Control system for loading machine, control method for loading machine, and remote-control system for loading machine

Abstract

An orientation specification unit specifies the position of a work tool. An earth removal point decision unit decides an earth removal point for loading cargo into a loading target on the basis of the position of the loading target. An automatic control determination unit determines whether or not to start automatic control for moving the work tool to the earth removal point on the basis of the position of the work tool and the position of the earth removal point.

Description

Loading machine control system, loading machine control method, and loading machine remote control system

[0001] This disclosure relates to a control system for a loading machine, a control method for a loading machine, and a remote operation system for a loading machine. This application claims priority to Japanese Patent Application No. 2023-141419, filed on August 31, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses a technology for automatically controlling a loading machine in which the implement is moved to an interference avoidance point to avoid contact with the transport vehicle that is the loading target, and then the implement is moved to a discharge point only by rotating the rotating body. The interference avoidance point in Patent Document 1 is a position that has the same height as the discharge point, is the same distance from the rotation center of the rotating body as the distance from the rotation center to the discharge point, and where there is no loading target below.

[0003] Japanese Patent Application Laid-Open No. 2022-079773

[0004] However, the location where the transport vehicle stops and the direction in which the loading machine faces for excavation are not the same every time and change. Therefore, the behavior of the automatic control that moves the load onto the transport vehicle may change depending on the positional relationship between the transport vehicle and the loading machine. In this case, if the behavior of the loading machine under automatic control differs from what the operator expects, the operator may become confused. An object of the present disclosure is to provide a control system for a loading machine, a control method for a loading machine, and a remote operation system for a loading machine that can prevent the operator from becoming confused by automatic control.

[0005] According to one aspect of the present invention, a control system for a loading machine is a control system for a loading machine that controls a loading machine that includes a rotating body that rotates around a rotation center, a support part that supports the rotating body, and a work machine that is attached to the rotating body and includes a working implement, and includes: an attitude identification part that identifies the position of the working implement; a discharge point determination part that determines a discharge point for loading a load onto a loading object based on the position of the loading object; and an automatic control determination part that determines whether to start automatic control to move the working implement to the discharge point based on the position of the working implement and the position of the discharge point.

[0006] According to the above aspect, the control system for the loading machine can prevent the operator from becoming confused during automatic control.

[0007] FIG. 1 is a schematic diagram showing the configuration of a remote control system according to the first embodiment. FIG. 2 is a schematic diagram showing the configuration of a loading machine according to the first embodiment. FIG. 3 is a schematic block diagram showing the configuration of a control device according to the first embodiment. FIG. 4 is a diagram showing an example of a travel route according to the first embodiment. FIG. 5 is a schematic block diagram showing the configuration of a control device for a loading machine according to the first embodiment. FIG. 6 is a diagram showing an example of movement of the loading machine under automatic control according to the first embodiment. FIG. 7 is a diagram showing a first example in which automatic control is not started in the first embodiment. FIG. 8 is a diagram showing a second example in which automatic control is not started in the first embodiment. FIG. 9 is a flowchart (part 1) showing an automatic control method for a work system according to the first embodiment. FIG. 10 is a flowchart (part 2) showing an automatic control method for a work system according to the first embodiment.

[0008] <First embodiment> <Work system> Fig. 1 is a schematic diagram showing the configuration of a remote operation system according to a first embodiment. The work system 1 includes a loading machine 100, one or more transport vehicles 300 to be loaded, a control device 500, and a remote operator's cab 700. The loading machine 100 and the transport vehicles 300 operate at a work site (e.g., a mine or a quarry). The remote operator's cab 700 is provided at a location away from the work site (e.g., in a city or within the work site).

[0009] The loading machine 100 operates at a construction site, excavates construction objects such as soil and sand, and loads them as cargo onto the bed of the transport vehicle 300. Examples of the loading machine 100 include a face shovel, a backhoe shovel, and a rope shovel. The loading machine 100 may be electrically driven or hydraulically driven. The loading machine 100 according to the first embodiment is a backhoe shovel. The loading machine 100 is remotely controlled based on an operation signal transmitted from a remote operator's cab 700. The loading machine 100 and the remote operator's cab 700 are connected by communication via an access point AP1. The operation device 730 of the remote operator's cab 700 receives an operation of the loading machine 100 from an operator, and the remote control device 800 transmits the operation signal to the control device 500. The loading machine 100 operates based on the operation signal received from the remote operator's cab 700. That is, the work system 1 includes a remote operation system made up of the loading machine 100 and the remote operator's cab 700. The access point AP1 is used for communication in the remote operation system.

[0010] The haulage vehicle 300 travels unmanned based on control information received from the control device 500. The haulage vehicle 300 and the control device 500 are connected by communication via an access point AP2. The control device 500 acquires the position and direction of the haulage vehicle 300 from the haulage vehicle 300, and generates course information to be used for the travel of the haulage vehicle 300 based on this information. The control device 500 transmits the course information to the haulage vehicle 300. The haulage vehicle 300 travels unmanned based on the received course information. In other words, the work system 1 includes an unmanned guided vehicle system including the haulage vehicle 300 and the control device 500. The access point AP2 is used for communication of the unmanned guided vehicle system.

[0011] The control device 500 receives instruction signals for the transport vehicle 300 from the loading machine 100 and the remote cab 700 and transmits these to the transport vehicle 300. The loading machine 100 and the control device 500 are connected by communication via an access point AP2. The remote cab 700 and the control device 500 are also connected via a network. Examples of instruction signals for the transport vehicle 300 received from the loading machine 100 and the remote cab 700 include an approach instruction signal and a departure instruction signal. The approach instruction signal is a signal that instructs the transport vehicle 300 to approach from the waiting point P1 to the loading point P3. The departure instruction signal is a signal that instructs the transport vehicle 300 to depart from the loading point P3 upon completion of loading and to exit the loading site A1.

[0012] <<Transportation Vehicle>> The transportation vehicle 300 according to the first embodiment is an unmanned dump truck that travels unmanned along a set travel route. Note that the transportation vehicle 300 according to other embodiments may be a transporter other than a dump truck. The transportation vehicle 300 includes a position and orientation detector 310 and a transport control device 400.

