frame 2b are connected so as to be bendable.

[0018] The front frame 2a is equipped with a working machine 3 and a pair of traveling wheels (front wheels) 4a. The working machine 3 is attached to the front of the vehicle body of the wheel loader 1. The working machine 3 is supported by the vehicle body of the wheel loader 1. Specifically, the working machine 3 is rotatably supported by the vehicle body frame 2, more specifically, the front frame 2a. The working machine 3 is arranged in front of the vehicle body frame 2.

[0019] The working machine 3 includes a boom 14. The 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 in a non - relative - movement manner by a joining member extending in the left - right direction, forming a boom 14 of an integral structure. The boom pin 9 includes a pair of left and right left boom pins 9L and right boom pins 9R. The boom 14 is rotatable with respect to the front frame 2a with the left boom pin 9L and the right boom pin 9R as the rotation centers. The left boom pin 9L and the right boom pin 9R support the working machine 3 rotatably with respect to the vehicle body frame 2.

[0020] The working machine 3 includes a bucket 6. The bucket 6 is arranged at the tip of the working machine 3. The bucket 6 is a working tool for excavation and loading. The cutting edge 6a is the tip portion of the bucket 6. The back surface 6b is a part of the outer surface of the bucket 6. The back surface 6b is formed 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 仃 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.

[0021] The work implement 3 further includes a bell crank 18 and a link 15. The bell crank 18 is rotatably supported on the boom 14 by a support pin 18a located approximately in the center of the boom 14 in the longitudinal direction 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 positioned between the left boom member 14L and the right boom member 14R in the left-right direction.

[0022] 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 cylinders 16 are hydraulic actuators that move the boom 14 up and down relative to the front frame 2a. As the boom 14 is raised and lowered, the bucket 6 attached to the tip of the boom 14 also moves up and down.

[0023] 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 on 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 a work tool cylinder that drives the bucket 6. The bucket cylinder 19 rotates the bucket 6 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.

[0024] The boom cylinder 16 and the bucket cylinder 19 constitute the work equipment actuator that drives the work equipment 3.

[0025] The rear frame 2b is fitted with a cab 5 where the operator sits, and a pair of running wheels (rear wheels) 4b. 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 vehicle frame 2. Inside the cab 5 are a seat where the wheel loader 1 operator sits, and control devices 8 (Figure 4), which will be described later.

[0026] The cab 5 is equipped with a sensing device 111. The sensing device 111 is located, for example, on the ceiling of the cab 5. The sensing device 111 is mounted, for example, on the top surface of the cab 5. The sensing device 111 is located, for example, at the front of the cab 5. The sensing device 111 is mounted on the cab 5 facing forward, for example, and is capable of acquiring information in front of the cab 5. Details of the sensing device 111 will be described later.

[0027] The length L1 shown in Figure 1 is the length from the cutting edge 6a of the bucket 6 to the rear end of the vehicle body in the front-rear direction (the total length of the wheel loader 1). The 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 (the bucket width). The bucket width is included in the dimensional information of the work equipment 3. The center point 6c in the width direction of the bucket 6 is the center point of the bucket 6 in the left-right direction.

[0028] The lengths L1 and L9 shown in Figures 1 and 2 are included in the specifications of the wheel loader 1. The specifications of the wheel loader 1 also include the minimum turning radius of the vehicle body. The wheel loader 1 has an articulated structure in which the front frame 2a and the rear frame 2b can bend relative to each other, resulting in a smaller minimum turning radius compared to a rigid structure. The specifications of the wheel loader 1 are unique to each individual wheel loader 1 and are stored in the vehicle body controller 50, which will be described later.

[0029] <Excavation and loading work> In this embodiment, the wheel loader 1 scoops up material into a bucket 6 and loads the material in the bucket 6 onto a loading target 300 such as a dump truck, performing an excavation and loading operation. The material is soil, rock, or ore, which is excavated at the work site or transported to the work site by a transport machine such as a dump truck. Figure 3 is a diagram illustrating the excavation and loading operation by the wheel loader 1 according to this embodiment.

[0030] Figure 3(A) shows a wheel loader 1 moving forward without a load. The wheel loader 1 moves forward towards the excavation target 200, which is a pile of material. The boom cylinder 16 and bucket cylinder 19 (Figure 1) operate to position the work implement 3 in an excavation posture with the tip of the boom 14 in a low position and the bucket 6 facing horizontally.

[0031] Figures 3(B) and 3(C) illustrate a wheel loader 1 performing an excavation operation. The wheel loader 1 plunges the cutting edge 6a of the bucket 6 into the excavation target 200 and stops moving forward. In the excavation (plungation) operation shown in Figure 3(B), the cutting edge 6a of the bucket 6 bites into the excavation target 200. In this state, the boom 14 and bucket 6 rise and the bucket 6 tilts back, causing the bucket 6 to move along the bucket trajectory BL as shown by the arrow in Figure 3(C). This operation performs an excavation (scooping) operation, as shown in Figure 3(C), to excavate the excavation target 200 and scoop up the material into the bucket 6.

[0032] Depending on the type of material to be excavated (200), the excavation (scooping) operation may be completed by simply tilting the bucket 6 back once. Alternatively, the excavation (scooping) operation may involve repeatedly tilting the bucket 6 back, returning it to the neutral position, and then tilting it back again.

[0033] Figure 3(D) shows a wheel loader 1 reversing with a load inside. The wheel loader 1 moves in reverse with material loaded in the bucket 6. The wheel loader 1 may also raise the bucket 6 while moving in reverse.

[0034] Figure 3(E) shows a wheel loader 1 moving forward to load a load. The wheel loader 1 moves forward toward the load to be loaded 300 while raising the bucket 6 or maintaining the bucket 6 in a raised position. The wheel loader 1 approaches the load to be loaded 300 until the bucket 6 reaches a predetermined position where it is located almost directly above the loading platform of the load to be loaded 300.

[0035] Figure 3(F) shows a wheel loader 1 performing an excavation operation onto the loading target 300. When the wheel loader 1 approaches the loading target 300 and reaches a predetermined position, it dumps the bucket 6 and loads the material in the bucket 6 onto the loading target 300. Then, while reversing to the position where it started moving forward in Figure 3(E), the wheel loader 1 lowers the boom 14 and returns the work machine 3 to the excavation position.

[0036] The above describes a typical operation that constitutes one cycle of excavation and loading work. The wheel loader 1 repeatedly performs the above operations in sequence to excavate the excavation target 200 and load the excavated material into the loading target 300, such as a dump truck.

[0037] When the wheel loader 1 excavates the excavation target 200 shown in Figures 3(B) and 3(C), it maintains a straight-ahead posture with the front frame 2a and rear frame 2b not bending relative to each other. When the wheel loader 1 loads the material in the bucket 6 shown in Figure 3(F) onto the loading target 300, it maintains a straight-ahead posture with the front frame 2a and rear frame 2b not bending relative to each other.

[0038] <System Configuration> Figure 4 is a block diagram showing the schematic configuration of the control system that controls the wheel loader 1.

[0039] The engine 21 is a drive source that generates driving force to drive the work equipment 3 and the travel device 4, and is, for example, a diesel engine. Instead of the engine 21, an electric motor driven by a storage battery may be used as the drive source, or both an engine and an electric 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.

[0040] The driving force generated by the engine 21 is transmitted to the transmission (T / M) 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 driving wheels 4a and 4b (Figures 1 and 2). This causes the wheel loader 1 to move. In the wheel loader 1 of this embodiment, both the driving wheels 4a and 4b constitute the drive wheels that receive the driving force and move the wheel loader 1.

