Automatic swing control system for work machine, work machine, and automatic swing control method for work machine

Abstract

A work machine (2) is attached to a swing body (3). A controller (50) executes automatic swing control for controlling swing of the swing body (3). The controller (50) reduces the swing speed of the swing body (3) on the basis of a second target swing angle (C) before reaching a first target swing angle (B) that serves as a target stop angle for the automatic swing control.

Description

Automatic turning control system for work machine, work machine, and automatic turning control method for work machine

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

[0002] Automatic loading control of a loading machine is disclosed, for example, in Japanese Patent Laid-Open No. 2019-148147 (Patent Document 1). Patent Document 1 discloses a technology for controlling a rotating body to stop facing a target stopping direction by controlling the pressure of hydraulic oil downstream of the rotating motor based on the orientation, rotation speed, and target stopping orientation of the rotating body while the rotating motor is being braked.

[0003] Japanese Patent Application Laid-Open No. 2019-148147

[0004] However, with the technology of Patent Document 1, if deceleration control is performed with a target of a swing end point in a target stopping orientation, the deceleration may not be fast enough, and the implement may exceed the swing end point position.

[0005] An object of the present disclosure is to provide an automatic swing control system for a work machine, a work machine, and an automatic swing control method for a work machine that can stop the work machine at a swing end point with high precision.

[0006] The automatic swing control system for a work machine and the work machine according to the present disclosure each include a swing unit, a work implement, and a controller. The work implement is attached to the swing unit. The controller executes automatic swing control for controlling the swing of the swing unit. The controller reduces the swing speed of the swing unit based on a second target swing angle that is shorter than a first target swing angle, which is a target stop angle for the automatic swing control.

[0007] The automatic swing control method for a work machine according to the present disclosure is a method for automatic swing control for a work machine having a swing body and a work implement attached to the swing body, and includes the following steps.

[0008] A first target swing angle is set as a target stop angle for automatic swing control that controls the swing of the swing body. A second target swing angle is set that is shorter than the first target swing angle. The swing speed of the swing body is reduced based on the second target swing angle.

[0009] According to the present disclosure, it is possible to realize an automatic swing control system for a work machine, a work machine, and an automatic swing control method for a work machine that can stop the work machine at a swing end point with high accuracy.

[0010] FIG. 1 is a diagram showing the configuration of a hydraulic excavator as an example of a work machine in an embodiment of the present disclosure. FIG. 2 is a diagram showing an operation flow of excavation and loading by a hydraulic excavator as an example of a work machine. FIG. 3 is a perspective view showing automatic excavation and loading as an example of work for which automatic swing control of a work machine is executed. FIG. 4 is a first block diagram showing the configuration of the automatic swing control system for a work machine shown in FIG. 1. FIG. 5 is a diagram for explaining overshoot. FIG. 6 is a diagram for explaining that overshoot is suppressed according to the automatic swing control system for a work machine in an embodiment of the present disclosure. FIG. 7 is a second block diagram showing the configuration of the automatic swing control system for a work machine shown in FIG. 1. FIG. 8 is a diagram showing the relationship between swing speed, time, and swing angle. FIG. 9 is a diagram for explaining why an offset angle is used in calculating swing brake torque. FIG. 10 is a diagram showing an example in which negative acceleration is 0 (zero) in low acceleration control after a predetermined swing speed ωp is reached. FIG. 11 is a flow diagram showing an automatic swing control method for a work machine in an embodiment of the present disclosure.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the specification and drawings, identical or corresponding components are designated by the same reference numerals, and redundant explanations will not be repeated. In addition, in the drawings, configurations may be omitted or simplified for the sake of convenience.

[0012] In the following description, the terms "up," "down," "front," "rear," "left," and "right" refer to directions relative to the operator seated in the driver's seat 4S in the driver's cab 4 shown in Figure 1.

[0013] <Configuration of Work Machine> The configuration of a hydraulic excavator as an example of a work machine of the present disclosure will be described with reference to FIG.

[0014] Fig. 1 is a diagram schematically illustrating the configuration of a hydraulic excavator as an example of a work machine according to an embodiment of the present disclosure. As shown in Fig. 1, the hydraulic excavator 100 of this embodiment has a main body 1 and a hydraulically operated work implement 2. The main body 1 corresponds to an example of a vehicle body according to the present disclosure. The main body 1 has a revolving unit 3 and a traveling unit 5.

[0015] The running body 5 has a pair of tracks 5Cr and a travel motor 5M. The hydraulic excavator 100 is capable of traveling by rotation of the tracks 5Cr. The travel motor 5M is provided as a drive source for the running body 5. The travel motor 5M is a hydraulic motor that is hydraulically operated. The running body 5 may have wheels (tires).

[0016] The rotating body 3 is disposed on the running body 5 and is supported by the running body 5. The rotating body 3 can be rotated relative to the running body 5 about a rotation axis RX by a rotation motor (not shown). The rotation axis RX is the rotation center of the rotating body 3. The rotation motor is a hydraulic motor operated by hydraulic pressure. The rotation axis RX is a virtual straight line that is the rotation center of the rotating body 3. Note that the traveling motor 5M or the rotation motor may be an electric motor.

[0017] The rotating body 3 has a driver's cab 4. A driver's seat 4S is provided in the driver's cab 4 where an operator sits. The operator (crew) sits in the driver's cab 4 and can operate the work equipment 2, rotate the rotating body 3 relative to the traveling body 5, and travel the hydraulic excavator 100 using the traveling body 5. The rotating body 3 has an exterior cover 9. The exterior cover 9 covers the machine room. The hydraulic excavator 100 may be remotely operated.

[0018] The work implement 2 is attached to the revolving unit 3. The work implement 2 has a boom 6, an arm 7, and a bucket 8. The work implement 2 further has a boom cylinder 10, an arm cylinder 11, and a bucket cylinder 12. The bucket 8 corresponds to an example of an attachment of the present disclosure.

[0019] The boom 6 is rotatably connected to the main body 1. Specifically, the base end of the boom 6 is rotatably connected to the rotating unit 3 with a boom foot pin 13 as a fulcrum. The arm 7 is rotatably connected to the boom 6. Specifically, the base end of the arm 7 is rotatably connected to the tip of the boom 6 with a boom top pin 14 as a fulcrum. The bucket 8 is rotatably connected to the arm 7. Specifically, the base end of the bucket 8 is rotatably connected to the tip of the arm 7 with an arm top pin 15 as a fulcrum. The bucket 8 may be another attachment such as a grapple.