[0013] The position and orientation detector 310 detects the position and orientation of the haulage vehicle 300. The position and orientation detector 310 includes two receivers that receive positioning signals from satellites that make up the Global Navigation Satellite System (GNSS). The two receivers are installed at different positions on the haulage vehicle 300. The position and orientation detector 310 detects the position of a representative point of the haulage vehicle 300 in a site coordinate system based on the positioning signals received by the receivers. The position and orientation detector 310 calculates the orientation of the haulage vehicle 300 as the relationship between the installation position of one receiver and the installation position of the other receiver using the positioning signals received by the two receivers. Note that this is not limited to this, and in other embodiments, the haulage vehicle 300 may include an inertial measurement unit (IMU), and the orientation may be calculated based on the measurement results of the IMU. In this case, drift of the IMU may be corrected based on the travel trajectory of the haulage vehicle 300. When the heading is calculated using an inertial measurement unit, the transport vehicle 300 only needs to be equipped with one receiver.

[0014] The transportation control device 400 transmits the position and direction detected by the position and direction detector 310 to the control device 500. The transportation control device 400 receives course information and instruction signals from the control device 500. The transportation control device 400 causes the transportation vehicle 300 to travel or raises and lowers the vessel of the transportation vehicle 300 based on the received course information and instruction signals.

[0015] 2 is a schematic diagram showing the configuration of the loading machine 100 according to the first embodiment. The loading machine 100 includes a traveling body 110, a revolving body 120, and a work machine 130.

[0016] The running body 110 supports the loading machine 100 so that it can travel. The running body 110 includes two caterpillar tracks 111 provided on the left and right sides, and two travel motors 112 for driving each caterpillar track 111. The running body 110 is an example of a support unit. The rotating body 120 is supported on the running body 110 so that it can rotate about a rotation center. The working implement 130 is hydraulically driven. The working implement 130 is supported on the front part of the rotating body 120 so that it can be driven in the vertical direction. Here, the part of the rotating body 120 to which the working implement 130 is attached is referred to as the front part. Furthermore, with respect to the rotating body 120, the part opposite the front part is referred to as the rear part, the part on the left side is referred to as the left part, and the part on the right side is referred to as the right part.

[0017] The revolving unit 120 includes an engine 121, a hydraulic pump 122, a control valve 123, and a swing motor 124. The engine 121 is a prime mover that drives the hydraulic pump 122. The engine 121 is an example of a power source. The hydraulic pump 122 is a variable displacement pump that is driven by the engine 121. The hydraulic pump 122 supplies hydraulic oil to each actuator (boom cylinder 131C, arm cylinder 132C, bucket cylinder 133C, travel motor 112, and swing motor 124) via a control valve 123. The control valve 123 controls the flow rate of hydraulic oil supplied from the hydraulic pump 122. The swing motor 124 is driven by hydraulic oil supplied from the hydraulic pump 122 via the control valve 123, causing the revolving unit 120 to swing.

[0018] The work machine 130 includes a boom 131, an arm 132, a bucket 133 as a work implement, a boom cylinder 131C, an arm cylinder 132C, and a bucket cylinder 133C. Other examples of the work implement include tip attachments such as a tilt bucket and a tilt rotate bucket.

[0019] The base end of the boom 131 is rotatably attached to the revolving unit 120 via a boom pin. In the loading machine 100 shown in FIG. 2 , the boom 131 is provided at the center of the front of the revolving unit 120, but this is not limiting. The boom 131 may be attached offset in the left-right direction. In this case, the center of rotation of the revolving unit 120 is not located on the operating plane of the work implement 130. The arm 132 connects the boom 131 and the bucket 133. The base end of the arm 132 is rotatably attached to the tip of the boom 131 via an arm pin. The bucket 133 is rotatably attached to the tip of the arm 132 via a pin. The boom 131 and the arm 132 are members that support the bucket 133. The bucket 133 functions as a container for collecting excavated soil and sand. The bucket 133 is attached with its opening facing the revolving unit 120 (rearward). That is, the loading machine 100 , which is a backhoe excavator, performs excavation by pulling the bucket 133 toward the front side of the rotating body 120 .

[0020] The boom cylinder 131C is a hydraulic cylinder for operating the boom 131. A base end of the boom cylinder 131C is attached to the revolving unit 120. A tip end of the boom cylinder 131C is attached to the boom 131. The arm cylinder 132C is a hydraulic cylinder for driving the arm 132. A base end of the arm cylinder 132C is attached to the boom 131. A tip end of the arm cylinder 132C is attached to the arm 132. The bucket cylinder 133C is a hydraulic cylinder for driving the bucket 133. A base end of the bucket cylinder 133C is attached to the arm 132. A tip end of the bucket cylinder 133C is attached to a link mechanism that rotates the bucket 133.

[0021] As shown in FIG. 2 , the loading machine 100 includes a position and orientation calculator 151 , an inclination measuring device 152 , a boom stroke sensor 153 , an arm stroke sensor 154 , a bucket stroke sensor 155 , an imaging device 156 , and a loading control device 200 .

[0022] The position and orientation calculator 151 calculates the position of the revolving unit 120 and the orientation in which the revolving unit 120 faces. The position and orientation calculator 151 includes two receivers that receive positioning signals from satellites that make up the GNSS. The two receivers are installed at different positions on the revolving unit 120. The position and orientation calculator 151 detects the position of a representative point of the revolving unit 120 in the on-site coordinate system (the origin of the vehicle body coordinate system) based on the positioning signals received by the receivers. The position and orientation calculator 151 uses the positioning signals received by the two receivers to calculate the orientation in which the revolving unit 120 faces as the relationship between the installation position of one receiver and the installation position of the other receiver. The orientation in which the revolving unit 120 faces is the direction perpendicular to the front of the revolving unit 120. The direction in which the rotating body 120 faces is equal to the horizontal component of the extension direction of a straight line extending from the boom 131 to the bucket 133 of the work implement 130 .

[0023] The inclinometer 152 measures the acceleration and angular velocity of the rotating unit 120, and detects the attitude (e.g., roll angle, pitch angle, yaw angle) and rotation speed of the rotating unit 120 based on the measurement results. The inclinometer 152 is installed, for example, on the underside of the rotating unit 120. The inclinometer 152 can be, for example, an inertial measurement unit (IMU).