[0041] A portion of the driving force from the engine 21 is transmitted to the work equipment pump 13. The work equipment pump 13 is a hydraulic pump driven by the engine 21 that operates the work equipment 3 with the hydraulic fluid it discharges. The work equipment 3 is driven by the hydraulic fluid from the work equipment pump 13. The hydraulic fluid discharged from the work equipment pump 13 is supplied to the boom cylinder 16 and the bucket cylinder 19 via the main valve 32. The boom 14 rises and falls as the boom cylinder 16 extends and retracts in response to the supply of hydraulic fluid. The bucket 6 rotates up and down as the bucket cylinder 19 extends and retracts in response to the supply of hydraulic fluid.

[0042] The wheel loader 1 is equipped with a vehicle controller 50. The vehicle controller 50 includes an engine controller 60, a transmission controller 70, and a work implement controller 80.

[0043] The vehicle controller 50 is generally implemented by a CPU (Central Processing Unit) that reads various programs. The vehicle controller 50 has memory (not shown). The memory functions as work memory and stores various programs for realizing the functions of the wheel loader 1.

[0044] The control device 8 is located in the cab 5. The control device 8 is operated by the operator. The control device 8 includes several types of operating members that the operator uses to operate the wheel loader 1. The control device 8 includes an accelerator pedal 41 and a work equipment operating lever 42. The control device 8 may also include a steering wheel, a shift lever, etc. (not shown).

[0045] The accelerator pedal 41 is operated to set a target rotational speed for 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. Increasing the amount of operation (pressure) of the accelerator pedal 41 increases the output of the engine 21. Decreasing the amount of operation of the accelerator pedal 41 decreases the output of the engine 21. The transmission controller 70 controls the transmission 23 based on the amount of operation of the accelerator pedal 41.

[0046] The implement operating lever 42 is operated to operate the implement 3. The implement controller 80 controls the electromagnetic proportional control valves 35 and 36 based on the amount of operation of the implement operating lever 42.

[0047] The electromagnetic proportional control valve 35 switches the main valve 32 so that the bucket cylinder 19 is retracted and the bucket 6 moves in the dump direction (the direction in which the tip of the bucket 6 moves downward). The electromagnetic proportional control valve 35 also switches the main valve 32 so that the bucket cylinder 19 is extended and the bucket 6 moves in the tilt direction (the direction in which the tip of the bucket 6 moves upward). The electromagnetic proportional control valve 36 switches the main valve 32 so that the boom cylinder 16 is retracted and the boom 14 moves downward. The electromagnetic proportional control valve 36 also switches the main valve 32 so that the boom cylinder 16 is extended and the boom 14 moves upward.

[0048] The machine monitor 51 receives command signals from the vehicle controller 50 and displays various information. The information displayed on the machine monitor 51 may include, for example, information related to the work performed by the wheel loader 1, vehicle information such as fuel level, coolant temperature and hydraulic oil temperature, and surrounding images taken around the wheel loader 1. The machine monitor 51 may also be a touch panel, in which 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 controller 50.

[0049] <Automatic control system for wheel loader 1> In automating the series of excavation and loading operations shown in Figure 3, it is desirable to replicate the operations of a skilled operator through automatic control in order to perform the work more quickly while ensuring sufficient work volume. Figure 5 is a block diagram showing the configuration of the automatic control system for wheel loader 1.

[0050] The automation controller 100 is configured to send and receive signals with the vehicle controller 50, which was described using Figure 4. The automation controller 100 is also configured to receive signals from the external information acquisition unit 110. The external information acquisition unit 110 includes a perception device 111 and a location information acquisition device 112. The perception device 111 and the location information acquisition device 112 are mounted on the vehicle body of the wheel loader 1.

[0051] The sensing device 111 acquires information about the surroundings of the wheel loader 1. The sensing device 111 is mounted, for example, on the front of the top surface of the cab 5. The sensing device 111 detects objects around the main body (working machine body) of the wheel loader 1. The sensing device 111 detects information such as the position and shape of the excavation target 200 and the loading target 300.

[0052] The sensing device 111 detects the direction and distance to an object outside the wheel loader 1 in a non-contact manner. The sensing device 111 is, for example, a LiDAR (Light Detection and Ranging) that emits laser light to acquire information about the object. The sensing device 111 may also be a visual sensor including a camera. The sensing device 111 may also be a Radar (Radio Detection and Ranging) that acquires information about the object by emitting radio waves. The sensing device 111 may also be an infrared sensor.

[0053] The position information acquisition device 112 acquires information about the current position of the wheel loader 1. The position information acquisition device 112 acquires the position information of the wheel loader 1 in a global coordinate system based on the Earth, for example, by using a satellite positioning system. 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 wheel loader 1 by calculating the position of the GNSS receiver's antenna based on the positioning signals received by the GNSS receiver from the satellite.

[0054] External information of the wheel loader 1 from the perception device 111, and position information of the wheel loader 1 from the position information acquisition device 112 are input to the automation controller 100.

[0055] The vehicle controller 50 is configured to receive signals from the vehicle information acquisition unit 120. The vehicle controller 50 receives information about the wheel loader 1 acquired by the vehicle information acquisition unit 120. The vehicle information acquisition unit 120 is composed of various sensors mounted on the wheel loader 1. The vehicle information acquisition unit 120 includes an articulated 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.

[0056] The articulated angle sensor 121 detects the articulated angle, which is the angle between the front frame 2a and the rear frame 2b, and generates a signal of the detected articulated angle. The articulated angle sensor 121 outputs the articulated angle signal to the vehicle controller 50.

[0057] The vehicle speed sensor 122 detects the movement speed of the wheel loader 1 by the running gear 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 controller 50. The vehicle speed sensor 122 detects the progress of the running gear 4 (driving body).

[0058] The boom angle sensor 123 consists of, for example, a rotary encoder provided on the boom pin 9, which is the mounting part of the boom 14 to the vehicle frame 2. The boom angle sensor 123 detects the angle of the boom 14 with respect to the horizontal direction (boom angle) and generates a signal of the detected boom angle 14. The boom angle sensor 123 outputs the boom angle signal of the boom 14 to the vehicle controller 50.

[0059] The bucket angle sensor 124 is composed of, for example, a rotary encoder provided on the support pin 18a, which is the rotation axis of the bell crank 18. The bucket angle sensor 124 detects the angle of the bell crank 18 relative to the boom 14 (bell crank angle) and generates a signal of the detected bell crank 18 angle. The vehicle information acquisition unit 120 or the vehicle body controller 50 calculates the angle of the bucket 6 relative to the boom 14 (bucket angle) from the detected bell crank 18 angle.

[0060] The boom angle sensor 123 and the bucket angle sensor 124 detect the posture of the work machine 3. The boom angle sensor 123 may be a stroke sensor located on the boom cylinder 16. The bucket angle sensor 124 may be a potentiometer or proximity switch attached to the bucket pin 17, or a stroke sensor located on the bucket cylinder 19.

[0061] The boom cylinder pressure sensor 125 detects the pressure at the bottom of the boom cylinder 16 (boom bottom pressure) and generates a signal of the detected boom bottom pressure. The boom bottom pressure increases when the bucket 6 is loaded and decreases when it is empty. The boom cylinder pressure sensor 125 outputs the boom bottom pressure signal to the vehicle controller 50.

[0062] The vehicle controller 50 outputs the information input from the vehicle information acquisition unit 120 to the automation controller 100. Detected values ​​from the articulated angle sensor 121, vehicle speed sensor 122, etc., are input to the automation controller 100 via the vehicle controller 50.

[0063] The electromagnetic proportional control valve 140 is configured to receive signals from the vehicle controller 50. The electromagnetic proportional control valve 140 is driven upon receiving a command signal from the vehicle controller 50. The electromagnetic proportional control valve 140 includes a brake EPC (electromagnetic proportional control valve) 141 for operating the brakes of the running gear 4, a steering EPC 142 for adjusting the direction of travel of the wheel loader 1, and a work implement EPC 143 for operating the work implement 3.