[0020] One end of the boom cylinder 10 is connected to the revolving unit 3, and the other end is connected to the boom 6. The boom 6 can be moved relative to the main body 1 by the boom cylinder 10. By the operation of the boom cylinder 10, the boom 6 can be rotated in the vertical direction relative to the revolving unit 3, with the boom foot pin 13 as a fulcrum.

[0021] One end of the arm cylinder 11 is connected to the boom 6, and the other end is connected to the arm 7. The arm 7 can be moved relative to the boom 6 by the arm cylinder 11. By the operation of the arm cylinder 11, the arm 7 can be rotated in the excavation direction or the dumping direction with the boom top pin 14 as a fulcrum.

[0022] One end of the bucket cylinder 12 is connected to the arm 7, and the other end is connected to a bucket link 17. The bucket 8 is movable relative to the arm 7 by the bucket cylinder 12. By the operation of the bucket cylinder 12, the bucket 8 can rotate in the excavation direction or the dumping direction with the arm top pin 15 as a fulcrum.

[0023] The boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 are each a hydraulic cylinder that is driven by hydraulic pressure, but may also be other actuators such as an electric cylinder.

[0024] <Excavation and Loading Operation Flow and Automatic Swing Control> Next, the excavation and loading operation flow and automatic swing control of the work machine will be described with reference to Figs. 2 and 3 .

[0025] Fig. 2 is a diagram showing an operation flow of excavation and loading by a hydraulic excavator as an example of a work machine, and Fig. 3 is a perspective view showing automatic excavation and loading as an example of work in which automatic swing control of a work machine is performed.

[0026] As shown in Figures 2 and 3, in excavation and loading using the hydraulic excavator 100, excavation is first performed (step SA). This excavation loads a load such as soil into the bucket 8. After excavation, with the load loaded into the bucket 8, the rotating body 3 rotates as shown by the solid arrow in Figure 3 (step SB). This rotation is a so-called loading rotation (hoist rotation). During this loading rotation, the operation of the work machine 2 is controlled so that the work machine 2 does not interfere with the object 200 to be loaded. The object 200 is, for example, a dump truck. The dump truck 200 has a vessel 200A for loading the load in the bucket 8.

[0027] When bucket 8 reaches the point where the load in bucket 8 is to be discharged into vessel 200A due to the loading swing, the swinging unit 3 stops swinging. After this, the load in bucket 8 is discharged (discharged) into vessel 200A of dump truck 200 (step SC). After the discharge, the swinging unit 3 swings back as shown by the dashed arrow in Figure 3 to start excavating again (step SD).

[0028] In this embodiment, the automatic swing control of the work machine is performed, for example, during the above-mentioned excavation and loading. In this embodiment, the automatic swing control of the work machine is performed, for example, during at least one of the loading swing (step SB) and the return swing (step SD) during the above-mentioned excavation and loading. In this embodiment, the automatic swing control of the hydraulic excavator 100 may be performed, for example, during the loading swing during the above-mentioned excavation and loading, or may be performed during the return swing, or may be performed during both the loading swing and the return swing.

[0029] As shown in Figure 3, in order to automate the above-mentioned excavation and loading work and perform automatic swing control, for example, it is necessary to set points (control target points) through which the bucket 8 passes during the excavation and loading operation. Therefore, when automatic swing control is performed during a loading swing (solid arrow), at least a discharge point P2 is set as the control target point. When automatic swing control is performed during a return swing (dashed arrow), at least a return point (digging point) P1 is set as the control target point. Whether automatic swing control is performed during a loading swing or a return swing, a passing point (interference avoidance point) P3 is set as the control target point so that the bucket 8 does not interfere with the loading target 200.

[0030] Return point P1 is, for example, a point located above the vicinity of the location where excavation is to be performed. Discharge point P2 is, for example, a point located directly above loading object 200 (for example, vessel 200A). Passing point P3 is, for example, a point located above the vicinity of side edge SE of loading object 200 (for example, side edge of vessel 200A). Each of control target points P1, P2, and P3 is, for example, a point through which the center of arm top pin 15 in the left-right direction passes during automatic swing control. Note that each of control target points P1, P2, and P3 may be set, for example, as a point through which a point on the cutting edge 8T of bucket 8 or a point on the bottom of bucket 8 passes.

[0031] <Automatic Swing Control System and Method for a Work Machine> Next, an automatic swing control system and method for a work machine according to this embodiment will be described with reference to FIGS. 1 and 4. FIG.

[0032] Figure 4 is a first block diagram showing the configuration of the automatic swing control system for the work machine shown in Figure 1. As shown in Figure 4, the hydraulic excavator 100 or its automatic swing control system has a work implement attitude sensor 20, a position and orientation sensor 21, an inclination sensor 22, and a detection sensor 23. The work implement attitude sensor 20 detects the attitude of the work implement 2 and outputs an attitude signal indicative of the attitude of the work implement 2. The work implement attitude sensor 20 can detect the attitude of each of the boom 6, the arm 7, and the bucket 8. The work implement attitude sensor 20 includes sensors arranged on each of the boom 6, the arm 7, and the bucket 8. The work implement attitude sensor 20 may be any one of an IMU (Inertial Measurement Unit), a stroke sensor, a potentiometer, an imaging device, etc., or any combination of these.

[0033] The position and orientation sensor 21 is, for example, a Global Navigation Satellite Systems (GNSS) receiver and a GNSS antenna. The position and orientation sensor 21 includes two GNSS antennas 21a and 21b ( FIG. 1 ). Each of the two GNSS antennas 21a and 21b is installed at a different position on the rotating unit 3. The GNSS receiver (not shown) calculates the position of the rotating unit 3 in the global coordinate system and the orientation of the rotating unit 3 from the satellite positioning signals received from satellites by each of the GNSS antennas 21a and 21b. The GNSS receiver outputs a position signal indicating the position of the rotating unit 3 and an orientation signal indicating the orientation of the rotating unit 3.

[0034] The position and orientation sensor 21 may include a rotation angle sensor. The rotation angle sensor is fixed to the rotating unit 3, for example. The rotation angle sensor detects the rotation angle of the rotating unit 3 relative to the running unit 5 and outputs a rotation angle signal indicating the rotation angle of the rotating unit 3. The rotation angle sensor can detect the rotation angle in a machine coordinate system (local coordinate system). The rotation angle sensor may be any one of an IMU, a potentiometer, an imaging device, etc., or any combination of these. The machine coordinate system is an orthogonal coordinate system whose origin is the center of rotation of the rotating unit 3 and is represented by axes extending in the front-to-back direction, the left-to-right direction, and the up-to-down direction (rotation axis RX: FIG. 1).

