Control system and work machine

Abstract

In the present invention, a control device includes: a plurality of phases related to automatic control of a body and a work machine; and switching of a flow divider / combiner valve in switching of at least one of the plurality of phases.

Description

Control systems and work machines

[0001] This application claims priority to Japanese Patent Application No. 2023-222252, filed on December 28, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 describes a hydraulic control device having a branching and joining valve that switches between a joining state in which the hydraulic oil discharged from a first hydraulic pump and a branching state in which the hydraulic oil discharged from a second hydraulic pump joins, and a branching state in which the hydraulic oils do not join. The hydraulic control device described in Patent Document 1 switches between the joining state and the branching state according to the operation pattern of an operating lever.

[0003] WO 2006 / 123704

[0004] Meanwhile, research is being conducted into technologies for automating the movement of a work machine between an excavation position and a loading position. In such automatic control, there is a possibility that the control of the branching and merging valve will not function properly. An object of the present disclosure is to provide a control system and a work machine that can perform appropriate branching and merging control in the automatic control of the work machine.

[0005] According to a first aspect of the present disclosure, a control system is a control system for a work machine comprising: a main body; a work machine that drives the main body; a plurality of actuators that drive the main body or the work machine; a plurality of fluid pumps that supply fluid to the plurality of actuators; a plurality of flow paths that connect each of the plurality of fluid pumps to an actuator among the plurality of actuators that corresponds to each of the fluid pumps; and a branch / combining valve that selectively connects the plurality of flow paths, wherein the control system includes a plurality of phases related to automatic control that adjusts the flow rate of the branch / combining valve and the fluid pump based on an operation signal of the main body or the work machine and causes the main body and the work machine to perform a predetermined operation, and at least one of the plurality of phases is switched to switch the branch / combining valve.

[0006] According to a second aspect of the present disclosure, a work system is a control system for a work machine comprising: a main body; a work implement that drives the main body; a plurality of actuators that drive the main body or the work implement; a plurality of fluid pumps that supply fluid to the plurality of actuators; a plurality of flow paths that connect each of the plurality of fluid pumps to an actuator among the plurality of actuators that corresponds to each of the fluid pumps; and a branching and merging valve that selectively connects the plurality of flow paths, and the work system adjusts the flow rates of the branching and merging valve and the fluid pump based on an operation signal of the main body or the work implement, and outputs a control signal that closes the branching and merging valve when at least one of a plurality of phases related to automatic control of the main body and the work implement is switched.

[0007] The work machine according to the above aspect can appropriately perform branching and merging control in automatic control.

[0008] FIG. 1 is a schematic diagram showing the configuration of a work machine according to a first embodiment. FIG. 2 is a block diagram showing the configuration of a hydraulic system according to the first embodiment. FIG. 3 is a diagram showing the internal configuration of a driver's cab according to the first embodiment. FIG. 4 is a schematic block diagram showing the configuration of a control device according to the first embodiment. FIG. 5 is a diagram showing an example of the movement of the work machine during a first swing according to the first embodiment. FIG. 6 is a diagram showing an example of the movement of the work machine during a second swing according to the first embodiment. FIG. 7 is an example of a table showing the relationship between operation patterns and branching and merging control according to the first embodiment. FIG. 8 is a flowchart showing automatic control by the control device according to the first embodiment. FIG. 9 is a flowchart showing the operation of the control device according to a second embodiment.

[0009] First Embodiment Hereinafter, an embodiment will be described in detail with reference to the drawings.

[0010] <Configuration of Work Machine 100> Figure 1 is a schematic diagram showing the configuration of a work machine 100 according to a first embodiment. The work machine 100 operates at a construction site, excavates a work object such as earth and sand, and loads the excavated material as cargo onto a loading platform such as a vessel of a loading object T such as a dump truck. Examples of the work machine 100 include a face shovel, a backhoe shovel, and a rope shovel. The work machine 100 may be electrically driven or hydraulically driven. The work machine 100 according to the first embodiment is a backhoe shovel. The work machine 100 includes a traveling body 110, a revolving body 120, a work implement 130, and a cab 140. Examples of the loading object T include a dump truck and a hopper.

[0011] The running body 110 supports the work machine 100 so that it can travel. The running body 110 is equipped with two endless tracks 111, one on the left and one on the right, and two travel motors 112 for driving each of the endless tracks 111. Hereinafter, the travel motor 112 for driving the left endless track 111 will be referred to as the first travel motor 112A, and the travel motor 112 for driving the right endless track 111 will be referred to as the second travel motor 112B. The running body 110 is an example of a support unit. The running body 110 is an example of a first main body. The rotating body 120 is supported on the running body 110 so that it can rotate about a rotation center. The rotating body 120 is an example of a second main body. The running body 110 and the rotating body 120 form the main body of the work machine 100. The work implement 130 is hydraulically driven. The work implement 130 is supported on the front of the rotating body 120 so that it can be driven in the vertical direction. The operator's cab 140 is a space where an operator sits and operates the work machine 100. The operator's cab 140 is provided at the front left of the revolving unit 120. Here, the portion of the revolving unit 120 to which the work implement 130 is attached is referred to as the front. Furthermore, with respect to the revolving unit 120, the portion opposite the front is referred to as the rear, the left portion as the left part, and the right portion as the right part.

[0012] <Configuration of Work Machine 130> 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 clam bucket, a tilt bucket, a tilt rotate bucket, a grapple, and a lifting magnet.