[0024] The boom stroke sensor 153 is attached to the boom cylinder 131C and detects the cylinder length of the boom cylinder 131C. The cylinder length of the boom cylinder 131C can be converted into the relative angle of the boom 131 with respect to the revolving unit 120. The arm stroke sensor 154 is attached to the arm cylinder 132C and detects the cylinder length of the arm cylinder 132C. The cylinder length of the arm cylinder 132C can be converted into the relative angle of the arm 132 with respect to the boom 131. The bucket stroke sensor 155 is attached to the bucket cylinder 133C and detects the cylinder length of the bucket cylinder 133C. The cylinder length of the bucket cylinder 133C can be converted into the relative angle of the bucket 133 with respect to the arm 132. The loading machine 100 according to the first embodiment uses the boom stroke sensor 153, the arm stroke sensor 154, and the bucket stroke sensor 155 to identify the angles of the link components of the work implement 130, but this is not limited to this in other embodiments. For example, in other embodiments, instead of the stroke sensor, a potentiometer that detects the relative rotation angle of the link parts may be provided, or an inclination sensor that detects the angle of each link part relative to the ground may be provided.

[0025] The imaging device 156 is installed in a portion of the loading machine 100 that corresponds to the driver's cab. The imaging device 156 captures an image of the area in front of the loading machine 100. Examples of the imaging device 156 include imaging devices that use a CCD (Charge Coupled Device) sensor and a CMOS (Complementary Metal Oxide Semiconductor) sensor. Note that in other embodiments, the imaging device 156 does not necessarily have to be installed in a portion that corresponds to the driver's cab, and it is sufficient that the imaging device 156 is installed in a position that allows at least an image of the work target and the work implement 130 to be captured.

[0026] The loading control device 200 transmits to the remote operator's cab 700 measurement data including images captured by the imaging device 156, the rotation speed, position, and orientation of the revolving unit 120, the traveling speed of the traveling unit 110, the attitude of the revolving unit 120, and the tilt angles of the boom 131, arm 132, and bucket 133. Note that measurement data in other embodiments is not limited to this. For example, measurement data in other embodiments may not include any of the rotation speed, position, orientation, tilt angle, traveling speed, and attitude, and may include values ​​measured by other sensors, or may include values ​​calculated from the measured values. The loading control device 200 receives operation signals from the remote operator's cab 700. The loading control device 200 drives the traveling unit 110, the revolving unit 120, or the work implement 130 based on the received operation signals.

[0027] <<Control Device>> Figure 3 is a schematic block diagram showing the configuration of a control device according to the first embodiment. The control device 500 manages the traveling of the haulage vehicle 300. The control device 500 is a computer including a processor 510, a main memory 520, a storage 530, and an interface 540. The storage 530 stores a control program. The processor 510 reads the control program from the storage 530, loads it into the main memory 520, and executes processing in accordance with the control program. The control device 500 is connected to a network via the interface 540. An access point AP2 is connected to the interface 540. The control device 500 is wirelessly connected to the loading machine 100 and the haulage vehicle 300 via the access point AP2.

[0028] The storage 530 has storage areas serving as a travel route storage unit 531 and a position and orientation storage unit 532. Examples of the storage 530 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. The storage 530 may be an internal medium directly connected to the common communication line of the control device 500, or may be an external medium connected to the control device 500 via an interface 540. The storage 530 is a non-transitory tangible storage medium.

[0029] The travel route storage unit 531 stores a travel route R for each transport vehicle 300. FIG. 4 is a diagram showing an example of a travel route. The travel route R includes a predetermined connecting route R1 connecting two areas A (e.g., a loading site A1 and a dumping site A2), as well as an entrance route R2, an approach route R3, and an exit route R4, which are routes within area A. The entrance route R2 connects a waiting point P1, which is one end of the connecting route R1, to a predetermined turning point P2 within area A. The approach route R3 connects the turning point P2 within area A to a loading point P3 or a dumping point P4. The exit route R4 connects a loading point P3 or a dumping point P4 within area A to an exit point P5, which is the other end of the connecting route R1. The loading point P3 is a point set by the operator of the loading machine 100. The turning point P2 is a point set by the control device 500 in accordance with the position of the loading point P3.

[0030] The position and direction storage unit 532 stores the position information and direction information of each of the transport vehicles 300 .

[0031] The processor 510 includes a position and direction collection unit 511 and a driving course generation unit 512 by executing a control program.

[0032] The position and orientation collection unit 511 receives the position information and orientation information of the delivery vehicle 300 from the delivery vehicle 300 via the access point AP2. The position and orientation collection unit 511 stores the received position information and orientation information in the position and orientation storage unit 532.

[0033] The travel course generation unit 512 generates course information including information on areas in which the transport vehicle 300 is permitted to move, based on the travel route stored in the travel route storage unit 531 and the position information and direction information stored in the position direction storage unit 532. The generated course information is transmitted to the transport vehicle 300. The course information includes position information of points set at predetermined intervals on the travel route, target speed information at those points, and information on permitted travel areas that do not overlap with permitted travel areas of other transport vehicles 300.

[0034] The travel course generation unit 512 does not include the approach route R2 and the approach route R3 in the area indicated by the course information until it receives an approach instruction signal from the remote driver's cab 700. As a result, the haulage vehicle 300 waits at the waiting point P1 until it receives the approach instruction signal. When the travel course generation unit 512 receives the approach instruction signal, it generates course information that includes the approach route R2 and the approach route R3 but does not include the exit route R4. As a result, the haulage vehicle 300 starts from the waiting point P1, travels to the loading point P3, and stops at the loading point P3. When the travel course generation unit 512 receives the departure instruction signal, it generates course information that includes the exit route R4. Note that in the work system 1 according to this embodiment, the haulage vehicle 300 waits at the waiting point P1 until it receives the approach instruction signal, but this is not limited to this. For example, in other embodiments, the waiting position of the haulage vehicle 300 may be the turning point P2 or a point along the approach route R2 or the approach route R3.

[0035] <<Remote Operator's Cabin>> The remote operator's cab 700 includes a driver's seat 710, a display device 720, an operation device 730, an operation terminal 740, and a remote control device 800. The display device 720 is disposed in front of the driver's seat 710. The display device 720 is located in front of the operator when the operator sits in the driver's seat 710. The display device 720 may be configured with multiple displays arranged side by side as shown in FIG. 1 , or may be configured with one large display. The display device 720 may also be configured to project an image onto a curved or spherical surface using a projector or the like.