[0035] The inclination sensor 22 measures the acceleration and rotation angular velocity (rotation speed) of the rotating unit 3, and detects the attitude (e.g., roll angle, pitch angle, yaw angle) of the rotating unit 3 based on the measurement results. The inclination sensor 22 is installed, for example, on the underside of the rotating unit 3. The inclination sensor 22 is, for example, an IMU. The inclination sensor 22 outputs an inclination signal obtained by the measurement.

[0036] The detection sensor 23 detects the terrain or objects around the work site of the hydraulic excavator 100. The detection sensor 23 may be attached to, for example, the operator's cab 4 as shown in Fig. 1, or to the exterior cover 9, or may be attached to a location other than these. The detection sensor 23 outputs a detection signal based on the detected object.

[0037] The detection sensor 23 is, for example, a LiDAR (Light Detection and Ranging) that emits laser light to acquire information about an object. The detection sensor 23 may also be a Radar (Radio Detection and Ranging) that acquires information about an object by emitting radio waves. The Radar may, for example, be a millimeter-wave radar that uses a receiving antenna to detect how millimeter-wave band radio waves emitted from a transmitting antenna are reflected off the surface of an object and returned. The detection sensor 23 may also be a visual sensor including a camera. Note that the detection sensor 23 may have a function to detect the attitude of the work implement 2, similar to the work implement attitude sensor 20. For example, the attitude of the work implement 2 may be detected by emitting laser light toward the work implement 2 using the LiDAR.

[0038] The hydraulic excavator 100 or its automatic swing control system further includes an instruction unit 24. The instruction unit 24 is disposed in the operator's cab 4. The instruction unit 24 accepts manual operations by the operator and outputs commands based on the manual operations.

[0039] The instruction unit 24 is an operation unit (such as a switch, button, or touch panel) that teaches a specific point in order to set a control target point in automatic swing control. The specific point in automatic swing control is a point that is taught by the operator. The control target point in automatic swing control is a target point through which the working point of the swinging bucket 8 passes while the automatic swing control is being executed. The control target point is set at a position offset in a safe direction from the specific point.

[0040] The control target points include a passing point and a swing end point. A passing point is a point through which the working point of bucket 8 passes during swing. A swing end point is a point where the working point of bucket 8 is located at the end of swing. The working point of bucket 8 may be, for example, the point where the center of arm top pin 15 in the left-right direction is located, or it may be the cutting edge 8T of bucket 8, the bottom surface of bucket 8, or the like.

[0041] If the automatic turning control is, for example, automatic turning control during automatic loading turning, the turning end point is, for example, the unloading point P2, and the passing point P3 is, for example, an interference avoidance point. The interference avoidance point is, for example, a point set so that the work machine 2 can avoid interference with the loading target 200 (FIG. 3). If the automatic turning control is, for example, automatic turning control during automatic return turning, the turning end point is, for example, the return point P1, and the passing point P3 is, for example, an interference avoidance point. As with the above, the interference avoidance point is, for example, a point set so that the work machine 2 can avoid interference with the loading target 200 (FIG. 3).

[0042] The automatic swing control system has a controller 50. The controller 50 executes automatic swing control of the swing body 3 based on target information. The controller 50 has a control target setting unit 51, an operation information acquisition unit 52, and an EPC (Electric Proportional Valve) control unit 53.

[0043] The control target setting unit 51 acquires an attitude signal of the work machine 2 output from the work machine attitude sensor 20. The control target setting unit 51 acquires a position signal and an orientation signal output from the position and orientation sensor 21. The control target setting unit 51 acquires an inclination signal that indicates the inclination state of the hydraulic excavator 100 output from the inclination sensor 22. The control target setting unit 51 acquires a detection signal output from the detection sensor 23. The control target setting unit 51 acquires an instruction signal output from the instruction unit 24.

[0044] Control target setting unit 51 sets the coordinates of a target point (control target point) through which the working point of swinging bucket 8 passes while automatic swing control is being executed. Control target setting unit 51 sets the coordinates of at least discharge point P2 during loading swing (solid arrow in FIG. 3 ), and sets the coordinates of at least return point P1 during return swing (dashed arrow in FIG. 3 ). Furthermore, whether automatic swing control is executed during loading swing or return swing, a passing point (interference avoidance point) P3 may be set so that bucket 8 does not interfere with loading target 200.

[0045] The control target setting unit 51 sets control target points (return point P1, earth unloading point P2, and passing point P3) based on the specific points. The control target setting unit 51 teaches the specific points from the coordinates of the center position in the left-right direction of the arm top pin 15 at the time when it receives an instruction signal from the instruction unit 24. The control target setting unit 51 teaches the specific points corresponding to the return point P1, earth unloading point P2, and passing point P3, respectively. Teaching of each specific point is performed, for example, during the first loading swing after excavation. The control target setting unit 51 sets the return point P1, earth unloading point P2, and passing point P3 based on each of the taught specific points.

[0046] The control target setting unit 51 has a return point setting unit 51A, an earth discharge point setting unit 51B, and a pass point setting unit 51C. The return point setting unit 51A sets a return point P1. Specifically, the operator operates the indicator 24 when he or she visually determines that the bucket 8 is positioned above the vicinity of the location to be excavated during the rotation of the rotating unit 3. The return point setting unit 51A calculates the coordinates in the machine coordinate system of a specific point corresponding to the return point P1 based on the attitude of the work implement 2 and the swing angle of the rotating unit 3 at the time the operator operates the indicator 24. The return point setting unit 51A sets the coordinates of the return point P1 to a point safely offset from the specific point corresponding to the return point P1 based on the calculated coordinates of the specific point corresponding to the return point P1 and the shape, dimensions, and attitude of the bucket 8.

[0047] The discharge point setting unit 51B sets the discharge point P2. Specifically, the operator operates the instruction unit 24 when he or she visually determines that the bucket 8 is positioned above the vicinity of the location where the load in the bucket 8 should be discharged during the rotation of the rotating unit 3. The discharge point setting unit 51B calculates the coordinates in the machine coordinate system of a specific point corresponding to the discharge point P2 based on the attitude of the work implement 2 and the rotation angle of the rotating unit 3 at the time the operator operates the instruction unit 24. The discharge point setting unit 51B sets the coordinates of the discharge point P2 to a point safely offset from the specific point corresponding to the discharge point P2 based on the calculated coordinates of the specific point corresponding to the discharge point P2 and the shape, dimensions, and attitude of the bucket 8.