[0013] The base end of the boom 131 is rotatably attached to the revolving unit 120 via a boom pin. Note that in the work machine 100 shown in FIG. 1 , the boom 131 is provided in the center portion of the front of the revolving unit 120, but this is not limited thereto. 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 boom 131 may be a bendable two-piece boom or an extendable offset boom. 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 so that its opening faces the rotating body 120 (rearward).

[0014] 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.

[0015] <<Configuration of Hydraulic System>> Figure 2 is a block diagram showing the configuration of the hydraulic system according to the first embodiment. The swing bed 120 has a hydraulic system for driving the work machine 100. The hydraulic system includes an engine 121, a first hydraulic pump 122A, a second hydraulic pump 122B, a first oil passage 123A, a second oil passage 123B, a bypass oil passage 124, a branching and merging valve 125, a first control valve 126A, a second control valve 126B, a swing motor 127, a boom cylinder 131C, an arm cylinder 132C, a bucket cylinder 133C, a first travel motor 112A, and a second travel motor 112B. Hereinafter, the first hydraulic pump 122A and the second hydraulic pump 122B will be collectively referred to as hydraulic pumps 122. Furthermore, hereinafter, the first control valve 126A and the second control valve 126B will be collectively referred to as control valves 126.

[0016] The engine 121 is a prime mover that drives the hydraulic pump 122. The first hydraulic pump 122A and the second hydraulic pump 122B are variable displacement pumps driven by the engine 121. The first hydraulic pump 122A supplies hydraulic oil to the first oil line 123A. The second hydraulic pump 122B supplies hydraulic oil to the second oil line 123B. The bypass oil line 124 connects the first oil line 123A and the second oil line 123B. The branching and merging valve 125 is an electromagnetic valve provided on the bypass oil line 124. The branching and merging valve 125 controls the opening and closing of the bypass oil line 124. In this way, the branching and merging valve 125 can switch between merging and separating the hydraulic oil flowing through the first oil line 123A and the hydraulic oil flowing through the second oil line 123B.

[0017] The first control valve 126A is connected to the first oil line 123A. The first control valve 126A distributes the hydraulic oil supplied from the first oil line 123A to the swing motor 127, the arm cylinder 132C, and the first traveling motor 112A. The second control valve 126B is connected to the second oil line 123B. The second control valve 126B distributes the hydraulic oil supplied from the second oil line 123B to the boom cylinder 131C, the bucket cylinder 133C, and the second traveling motor 112B.

[0018] The swing motor 127 is driven by hydraulic oil supplied from the first control valve 126A to swing the swing body 120.

[0019] <Configuration of Cab 140> Figure 3 is a diagram showing the internal configuration of the cab 140 according to the first embodiment. A driver's seat 141, an operation terminal 142, and an operation device 143 are provided inside the cab 140. The operation terminal 142 is provided near the driver's seat 141 and serves as a user interface with the control device 160, which will be described later. The operation terminal 142 is a display device formed, for example, of a touch panel, and may have an operation unit operated by an operator and an input reception unit that receives operations. The display device also displays measurement data from an engine water temperature gauge, a fuel gauge, and the like. The operation terminal 142 may also have a display unit such as an LCD.

[0020] The operation device 143 is a device for driving the traveling body 110, the revolving body 120, and the work machine 130 through manual operation by an operator. The operation device 143 includes a left operation lever 143LO, a right operation lever 143RO, a left foot pedal 143LF, a right foot pedal 143RF, a left travel lever 143LT, a right travel lever 143RT, a teaching switch 143TS, and a start switch 143SW.

[0021] The left operating lever 143LO is provided on the left side of the driver's seat 141. The right operating lever 143RO is provided on the right side of the driver's seat 141.

[0022] The left operation lever 143LO is an operation mechanism for performing the swing operation of the revolving unit 120 and the excavation / dump operation of the arm 132. Specifically, when the operator of the work machine 100 tilts the left operation lever 143LO forward, the arm 132 performs a dump operation. When the operator of the work machine 100 tilts the left operation lever 143LO rearward, the arm 132 performs an excavation operation. When the operator of the work machine 100 tilts the left operation lever 143LO to the right, the revolving unit 120 swings to the right. When the operator of the work machine 100 tilts the left operation lever 143LO to the left, the revolving unit 120 swings to the left. Note that in other embodiments, the revolving unit 120 may swing to the right or left when the left operation lever 143LO is tilted forward or backward, and the arm 132 may perform an excavation or dump operation when the left operation lever 143LO is tilted left or right.

[0023] The right operating lever 143RO is an operating mechanism for performing the excavation / dumping operation of the bucket 133 and the raising / lowering operation of the boom 131. Specifically, when the operator of the work machine 100 tilts the right operating lever 143RO forward, the boom 131 is lowered. When the operator of the work machine 100 tilts the right operating lever 143RO rearward, the boom 131 is raised. When the operator of the work machine 100 tilts the right operating lever 143RO to the right, the bucket 133 is dumped. When the operator of the work machine 100 tilts the right operating lever 143RO to the left, the bucket 133 is excavated. Note that in other embodiments, when the right operating lever 143RO is tilted forward or backward, the bucket 133 may be dumped or excavated, and when the right operating lever 143RO is tilted left or right, the boom 131 may be raised or lowered.

[0024] The left foot pedal 143LF is located on the left side of the floor in front of the driver's seat 141. The right foot pedal 143RF is located on the right side of the floor in front of the driver's seat 141. The left travel lever 143LT is pivotally supported by the left foot pedal 143LF, and is configured so that tilting the left travel lever 143LT and pushing down the left foot pedal 143LF are linked. The right travel lever 143RT is pivotally supported by the right foot pedal 143RF, and is configured so that tilting the right travel lever 143RT and pushing down the right foot pedal 143RF are linked.