[0036] The operation device 730 is an operation device for the remote operation system. In response to operation by the operator, the operation device 730 generates operation signals for the boom cylinder 131C, the arm cylinder 132C, the bucket cylinder 133C, operation signals for swinging the revolving body 120 left and right, and travel operation signals for moving the traveling body 110 forward and backward, and outputs these to the remote control device 800. The operation device 730 is composed of, for example, a lever, a knob switch, and a pedal. An automatic control instruction signal for instructing the start of automatic control is generated by operating the knob switch.

[0037] The automatic control is a control in which the loading machine 100 autonomously controls the drive of the work implement 130 and the rotating body 120 to achieve a predetermined operation. In the first embodiment, the automatic control is a control in which the loading machine 100 autonomously performs a series of operations, from a state in which the bucket 133 is positioned outside the transport vehicle 300 due to excavation of the excavation target, to a state in which the loading machine 100 swings while raising the boom 131 to a direction facing the transport vehicle 300. In the example shown in FIG. 6 , the height of the transport vehicle 300 is higher than the excavation height, so the boom 131 is raised while swinging, but this is not limited to this. For example, if the height of the transport vehicle 300 is lower than the excavation height, the boom 131 is lowered while swinging. In other embodiments, the automatic control may not only move the bucket 133 from the outside of the transport vehicle 300 to above the transport vehicle 300, but may also perform an earth-discharging operation and move the bucket 133 from above the transport vehicle 300 to the outside of the transport vehicle 300. Typically, the excavation target is located lower than the height of the transport vehicle 300. Therefore, in the automatic control, the loading machine 100 controls the driving of the work machine 130 so that the transport vehicle 300 does not come into contact with the work machine 130. Details of the automatic control will be described later.

[0038] The operation terminal 740 transmits a start instruction signal to the control device 500 in response to an operation by the operator. The operation terminal 740 is configured, for example, with a touch panel or the like. The operation device 730 and the operation terminal 740 are arranged near the driver's seat 710. The operation device 730 and the operation terminal 740 are located within a range that the operator can operate when sitting in the driver's seat 710.

[0039] The remote control device 800 displays the image received from the loading machine 100 on the display device 720 , and transmits an operation signal representing the operation of the operation device 730 to the loading machine 100 .

[0040] <<Control Device of Loading Machine 100>> Figure 5 is a schematic block diagram showing the configuration of the control device of the loading machine according to the first embodiment. The loading control device 200 is a computer including a processor 210, a main memory 220, a storage 230, and an interface 240. The storage 230 stores a loading control program. The processor 210 reads the loading control program from the storage 230, loads it into the main memory 220, and executes processing in accordance with the loading control program. The loading control device 200 is connected to a network via the interface 240.

[0041] Examples of storage 230 include HDD, SSD, magnetic disk, magneto-optical disk, CD-ROM, DVD-ROM, semiconductor memory, etc. Storage 230 may be an internal medium directly connected to the common communication line of loading control device 200, or may be an external medium connected to loading control device 200 via interface 240. Storage 230 is a non-transitory tangible storage medium.

[0042] By executing the loading control program, the processor 210 is equipped with an acquisition unit 211, a display control unit 212, an operation signal input unit 213, an attitude identification unit 214, a discharge point determination unit 215, a turning direction determination unit 216, an interference avoidance point determination unit 217, an automatic control judgment unit 218, and a control unit 219.

[0043] The acquisition unit 211 acquires measurement data of the loading machine 100 and each transport vehicle 300. The measurement data of each transport vehicle 300 is acquired from the control device 500 or the remote control device 800.

[0044] The display control unit 212 generates a display signal for displaying the image acquired by the acquisition unit 211 from the imaging device 156 , and outputs the signal to the remote control device 800 .

[0045] The operation signal input unit 213 receives input of an operation signal for the operation device 730 from the remote control device 800. The operation signals include an operation signal for the boom 131, an operation signal for the arm 132, an operation signal for the bucket 133, a rotation operation signal for the revolving unit 120, a travel operation signal for the traveling unit 110, and an automatic control instruction signal for the loading machine 100.

[0046] The posture identifying unit 214 identifies the posture of the loading machine 100 based on the measurement data received by the acquisition unit 211. Specifically, the posture identifying unit 214 identifies at least the position of the tip of the arm 132 in the vehicle body coordinate system. The posture identifying unit 214 determines the vertical and horizontal components of the length of the boom 131 based on the tilt angle of the boom 131 and the known length of the boom 131 (the distance from the pin at the base end to the pin at the tip end). Similarly, the posture identifying unit 214 determines the vertical and horizontal components of the length of the arm 132. The posture identifying unit 214 identifies, as the position of the tip of the arm 132, a position that is away from the position of the loading machine 100 in a direction identified from the orientation and posture of the loading machine 100 by the sum of the vertical and horizontal components of the lengths of the boom 131 and the arm 132.

[0047] When an automatic control instruction signal is input to the operation signal input unit 213, the discharge point determination unit 215 determines a discharge point p3, which is a target point for automatic control. The discharge point p3 is an example of a control point. The discharge point p3 may be expressed in a polar coordinate system based on the attitude of the revolving unit 120 when the automatic control instruction signal is input. In other words, the position of the discharge point p3 is expressed by the angle of deviation from the direction in which the revolving unit 120 is facing when the automatic control instruction signal is input, the radius vector which is the distance from the center of rotation of the revolving unit 120, and the height.

[0048] The unloading point determination unit 215 identifies the position of the unloading point p3 based on the measurement data of the position and orientation of the haulage vehicle 300 acquired by the acquisition unit 211. The unloading point p3 is a point located at the center of the vessel of the haulage vehicle 300 in a plan view from above. The height of the unloading point p3 is the height of the haulage vehicle 300 plus the length from the pin of the bucket 133 to the farthest point of the bucket 133 and a clearance value. The length from the pin of the bucket 133 to the farthest point of the bucket 133 is, for example, the length from the pin of the bucket 133 to the cutting edge of the bucket 133. The clearance value is a constant set so that the load loaded on the haulage vehicle 300 does not interfere with the bucket 133. The clearance value may be a value determined in advance depending on the model of the haulage vehicle 300.