[0048] Passing point setting unit 51C sets passing point P3. Specifically, the operator operates indicator 24 when he or she visually determines that bucket 8 is positioned above and near side edge SE of loading target 200 (for example, side edge of vessel 200A) during the rotation of rotating unit 3. Passing point setting unit 51C calculates the coordinates in the machine coordinate system of a specific point corresponding to passing point P3 based on the attitude of work implement 2 and the swing angle of rotating unit 3 at the time the operator operates indicator 24. Passing point setting unit 51C sets the coordinates of passing point P3 to a point safely offset from the specific point corresponding to passing point P3 based on the calculated coordinates of the specific point corresponding to passing point P3 and the shape, dimensions, and attitude of bucket 8.

[0049] The coordinates of each of the control target points P1, P2, and P3 are calculated based on signals acquired from the work machine attitude sensor 20, the position and orientation sensor 21, and the inclination sensor 22. However, the signal acquired from the position and orientation sensor 21 is not essential, and the coordinates of each of the control target points P1, P2, and P3 may be calculated based on signals acquired from the work machine attitude sensor 20 and the inclination sensor 22. In this case, the control target setting unit 51 may refer to the dimensions of each component of the work machine 2 stored in the controller 50 or the like.

[0050] The control target setting unit 51 acquires specific points by teaching as described above, and sets control target points P1, P2, and P3 based on the specific points. The control target setting unit 51 outputs coordinate signals of the set return point P1, earth discharge point P2, and passing point P3 to the operation information acquisition unit 52.

[0051] 4, the return point setting unit 51A, the discharge point setting unit 51B, and the pass point setting unit 51C are shown as separate units, but the return point setting unit 51A, the discharge point setting unit 51B, and the pass point setting unit 51C may not be separate units and may be the same unit. In other words, the control target points P1, P2, and P3 may be set by the same unit of the control target setting unit 51.

[0052] The operation information acquisition unit 52 outputs operation commands for automatic swing control such as the operation of the work implement 2 and the swing of the swing body 3, based on the coordinate signals of the return point P1, the earth discharge point P2, and the passing point P3 acquired from the control target setting unit 51. The EPC valve control unit 53 controls the EPC valve 28 based on the operation commands acquired from the operation information acquisition unit 52.

[0053] The EPC valve 28 controls the hydraulic valve 30 based on a command current from an EPC valve control unit 53 of the controller 50. As a result, the supply of oil pumped up from an oil tank (not shown) by the hydraulic pump 27 to the actuator 29 is controlled via the hydraulic valve 30. The actuator 29 is, for example, a hydraulic actuator, such as the boom cylinder 10, the arm cylinder 11, the bucket cylinder 12, or a swing motor.

[0054] By controlling the EPC valve 28 by the EPC valve control unit 53, each hydraulic actuator is controlled so that the working point of the bucket 8 during automatic swing control for loading swing passes through pass point P3 from the position at the start of automatic swing control to reach unloading point P2 as shown in Figure 3. Also, by controlling the EPC valve 28 by the EPC valve control unit 53, each hydraulic actuator is controlled so that the working point of the bucket 8 during automatic swing control for return swing passes through pass point P3 from the position at the start of automatic swing control to reach return point P1 as shown in Figure 3. This makes automatic swing control possible.

[0055] In the automatic turning control described above, as shown by the solid line L1a in Fig. 5, in order to end the turn at the turning end point B, the turning speed is decelerated with the turning end point B as the target. In Fig. 5, the horizontal axis represents the turning angle, and the vertical axis represents the turning speed (turning angular velocity).

[0056] However, in this case, as shown by the dashed dotted line L2a, the turning speed may not be slowed down in time, and the turning stop position may exceed the position of the turning end point B, which is called overshooting.

[0057] To solve this problem, in this embodiment, as shown by the solid line L1 in FIG. 6 , the rotation speed of the rotating body 3 is decelerated based on a second target rotation angle C that is shorter than the first target rotation angle B, which is the target stop angle for automatic rotation control. In other words, the rotation speed is decelerated with the goal of stopping at the second target rotation angle C that is shorter than the first target rotation angle B. However, in this case, there is a possibility that the rotating body will stop before the first target rotation angle B. Therefore, in this embodiment, if the rotation speed reaches a predetermined rotation speed ωp before reaching the second target rotation angle C, low-speed control or low-acceleration control, which will be described later, is performed. The predetermined rotation speed ωp is adjustable, and the adjusted predetermined rotation speed ωp is stored in advance in the memory unit 504 ( FIG. 7 ). The predetermined rotation speed ωp may be set to a speed that is small enough to stop the rotating body immediately when the rotation stop control is executed. Also, if the rotation angle of the rotating unit 3 reaches the second target rotation angle C without the rotation speed of the rotating unit 3 reaching the predetermined rotation speed ωp, low speed control or low acceleration control, which will be described later, is implemented.

[0058] A case where the swing angle of the swing unit 3 reaches the second target swing angle C without the swing speed of the swing unit 3 reaching the predetermined swing speed ωp will be described in detail. After the swing angle reaches the second target swing angle C, the swing unit 3 swings at a low speed until it reaches the first target swing angle B. The swing speed of the swing unit 3 from the second target swing angle C to the first target swing angle B is slower than the swing speed from the swing angle at the deceleration start point A to the second target swing angle C. In this way, low-speed control is implemented in which the swing unit 3 swings at a low speed from the second target swing angle C to the first target swing angle B.

[0059] Furthermore, the degree of deceleration of the turning speed after the turning angle reaches the second target turning angle C is set to be smaller than the degree of deceleration of the turning speed until the turning angle reaches the second target turning angle C. In other words, the absolute value of the negative target turning acceleration after the turning angle reaches the second target turning angle C is set to be smaller than the absolute value of the negative target turning acceleration before the turning angle reaches the second target turning angle C. In this way, at a turning angle from the second target turning angle C to the first target turning angle B, low acceleration control is executed in which the degree of deceleration of the turning unit 3 is smaller than the degree of deceleration of the turning unit 3 from the turning angle at the deceleration start point A to the second target turning angle C. Note that the negative target turning acceleration is a negative acceleration, or what is called deceleration. Note that, as will be described later with reference to FIG. 10 , in the low acceleration control, the absolute value of the negative target turning acceleration after the second target turning angle C is reached may be set to 0 (zero). Therefore, the above-described low speed control can be said to be low acceleration control when the absolute value of the negative target turning acceleration is 0. In other words, the low speed control is an example of low acceleration control.

[0060] An automatic rotation control system and an automatic rotation control method for reducing the rotation speed of the rotating body 3 based on the second target rotation angle C will be described below.

[0061] As shown in FIG. 7, the controller 50 includes a turning angle determination unit 501 , a target turning acceleration determination unit 502 , an EPC valve control unit 503 , and a storage unit 504 .