[0025] The left foot pedal 143LF and left travel lever 143LT correspond to the rotational drive of the left crawler belt of the traveling body 110. Specifically, when the operator of the work machine 100 pushes the left foot pedal 143LF or the left travel lever 143LT forward, the left crawler belt rotates in the forward direction. Conversely, when the operator of the work machine 100 pushes the left foot pedal 143LF or the left travel lever 143LT backward, the left crawler belt rotates in the reverse direction.

[0026] The right foot pedal 143RF and right travel lever 143RT correspond to the rotational drive of the right crawler of the running body 110. Specifically, when the operator of the work machine 100 pushes the right foot pedal 143RF or the right travel lever 143RT forward, the right crawler rotates in the forward direction. Conversely, when the operator of the work machine 100 pushes the right foot pedal 143RF or the right travel lever 143RT backward, the right crawler rotates in the reverse direction.

[0027] The teaching switch 143TS is provided, for example, on the handle portion of the right operating lever 143RO. The teaching switch 143TS may be located near the operator seated in the driver's seat 141. When the teaching switch 143TS is pressed, the control device 160 stores the posture of the work machine 100 at the time the switch was pressed as a reference for automatic control.

[0028] The start switch 143SW is provided, for example, on the handle portion of the right operating lever 143RO. The start switch 143SW may be located near the operator seated in the driver's seat 141. When the start switch 143SW is pressed, an automatic control instruction signal is output to the control device 160. When the control device 160 receives the input of the automatic control instruction signal, it starts automatic control.

[0029] Automatic control refers to autonomous control by the work machine 100 of the drive of the work implement 130 and the rotating unit 120 to achieve a predetermined operation. In the first embodiment, the automatic control is performed autonomously by the work machine 100. The first rotation is a series of operations in which the bucket 133 is positioned to the side of the loading target T due to excavation of the excavation target, and the boom 131 is raised while the bucket 133 is rotated to a direction facing the loading target T. The second rotation is a series of operations in which the bucket 133 is positioned above the loading target T due to loading, and the boom 131 is lowered while the bucket 133 is rotated to a predetermined direction. The side of the loading target T refers to the outside of a loading platform, such as a vessel, onto which cargo is loaded. Note that automatic control according to other embodiments may involve only the second rotation. In the first embodiment, the target orientation of the rotating unit 120 and the target attitude of the bucket 133 during the first rotation and the second rotation are predetermined orientations and attitudes, respectively. Note that the excavation target is typically located lower than the height of the loading target T. Therefore, the work machine 100 controls the drive of the work machine 130 during the first swing and the second swing so that the loading target T does not come into contact with the work machine 130. Details of the automatic control will be described later. Each time the start switch 143SW is pressed, the automatic control that is executed switches between the first swing and the second swing. In another embodiment, the operation device 143 may be provided with two start switches 143SW, each assigned to the first swing and the second swing.

[0030] <Configuration of Measurement System> As shown in FIG. 1 , the work machine 100 is equipped with a position and orientation calculator 151 , an inclination measuring device 152 , a boom stroke sensor 153 , an arm stroke sensor 154 , and a bucket stroke sensor 155 .

[0031] 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 constitute 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 (the origin of the excavator coordinate system) in the site 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 a direction perpendicular to the front of the revolving unit 120. The position and orientation calculator 151 is an example of a sensor that acquires GNSS measurement data.

[0032] The inclinometer 152 measures the acceleration and angular velocity of the rotating unit 120, and detects the attitude (roll angle, pitch 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).

[0033] 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 work 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 angle of each link component 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.

[0034] <Configuration of the Control Device 160> FIG. 4 is a schematic block diagram showing the configuration of the control device 160 according to the first embodiment. The work machine 100 is equipped with the control device 160. The control device 160 may be implemented in the operation terminal 142, or may be provided separately from the operation terminal 142 and receive input and output from the operation terminal 142. The control device 160 receives operation signals from the operation device 143. The control device 160 drives the work implement 130, the revolving body 120, and the traveling body 110 by outputting the received operation signals or operation signals generated for automatic control to the control valve 126. Hereinafter, operation signals received from the operation device 143 will also be referred to as manual operation signals, and operation signals generated for automatic control will also be referred to as automatic operation signals. Note that automatic operation signals consist of operation signals that drive the revolving body 120 and the work implement 130, but do not include operation signals that drive the traveling body 110. If a manual operation signal from the operator is received during automatic control, the control device 160 may stop the automatic control.

[0035] The control device 160 is a computer including a processor 610, a main memory 630, a storage 650, and an interface 670. The storage 650 stores a program. The processor 610 reads the program from the storage 650, loads it into the main memory 630, and executes processing in accordance with the program.

[0036] Examples of storage 650 include semiconductor memory, magnetic disks, magneto-optical disks, optical disks, etc. Storage 650 may be an internal medium directly connected to a common communication line of control device 160, or may be an external medium connected to control device 160 via interface 670. Main memory 630 and storage 650 are non-transitory tangible storage media.

[0037] By executing a program, the processor 610 is equipped with a measurement data acquisition unit 611, an operation signal input unit 612, a work machine position identification unit 613, a reference identification unit 614, an angle identification unit 615, a movement control unit 616, an operation signal output unit 617, and a branching and merging control unit 618.

[0038] The measurement data acquisition unit 611 acquires measurement data from the measurement system of the work machine 100. Specifically, the measurement data acquisition unit 611 acquires measurement data from the position and orientation calculator 151, the inclination measuring device 152, the boom stroke sensor 153, the arm stroke sensor 154, and the bucket stroke sensor 155.