[0049] The swing direction determination unit 216 determines whether to swing right or left under automatic control based on the positional relationship between the start point p1, which is the position of the tip of the arm 132 when the automatic control command signal is input, and the unloading point p3. The swing direction determination unit 216 determines the swing direction in the direction that minimizes the angle (target swing angle) between the direction from the swing center toward the start point p1 and the direction from the swing center toward the unloading point p3. For example, if the target swing angle is 90 degrees for a clockwise rotation and 270 degrees for a counterclockwise rotation, the swing direction determination unit 216 determines the swing direction to be right. In other words, the loading machine 100 swings in a direction with a swing angle of 180 degrees or less.

[0050] The interference avoidance point determiner 217 identifies the position of an interference avoidance point p2 at which the loading machine 100 and the haulage vehicle 300 do not come into contact with each other under automatic control, based on the position and orientation of the loading machine 100 and the position and orientation of the haulage vehicle 300 acquired by the acquirer 211. The interference avoidance point p2 is a position whose distance from the center of rotation of the revolving unit 120 is equal to the distance from the center of rotation to the earth unloading point p3, and below which the haulage vehicle 300 is not present. For example, the interference avoidance point determiner 217 identifies a circle related to the radius vector of the earth unloading point p3, and identifies the angle on the circle at which the outline of the bucket 133 does not interfere with the haulage vehicle 300 in a plan view and is closest to the deflection angle of the earth unloading point p3 as the deflection angle of the interference avoidance point p2. The radius vector and height of the interference avoidance point p2 are equal to the radius vector and height of the earth unloading point p3. The interference avoidance point determination unit 217 can determine whether or not the transport vehicle 300 and the bucket 133 will interfere with each other, based on the position, orientation, and known outer shape of the transport vehicle 300, and the known shape of the bucket 133. Here, "same height" and "equal distance" do not necessarily mean that the height or distance is completely the same, but rather allow for some error or margin.

[0051] The automatic control determination unit 218 determines whether to start automatic control based on the target turning angle related to the turning direction determined by the turning direction determination unit 216. Specifically, the automatic control determination unit 218 determines not to start automatic control when the target turning angle is smaller than the angle (first threshold) formed between the direction from the turning center toward the interference avoidance point p2 and the direction from the turning center toward the unloading point p3. The automatic control determination unit 218 also determines not to start automatic control when the target turning angle is greater than 150 degrees (second threshold). The angle formed between the direction from the turning center toward the interference avoidance point p2 and the direction from the turning center toward the unloading point p3 is an example of the first threshold. In other embodiments, the first threshold may be a fixed value, such as 30 degrees. 150 degrees is an example of the second threshold. In other embodiments, the second threshold may be another value close to 180 degrees.

[0052] When the automatic control determination unit 218 determines to start automatic control, the control unit 219 generates an operation signal for executing automatic control based on the position of the control point identified by the discharge point determination unit 215. The control unit 219 outputs the operation signal input to the operation signal input unit 213 or the generated operation signal to the loading machine 100.

[0053] <<Operation During Automatic Control>> Here, the movement of the loading machine 100 during automatic control according to the first embodiment will be described with reference to the drawings. Fig. 6 is a diagram showing an example of the movement of the loading machine 100 during automatic control according to the first embodiment.

[0054] When automatic control is initiated, as shown in FIG. 6 , the loading machine 100 first starts driving the work implement 130 (boom 131, arm 132, and bucket 133), and raises the boom 131 to move the bucket 133 upward. After a delay, the loading control device 200 starts rotating the revolving unit 120. The loading control device 200 adjusts the timing of the start of rotation so that the height of the tip of the arm 132 reaches the height of the interference avoidance point p2 by the time the rotation angle of the revolving unit 120 matches the interference avoidance angle (the deflection angle of the interference avoidance point p2), and so that the distance from the center of rotation to the tip of the arm 132 is equal to the distance of the interference avoidance point p2. Note that if the height of the work implement 130 reaches the height of the interference avoidance point p2 by the time the rotation angle of the revolving unit 120 matches the interference avoidance angle, the work implement 130 will not come into contact with the transport vehicle 300 due to the rotation of the revolving unit 120. When the rotation angle of the rotating body 120 reaches the interference avoidance angle, the loading control device 200 drives the rotating body 120 so that the position of the tip of the arm 132 coincides with the earth unloading point p3.

[0055] Although FIG. 6 shows an example in which the positional relationship between the excavation position and the transport vehicle 300 is approximately 90 degrees around the rotating body 120, the positional relationship between the excavation position and the transport vehicle 300 changes for each loading.

[0056] Here, the reason why it is determined not to start automatic control when the target turning angle is smaller than the angle (first threshold) between the direction from the turning center toward the interference avoidance point p2 and the direction from the turning center toward the unloading point p3 is explained. FIG. 7 is a diagram showing a first example in which automatic control is not started in the first embodiment. In the example shown in FIG. 7 , the angle (target turning angle) between the direction from the turning center toward the start point p1 and the direction from the turning center toward the unloading point p3 is smaller than the angle between the direction from the turning center toward the interference avoidance point p2 and the direction from the turning center toward the unloading point p3. In this case, if the radius vector of the work implement 130 is extended by automatic control, there is a possibility that the work implement 130 and the haulage vehicle 300 will come into contact, as shown in FIG. 7 . In this way, if automatic control is performed when the target turning angle is smaller than the angle formed by the direction from the turning center toward the interference avoidance point p2 and the direction from the turning center toward the earth unloading point p3, the loading machine 100 may behave in a manner that is not anticipated by the operator. For example, when excavating near the transport vehicle 300 and loading the excavated load onto the transport vehicle 300, automatic control is not started.

[0057] The reason why automatic control is not started when the target turning angle is greater than 150 degrees (second threshold) will be described. FIG. 8 is a diagram showing a second example in which automatic control is not started in the first embodiment. In the example shown in FIG. 8 , the angle (target turning angle) formed by the direction from the turning center toward the start point p1 and the direction from the turning center toward the unloading point p3 is approximately 180 degrees. In this case, whether the target turning angle is greater than or less than 180 degrees determines whether the loading machine 100 will turn left or right. However, since the operator has no way to accurately recognize the target turning angle, it is difficult for him or her to predict whether the automatic control will result in a right turn or a left turn. Therefore, if automatic control is performed when the target turning angle is greater than the second threshold of 150 degrees, the loading machine 100 may behave in a manner that is not anticipated by the operator.