[0062] The turning angle determination unit 501 acquires a signal indicating the turning angle detected by the turning angle sensor 32. The turning angle sensor 32 may be the same as the position and orientation sensor 21 (FIG. 4). The turning angle determination unit 501 determines the turning angle of the rotating unit 3 based on the acquired signal indicating the turning angle.

[0063] The target turning acceleration determination unit 502 acquires the turning angle of the turning unit 3 from the turning angle determination unit 501. The target turning acceleration determination unit 502 acquires a signal indicating the turning speed (turning angular velocity) of the turning unit 3 detected by the turning speed sensor 33. The turning speed sensor 33 may be the same as the inclination sensor 22 or the position and orientation sensor 21. The target turning acceleration determination unit 502 determines the current turning speed ω of the turning unit 3. C (rad / s 2 ), target turning angle θ1 (rad), offset angle θ O (rad) and the current turning angle θ C (rad) based on the following equation (1): G (rad / s 2 ) is calculated.

[0064] The current turning angle θ in the following equation (1) C is the current rotation angle of the rotating unit 3, and is detected by the rotation angle sensor 32. For example, the controller 50 calculates the angle of the direction in which the rotating unit 3 faces when north is defined as 0°, east as 90°, south as 180°, and west as 270° as the current rotation angle. The same applies to other rotation angles. Current rotation speed ω C is the current rotation speed of the rotating body 3, and is detected by the rotation speed sensor 33. The target rotation angle θ1 is the rotation angle at the first target rotation angle B. The target rotation angle θ1 is the rotation angle at the current rotation angle θ C Similarly, the offset angle θ is calculated by the above-mentioned calculation method. O is the turning angle from the second target turning angle C to the first target turning angle B in FIG. 6. The target turning angle θ1 and the offset angle θ O are stored in advance in the storage unit 504. Therefore, the target turning acceleration determination unit 502 determines the target turning acceleration α GWhen calculating the target turning angle θ and the offset angle θ stored in the storage unit 504, O Refer to.

[0065]

[0066] The control target point (earth unloading point) is determined by teaching, and the first target swing angle B at the control target point (earth unloading point) is determined. The target swing angle θ1 as the first target swing angle B is stored in the memory unit 504. The offset angle θ0 can be freely adjusted, and is adjusted in advance and stored in the memory unit 504. The second target swing angle C is determined by the ratio of the first target swing angle B to the offset angle θ O and stored in the storage unit 504.

[0067] Furthermore, equation (1) is derived from the following equations (2) and (3). As shown in FIG. 8, equations (2) and (3) are obtained from the relationship between the rotation speed ω and time t. Time t is the elapsed time from the present until the rotation stops. In FIG. 8, the area surrounded by the vertical axis indicating the rotation speed, the horizontal axis indicating the time, and the diagonal line IL indicates the rotation angle that the rotating body 3 will rotate until it stops. Therefore, the current rotation angle θ C to the second target turning angle C (θ1-θ0-θ C ) is expressed by the following equation (2). In addition, the slope of the diagonal line IL in FIG. 8 represents a negative acceleration. Therefore, the target turning acceleration α G is expressed by the following equation (3): By eliminating the time t from equations (2) and (3), equation (1) can be obtained.

[0068]

[0069]

[0070] The turning brake torque T is calculated by the turning inertia J and the target turning acceleration α G is defined as the value obtained by multiplying G From equation (1), the offset angle θ is used to calculate the turning brake torque T. O It can be seen that is used.

[0071] The EPC valve control unit 503 determines the final swing speed command value (rad / s) based on the calculated swing brake torque T and the like, and in accordance with the actual swing speed. If the actual swing speed is less than the threshold value, or if the actual swing speed is less than the threshold value (target swing angle θ1 - current swing angle θ), C - Offset angle θ O ) ≦0, the turning speed command is set to the angular speed before the turning stop (predetermined turning speed ωp). Here, when the actual turning speed is less than the threshold, it means that, for example, if the turning speed drops too much before the turning angle reaches the second target turning angle C, the turning speed is not continued to be reduced as it is, but is set to the angular speed before the stop (predetermined turning speed ωp). For this reason, the threshold may be the same as the predetermined turning speed ωp. Also, (target turning angle θ1 - current turning angle θ C - Offset angle θ O )≦0 means that the turning speed is set to the pre-stop angular speed (predetermined turning speed ωp) when the turning angle reaches the second target turning angle C, which is earlier than the first target turning angle B. The pre-stop angular speed may be set to a speed that is small enough to stop the turning immediately after the automatic turning control is completed.

[0072] The EPC valve control unit 503 controls the EPC valve 28 by outputting the final swing speed command value determined as described above to the EPC valve 28. As a result, the EPC valve 28 is controlled so that the swing speed of the swing body 3 is decelerated based on the second target swing angle C that is offset earlier than the first target swing angle B in the automatic swing control.

[0073] Here, the offset angle θ is used to calculate the turning brake torque T. O The reason why is used will be explained with reference to FIGS.

[0074] 9A to 9C show the calculation of the turning brake torque T using the offset angle θ O 9A to 9C are diagrams for explaining why the EPC valve 28 is used. The horizontal axis in each of FIGS. 9A to 9C indicates the swing angle, and the vertical axis indicates the swing speed.

[0075] The command signal shown in Figure 9(B) decelerates the turning speed so that it stops at a second target turning angle C, which is before the first target turning angle B. Therefore, the degree of deceleration (inclination T2) from the deceleration start angle A1 shown in Figure 9(B) to the second target turning angle C is greater than the degree of deceleration (inclination T1) from the deceleration start angle A1 to the first target turning angle B shown in Figure 9(A). Therefore, there are cases where the actual braking force under the control shown in Figure 9(B) is not enough to suddenly stop the vehicle.

[0076] Therefore, as shown in Fig. 9C, an offset is provided to the deceleration start angle A1, so that deceleration starts at a turning angle A2 that is earlier than the deceleration start angle A1. As a result, the degree of deceleration (inclination T3) from the turning angle A2 until the second target turning angle C is reached is smaller than in the case of Fig. 9B, and the turning can be stopped with the actual braking force. In this way, in order to reliably stop the turning, the offset angle θ is used in the calculation of the turning brake torque T. O is used.

[0077] Offset angle θ O is adjusted by the controller 50. Specifically, the controller 50 adjusts the deceleration start turning angle at which the turning speed starts to be decelerated toward the second target turning angle C, based on the angle difference between the first target turning angle B and the second target turning angle C.