[0064] The electromagnetic proportional control valves 35 and 36 shown in Figure 4 constitute the work machine EPC 143. The transmission 23 shown in Figure 4 is implemented as a mechanical transmission. The transmission 23 may be an HST (Hydro-Static Transmission). The transmission 23 may also be an HMT (Hydraulic Mechanical Transmission), which combines an HST and a mechanical transmission. The power transmission device that transmits power from the engine 21 to the running wheels 4a and 4b may include an electric drive system such as a diesel-electric system, or it may include any combination of HMT, HST, or electric drive system.

[0065] The transmission controller 70 includes a brake control unit 71 and an accelerator control unit 72. The brake control unit 71 outputs a command signal to the brake EPC 141 for controlling the operation of the brakes. The accelerator control unit 72 outputs a command signal to the transmission 23 for controlling the vehicle speed.

[0066] The work equipment controller 80 includes a steering control unit 81 and a work equipment control unit 82. The steering control unit 81 outputs a command signal to the steering EPC 142 for controlling the direction of travel of the wheel loader 1. The work equipment control unit 82 outputs a command signal to the work equipment EPC 143 for controlling the operation of the work equipment 3.

[0067] The automated controller 100 includes a current position estimation unit 101, a target position setting unit 102, a path generation unit 103, and a path following control unit 104.

[0068] The current position estimation unit 101 estimates the current position of the wheel loader 1 based on the information acquired by the external information acquisition unit 110. Specifically, the current position estimation unit 101 estimates the current position of the wheel loader 1 based on positioning signals received from satellites by a GNSS receiver, which is an example of a position information acquisition device 112, or detection signals from a LiDAR, which is an example of a perception device 111. The current position estimation unit 101 may also estimate its own position by creating a high-precision surrounding map using data acquired by LiDAR and comparing that surrounding map with a map that has been stored in advance (SLAM: Simultaneous Localization and Mapping).

[0069] The target position setting unit 102 sets the target position based on the external information acquired by the external information acquisition unit 110. The target position is, for example, the excavation position at the excavation target 200 where the wheel loader 1 excavates the excavation target 200 with the bucket 6. Alternatively, the target position is the loading position at the loading target 300, which is the relative position of the work machine 3 (bucket 6) to the loading target 300 when loading material onto the loading target 300. The perception device 111 may recognize the target position and input it to the automation controller 100, or the target position setting unit 102 may set the target position based on the detection result detected by the perception device 111.

[0070] The path generation unit 103 generates the optimal path for the wheel loader 1 when the wheel loader 1 is automatically controlled. The optimal path includes the path for travel by the traveling device 4 and the path for operation of the work equipment 3. The travel path for the wheel loader 1 generated by the path generation unit 103 has a V-shape, for example, for V-shaped travel.

[0071] For example, the path generation unit 103 generates the travel path of the wheel loader 1 as it moves forward empty toward the excavation target 200. The path generation unit 103 generates the movement path of the work machine 3 during the excavation work. The path generation unit 103 generates the travel path of the wheel loader 1 as it moves backward with a load toward the excavation target 200, and the movement path of the work machine 3 while it is moving backward with a load. The path generation unit 103 generates the travel path of the wheel loader 1 as it moves forward with a load toward the loading target 300, and the movement path of the work machine 3 while it is moving forward with a load. The path generation unit 103 generates the movement path of the work machine 3 as it discharges the material scooped into the bucket 6 toward the loading target 300. The path generation unit 103 generates the travel path of the wheel loader 1 as it moves backward empty toward the loading target 300, and the movement path of the work machine 3 while it is moving backward empty with a load.

[0072] The path generation unit 103 also generates an optimal path connecting the current position of the wheel loader 1 and the target position to which the wheel loader 1 is headed while the excavation and loading operation is being performed.

[0073] The path-following control unit 104 commands the operation of the traveling device 4 and the work equipment 3. The path-following control unit 104 controls the accelerator, brakes, and steering so that the wheel loader 1 travels following the optimal path generated by the path generation unit 103. The path-following control unit 104 outputs command signals 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 104 controls the boom cylinder 16 and bucket cylinder 19 so that the work equipment 3 operates along the optimal path generated by the path generation unit 103. The path-following control unit 104 outputs a command signal to the work equipment control unit 82 to cause the work equipment 3 to move along the optimal path.

[0074] As shown in Figure 5, the wheel loader 1 may be remotely controlled by an operator using an external control device 350. The wheel loader 1 and the control device 350 each have communication devices 150 and 310, respectively, for communication with each other.

[0075] The wheel loader 1's communication device 150 includes a receiving unit 150a for receiving remote control commands from the operating device 350, and a transmitting unit 150b for transmitting operation information of the wheel loader 1 to the operating device 350. The automation controller 100 is configured to send and receive signals with the communication device 150.

[0076] On the other hand, the communication device 310 of the operating device 350 has a receiving unit 310a for receiving information transmitted from the transmitting unit 150b of the wheel loader 1, and a transmitting unit 310b for transmitting remote control commands to the receiving unit 150a of the wheel loader 1.

[0077] In addition to the communication device 310, the operating device 350 includes an operating unit 320 operated by an operator and a display unit 330 that displays various information. The operating unit 320 includes, for example, an accelerator pedal, a work equipment operating lever, a steering wheel, a shift lever, etc. The operator can remotely control the driving of the work equipment 3 and the travel device 4 on the wheel loader 1 via the operating unit 320.

[0078] The display unit 330 displays, for example, information related to the work performed by the wheel loader 1, vehicle information such as fuel level, coolant temperature and hydraulic oil temperature, and surrounding images taken of the area around the wheel loader 1. The display unit 330 may also be a touch panel, in which case a signal generated by the operator touching a part of the display unit 330 is transmitted from the transmission unit 310b to the reception unit 150a. In this case, the display unit 330 can function as an operation unit 320.

[0079] The operating device 350 is located away from the wheel loader 1. The operating device 350 may be located at the work site where the wheel loader 1 is performing its work. The operator may remotely control the excavation and loading work by operating the operating device 350 while visually observing the wheel loader 1 from outside the wheel loader 1. The operating device 350 may be located away from the work site. The operator may remotely control the excavation and loading work by operating the operating device 350 while viewing the image displayed on the display unit 330. The operating device 350 may be a portable device.

[0080] The automatic control system for the wheel loader 1 is configured so that the automation controller 100 can command the operation of various functions of the wheel loader 1 based on information acquired from the communication device 150. The automatic control system for the wheel loader 1 is also configured so that the information held by the automation controller 100 can be commanded to the loading target 300, such as a dump truck, via the communication device 150.

[0081] Interface 130 is configured to enable the transmission and reception of signals with the vehicle controller 50. Interface 130 includes an engine emergency stop switch 131 and a mode lamp 132.

[0082] The engine emergency stop switch 131 is operated by the operator. When an event occurs that requires the engine 21 to be stopped in an emergency, the operator operates the engine emergency stop switch 131. The signal indicating the operation of the engine emergency stop switch 131 is input to the vehicle controller 50.

[0083] The mode lamp 132 indicates whether the wheel loader 1 is currently in a mode operated manually by an operator or in an automatically controlled mode. The vehicle controller 50 outputs a command signal to the mode lamp 132 to control the illumination of the lamp.

[0084] <Setting the automatic driving switching area> Figure 6 is a schematic diagram of the work area 600 in which the wheel loader 1 performs its work, viewed from above. The work area 600 is a region set up to encompass, in a plan view, the area in which the wheel loader 1 travels to perform a series of excavation and loading operations. The work area 600 is set up as a roughly rectangular area.