[0058] <<Operation of the Loading Control Device 200>> The haulage vehicle 300 travels along the travel route R according to the course information generated by the control device 500, and stops at the waiting point P1. The operator of the loading machine 100 operates the operation terminal 740 (for example, by pressing a predetermined button) to input an entry instruction signal to the operation terminal 740. The entry instruction signal is transmitted from the operation terminal 740 to the control device 500. As a result, the control device 500 generates course information indicating the areas of the entry route R2 and the approach route R3. The haulage vehicle 300 travels along the approach route R3 and stops at the loading point P3. The operator operates the operation device 730 to scoop up earth and sand with the bucket 133 of the loading machine 100, and operates the knob switch of the operation device 730 to generate and output an automatic control instruction signal.

[0059] Fig. 9 is a flowchart (part 1) showing the automatic control method of the work system 1 according to the first embodiment. Fig. 10 is a flowchart (part 2) showing the automatic control method of the work system 1 according to the first embodiment. When the loading control device 200 receives an input of an automatic control instruction signal from the remote control device 800 by operation of the operator, it executes the automatic control shown in Figs. 9 and 10.

[0060] The acquisition unit 211 acquires measurement data of the loading machine 100 and the transport vehicle 300 (step S1). Specifically, the acquisition unit 211 acquires measurement data from the position / orientation calculator 151, the inclination measuring device 152, the boom stroke sensor 153, the arm stroke sensor 154, the bucket stroke sensor 155, and the imaging device 156. That is, the acquisition unit 211 acquires measurement data of the position and orientation of the revolving unit 120, the tilt angles of the boom 131, the arm 132, and the bucket 133, and the attitude of the revolving unit 120 from the loading machine 100. The acquisition unit 211 also acquires measurement data of the position and orientation of the transport vehicle 300 from the control device 500. The attitude identification unit 214 identifies the position of the tip of the arm 132 at the time of input of the automatic control instruction signal based on the measurement data acquired by the acquisition unit 211 (step S2).

[0061] The discharge point determination unit 215 specifies the position of the discharge point p3 based on the position information and orientation information of the haulage vehicle 300 acquired by the acquisition unit 211 and the known shape of the haulage vehicle 300 (step S3). The discharge point determination unit 215 specifies the planar position (declination angle and radius vector) of the discharge point p3 based on the position information and orientation information of the haulage vehicle 300 and the known shape of the haulage vehicle 300. The discharge point determination unit 215 also specifies the height of the discharge point p3 by adding the length from the pin to the cutting edge of the bucket 133 and a margin value to the known height of the haulage vehicle 300.

[0062] The swing direction determination unit 216 determines the swing direction for automatic control based on the positional relationship between the start point p1, which is the position of the tip of the arm 132 determined in step S3, and the unloading point p3 determined in step S3 (step S4). The interference avoidance point determination unit 217 determines the position of the interference avoidance point p2 based on the position and orientation of the loading machine 100 and the position and orientation of the haulage vehicle 300 acquired in step S1, and the swing direction determined in step S4 (step S5). The interference avoidance point determination unit 217, for example, determines a circle related to the radius vector of the unloading point p3, and determines the angle on the circle that is closest to the deflection angle of the unloading point p3 in the direction determined by the swing direction determination unit 216, at which the outline of the bucket 133 does not interfere with the haulage vehicle 300 in a planar view. The radius vector and height of the interference avoidance point p2 are equal to the radius vector and height of the unloading point p3.

[0063] The automatic control determination unit 218 determines whether the target swing angle, which is the angle from the start point p1 to the unloading point p3 in the swing direction determined in step S4, is smaller than the angle from the interference avoidance point p2 to the unloading point p3 (step S6). The target swing angle is calculated by the difference between the deflection angle of the start point p1 and the deflection angle of the unloading point p3. The angle from the interference avoidance point p2 to the unloading point p3 is calculated by the difference between the deflection angle of the interference avoidance point p2 and the deflection angle of the unloading point p3. If the target swing angle is smaller than the angle from the interference avoidance point p2 to the unloading point p3 (step S6: YES), the automatic control determination unit 218 determines not to start automatic control. In this case, the display control unit 212 sends a display signal to the remote control device 800 to display on the control terminal 740 that automatic control is not possible (step S8). The loading control device 200 then ends the processing without performing automatic control.

[0064] On the other hand, if the target turning angle is equal to or greater than the angle from the interference avoidance point p2 to the unloading point p3 (step S6: NO), the automatic control determination unit 218 determines whether the target turning angle exceeds 150 degrees (step S7). If the target turning angle exceeds 150 degrees (step S7: YES), the automatic control determination unit 218 determines not to start automatic control. In this case, the display control unit 212 sends a display signal to the remote control device 800 to cause the control terminal 740 to display a message that automatic control is not possible (step S8). The loading control device 200 then ends the process without performing automatic control.

[0065] If the target turning angle is equal to or greater than the angle from the interference avoidance point p2 to the earth-discharging point p3 and does not exceed 150 degrees (step S7: NO), the automatic control determination unit 218 determines to start automatic control.

[0066] When automatic control is started, the acquisition unit 211 acquires measurement data on the position and orientation of the revolving unit 120, the tilt angles of the boom 131, arm 132, and bucket 133, and the attitude of the revolving unit 120 (step S9). The attitude identification unit 214 identifies the position of the tip of the arm 132 based on the measurement data (step S10).

[0067] The control unit 219 determines whether or not the swing angle of the loading machine 100 is smaller than the deflection angle of the interference avoidance point p2 determined in step S5 (step S11). The swing angle of the loading machine 100 is the angle of difference between the direction in which the swing unit 120 faces when the automatic control instruction signal is input (initial direction) and the direction in which the swing unit 120 is currently facing.

[0068] If the rotation angle of the loading machine 100 is smaller than the deflection angle of the interference avoidance point p2 (step S11: YES), that is, if the rotating body 120 is facing outward from the transport vehicle 300, the control unit 219 determines whether the difference between the radius vector and height of the tip of the arm 132 identified in step S10 when expressed in a polar coordinate system and the radius vector and height of the interference avoidance point p2 is smaller than a predetermined threshold value (step S12).