[0078] Note that the controller 50 may control the negative acceleration to 0 (zero) during the low acceleration control after the second target swing angle C is reached. In this case, as shown in Fig. 10 , both when the swing angle of the swing unit 3 reaches the second target swing angle C (L1) and when the swing speed of the swing unit 3 reaches a predetermined swing speed ωp at a predetermined angle D (L2), the swing speed of the swing unit 3 is maintained at the predetermined swing speed ωp and controlled to a constant speed until the first target swing angle B is reached. In this case, when the swing angle of the swing unit 3 reaches the first target swing angle B, the brakes are applied to quickly reduce the swing speed to 0 (zero), and the swing of the swing unit 3 is stopped.

[0079] The controller 50 includes a processor, a main memory, and a storage unit 504. The processor is, for example, a CPU (Central Processing Unit). The main memory includes, for example, a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). The controller 50 reads a program stored in the storage unit 504, loads it into the main memory, and executes predetermined processing in accordance with the program. The storage unit 504 may be provided separately from the controller 50.

[0080] In the above, a case has been described in which the control is switched to low acceleration control after the swing angle of the swing unit 3 reaches the second target swing angle C. However, as shown by the two-dot chain line L2 in Fig. 6 , when the swing angle of the swing unit 3 reaches the predetermined swing speed ωp at a predetermined angle D before reaching the second target swing angle C, the control may be switched to low acceleration control after the predetermined angle D is reached. In other words, the absolute value of the negative target swing acceleration after the swing angle of the swing unit 3 reaches the predetermined angle D may be set by the controller 50 to be smaller than the absolute value of the negative target swing acceleration before the swing angle of the swing unit 3 reaches the predetermined angle D. In other words, the absolute value of the negative target swing acceleration from the predetermined angle D to the first target swing angle B may be set by the controller 50 to be smaller than the absolute value of the negative target swing acceleration from the swing angle at the deceleration start point A to the predetermined angle D.

[0081] Furthermore, the absolute value of the average negative target turning acceleration after the turning angle of the turning unit 3 reaches the second target turning angle C may be set by the controller 50 to be smaller than the absolute value of the average negative target turning acceleration before the turning angle of the turning unit 3 reaches the second target turning angle C. In other words, the absolute value of the average negative target turning acceleration from the second target turning angle C to the first target turning angle B may be set by the controller 50 to be smaller than the absolute value of the average negative target turning acceleration from the turning angle at the deceleration start point A to the second target turning angle C.

[0082] <Automatic Turn Control Method> Next, an automatic turn control method according to this embodiment will be described with reference to FIGS. 7 and 11. FIG.

[0083] 11 is a flow diagram showing an automatic swing control method for a work machine in one embodiment of the present disclosure. As shown in FIG. 11 , automatic swing control is started (step S1). Automatic swing control is started when an operator presses a start switch for automatic swing control, for example, and conditions for starting automatic swing control are satisfied. When automatic swing control is started, the swing unit 3 starts swinging. One of the conditions for starting automatic swing control is, for example, that the orientation of the swing unit 3 is within a predetermined range. As a result, the bucket 8 swings toward the set coordinates of the swing end point.

[0084] The swing angle determination unit 501 of the controller 50 determines whether or not to start deceleration control (step S2). Whether or not to start deceleration control is determined based on whether or not the swing angle has reached deceleration start point A shown in FIG. 6. In this determination, as will be described later, whether or not the swing angle has reached deceleration start point A is determined based on whether or not the swing can be stopped at target swing angle C when decelerated from the current swing angle at a predetermined tentative target swing acceleration. The swing angle of the swing unit 3 at deceleration start point A is, for example, deceleration start angle A1 ( FIG. 9B ) or deceleration start angle A2 ( FIG. 9C ). If the swing angle determination unit 501 determines that the swing angle has not reached deceleration start point A ( FIG. 6 ), step S2 is repeated.

[0085] On the other hand, when the turning angle determination unit 501 determines that the turning angle has reached the deceleration start point A, the deceleration control is started (step S3). During the execution of the deceleration control, the negative target turning acceleration α calculated by the target turning acceleration determination unit 502 is G The rotation speed is reduced based on the

[0086] During execution of the deceleration control, the swing angle determination unit 501 of the controller 50 determines whether the swing angle of the swing unit 3 has reached the second target swing angle C (step S4). In this determination, the swing angle determination unit 501 refers to the second target swing angle C stored in advance in the storage unit 504. If the swing angle determination unit 501 determines that the swing angle has reached the second target swing angle C, low acceleration control (step S6), which will be described later, is executed.

[0087] On the other hand, if the swing angle determination unit 501 determines that the swing angle has not reached the second target swing angle C, it is determined whether the swing speed of the swing unit 3 is equal to or less than a predetermined swing speed ωp (step S5). When making this determination, the predetermined swing speed ωp stored in advance in the memory unit 504 is referenced. Specifically, it is determined whether the current swing speed acquired from the swing speed sensor 33 is equal to or less than the predetermined swing speed ωp stored in advance in the memory unit 504. If it is determined that the current swing speed of the swing unit 3 is greater than the predetermined swing speed ωp, step S3 and subsequent steps are repeated.

[0088] On the other hand, if it is determined that the current rotation speed of the rotating unit 3 is equal to or less than the predetermined rotation speed ωp, low acceleration control (step S6) is executed. Specifically, as shown by the two-dot chain line L2 in FIG. 6 , when the rotation speed reaches the predetermined rotation speed ωp at a predetermined angle D before the rotation angle of the rotating unit 3 reaches the second target rotation angle C, low acceleration control (step S6) is executed. In this low acceleration control, the rotation speed is decelerated at a rate smaller than the rate of deceleration before the rotation angle reaches the predetermined angle D ( FIG. 6 ). Specifically, the absolute value of the negative target rotation acceleration after the rotation angle reaches the predetermined angle D is set smaller than the absolute value of the negative target rotation acceleration before the rotation angle reaches the predetermined angle D.

[0089] Also, when it is determined in step S4 that the swing angle has reached the second target swing angle C, low acceleration control (step S6) is executed. Specifically, as shown by the solid line L1 in Fig. 6 , when the swing angle of the swing unit 3 reaches the second target swing angle C and the swing speed reaches a predetermined swing speed ωp, low acceleration control (step S6) is executed. In this low acceleration control, the swing speed is decelerated at a rate smaller than the rate of deceleration before the swing angle reaches the predetermined angle C ( Fig. 6 ). Specifically, the absolute value of the negative target swing acceleration after the swing angle reaches the predetermined angle C is set smaller than the absolute value of the negative target swing acceleration before the swing angle reaches the predetermined angle C.