[0085] The work area 600 includes the travel path of the wheel loader 1 as it moves forward empty toward the excavation target 200 and as it moves backward loaded after excavating the excavation target 200. The work area 600 also includes the travel path of the wheel loader 1 as it moves forward loaded toward the loading target 300 and as it moves backward empty after loading onto the loading target 300.

[0086] The work area 600 encompasses the travel path of the wheel loader 1 when it travels in a V-shape. V-shape travel is a typical travel path when the wheel loader 1 performs excavation and loading work, where the travel path of the wheel loader 1 forms a V shape. When the wheel loader 1 travels in a V-shape while performing excavation and loading work, the travel distance of the wheel loader 1 is minimized, making it an efficient travel path.

[0087] After excavating the excavation target 200, the wheel loader 1, which travels in a V-shape, switches from forward to reverse and moves the load in a straight line backward. The wheel loader 1 then switches from reverse to forward and moves the load forward towards the loading target 300. The switching position where the wheel loader 1 switches between reverse and forward may be set at a position a distance L1 (Figure 1) from the excavation target 200. The travel path of the wheel loader 1 as it moves the load forward towards the loading target 300, starting from the switching position, may include at least a curved, typically arc-shaped, path and may also include a straight path.

[0088] The work area 600 includes a roughly rectangular area schematically viewed from above, which is the excavation target 200 to be excavated by the wheel loader 1. The excavation target 200 may be a pile of material formed on a cleared area. The excavation target 200 may be a pile of material accumulated in a material storage area such as a stockyard.

[0089] The work area 600 includes the loading area 620. The loading area 620 is a roughly rectangular area in plan view, representing the area where the loading target 300 (dump truck) is positioned when the wheel loader 1 loads the excavated material onto the loading target 300. The layout of the loading area 620 is set relative to the excavation target 200.

[0090] The automated controller 100 transmits the arrangement of the loading area 620 relative to the position of the excavation target 200 to the loading target 300 (dump truck) via the communication device 150. The dump truck parks within the designated loading area 620. The wheel loader 1 loads the excavated material onto the dump truck parked in the loading area 620. The dump truck, which is an example of the loading target 300, has a vessel 301 for loading the material.

[0091] The work area 600 includes an automatic operation switching area where the wheel loader 1 performs work under automatic operation. When the wheel loader 1 travels through the work area 600 under manual operation and reaches the automatic operation switching area, the wheel loader 1 switches from manual operation to automatic operation. The automatic operation switching area includes an automatic excavation switching area 610 and an automatic loading switching area 630. The automatic excavation switching area 610 and the automatic loading switching area 630 are set as roughly rectangular areas.

[0092] The automatic excavation switching area 610 indicates the area where the wheel loader 1 automatically performs excavation work to excavate the excavation target 200. When the wheel loader 1 reaches the automatic excavation switching area 610 under manual operation, the wheel loader 1 switches to automatic operation and performs the excavation work under automatic operation. The automatic loading switching area 630 indicates the area where the wheel loader 1 automatically performs loading work to load the excavated material onto the loading target 300. When the wheel loader 1 reaches the automatic loading switching area 630 under manual operation, the wheel loader 1 switches to automatic operation and performs the loading work under automatic operation.

[0093] The automation controller 100 uses information from both the wheel loader 1 and the excavation target 200 to set up an automatic excavation switching area 610 within the work area 600. Hereinafter, the dimension of the automatic excavation switching area 610 in the direction in which the wheel loader 1 moves straight toward the excavation target 200 will be referred to as the depth of the automatic excavation switching area 610. The dimension of the automatic excavation switching area 610 in the direction perpendicular to the direction in which the wheel loader 1 moves straight toward the excavation target 200 will be referred to as the width of the automatic excavation switching area 610. Figure 7 is a schematic diagram showing the setting of the width of the automatic excavation switching area 610.

[0094] The excavation target 200 shown in Figure 7 is a pile of material formed on a vacant lot. The height of the excavation target 200 is not uniform, and the height gradually increases from the base 211,212 to the top 214. The amount of material is relatively small near the base 211,212. If the excavation target 200 is attempted near the base 211,212, the travel distance of the wheel loader 1 to fill the bucket 6 with material may be long, or it may not be possible to fill the bucket 6 with material at all.

[0095] The width of the automatic excavation switching area 610 is set using both the dimensional information of the bucket 6 and the dimensional information of the excavation target 200 to ensure a sufficient material filling rate for the bucket 6. The dimensional information of the excavation target 200 can be obtained using the sensing device 111. The objects within the work area 600 detected by the sensing device 111 include the excavation target 200. The sensing device 111 corresponds to an example of an information acquisition device that acquires information about objects. The sensing device 111 inputs the detection result of the excavation target 200 to the automation controller 100. The target position setting unit 102 of the automation controller 100 recognizes the position, shape, and dimensions of the excavation target 200 based on the detection result of the sensing device 111.

[0096] The dimensional information of bucket 6 is stored in the memory or other storage device of the automation controller 100, and the automation controller 100 can read and use the stored dimensional information of bucket 6 at any time.

[0097] The virtual bucket position 6V1, shown as a rectangle in Figure 7, is located a short distance from the base of the hill 211 of the excavation target 200. By positioning the bucket 6 at the virtual bucket position 6V1 and driving the wheel loader 1 in a straight line toward the excavation target 200, a certain amount of material can be loaded into the bucket 6 in a short travel distance, and typically the bucket 6 can be fully loaded with material. If the wheel loader 1 is positioned closer to the base of the hill 211 than the virtual bucket position 6V1 and driven in a straight line toward the excavation target 200, the travel distance of the wheel loader 1 to fully load the bucket 6 with material will be longer.

[0098] The vertical dimension of the bucket 6 when its back surface 6b, as shown in Figure 1, is parallel to the ground G in the vicinity of the ground G is referred to as the bucket height. The virtual bucket position 6V1 can be set, for example, by positioning the left end of the bucket 6 at a location where the height of the mound to be excavated 200 is the same as the bucket height.

[0099] The virtual bucket position 6V2, shown as a rectangle in Figure 7, is located slightly away from the base of the hill 212 of the excavation target 200. By positioning the bucket 6 at the virtual bucket position 6V2 and driving the wheel loader 1 in a straight line toward the excavation target 200, a certain amount of material can be loaded into the bucket 6 in a short travel distance, and typically the bucket 6 can be fully loaded with material. If the wheel loader 1 is positioned closer to the base of the hill 212 than the virtual bucket position 6V2 and driven in a straight line toward the excavation target 200, the travel distance of the wheel loader 1 to fully load the bucket 6 with material will be longer.

[0100] The virtual bucket position 6V2 can be set, for example, as the position where the right end of bucket 6 is placed at a location where the height of the mound to be excavated 200 is the same as the bucket height.

[0101] The center point 6V1c shown in Figure 7 is the center point of the virtual bucket position 6V1 in the left-right direction. The center point 6V2c is the center point of the virtual bucket position 6V2 in the left-right direction. The center points 6V1c and 6V2c are determined from the widthwise dimension information of bucket 6. The distance between the center points 6V1c and 6V2c in the left-right direction is the width W1 shown in Figure 7. This width W1 can be set as the width of the automatic excavation switching area 610. If the excavation target 200 has an uneven mound height as shown in Figure 7, the width of the automatic excavation switching area 610 can be set to be smaller than the width of the excavation target 200.

[0102] When the wheel loader 1 is in a straight-ahead position with an articulation angle of 0°, the center point 6c of the bucket 6 and the center pin 10 are positioned at the same location in the left-right direction of the wheel loader 1 (see also the plan view of the wheel loader 1 shown in Figure 2). By positioning the wheel loader 1 so that the center pin 10 is located within the width W1 shown in Figure 7, and then having the wheel loader 1 move straight toward the excavation target 200 from that position, the bucket 6 can be fully loaded with material in a short travel distance, thus enabling efficient excavation work.