[0039] The operation signal input unit 612 receives input of operation signals manually operated by the operator from the operation device 143. The operation signals include a drive signal for raising or lowering the boom 131, a drive signal for raising or lowering the arm 132, a drive signal for dumping or digging the bucket 133, a drive signal for turning the rotating unit 120 right or left, a drive signal for operating the traveling unit 110 to travel, and an automatic control instruction signal for the work machine 100.

[0040] The work implement position identifying unit 613 identifies the position of the tip P of the arm 132 ( FIG. 5 ) and the position of the lowest point Q of the bucket 133 ( FIG. 5 ) in the vehicle body coordinate system based on the revolving unit 120, based on the measurement data acquired by the measurement data acquiring unit 611. The lowest point Q of the bucket 133 refers to the point on the outer shape of the bucket 133 that is the shortest distance from the ground surface.

[0041] The work implement position identifying unit 613 determines the vertical and horizontal components of the length of the boom 131 based on the inclination 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 work implement position identifying unit 613 determines the vertical and horizontal components of the length of the arm 132. The work implement position identifying unit 613 identifies, as the position of the tip P of the arm 132, a position that is away from the position of the work machine 100 in a direction identified from the orientation and posture of the work machine 100 by the sum of the vertical and horizontal components of the lengths of the boom 131 and the arm 132. The work implement position identifying unit 613 also identifies the position of the lowest point Q of the bucket 133 based on the inclination angle of the bucket 133 and the known shape of the bucket 133. For example, the work implement position identifying unit 613 calculates the position of each of a plurality of points on the outer shell of the bucket 133 based on the tilt angle of the bucket 133, and identifies the point with the lowest height among the plurality of points as the lowest point Q. Furthermore, for example, the work implement position identifying unit 613 may determine as the lowest point Q a point obtained by offsetting the distance between the bucket pin and a point on the bucket 133 that is farthest from the bucket pin downward in the height direction from the bucket pin. Furthermore, for example, the work implement position identifying unit 613 may determine as the lowest point Q a point obtained by offsetting the maximum amount of the bucket movable range downward in the height direction from the bucket pin. Furthermore, the work implement position identifying unit 613 may determine as the lowest point Q a point obtained by offsetting a height with a margin from the height identified above, taking into account control errors and GNSS measurement errors.

[0042] Before executing automatic control, the reference specifying unit 614 receives teachings from the operator of the excavation preparation position, interference avoidance position, and loading position of the bucket 133 as reference points for automatic control. Teaching is performed, for example, in the following procedure.

[0043] The reference identification unit 614 displays an instruction to move the bucket 133 to the excavation preparation position on the operation terminal 142. The operator operates the operation device 143 to move the bucket 133 to the excavation preparation position and presses the teaching switch 143TS. The reference identification unit 614 sets the attitude of the work implement 130 identified by the work implement position identification unit 613 when the teaching switch 143TS is pressed as the target attitude for the second swing, sets the position of the tip P of the arm 132 as the target position for the second swing, and records in storage 650 the orientation of the rotating body 120 as the target orientation for the second swing.

[0044] Next, the reference identification unit 614 displays on the operation terminal 142 an instruction to move the cutting edge of the bucket 133 to an interference avoidance position that is the same height as the upper end of the vessel wall of the loading target T and where the work implement 130 and the loading target T do not overlap in a plan view from above. The vessel wall used for teaching may be any of the side, front, or rear walls of the vessel. The operator operates the operation device 143 to move the cutting edge of the bucket 133 to the interference avoidance position and presses the teaching switch 143TS. The interference avoidance positions are input for both the right and left ends of the loading target T. This allows the reference identification unit 614 to identify the range of the loading target T's platform. The height of the interference avoidance position may be offset upward to allow for a margin of error, taking into account control errors and measurement errors. The interference avoidance position is information for identifying the phase of automatic control, which will be described later.

[0045] The reference identification unit 614 sets the height of the lowest point Q of the bucket 133 identified by the work machine position identification unit 613 when the teaching switch 143TS is pressed as the wall height Ht of the loading target T, and records the orientation of the rotating unit 120 as the interference avoidance orientation in the storage 650. The wall height Ht is an example of the height of the loading target T.

[0046] Next, the reference specification unit 614 displays on the operation terminal 142 an instruction to move the bucket 133 to a loading position above the loading target T. The operator operates the operation device 143 to move the bucket 133 to the loading position and presses the teaching switch 143TS. The reference specification unit 614 sets the attitude of the work implement 130 when the teaching switch 143TS is pressed as the target attitude for the first swing, the position of the tip P of the arm 132 as the target position for the first swing, and the orientation of the rotating body 120 identified by the work implement position specification unit 613 as the target orientation for the first swing, and records these in the storage 650. The height of the lowest point Q of the bucket 133 identified at the loading position may also be set as the wall height Ht. In other embodiments, the height of the loading target T does not necessarily have to be the wall height Ht, which is the height of the side wall of the loading platform, but may be the height of the highest point of the entire loading target T.

[0047] The angle identification unit 615 identifies, as a target swing angle, the angle between the initial orientation to which the revolving unit 120 faces when an automatic control instruction signal is input to the operation signal input unit 612 and the target orientation recorded in the storage 650. The angle identification unit 615 identifies, as an interference avoidance angle, the angle between the initial orientation to which the revolving unit 120 faces when an automatic control instruction signal is input to the operation signal input unit 612 and the interference avoidance orientation recorded in the storage 650. The interference avoidance angle is the swing angle at which the work machine 130 and the loading target T do not overlap in a plan view from above.