[0090] During execution of the low acceleration control, the swing angle determination unit 501 of the controller 50 determines whether the swing angle of the swing unit 3 has reached the first target swing angle B (step S7). In this determination, the swing angle determination unit 501 refers to the first target swing angle B stored in advance in the memory unit 504. In this determination, if the swing angle determination unit 501 determines that the swing angle has not reached the first target swing angle B, step S6 and subsequent steps are repeated. On the other hand, if the swing angle determination unit 501 determines that the swing angle has reached the first target swing angle B, the automatic swing control is stopped (step S8).

[0091] The automatic swing control method of this embodiment is carried out as described above. Whether or not the swing angle of the swing unit 3 has reached the deceleration start point A is determined as follows.

[0092] First, a predetermined degree of deceleration is determined in advance and stored, for example, in the storage unit 504. This becomes a provisional target turning acceleration for determining the deceleration start point A. In the example of FIG. 9A, this is like the gradient of the inclination T1 being stored in advance.

[0093] The target turning angle B is determined from the teaching control target point, and the pre-stored offset angle θ O The target turning angle C is determined by taking these factors into consideration. The current turning angle and turning speed are constantly monitored.

[0094] From the above, it is possible to determine whether the rotation can be stopped at the target rotation angle C when decelerating from the current rotation angle at a predetermined provisional target rotation acceleration. If the rotation can be stopped at the target rotation angle C, it is determined that the rotation angle of the rotating unit 3 has reached the deceleration start point A, and deceleration control is started.

[0095] <Effects> Next, the effects of this embodiment will be described.

[0096] 6 and 7, in this embodiment, the controller 50 reduces the rotation speed of the rotating body 3 based on the second target rotation angle C, which is shorter than the first target rotation angle B, which is the target stop angle for automatic rotation control. This makes it possible to suppress overshooting.

[0097] 6 and 7 , the controller 50 calculates the negative target rotation acceleration of the rotating unit 3 until it reaches the second target rotation angle C based on the current rotation speed and the second target rotation angle C. This makes it possible to control the rotation of the rotating unit 3 so that it rotates at a predetermined rotation speed at the second target rotation angle C.

[0098] 6 and 7 , according to this embodiment, the controller 50 sets the absolute value of the negative target rotation acceleration after the rotation angle of the rotating unit 3 reaches the second target rotation angle C to be smaller than the absolute value of the negative target rotation acceleration before the rotation angle of the rotating unit 3 reaches the second target rotation angle C. This makes it possible to suppress overshooting.

[0099] 6 and 7 , according to this embodiment, the controller 50 sets the absolute value of the average negative target rotation acceleration after the rotation angle of the rotating unit 3 reaches the second target rotation angle C to be smaller than the absolute value of the average negative target rotation acceleration before the rotation angle of the rotating unit 3 reaches the second target rotation angle C. This makes it possible to suppress overshooting.

[0100] 6 and 7, according to this embodiment, when the rotation speed ωp of the rotating unit 3 reaches the second target rotation angle C, the controller 50 makes the absolute value of the negative target rotation acceleration after the rotation speed ωp is reached smaller than the absolute value of the negative target rotation acceleration before the rotation speed ωp is reached. This makes it possible to reliably perform low acceleration control before the rotation speed of the rotating unit 3 becomes 0 (zero).

[0101] 10 , in this embodiment, the controller 50 maintains the rotation speed of the rotating unit 3 at a constant speed during low acceleration control until it reaches the first target rotation angle B. Controlling the rotation speed of the rotating unit 3 to a constant speed of the predetermined rotation speed ωp prevents the rotation speed from becoming 0 (zero) before it reaches the first target angle B. Furthermore, by reducing the predetermined rotation speed ωp to a level that allows for immediate stopping, shock when stopping the rotation can be suppressed, and the rotation can be stopped immediately when the rotation angle of the rotating unit 3 reaches the first target rotation angle B.

[0102] 9C, the controller 50 adjusts the deceleration start turning angle, at which the turning speed starts to be decelerated toward the second target turning angle C, based on the angle difference between the first target turning angle B and the second target turning angle C. This makes it possible to stop the turning with the actual braking force.

[0103] <Additional Notes> The above-described embodiment includes the following technical ideas.

[0104] (Supplementary Note 1) An automatic rotation control system for a work machine, comprising: a rotating body; a work machine attached to the rotating body; and a controller that executes automatic rotation control to control the rotation of the rotating body, wherein the controller reduces the rotation speed of the rotating body based on a second target rotation angle that is shorter than a first target rotation angle that is a target stop angle for the automatic rotation control.

[0105] (Supplementary Note 2) The automatic swing control system for a work machine according to Supplementary Note 1, wherein the controller calculates a negative target swing acceleration of the swing body until the second target swing angle is reached based on a current swing speed and the second target swing angle.

[0106] (Supplementary Note 3) The automatic swing control system for a work machine described in Supplementary Note 1 or Supplementary Note 2, wherein the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the swing angle of the swing body reaches the second target swing angle smaller than the absolute value of the negative target swing acceleration before the swing angle of the swing body reaches the second target swing angle.

[0107] (Supplementary Note 4) The automatic swing control system for a work machine described in Supplementary Note 1 or Supplementary Note 2, wherein the controller switches to low acceleration control by making the absolute value of the average negative target swing acceleration after the swing angle of the swing body reaches the second target swing angle smaller than the absolute value of the average negative target swing acceleration before the swing angle of the swing body reaches the second target swing angle.

[0108] (Supplementary Note 5) In the automatic swing control system for a work machine described in Supplementary Note 1 or Supplementary Note 2, when the swing angle of the swing body reaches a predetermined swing speed before the second target swing angle, the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the predetermined swing speed is reached smaller than the absolute value of the negative target swing acceleration before the predetermined swing speed is reached.

[0109] (Supplementary Note 6) The automatic swing control system for a work machine according to any one of Supplementary Note 3 to Supplementary Note 5, wherein the controller maintains the swing speed of the swing body at a constant speed until the swing angle reaches the first target swing angle during the low acceleration control.

[0110] (Supplementary Note 7) The automatic swing control system for a work machine described in any one of Supplementary Note 1 to Supplementary Note 6, wherein the controller adjusts a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle begins, based on an angle difference between the first target swing angle and the second target swing angle.

[0111] (Supplementary Note 8) A work machine comprising: a rotating body; a work implement attached to the rotating body; and a controller that executes automatic rotation control to control the rotation of the rotating body, wherein the controller reduces the rotation speed of the rotating body based on a second target rotation angle that is shorter than a first target rotation angle that is a target stop angle for the automatic rotation control.

[0112] (Supplementary Note 9) The work machine according to Supplementary Note 8, wherein the controller calculates a negative target rotation acceleration of the rotating body until the second target rotation angle is reached based on a current rotation speed and the second target rotation angle.