[0103] When excavating the excavation target 200, the wheel loader 1 moves forward in a straight line toward the excavation target 200 at a predetermined speed in order to penetrate the cutting edge 6a of the bucket 6 into the excavation target 200. The depth of the automatic excavation switching area 610 can be set to a distance that includes a margin of safety in addition to the distance required to accelerate the wheel loader 1 to that predetermined speed. The depth of the automatic excavation switching area 610 may be set to a constant dimension regardless of the speed at which the wheel loader 1 reaches the automatic excavation switching area 610. The depth of the automatic excavation switching area 610 may be changed based on the speed at which the wheel loader 1 reaches the automatic excavation switching area 610.

[0104] The automation controller 100 uses information from both the wheel loader 1 and the loading target 300 to set up an automatic loading changeover area 630 within the work area 600. Hereinafter, the dimension of the automatic loading changeover area 630 in the direction in which the wheel loader 1 moves straight toward the loading target 300 will be referred to as the depth of the automatic loading changeover area 630. The dimension of the automatic loading changeover area 630 in the direction perpendicular to the direction in which the wheel loader 1 moves straight toward the loading target 300 will be referred to as the width of the automatic loading changeover area 630. Figure 8 is a schematic diagram showing the setting of the width of the automatic loading changeover area 630.

[0105] The vessel 301 shown in Figure 8 is located at the rear of the loading object 300 (dump truck). The dump truck has a cab at the front, and the vessel 301 is positioned behind the cab. The vessel 301 has a front edge 304 and a rear edge 306. The front edge 304 constitutes the front edge of the vessel 301. The rear edge 306 constitutes the rear edge of the vessel 301.

[0106] The width of the automatic loading switching area 630 is set using both the dimensional information of the bucket 6 and the dimensional information of the vessel 301 of the loading target 300, so that the bucket 6 can load the material onto the vessel 301 without interfering with the vessel 301. The dimensional information of the loading target 300 can be obtained using the sensing device 111. The objects within the work area 600 detected by the sensing device 111 include the loading target 300. The sensing device 111 corresponds to an example of an information acquisition device that acquires information about objects. The sensing device 111 inputs the detection result of the loading target 300 to the automation controller 100. The target position setting unit 102 of the automation controller 100 recognizes the position, shape, and dimensions of the loading target 300 based on the detection result of the sensing device 111.

[0107] The wheel loader 1 and the load to be loaded 300 (dump truck) may communicate with each other. The location and dimensions of the vessel 301 may be transmitted from the dump truck to the wheel loader 1 via vehicle-to-vehicle communication between the communication device 150 of the wheel loader 1 and the communication device of the dump truck. In this case, the communication device 150 of the wheel loader 1 corresponds to an example of an information acquisition device that acquires information about the object.

[0108] The virtual bucket position 6V1, shown as a rectangle in Figure 8, can be set, for example, as the position where the left end of bucket 6 is located just behind the leading edge 304 of the vessel 301. The virtual bucket position 6V2, shown as a rectangle in Figure 8, can be set, for example, as the position where the right end of bucket 6 is located just in front of the trailing edge 306 of the vessel 301.

[0109] The center point 6V1c shown in Figure 8 is the center point of the virtual bucket position 6V1 in the left-right direction. The center point 6V2c is the center point of the virtual bucket position 6V2 in the left-right direction. The distance between the center points 6V1c and 6V2c in the left-right direction is the width W2 shown in Figure 8. This width W2 can be set as the width of the automatic loading switching area 630. By positioning the wheel loader 1 so that the center pin 10 is located within the range of width W2 shown in Figure 8, and having the wheel loader 1 move straight toward the loading target 300 from that position, the material in the bucket 6 can be reliably loaded into the vessel 301, thus enabling efficient loading work.

[0110] The depth of the automatic loading switching area 630 can be set to a distance that is greater than the distance required to raise the boom 14 while moving the wheel loader 1 forward in a straight position, so that the bucket 6 can be moved above the vessel 301 without interfering with the work machine 3 with the loading target 300.

[0111] The depth of the automatic loading switching area 630 may be set to a constant dimension, regardless of the vehicle speed at which the wheel loader 1 reaches the automatic loading switching area 630. When the wheel loader 1 reaches the automatic loading switching area 630, the wheel loader 1 switches to automatic operation and performs the loading work under automatic control. Since the travel of the wheel loader 1 and the raising of the boom 14 can be controlled in conjunction, the travel speed of the wheel loader 1 and the raising speed of the boom 14 can be set appropriately, enabling efficient loading work.

[0112] <Automatic control method> The following describes a control method for operating the wheel loader 1 manually within the work area 600 and performing excavation and loading work automatically. Figure 9 is a flowchart showing the automatic control method for the wheel loader 1.

[0113] As shown in Figure 9, in step S1, the operator manually positions the wheel loader 1 at its initial position from a remote location. The initial position can be set based on the relative positional relationship between the wheel loader 1 and the object to be loaded 300. For example, the initial position may be set at a location where the loading area 620 is included within the field of view of the sensing device 111 mounted on the wheel loader 1, and the sensing device 111 can detect the object to be loaded 300. Alternatively, the initial position may be set at a location appropriate for recognizing the position of the object to be loaded 300. The centerline of the wheel loader 1 at the initial position may overlap with the centerline of the excavation target 200. Or, the wheel loader 1 at the initial position may be facing directly towards the object to be loaded 300.

[0114] In step S2, the operator operates the control unit 320, or a command is received from the automation controller 100, to cause the wheel loader 1 to recognize the position of the load target 300 within the loading area 620. A sensing device 111 mounted on the wheel loader 1 detects the load target 300. The sensing device 111 inputs the detection result of the load target 300 to the automation controller 100. The target position setting unit 102 recognizes the position and shape of the load target 300 based on the detection result of the sensing device 111.

[0115] The target position setting unit 102 uses information on the position and shape of the loading target 300 and the dimensions of the bucket 6 to set an automatic loading switching area 630 in front of the loading target 300.

[0116] In step S3, the operator remotely controls the wheel loader 1 to move towards the excavation target 200. The forward-moving wheel loader 1 faces the excavation target 200 directly. At this time, the sensing device 111 mounted on the wheel loader 1 detects the excavation target 200. The sensing device 111 inputs the detection result of the excavation target 200 to the automation controller 100. The target position setting unit 102 recognizes the position and shape of the excavation target 200 based on the detection result of the sensing device 111. The target position setting unit 102 uses both the position and shape information of the excavation target 200 and the dimensional information of the bucket 6 to set an automatic excavation switching area 610 in front of the excavation target.

[0117] In step S4, it is determined whether the reference point of the wheel loader 1 has reached the automatic excavation switching area 610. This determination is performed by the current position estimation unit 101 of the automation controller 100. Based on the information obtained from the external information acquisition unit 110, the current position estimation unit 101 determines whether the reference point of the wheel loader 1 is within the automatic excavation switching area 610.

[0118] The information acquired from the external information acquisition unit 110 is, for example, a positioning signal received from a satellite by a GNSS receiver, which is an example of a location information acquisition device 112. Alternatively, the information acquired from the external information acquisition unit 110 may also be, for example, a detection signal from a LiDAR, which is an example of a perception device 111.

[0119] Furthermore, the above-mentioned reference point of the wheel loader 1 is, for example, the center position of the center pin 10, which is the articulation center. Therefore, the current position estimation unit 101 determines that the wheel loader 1 has reached the automatic excavation switching area 610 when it determines that the center position of the center pin 10 is within the automatic excavation switching area 610 in a top view.