[0048] The movement control unit 616 generates an automatic operation signal that realizes automatic control when the operation signal input unit 612 receives an input of an automatic control instruction signal. When the automatic control instruction signal is input, the movement control unit 616 executes automatic control that realizes a first swing that moves the bucket 133 to a loading position, or automatic control that realizes a second swing that moves the bucket 133 to an excavation preparation position. The movement control unit 616 determines whether to execute the first swing or the second swing in the automatic control based on whether the bucket 133 is within the range of the loading target T in a plan view from above when the automatic control instruction signal is input. If the bucket 133 is not within the range of the loading target T's bed, the movement control unit 616 executes the first swing, and if the bucket 133 is within the range of the loading target T's bed, the movement control unit 616 executes the second swing. At this time, the movement control unit 616 controls the revolving unit 120 and the work implement 130 to prevent contact between the loading target T and the work implement 130 based on the wall height Ht and the interference avoidance angle stored in the storage 650.

[0049] The operation signal output unit 617 outputs the manual operation signal input to the operation signal input unit 612 or the automatic operation signal generated by the movement control unit 616 to the control valve 126 .

[0050] The branching and merging control unit 618 controls the branching and merging valve 125 to switch between branching and merging of the first oil passage 123A and the second oil passage 123B.

[0051] When the work machine 100 is controlled manually by operating the operation device 143, the branching and merging control unit 618 generates a control signal for the branching and merging valve 125 based on the operation pattern of the operation device 143. Figure 7 is an example of a table showing the relationship between the operation pattern and branching and merging control according to the first embodiment.

[0052] 7 , when the operation signal for swinging and the operation signal for raising the boom 131 are ON, the branching and merging control unit 618 opens the branching and merging valve 125 to merge the first oil line 123A and the second oil line 123B. Because the flow rate of hydraulic oil required for the boom 131 raising operation is greater than the flow rate of hydraulic oil required for the swing operation, branching the first oil line 123A and the second oil line 123B may result in an insufficient flow rate for driving the boom 131. Therefore, the branching and merging control unit 618 merges the first oil line 123A and the second oil line 123B to increase the flow rate of second oil line 123B, which supplies hydraulic oil to the boom cylinder 131C, thereby allowing sufficient hydraulic oil to be supplied for driving the boom 131.

[0053] 7 , when the swing operation signal is ON and the operation signal for the work implement 130 is OFF, the branching and merging control unit 618 closes the branching and merging valve 125 and branches the first oil line 123A and the second oil line 123B. When the swing unit 120 operates alone, the required flow rate is satisfied by the discharge volume of a single pump, and therefore the assistance of multiple hydraulic pumps 122 is not required. Therefore, by branching the first oil line 123A and the second oil line 123B, the branching and merging control unit 618 prevents pressure loss in the second oil line 123B connected to an actuator that is not being driven, thereby improving energy efficiency.

[0054] When controlling the work machine 100 under automatic control, the branching and merging control unit 618 generates a control signal for the branching and merging valve 125 based on the phase of the automatic control.

[0055] <<Operation During Automatic Control>> Here, the movement of the work machine 100 during automatic control according to the first embodiment will be described with reference to the drawings. Figure 5 is a diagram showing an example of the movement of the work machine 100 during a first swing according to the first embodiment. Figure 6 is a diagram showing an example of the movement of the work machine 100 during a second swing according to the first embodiment.

[0056] When automatic control for the first swing is initiated, as shown in Fig. 5 , the control device 160 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 (first phase P1). The target position of the bucket 133 for the first swing is a loading position above the loading target T. After a delay, the control device 160 starts swinging the rotating unit 120 (second phase P2). The control device 160 adjusts the timing of switching between the first phase P1 and the second phase P2 so that the attitude of the work implement 130 becomes the target attitude for the first swing by the time the swing angle of the rotating unit 120 matches the first interference avoidance angle θ1. If the attitude of the work implement 130 reaches the target attitude for the first swing by the time the swing angle of the swing unit 120 matches the first interference avoidance angle θ1, that is, if the height of the lowest point Q of the bucket 133 is higher than the wall height Ht of the loading target T, the swing of the swing unit 120 will not cause the work implement 130 to come into contact with the loading target T. If the work implement 130 is driven simultaneously with the swing and the attitude of the work implement 130 reaches the target attitude for the first swing by the time the swing angle matches the first interference avoidance angle θ1, the control device 160 may skip the first phase P1 and start driving and swinging the work implement 130 simultaneously. After the swing angle reaches the first interference avoidance angle θ1, the control device 160 operates only the swing unit 120 without operating the work implement 130 (third phase P3). Thereafter, when the bucket 133 reaches the loading position, the automatic control ends. In this embodiment, the first phase P1, the second phase P2, and the third phase P3 are consecutive in time, but in other embodiments, the phases may not be consecutive in time.

[0057] The operator then manually performs a dump operation by rotating the bucket 133 in the dump direction. During a manual dump operation, the operator may load the load at a low position to reduce the impact on the object T to be loaded. The operator may also operate the work machine 100 to level the load loaded on a bed such as a vessel. At this time, the lowest point Q of the bucket 133 may be lower than the wall of the object T to be loaded. Therefore, if the control device 160 continues to swing the work machine 100 in this state, the bucket 133 will come into contact with the inner wall of the object T to be loaded.