[0069] If the difference between the radius vector and height of the tip of the arm 132 and the radius vector and height of the interference avoidance point p2 is equal to or greater than the threshold (step S12: NO), the control unit 219 generates automatic operation signals for the boom 131 and the arm 132 so as to bring the tip of the arm 132 closer to the radius vector and height of the interference avoidance point p2 (step S13). At this time, the control unit 219 generates the automatic operation signals based on the positions and speeds of the boom 131 and the arm 132 identified from the measurement data acquired in step S9.

[0070] The control unit 219 also calculates the sum of the drive speeds of the boom 131 and the arm 132 based on the generated automatic operation signals for the boom 131 and the arm 132, and generates an automatic operation signal for driving the bucket 133 at a speed equal to the sum of the drive speeds (step S14). This allows the control unit 219 to generate an operation signal that maintains the ground angle of the bucket 133. In other words, the control unit 219 maintains a state in which the bottom surface of the bucket 133 is at its lowest point during automatic control. Note that in other embodiments, the control unit 216 may generate the automatic operation signal for the bucket 133 by feedback control based on the difference between the target ground angle of the bucket 133 (e.g., the ground angle of the bucket 133 at the start of automatic control) and the actual ground angle of the bucket 133 identified from the measurement data acquired in step S9.

[0071] The control unit 219 determines whether the work implement 130 is currently rotating (step S15). For example, the control unit 219 determines that the work implement 130 is currently rotating if the rotation speed of the revolving unit 120 is equal to or greater than a predetermined speed. If the work implement 130 is not currently rotating (step S15: NO), the control unit 219 calculates a completion time required for the difference between the radius vector and height of the tip of the arm 132 and the radius vector and height of the interference avoidance point p2 to become equal based on the speeds of the boom 131 and the arm 132 (step S16). The control unit 219 also calculates an arrival time required for the rotation angle of the revolving unit 120 to reach the deflection angle of the interference avoidance point p2 identified in step S5 when the revolving unit 120 starts rotating (step S17). The control unit 219 determines whether the completion time calculated in step S16 is less than the arrival time calculated in step S17 (step S18). That is, the control unit 219 determines whether the radius vector and height of the tip of the arm 132 match the radius vector and height of the interference avoidance point p2 when the rotation angle reaches the deflection angle of the interference avoidance point p2.

[0072] If the completion time is equal to or greater than the arrival time (step S18: NO), that is, if the radius vector and height of the tip of the arm 132 do not match those of the interference avoidance point p2 by the time the swing angle reaches the deflection angle of the interference avoidance point p2, the control unit 219 does not generate a swing operation signal for the swing unit 120. On the other hand, if the completion time is less than the arrival time (step S18: YES), that is, if the radius vector and height of the tip of the arm 132 match those of the interference avoidance point p2 by the time the swing angle reaches the deflection angle of the interference avoidance point p2, the control unit 219 generates a swing operation signal for the swing unit 120 (step S19). This allows the loading control device 200 to prevent the work implement 130 from swinging at a low height and coming into contact with the transport vehicle 300.

[0073] The control section 219 outputs the generated automatic operation signal to the control valve 123 (step S20), thereby driving the loading machine 100. Then, the loading control device 200 returns the process to step S9 and continues control.

[0074] On the other hand, if it is determined in step S15 that the work implement 130 is swinging (step S15: YES), the control unit 219 generates a swing operation signal in step S19, and outputs the swing operation signal to the control valve 123 in step S20. Then, the loading control device 200 returns the process to step S9 and continues control.

[0075] On the other hand, if the swing angle is equal to or greater than the deflection angle of the interference avoidance point p2 (step S11: NO), that is, if the swing unit 120 is facing the transport vehicle 300, the control unit 219 determines, based on the swing speed of the swing unit 120, whether the swing angle will reach the deflection angle of the unloading point p3 due to inertial swing when the swing operation signal is stopped (step S21). If the swing angle does not reach the deflection angle of the unloading point p3 due to inertial swing (step S21: NO), the control unit 219 generates a swing operation signal (step S22). If the swing angle reaches the deflection angle of the unloading point p3 due to inertial swing (step S21: YES), the control unit 219 does not generate a swing operation signal and instead outputs a neutral signal. The control unit 219 outputs the generated operation signal for the work implement 130 and / or the swing operation signal to the control valve 123 (step S23).

[0076] The control unit 219 determines whether the tip of the arm 132 has reached the unloading point p3 (step S24). If the tip of the arm 132 has not reached the unloading point p3 (step S24: NO), the process returns to step S9 and automatic control continues.

[0077] When the tip of the arm 132 reaches the unloading point p3 (step S24: YES), the loading control device 200 ends the automatic control.

[0078] The above-described automatic control allows the loading machine 100 to automatically move the bucket 133 above the haulage vehicle 300. The operator operates the operation device 730 to load earth and sand onto the haulage vehicle 300 and then performs excavation again. The operator repeats this operation to the extent that the load capacity of the haulage vehicle 300 does not exceed the maximum load capacity. The operator then operates the operation terminal 740 to input a departure instruction signal to the operation terminal 740. The departure instruction signal is transmitted from the operation terminal 740 to the control device 500. As a result, the control device 500 generates course information including the area of ​​the exit route R4. The haulage vehicle 300 departs from the loading point P3, travels along the exit route R4, and exits the loading site A1.

[0079] <<Functions and Effects>> According to the first embodiment, the loading control device 200 executes the following processes. The attitude identification unit 214 identifies the position of the bucket 133. The discharge point determination unit 215 determines a discharge point p3 for loading a load onto the haulage vehicle based on the position of the haulage vehicle 300. The automatic control determination unit 218 determines whether to start automatic control based on the position of the bucket 133 and the position of the discharge point p3 when the automatic control instruction signal is input. In this way, the loading control device 200 can prevent the operator from becoming confused by the automatic control.