[0120] If it is determined that the reference point of wheel loader 1 has not reached the automatic excavation switching area 610 (NO in the determination in step S4), the process returns to step S3. The operation of wheel loader 1 by the operator in step S3 continues, and the determination in step S4 is repeated.

[0121] When it is determined that the reference point of the wheel loader 1 has reached the automatic excavation switching area 610 (YES in the determination in step S4), in step S5, the automation controller 100 determines whether the operation information of the wheel loader 1 satisfies the automatic excavation switching conditions. The wheel loader 1 has a vehicle information acquisition unit 120. The automation controller 100 acquires the operation information of the wheel loader 1 from the vehicle information acquisition unit 120.

[0122] The operating information of the wheel loader 1 includes, for example, the direction of travel of the wheel loader 1, the articulate angle, the travel speed, and the attitude of the bucket 6. The automated controller 100 obtains the direction of travel of the wheel loader 1 based on the operation of the control unit 320 by the operator. The automated controller 100 obtains the articulate angle based on the detection result of the articulate angle sensor 121. The automated controller 100 obtains the travel speed based on the detection result of the vehicle speed sensor 122. The direction of travel of the wheel loader 1 may also be obtained based on the detection result of the vehicle speed sensor 122. The automated controller 100 obtains the attitude of the bucket 6 based on the detection results of the boom angle sensor 123 and the bucket angle sensor 124.

[0123] When the cutting edge 6a of the bucket 6 is thrust into the excavation target 200, it is desirable that the wheel loader 1 is moving in a straight line. Therefore, the automatic excavation switching conditions may include the wheel loader 1 traveling forward and the articulation angle being 0°. If the travel speed of the wheel loader 1 is too low, the cutting edge 6a of the bucket 6 will not bite into the excavation target 200 sufficiently. If the travel speed is too high, the shock when the cutting edge 6a of the bucket 6 contacts the excavation target 200 will be large. For this reason, the automatic excavation switching conditions may include the travel speed of the wheel loader 1 being within a predetermined range. As explained with reference to Figure 3(A), the cutting edge 6a of the bucket 6 is in a low position when in the excavation position, so the automatic excavation switching conditions may also include the cutting edge 6a of the bucket 6 being in contact with the ground G.

[0124] The automation controller 100 may display the automatic excavation switching conditions on the display unit 330 so that the operator can recognize the current operation information of the wheel loader 1 by looking at the display unit 330. Figure 10 is a schematic diagram showing an example of the display screen of the display unit 330. In the example shown in Figure 10, image information 331 and text information 332 are displayed on the display unit 330. The image information 331 includes information within the work area 600, which includes the wheel loader 1 and the automatic operation switching area.

[0125] The text information 332 includes the current operating mode of the wheel loader 1 (whether the wheel loader 1 is remotely controlled or in automatic operation), the automatic excavation switching conditions, and the result of determining whether the current operation information of the wheel loader 1 satisfies the automatic excavation switching conditions. In the example shown in Figure 10, the reference point of the wheel loader 1 is in the automatic excavation switching area 610, it is moving forward, the articulation angle is 0°, and the travel speed satisfies the conditions, but the condition that the cutting edge 6a of the bucket 6 is in contact with the ground is not satisfied. Therefore, the wheel loader 1 has not switched to automatic mode, and the current mode is remote control.

[0126] Returning to Figure 9, if it is determined that the operating conditions of wheel loader 1 do not satisfy the automatic excavation switching conditions (NO in the determination in step S5), the process returns to step S3. The operation of wheel loader 1 by the operator in step S3 continues, and the determinations in steps S4 and S5 are repeated.

[0127] When it is determined that the operating conditions of the wheel loader 1 satisfy the automatic excavation switching conditions (YES in the determination in step S5), in step S6, the operating mode of the wheel loader 1 switches to automatic mode. The operation of the wheel loader 1 is switched from manual operation by the operator to automatic operation based on commands from the automation controller 100. The wheel loader 1 automatically performs the excavation work to excavate the excavation target 200. The path-following control unit 104 of the automation controller 100 outputs command signals to the electromagnetic proportional control valve 140 via the vehicle controller 50 to make the wheel loader 1 travel along the optimal path and move the work machine 3 along the optimal path. As a result, the wheel loader 1 performs the excavation work by automatic operation within the automatic excavation switching area 610.

[0128] In step S7, when the excavation work by automated operation is completed, the operator is notified that the excavation work has been completed. The completion of the excavation work may also be determined by the bucket angle sensor 124 detecting that the bucket 6 is in a fully tilted position. Notification to the operator can be made using the display unit 330 and other types of visual devices such as lamps, or auditory devices such as speakers. Furthermore, the operating mode of the wheel loader 1 switches to remote control mode. The wheel loader 1 is operated by the operator using the control unit 320.

[0129] In step S8, the operator remotely controls the wheel loader 1 to move towards the excavation target 200.

[0130] In step S9, it is determined whether the reference point of the wheel loader 1 has reached the automatic loading switching area 630. This determination is performed by the current position estimation unit 101 of the automation controller 100. Based on the information obtained from the external information acquisition unit 110, the current position estimation unit 101 determines whether the reference point of the wheel loader 1 is within the automatic loading switching area 630.

[0131] If it is determined that the reference point of wheel loader 1 has not reached the automatic loading switching area 630 (NO in the determination in step S9), the process returns to step S8. The operation of wheel loader 1 by the operator in step S8 continues, and the determination in step S9 is repeated.

[0132] When it is determined that the reference point of the wheel loader 1 has reached the automatic loading switching area 630 (YES in the determination in step S9), in step S10, the automation controller 100 determines whether the operation information of the wheel loader 1 satisfies the automatic loading switching conditions. The wheel loader 1 has a vehicle information acquisition unit 120. The automation controller 100 acquires the operation information of the wheel loader 1 from the vehicle information acquisition unit 120.

[0133] The operating information of the wheel loader 1 includes, for example, the direction of travel of the wheel loader 1, the articulation angle, the travel speed, and the posture of the work equipment 3. The automation controller 100 obtains the direction of travel of the wheel loader 1 based on the operation of the control unit 320 by the operator. The automation controller 100 obtains the articulation angle based on the detection result of the articulation angle sensor 121. The automation controller 100 obtains the travel speed based on the detection result of the vehicle speed sensor 122. The direction of travel of the wheel loader 1 may also be obtained based on the detection result of the vehicle speed sensor 122. The automation controller 100 obtains the posture of the work equipment 3 based on the detection results of the boom angle sensor 123 and the bucket angle sensor 124.

[0134] When loading the material in bucket 6 onto the loading target 300, it is desirable for the wheel loader 1 to be moving in a straight line, so the automatic loading switching conditions may include the wheel loader 1 traveling forward and having an articulation angle of 0°. If the travel speed of the wheel loader 1 is too high, the wheel loader 1 will get too close to the loading target 300, so the automatic loading switching conditions may also include the wheel loader 1's travel speed being below a predetermined value.

[0135] To prevent material from spilling out of the bucket 6 when the wheel loader 1 travels with material loaded in the bucket 6, the automatic loading switching condition may include the posture of the work machine 3 being a predetermined travel posture. This travel posture may include the bucket 6 being in a fully tilted position. Since it is desirable for the wheel loader 1 to be directly facing the loading target 300 during loading, the automatic excavation switching condition may include the angular error between the loading target 300 and the wheel loader 1 being less than or equal to a predetermined value.

[0136] If it is determined that the operating conditions of wheel loader 1 do not satisfy the automatic loading switching conditions (NO in the determination in step S10), the process returns to step S8. The operation of wheel loader 1 by the operator in step S8 continues, and the determinations in steps S9 and S10 are repeated.