[0058] When automatic control for the second swing is initiated, the control device 160 determines whether the lowest point of the bucket 133 is higher than the wall of the loading target T. As shown in Figure 6, if the lowest point Q of the bucket 133 is lower than the wall height Ht, the control device 160 raises the boom 131 (fourth phase P4). When the lowest point Q of the bucket 133 becomes higher than the wall height Ht, the control device 160 starts swinging the rotating unit 120 without operating the work implement 130. The control device 160 swings the rotating unit 120 without moving the work implement 130 until the swing angle of the rotating unit 120 exceeds the second interference avoidance angle θ2, thereby maintaining the height of the lowest point of the bucket 133 (fifth phase P5).

[0059] When the rotation angle of the rotating unit 120 exceeds the second interference avoidance angle θ2, the control device 160 drives the boom 131, arm 132, and bucket 133 in addition to the rotating unit 120 (sixth phase). At this time, the control device 160 may drive all of the boom 131, arm 132, and bucket 133, or may drive only a portion of the boom 131, arm 132, and bucket 133, depending on the relationship between the attitude at the start of rotation and the target attitude. When the rotation angle of the rotating unit 120 reaches the target rotation angle θ0, the control device 160 terminates driving of the rotating unit 120. Furthermore, when the attitude of the work implement 130 reaches the target attitude at the start of excavation, the control device 160 terminates driving of the work implement 130. Note that in this embodiment, the fourth phase P4, the fifth phase P5, and the sixth phase P6 are continuous in time, but in other embodiments, the phases may not be continuous in time.

[0060] 5 and 6 show an example in which the positional relationship between the excavation position and the loading target T is approximately 90 degrees around the rotating unit 120, but this is not limited to this in other embodiments. For example, in other embodiments, the positional relationship between the excavation position and the loading target T may be another rotation angle position, such as approximately 180 degrees around the rotating unit 120.

[0061] When controlling the work machine 100 under automatic control, the branching and merging control unit 618 generates a control signal for the branching and merging valve 125 based on the phase of the automatic control. Specifically, when the phase of the automatic control is the third phase P3 or the fifth phase P5 in which the rotating unit 120 is operated independently, the branching and merging control unit 618 closes the branching and merging valve 125 and branches the first oil line 123A and the second oil line 123B. In the third phase P3 or the fifth phase P5, the rotating unit 120 is operated independently, so the branching and merging control unit 618 branches the first oil line 123A and the second oil line 123B, thereby preventing pressure loss in the second oil line 123B connected to an actuator that is not being driven and improving energy efficiency.

[0062] On the other hand, when the automatic control phase is the first phase P1, the second phase P2, the fourth phase P4, or the sixth phase P6, which involves operation of the work implement 130, the branching and merging control unit 618 opens the branching and merging valve 125 to merge the first oil line 123A and the second oil line 123B. In the first phase P1, the second phase P2, the fourth phase P4, and the sixth phase P6, at least two of the rotating body 120, the boom 131, the arm 132, and the bucket 133 are controlled simultaneously. Therefore, by merging the first oil line 123A and the second oil line 123B, the branching and merging control unit 618 can supply sufficient hydraulic oil to drive each actuator.

[0063] 8 is a flowchart showing automatic control by the control device 160 according to the first embodiment. When the operator presses the start switch 143SW, the operation signal input unit 612 of the control device 160 receives an input of an automatic control instruction signal. When the automatic loading instruction signal is received, the control device 160 determines whether to perform a first rotation or a second rotation based on whether the bucket 133 is within a range above the loading platform of the loading target T in a plan view from above (Step S1). When performing a first rotation, the control device 160 performs automatic control based on the first interference avoidance angle θ1 and the target rotation angle θ0. When performing a second rotation, the control device 160 performs automatic control based on the second interference avoidance angle θ2 and the target rotation angle θ0.

[0064] When the first swing is to be performed (step S1: YES), the movement control unit 616 executes control in a first phase P1 in which the swing unit 120 is not rotated and only the work implement 130 is raised until the height of the lowest point of the bucket 133 reaches a predetermined height (step S2). Because the automatic control phase is the first phase P1, the branching and merging control unit 618 outputs a control signal to open the branching and merging valve 125 (step S3). This causes the branching and merging control unit 618 to merge the first oil line 123A and the second oil line 123B. At this time, the branching and merging control unit 618 may branch the first oil line 123A and the second oil line 123B when the pump discharge pressure is high, as shown in FIG. 7 .

[0065] When the height of the lowest point of the bucket 133 exceeds a predetermined height, the movement control unit 616 executes control of the second phase P2, which simultaneously operates the revolving body 120 and the work machine 130 (step S4). Because the automatic control phase is the second phase P2, the branching and merging control unit 618 continues to output a control signal to open the branching and merging valve 125 (step S5). At this time, the branching and merging control unit 618 may branch the first oil line 123A and the second oil line 123B depending on the relationship between the pump discharge pressure and the actuator to be driven, as shown in FIG. 7.

[0066] When the rotation angle of the rotating unit 120 exceeds the first interference avoidance angle θ1, the movement control unit 616 executes control in a third phase P3 in which the rotating unit 120 operates independently until the rotation angle of the rotating unit 120 reaches the target rotation angle θ0 (step S6). Because the automatic control phase is the third phase P3, the branching and merging control unit 618 outputs a control signal to close the branching and merging valve 125 (step S7). This causes the branching and merging control unit 618 to branch the first oil line 123A and the second oil line 123B. When the rotation angle of the rotating unit 120 reaches the target rotation angle θ0, the control device 160 ends the automatic control of the first rotation.