[0080] Other Embodiments Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0081] The turning direction determination unit 216 of the loading control device 200 according to the embodiment described above determines the turning direction based on the direction in which the angle between the orientation of the start point p1 and the orientation of the unloading point p3 is smallest, but this is not limited to this. For example, the turning direction determination unit 216 according to other embodiments may determine the turning direction based on the orientation of the haulage vehicle 300. For example, the turning direction determination unit 216 may determine the turning direction based on the angle between a vector extending from the center of turning to the unloading point p3 and a vector representing the direction in which the haulage vehicle 300 is facing. For example, if the angle between the two vectors is greater than 0 degrees, the turning direction determination unit 216 determines the turning direction to be right. On the other hand, if the angle between the two vectors is not greater than 0 degrees, the turning direction determination unit 216 determines the turning direction to be left.

[0082] The loading control device 200 according to the embodiment described above determines the start point p1, the interference avoidance point p2, and the earth unloading point p3, and controls the revolving unit 120 and the work machine 130 so that they pass through these points, but this is not limited to this in other embodiments. For example, in other embodiments, the loading control device 200 may include a trajectory generating unit that generates a trajectory that passes through the start point p1, the interference avoidance point p2, and the earth unloading point p3, and the control unit 219 may control the revolving unit 120 and the work machine 130 so that they follow the generated trajectory.

[0083] The loading machine 100 according to the embodiment described above acquires the position information and orientation information of the haulage vehicle 300 from the control device 500, but is not limited to this. For example, the loading machine 100 according to another embodiment includes a detection device that detects the spatial position of an object present in the detection direction, and acquires the position information and orientation information of the haulage vehicle 300 based on the detection result of the detection device. In this way, the loading machine 100 may acquire the position information and orientation information of the haulage vehicle 300 without relying on the control device 500.

[0084] In the above-described embodiment, the loading machine 100 is remotely controlled via the remote control device 800, but this is not limiting. For example, the loading machine 100 according to other embodiments may be operated by an operator on board. In this case, the loading control device 200 of the loading machine 100 controls the loading machine 100 by an operation signal from an operation device (not shown) provided in the driver's seat. The operator may output an automatic digging and loading instruction to the loading control device 200 by pressing an automatic digging and loading button (not shown) provided in the driver's seat. Furthermore, in other embodiments, the loading machine 100 may transmit and receive signals via vehicle-to-vehicle communication instead of communication via an access point.

[0085] The control device according to the above-described embodiment (for example, the loading control device 200) may be configured by a single computer, or may be configured by distributing the control device among multiple computers that cooperate with each other to function as a control device. In this case, some of the components of the control device may be realized by the loading control device 200, the control device 500, the remote control device 800, etc.

[0086] According to the above aspect, the control system for the loading machine can prevent the operator from becoming confused during automatic control.

[0087] DESCRIPTION OF SYMBOLS 1...Work system 100...Loading machine 110...Traveling body 111...Crawler 112...Travel motor 120...Swinging body 121...Engine 122...Hydraulic pump 123...Control valve 124...Swing motor 130...Work machine 131...Boom 131C...Boom cylinder 132...Arm 132C...Arm cylinder 133...Bucket 133C...Bucket cylinder 151...Position and orientation calculator 152...Inclination measuring device 153...Boom stroke sensor 154...Arm stroke sensor 155...Bucket stroke sensor 156...Imaging device 200...Loading control device 300...Transportation vehicle 310...Position and orientation detector 400...Transportation control device 500...Control device 510...Processor 511...Position and orientation collection unit 512...Travel course generation unit 520...Main memory 530...Storage 531: Travel route storage unit 532: Position and orientation storage unit 540: Interface 700: Remote driver's cab 710: Driver's seat 720: Display device 730: Operation device 740: Operation terminal 800: Remote control device 210: Processor 211: Acquisition unit 212: Display control unit 213: Operation signal input unit 214: Attitude identification unit 215: Earth discharge point determination unit 216: Turning direction determination unit 217: Interference avoidance point determination unit 218: Automatic control determination unit 219: Control unit 220: Main memory 230: Storage 240: Interface

Claims

1. A control system for a loading machine that controls a loading machine having a rotating body that rotates around a rotation center, a support unit that supports the rotating body, and a working machine including a working tool attached to the rotating body, the control system for a loading machine comprising: a posture identification unit that identifies a position of the working tool; a discharge point determination unit that determines a discharge point for loading a load onto a loading object based on the position of the loading object; and an automatic control determination unit that determines whether to start automatic control to move the working tool to the discharge point based on the position of the working tool and the position of the discharge point.

2. A control system for a loading machine according to claim 1, wherein the automatic control determination unit determines whether or not to start the automatic control depending on the direction in which the work implement is facing.

3. A control system for a loading machine as described in claim 2, wherein the automatic control determination unit determines whether or not to start the automatic control based on the relative angle between the direction in which the unloading point faces from the center of rotation of the rotating body and the direction in which the work implement faces from the center of rotation of the rotating body.

4. A control system for a loading machine as described in claim 3, wherein the automatic control judgment unit does not start the automatic control when the relative angle between the direction from the center of rotation of the rotating body to the unloading point and the direction from the center of rotation of the rotating body to the work implement is smaller than a first threshold value.

5. A control system for a loading machine as described in claim 3, wherein the automatic control judgment unit does not start the automatic control when the relative angle between the direction from the center of rotation of the rotating body to the unloading point and the direction from the center of rotation of the rotating body to the direction of the work implement is greater than a second threshold value.

6. A control system for a loading machine according to claim 1, further comprising a rotation direction determination unit that determines a direction in which the rotating body rotates to move the working implement to the earth unloading point.

7. A control system for a loading machine according to claim 6, wherein the turning direction determining unit determines the turning direction in a direction in which the driver's cab of the machine to be loaded and a working implement do not overlap in a plan view from above.

8. A control system for a loading machine according to claim 6, wherein said turning direction determining unit determines the turning direction in a direction that minimizes the angle between the heading of said working implement and the heading of said earth unloading point.

9. A control method for a loading machine that controls a loading machine having a rotating body and a working machine including a working tool attached to the rotating body, comprising: a step of identifying a position of the working tool; a step of identifying an unloading point for loading a load onto the loading object based on the position of the loading object; and a step of determining whether to start automatic control for moving the working tool to the unloading point based on the position of the working tool and the position of the unloading point.

10. A remote control system for a loading machine, comprising: a control system for a loading machine according to any one of claims 1 to 8; and a display device and an operating device provided remotely from the control system for the loading machine.

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