[0137] When it is determined that the operating conditions of the wheel loader 1 satisfy the automatic loading switching conditions (YES in the determination in step S10), in step S11, the operating mode of the wheel loader 1 switches to automatic mode. The operation of the wheel loader 1 is switched from manual operation by the operator to automatic operation based on commands from the automation controller 100. The wheel loader 1 automatically performs the loading operation of loading the material onto the loading target 300. The path following control unit 104 of the automation controller 100 outputs command signals to the electromagnetic proportional control valve 140 via the vehicle controller 50 to make the wheel loader 1 travel along the optimal path and move the work machine 3 along the optimal path. As a result, the wheel loader 1 performs the loading operation by automatic operation within the automatic loading switching area 630.

[0138] In step S12, when the loading operation by automated driving is completed, the operator is notified that the loading operation is complete. The completion of the loading operation may also be determined by the external information acquisition unit 110 detecting that the wheel loader 1 has reversed and moved away from the loading target 300. Notification to the operator can be made using the display unit 330 and other types of visual devices such as lamps, or auditory devices such as speakers. Furthermore, the operating mode of the wheel loader 1 switches to remote control mode. The wheel loader 1 is operated by the operator using the control unit 320.

[0139] In step S13, the operator moves the wheel loader 1 to a standby position by manual operation from a remote location. The standby position may be a turning point where the wheel loader 1, which is traveling in a V-shape, switches between reverse and forward movement. Alternatively, if the loading target 300, loaded with the maximum load capacity of material, moves outside the work area 600 and the operator is waiting for the next empty loading target 300 to arrive in the loading area 620, the operator may move the wheel loader 1 to an appropriate standby position. This standby position may be different from the initial position in step S1, or it may be the same as the initial position. The process then ends ("End" in Figure 9).

[0140] Even if the wheel loader 1's operating mode switches to automatic mode in steps S6 and S11 and the wheel loader 1 is operating under automatic control, the operator's input takes precedence. Suppose that while the wheel loader 1 is operating under automatic control, the operator operates the control unit 320 and the automation controller 100 receives an operation command. In this case, the wheel loader 1's operating mode is switched to remote control mode, and the wheel loader 1 operates according to the operator's input.

[0141] The above description has described an example in which an operator remotely controls the wheel loader 1 by operating an operating unit 320 located outside the wheel loader 1. An operator remotely controlling the wheel loader 1 may operate multiple wheel loaders 1 simultaneously. In this case, the number of operators required to operate multiple wheel loaders 1 can be reduced. Multiple wheel loaders 1 may work at the same work site or at different work sites.

[0142] Alternatively, the operator may manually operate the wheel loader 1 by boarding the cab 5 and operating the control device 8 located in the cab 5. Excavation and loading operations are complex tasks that require simultaneous and complex operation of the work equipment 3 while driving, and also require alignment of the work equipment 3 with the object to be worked. When the operator's skill level is not high, assisting the excavation and loading operations with automated operation can suppress a decrease in work efficiency.

[0143] The work area 600, the automatic excavation switching area 610, and the automatic loading switching area 630 shown in Figure 6 all have a rectangular shape, but the shape of each area is not limited to a rectangle, and each area may be set to any shape.

[0144] The automation controller 100, which constitutes the automatic control system of the wheel loader 1, does not necessarily have to be mounted on the wheel loader 1. An external controller may construct the system that constitutes the automation controller 100. A controller mounted on the wheel loader 1 may perform the process of transmitting information acquired by the external information acquisition unit 110 and the vehicle information acquisition unit 120, etc., to an external controller, and the external controller that receives the signal may generate the travel path of the wheel loader 1.

[0145] The external controller may be located at the work site of the wheel loader 1, or it may be located in a remote location 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 the operator, such as a laptop computer, tablet computer, or smartphone.

[0146] In this embodiment, a dump truck was used as an example of the loading target 300, and the operation of loading the material loaded on the work machine 3 (bucket 6) into the vessel 301 was described. The loading target 300 for loading the material in the bucket 6 is not limited to the vessel 301 of a dump truck, but may be a hopper or the like. <Mechanism of Action and Effects> The characteristic configuration and effects of this embodiment are summarized below.

[0147] As shown in Figures 6-8, the automation controller 100 sets an automatic operation switching area within the work area 600, using information from both the wheel loader 1 and the object to be worked on. When the wheel loader 1 reaches the automatic operation switching area under manual operation, the automation controller 100 switches the wheel loader 1 from manual operation to automatic operation.

[0148] Using information from both the wheel loader 1 performing the work and the objects within the work area 600, an automatic operation switching area is set to switch the wheel loader 1 from manual to automatic operation. Since the automatic operation switching area is set according to the current conditions of the work site, it is possible to set the automatic operation switching area appropriately. When the wheel loader 1 reaches the automatic operation switching area, the wheel loader 1 switches from manual to automatic operation and performs the work automatically. By automatically controlling tasks that require complex operations, even when the wheel loader 1 is remotely controlled, a decrease in work efficiency can be suppressed even if the operator operating the wheel loader 1 is not highly skilled.

[0149] As shown in Figures 6-8, the automatic operation switching area may include at least one of the following: an automatic excavation switching area 610 in which the wheel loader 1 automatically performs excavation work to excavate the excavation target 200, and an automatic loading switching area 630 in which the wheel loader 1 automatically performs loading work to load the material onto the loading target 300. By setting the automatic excavation switching area 610 using information from both the excavation target 200 and the wheel loader 1, the automatic excavation switching area 610 can be set appropriately, allowing for efficient excavation work. By setting the automatic loading switching area 630 using information from both the loading target 300 and the wheel loader 1, the automatic loading switching area 630 can be set appropriately, allowing for efficient loading work.

[0150] As shown in Figures 1 and 2, the wheel loader 1 has a work implement 3, and the automation controller 100 may set the automatic operation switching area using the dimensional information of the work implement 3. The work implement 3 is used for excavation work to excavate the excavation target 200 and for loading work to load the material onto the loading target 300. The automatic operation switching area can be appropriately set using the dimensional information of the work implement 3 used in the actual work.

[0151] As shown in Figure 7, the automation controller 100 may set the automatic excavation switching area 610 using the dimensional information of the excavation target 200. As shown in Figure 8, the automation controller 100 may set the automatic loading switching area 630 using the dimensional information of the loading target 300. The automatic operation switching area can be appropriately set using the actual dimensional information of the excavation target 200 and the loading target 300 on which the wheel loader 1 will perform its work.

[0152] As shown in Figure 9, the automation controller 100 may start work using automated operation when the wheel loader 1 reaches the automated operation switching area by manual operation and the operation information of the wheel loader 1 satisfies the automated operation start conditions. If the automated operation start conditions are not met when the wheel loader 1 reaches the automated operation switching area, work will not start at that time. Work will start when the automated operation start conditions are met. In this way, high-quality work can be performed.

[0153] As shown in Figure 5, the wheel loader 1 may have sensors that detect the operation information of the wheel loader 1. The automation controller 100 can acquire the operation information of the wheel loader 1 based on the sensor detection results and automatically control the wheel loader 1 so that it starts work automatically when the acquired operation information satisfies the automatic operation start conditions.

[0154] <Note> The above description includes the following features.

[0155] (Note 1) A control system for controlling work machines that can be operated automatically and manually, An information acquisition device that acquires information about objects within the work area where the aforementioned work machine performs work, A control system for a work machine, comprising: a controller that sets an automatic operation switching area within the work area, where the work machine performs work by automatic operation, using information on both the work machine and the object, and switches the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area by manual operation.

[0156] (Note 2) The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The control system for a work machine as described in Appendix 1, wherein the automatic operation switching area includes at least one of the following: an automatic excavation switching area in which the work machine automatically performs an excavation operation to excavate the target to be excavated, and an automatic loading switching area in which the work machine automatically performs a loading operation to load the material onto the target to be loaded.