[0067] If the second swing is to be performed (step S1: NO), the movement control unit 616 executes control of a fourth phase P4 in which the swing unit 120 is not rotated and only the work implement 130 is raised until the height of the lowest point of the bucket 133 reaches the wall height Ht (step S8). Because the automatic control phase is the fourth phase P4, the branching and merging control unit 618 outputs a control signal to open the branching and merging valve 125 (step S9). This causes the branching and merging control unit 618 to merge the first oil line 123A and the second oil line 123B. At this time, the branching and merging control unit 618 may branch the first oil line 123A and the second oil line 123B when the pump discharge pressure is high, as shown in FIG. 7 .

[0068] When the height of the lowest point of the bucket 133 exceeds the wall height Ht, the movement control unit 616 executes control of the fifth phase P5 to independently operate the revolving body 120 (step S10). Because the automatic control phase is the fifth phase P5, the branching and merging control unit 618 outputs a control signal to close the branching and merging valve 125 (step S11).

[0069] When the rotation angle of the revolving unit 120 exceeds the second interference avoidance angle θ2, the movement control unit 616 executes control in a sixth phase P6, which simultaneously operates the revolving unit 120 and the work implement 130 until the rotation angle of the revolving unit 120 reaches the target rotation angle θ0 (step S12). Because the automatic control phase is the sixth phase P6, the branching and merging control unit 618 outputs a control signal to open the branching and merging valve 125 (step S13). At this time, the branching and merging control unit 618 may branch the first oil line 123A and the second oil line 123B depending on the relationship between the pump discharge pressure and the actuator to be driven, as shown in FIG. 7 . As a result, the branching and merging control unit 618 merges the first oil line 123A and the second oil line 123B. When the rotation angle of the revolving unit 120 reaches the target rotation angle θ0, the control device 160 terminates the automatic control of the second rotation.

[0070] Second Embodiment The control device 160 according to the first embodiment controls the opening and closing of the branching and merging valve 125 according to the phase. The lifting speed of the work implement 130 varies depending on the weight of the load. Therefore, in the second phase P2 of the first swing, the height of the lowest point of the bucket 133 may reach the height of the loading position before the swing angle reaches the second interference avoidance angle θ2. Because the branching and merging valve 125 is open in the second phase P2, the first oil line 123A and the second oil line 123B merge until the swing angle reaches the second interference avoidance angle θ2.

[0071] The control device 160 according to the second embodiment improves energy efficiency by closing the branching and merging valve 125 without waiting for the third phase P3 when the lowest point of the bucket 133 reaches the height of the loading position in the second phase P2.

[0072] FIG. 9 is a flowchart showing the operation of the control device 160 according to the second embodiment. The control device 160 according to the second embodiment executes the following steps S21 and S22 in the second phase P2. In the second phase P2, the branching and merging control unit 618 determines whether the height of the lowest point of the bucket 133 has reached the height of the loading position (step S21). If the height of the lowest point of the bucket 133 is less than the height of the loading position (step S21: NO), the branching and merging valve 125 remains open. On the other hand, if the height of the lowest point of the bucket 133 has reached the height of the loading position (step S21: YES), the branching and merging control unit 618 outputs a control signal to close the branching and merging valve 125 without waiting for the third phase P3 (step S22).

[0073] In this way, in the second phase P2, the control device 160 according to the second embodiment determines whether to close the branching and merging valve 125 based on the attitude of the work implement 130. This allows the control device 160 to prevent energy loss due to pressure loss when there is no longer a need to drive the work implement 130.

[0074] In addition, the control device 160 may close the branch and merge valve 125 in the sixth phase P6 of the second rotation if the posture of the work implement 130 reaches the target posture for the second rotation before the rotation angle reaches the target rotation angle.

[0075] Other Embodiments Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to that described above, and various design modifications and the like 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. The control device 160 according to the above-described embodiment may be configured by a single computer, or the configuration of the control device 160 may be divided into multiple computers that function as the control device 160 by working together. In this case, some of the computers that make up the control device 160 may be mounted inside the work machine, and other computers may be mounted outside the work machine. For example, the work machine 100 according to the above-described embodiment is operated by an operator on board, but this is not limited to this, and the work machine 100 may also be remotely operated. That is, manual control of the operation device 143 includes manual control of a remotely provided operation device 143. In this case, the computer mounted inside the work machine 100 and the remote computer may work together to function as the control device 160.

[0076] The control device 160 according to the embodiment described above identifies the point at which the automatic control phase switches by teaching a reference point, but this is not limited to this. For example, the control device 160 according to another embodiment may identify multiple phases by teaching the trajectory of the bucket 133 during automatic control and analyzing the trajectory. For example, the control device 160 according to another embodiment may identify a section of the trajectory where the horizontal position changes without changing the height as the phase in which the rotating unit 120 operates independently.

[0077] In addition, the control device 160 according to another embodiment may identify the position of the loading object T using a depth sensor or the like, or receive position information from the loading object T, and determine the interference avoidance angle based on the position of the loading object T.

[0078] Furthermore, the control device 160 according to another embodiment may identify the phase of automatic control based on the control signal output by the operation signal output unit 617. Examples of the control signal output by the operation signal output unit 617 may be a target speed command, a target angular velocity command, a target spool stroke amount, a current command, etc. In the case of a pilot hydraulic type work machine 100 in which each lever of the operation device 143 is connected to a pilot valve of a pilot hydraulic circuit and the control valve is driven by hydraulic pressure supplied from the pilot valve, the control signal may be identified by the measurement value of a pressure sensor provided in each pilot valve of the control valve 126. In this case, the branching and joining control unit 618 may perform branching and joining control without distinguishing between manual control and automatic control.

[0079] Furthermore, although the control device 160 according to the embodiment described above automatically controls the revolving unit 120 and the work implement 130 during the first and second rotations, this is not limiting. For example, a control device 160 according to another embodiment may accept manual operation of the revolving unit 120 during the first and second rotations and automatically control the work implement 130 according to the rotation angle. In this case as well, the branching and merging control unit 618 controls the branching and merging valve 125 according to the phase of automatic control of the work implement 130.

[0080] In another embodiment, the phases of automatic control may include a phase in which the traveling vehicle 110 is caused to travel. In this case, the branching and merging control unit 618 outputs a control instruction to the branching and merging valve 125 to branch the first oil line 123A and the second oil line 123B during the phase in which the traveling vehicle 110 is caused to travel. This allows the flow rate of hydraulic oil supplied to the first traveling motor 112A to be controlled by the first hydraulic pump 122A, and the flow rate of hydraulic oil supplied to the second traveling motor 112B to be controlled by the second hydraulic pump 122B. In addition, the implement of the work machine 130 according to another embodiment is not limited to the bucket 133. For example, the work machine 130 according to another embodiment may be equipped with another implement (attachment), such as a tilt bucket, tilt rotator bucket, grapple, lift magnet, or breaker. In this case, the phases of automatic control may include a phase in which an actuator provided on the implement is driven.

[0081] The work machine according to the above aspect can appropriately perform branching and merging control in automatic control.

[0082] DESCRIPTION OF SYMBOLS 100...Work machine 110...Traveling body 111...Crawler 112...Travel motor 112A...First travelling motor 112B...Second travelling motor 120...Swinging body 121...Engine 122...Hydraulic pump 122A...First hydraulic pump 122B...Second hydraulic pump 123A...First oil passage 123B...Second oil passage 124...Bypass oil passage 125...Dividing and merging valve 126...Control valve 126A...First control valve 126B...Second control valve 127...Swing motor 130...Working machine 131...Boom 131C...Boom cylinder 132...Arm 132C...Arm cylinder 133...Bucket 133C...Bucket cylinder 140...Driver's cab 141...Driver's seat 142...Operation terminal 143...Operation device 143LF...Left foot pedal 143LO...Left operation lever 143LT...Left travel lever 143RF...Right foot pedal 143RO...Right operation lever 143RT...Right travel lever 143SW...Start switch 143TS...Teaching switch 151...Position and direction calculator 152...Inclination measuring device 153...Boom stroke sensor 154...Arm stroke sensor 155...Bucket stroke sensor 160...Control device 610...Processor 611...Measurement data acquisition unit 612...Operation signal input unit 613...Work implement position identification unit 614...Reference identification unit 615...Angle identification unit 616...Movement control unit 617...Operation signal output unit 618...Dividing and merging control unit 630...Main memory 650...Storage 670...Interface T...Loading target

Claims

1. A control system for a working machine, comprising: a main body; a working implement driven with respect to the main body; a plurality of actuators for driving the main body or the working implement; a plurality of fluid pumps for supplying fluid to the plurality of actuators; a plurality of flow paths connecting each of the plurality of fluid pumps and an actuator corresponding to each fluid pump among the plurality of actuators; and a diverter valve for selectively connecting the plurality of flow paths, wherein, based on an operation signal of the main body or the working implement, the flow rates of the diverter valve and the fluid pumps are adjusted to execute a predetermined operation of the main body and the working implement, and the control system includes a plurality of phases related to automatic control, and switching of the diverter valve is included in switching of at least one of the plurality of phases.

2. The control system according to claim 1, which outputs control signals for the plurality of actuators and the diverter valve based on a phase specified from the detected operation of the working implement.

3. The control system according to claim 2, wherein the plurality of phases include at least a first phase for driving the working implement and a second phase for driving the main body without driving the working implement, and outputs a control signal for switching the diverter valve when switching from the first phase to the second phase.

4. The control system according to claim 1, wherein the main body includes a lower traveling body and an upper revolving body, and the plurality of actuators include a slewing motor for driving the upper revolving body with respect to the lower traveling body.

5. The control system according to claim 1, wherein the main body includes a lower traveling body, and the plurality of actuators include a traveling motor for driving the lower traveling body.

6. The control system according to claim 5, wherein the plurality of phases include a third phase for driving the traveling motor, and in the third phase, the plurality of flow paths are separated in the diverter valve.

7. A control system for a working machine, comprising: a main body; a working implement driven with respect to the main body; a plurality of actuators for driving the main body or the working implement; a plurality of fluid pumps for supplying fluid to the plurality of actuators; a plurality of flow paths connecting each of the plurality of fluid pumps and the actuator corresponding to each fluid pump among the plurality of actuators; and a diverter valve for selectively connecting the plurality of flow paths, wherein, based on an operation signal of the main body or the working implement, a flow rate of the diverter valve and the fluid pump is adjusted, and a control signal for closing the diverter valve is output at least at a switching of at least one of a plurality of phases related to automatic control of the main body and the working implement.

8. The control system according to claim 7, wherein the plurality of phases include at least a first phase for driving the working implement and a second phase for driving the main body without driving the working implement, and a control signal for closing the diverter valve is output when switching from the first phase to the second phase.

9. The control system according to claim 8, wherein in the first phase, it is determined whether to close the diverter valve based on the posture of the working implement.

10. A working machine, comprising: a main body; a working implement driven with respect to the main body; a plurality of actuators for driving the main body or the working implement; a plurality of fluid pumps for supplying fluid to the plurality of actuators; a plurality of flow paths connecting each of the plurality of fluid pumps and the actuator corresponding to each fluid pump among the plurality of actuators; a diverter valve for selectively connecting the plurality of flow paths; and the control system according to any one of claims 1 to 8.

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