[0157] (Note 3) The aforementioned work machine has a work implement, and the information of the work machine includes dimensional information of the work implement, as described in Appendix 1 or Appendix 2, for the control system of the work machine.

[0158] (Note 4) The information of the object includes the dimensional information of the object, as described in the control system of the work machine described in any one of Appendix 1 to Appendix 3.

[0159] (Note 5) The controller is a control system for a work machine as described in any one of Appendix 1 to Appendix 4, wherein the controller starts the work of the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation.

[0160] (Note 6) The aforementioned work machine is a control system for the work machine as described in Appendix 5, which has a sensor for detecting the operation information.

[0161] (Note 7) A control method for an automated and manually operated work machine, The aforementioned work machine acquires information about the objects within the work area where it performs its work, The automatic operation switching area in which the work machine performs work under automatic operation is set within the work area using information from both the work machine and the object. A method for controlling a work machine, comprising: switching the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area while being operated manually.

[0162] (Note 8) The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The control method for a work machine as described in Appendix 7, wherein the setting includes at least one of the following: setting an automatic excavation switching area in which the work machine automatically performs an excavation operation to excavate the target to be excavated; and setting an automatic loading switching area in which the work machine automatically performs a loading operation to load the material onto the target to be loaded.

[0163] (Note 9) The method for controlling a work machine as described in Appendix 7 or Appendix 8, wherein the work machine has a work implement, and the information of the work machine includes dimensional information of the work implement.

[0164] (Note 10) The information of the object includes the dimensional information of the object, as described in any one of the appendices 7 to 9, and is a control method for a work machine.

[0165] (Note 11) The control method for a work machine according to any one of the appendices 7 to 10, wherein the switching includes starting work by the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation.

[0166] (Note 12) The control method for a work machine according to Appendix 11, further comprising detecting the operation information of the work machine.

[0167] (Note 13) A work machine capable of both automatic and manual operation, An information acquisition device that acquires information about objects within the work area where the aforementioned work machine performs work, A work machine comprising a controller that sets an automatic operation switching area within the work area, where the work machine performs work by automatic operation, using information from both the work machine and the object, and switches the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area by manual operation.

[0168] (Note 14) The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The work machine according to Appendix 13, wherein the automatic operation switching area includes at least one of the following: an automatic excavation switching area in which the work machine automatically performs an excavation operation to excavate the target to be excavated, and an automatic loading switching area in which the work machine automatically performs a loading operation to load the material onto the target to be loaded.

[0169] (Note 15) Equipped with additional work equipment, The information of the aforementioned work machine includes the dimensional information of the work machine, as described in Appendix 13 or Appendix 14.

[0170] (Note 16) The information of the object includes the dimensions of the object, and is a working machine as described in any one of the appendices 13 to 15.

[0171] (Note 17) The controller starts the work of the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation, as described in any one of Appendix 13 to Appendix 16.

[0172] (Note 18) The work machine described in Appendix 17, further comprising a sensor for detecting the aforementioned operation information.

[0173] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0174] 1 Wheel loader, 2 Body frame, 2a Front frame, 2b Rear frame, 3 Work equipment, 4 Traveling gear, 4a, 4b Driving wheels, 5 Cab, 6 Bucket, 6V1, 6V2 Virtual bucket position, 6V1c, 6V2c, 6c Center point, 6a Cutting edge, 6b Rear, 8, 350 Operating device, 10 Center pin, 14 Boom, 16 Boom cylinder, 19 Bucket cylinder, 50 Body controller, 60 Engine controller, 70 Transmission controller, 80 Work equipment controller, 100 Automation controller, 101 Current position estimation unit, 102 Target position setting unit, 103 Path generation unit, 104 Path following control unit, 110 External information acquisition unit, 111 Perception device, 112 Position information acquisition device, 120 Vehicle information acquisition unit, 121 Articulated angle sensor, 122 Vehicle speed sensor, 123 Boom angle sensor, 124 Angle sensor, 125 Boom cylinder pressure sensor, 140 Electromagnetic proportional control valve, 141 Brake EPC, 142 Steering EPC, 143 Work equipment EPC, 150, 310 Communication device, 150a, 310a Receiver, 150b, 310b Transmitter, 200 Excavation target, 211, 212 Mountain base, 214 Mountain summit, 300 Loading target, 301 Vessel, 304 Leading edge, 306 Trailing edge, 320 Operation unit, 330 Display unit, 331 Image information, 332 Text information, 600 Work area, 610 Automatic excavation switching area, 620 Loading area, 630 Automatic loading switching area, W1, W2 Width.

Claims

1. A control system for controlling work machines that can be operated automatically and manually, An information acquisition device that acquires information about objects within the work area where the aforementioned work machine performs work, A control system for a work machine, comprising: a controller that sets an automatic operation switching area within the work area, where the work machine performs work by automatic operation, using information on both the work machine and the object, and switches the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area by manual operation.

2. The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The control system for a work machine according to claim 1, wherein the automatic operation switching area includes at least one of an automatic excavation switching area in which the work machine automatically performs an excavation operation in which it excavates the target to be excavated, and an automatic loading switching area in which the work machine automatically performs a loading operation in which it loads the material onto the target to be loaded.

3. The control system for a work machine according to claim 1, wherein the work machine has a work implement, and the information of the work machine includes dimensional information of the work implement.

4. The control system for a work machine according to claim 1, wherein the information of the object includes dimensional information of the object.

5. The control system for a work machine according to claim 1, wherein the controller starts the work of the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation.

6. The control system for the work machine according to claim 5, wherein the work machine has a sensor for detecting the operation information.

7. A control method for an automated and manually operated work machine, The aforementioned work machine acquires information about the objects within the work area where it performs its work, The automatic operation switching area in which the work machine performs work under automatic operation is set within the work area using information from both the work machine and the object. A method for controlling a work machine, comprising: switching the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area while being operated manually.

8. The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The method for controlling a work machine according to claim 7, wherein the setting includes at least one of the following: setting an automatic excavation switching area in which the work machine automatically performs an excavation operation to excavate the target to be excavated; and setting an automatic loading switching area in which the work machine automatically performs a loading operation to load the material onto the target to be loaded.

9. The method for controlling a work machine according to claim 7, wherein the work machine has a work implement, and the information of the work machine includes dimensional information of the work implement.

10. The control method for a work machine according to claim 7, wherein the information of the object includes dimensional information of the object.

11. The method for controlling a work machine according to claim 7, wherein the switching includes starting work by the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation.

12. The control method for a work machine according to claim 11, further comprising detecting the operation information of the work machine.

13. A work machine capable of both automatic and manual operation, An information acquisition device that acquires information about objects within the work area where the aforementioned work machine performs work, A work machine comprising a controller that sets an automatic operation switching area within the work area, where the work machine performs work by automatic operation, using information from both the work machine and the object, and switches the work machine from manual operation to automatic operation when the work machine reaches the automatic operation switching area by manual operation.

14. The object includes an excavation target, which is a pile of material excavated by the work machine, and a loading target, on which the material is loaded. The work machine according to claim 13, wherein the automatic operation switching area includes at least one of an automatic excavation switching area in which the work machine automatically performs an excavation operation to excavate the target to be excavated, and an automatic loading switching area in which the work machine automatically performs a loading operation to load the material onto the target to be loaded.

15. Equipped with additional work equipment, The work machine according to claim 13, wherein the information of the work machine includes dimensional information of the work machine.

16. The work machine according to claim 13, wherein the information of the object includes dimensional information of the object.

17. The work machine according to claim 13, wherein the controller starts the work of the work machine in automatic operation mode when the work machine reaches the automatic operation switching area by manual operation and the operation information of the work machine satisfies the conditions for starting automatic operation.

18. The work machine according to claim 17, further comprising a sensor for detecting the aforementioned operation information.

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