[0113] (Supplementary Note 10) The work machine according to Supplementary Note 8 or Supplementary Note 9, wherein the controller switches to low acceleration control by making the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle smaller than the absolute value of the negative target rotation acceleration before the rotation angle of the rotating body reaches the second target rotation angle.

[0114] (Supplementary Note 11) The work machine according to Supplementary Note 8, wherein, when a predetermined rotation speed is reached before the rotation angle of the rotating body reaches the second target rotation angle, the controller switches to low acceleration control by making the absolute value of the negative target rotation acceleration after the predetermined rotation speed is reached smaller than the absolute value of the negative target rotation acceleration before the predetermined rotation speed is reached.

[0115] (Supplementary Note 12) The work machine according to Supplementary Note 10 or Supplementary Note 11, wherein the controller maintains the rotation speed of the rotating body at a constant speed until the rotation speed reaches the first target rotation angle during the low acceleration control.

[0116] (Supplementary Note 13) The work machine according to any one of Supplementary Note 8 to Supplementary Note 12, wherein the controller adjusts a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle starts, based on an angle difference between the first target swing angle and the second target swing angle.

[0117] (Supplementary Note 14) An automatic rotation control method for a work machine having a rotating body and a work implement attached to the rotating body, comprising the steps of: setting a first target rotation angle that is a target stop angle for automatic rotation control that controls the rotation of the rotating body; setting a second target rotation angle that is shorter than the first target rotation angle; and slowing down the rotation speed of the rotating body based on the second target rotation angle.

[0118] (Supplementary Note 15) The automatic swing control method for a work machine according to Supplementary Note 14, wherein a negative target swing acceleration of the swing body until the second target swing angle is reached is calculated based on a current swing speed and the second target swing angle.

[0119] (Supplementary Note 16) An automatic rotation control method for a work machine as described in Supplementary Note 14 or Supplementary Note 15, wherein switching to low acceleration control is performed by making the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle smaller than the absolute value of the negative target rotation acceleration before the rotation angle of the rotating body reaches the second target rotation angle.

[0120] (Supplementary Note 17) An automatic rotation control method for a work machine as described in Supplementary Note 14 or Supplementary Note 15, wherein switching to low acceleration control is performed by making the absolute value of the average negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle smaller than the absolute value of the average negative target rotation acceleration before the rotation angle of the rotating body reaches the second target rotation angle.

[0121] (Supplementary Note 18) An automatic swing control method for a work machine as described in Supplementary Note 14, wherein, when a predetermined swing speed is reached before the swing angle of the swing body reaches the second target swing angle, the absolute value of the negative target swing acceleration after the predetermined swing speed is reached is made smaller than the absolute value of the negative target swing acceleration before the predetermined swing speed is reached, thereby switching to low acceleration control.

[0122] (Supplementary Note 19) The automatic swing control method for a work machine according to any one of Supplementary Note 16 to Supplementary Note 18, wherein the swing speed of the swing body is maintained at a constant speed until the first target swing angle is reached in the low acceleration control.

[0123] (Supplementary Note 20) An automatic swing control method for a work machine as described in any one of Supplementary Note 14 to Supplementary Note 19, wherein a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle begins is adjusted based on an angle difference between the first target swing angle and the second target swing angle.

[0124] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0125] DESCRIPTION OF SYMBOLS 1 Main body, 2 Work machine, 3 Swing body, 4 Cab, 4S Driver's seat, 5 Travel body, 5Cr Track, 5M Travel motor, 6 Boom, 7 Arm, 8 Bucket, 8T Cutting edge, 9 Exterior cover, 10 Boom cylinder, 11 Arm cylinder, 12 Bucket cylinder, 13 Boom foot pin, 14 Boom top pin, 15 Arm top pin, 17 Bucket link, 20 Work machine attitude sensor, 21 Position and orientation sensor, 21a, 21b GNSS antenna, 22 Inclination sensor, 23 Detection sensor, 24 Indicator, 27 Hydraulic pump, 28 EPC valve, 29 Actuator, 30 Hydraulic valve, 32 Swing angle sensor, 33 Swing speed sensor, 50 Controller, 51 Control target setting unit, 51A Return point setting unit, 51B Earth removal point setting unit, 51C Passing point setting unit, 52 Operation information acquisition unit, 53, 503 EPC valve control unit, 100 Hydraulic excavator, 200 Loading object, 200A Vessel, 501 Swing angle determination unit, 502 Target swing acceleration determination unit, 504 Memory unit, B First target swing angle, C Second target swing angle, RX Swing axis.

Claims

A rotating body; a work machine attached to the rotating body; a controller that executes automatic rotation control to control the rotation of the rotating body, The controller reduces the rotation speed of the rotating body based on a second target rotation angle that is shorter than a first target rotation angle, which is a target stop angle for automatic rotation control.

2. The automatic swing control system for a work machine according to claim 1, wherein the controller calculates a negative target swing acceleration of the swing body until the second target swing angle is reached based on a current swing speed and the second target swing angle.

2. The automatic swing control system for a work machine according to claim 1, wherein the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the swing angle of the swing body reaches the second target swing angle smaller than the absolute value of the negative target swing acceleration before the swing angle of the swing body reaches the second target swing angle.

2. The automatic swing control system for a work machine according to claim 1, wherein the controller switches to low acceleration control by making the absolute value of the average negative target swing acceleration after the swing angle of the swing unit reaches the second target swing angle smaller than the absolute value of the average negative target swing acceleration before the swing angle of the swing unit reaches the second target swing angle.

2. The automatic swing control system for a work machine according to claim 1, wherein, when a predetermined swing speed is reached before the swing angle of the swing body reaches the second target swing angle, the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the predetermined swing speed is reached smaller than the absolute value of the negative target swing acceleration before the predetermined swing speed is reached.

6. The automatic swing control system for a work machine according to claim 3, wherein the controller maintains the swing speed of the swing body at a constant speed during the low acceleration control until the swing angle reaches the first target swing angle.

2. The automatic swing control system for a work machine according to claim 1, wherein the controller adjusts a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle begins, based on an angle difference between the first target swing angle and the second target swing angle. 　 A rotating body; a work machine attached to the rotating body; a controller that executes automatic rotation control to control the rotation of the rotating body, The controller reduces the rotation speed of the rotating body based on a second target rotation angle that is shorter than a first target rotation angle that is a target stop angle for automatic rotation control. 　 The work machine according to claim 8 , wherein the controller calculates a negative target swing acceleration of the swing body until the second target swing angle is reached based on a current swing speed and the second target swing angle.

9. The work machine according to claim 8, wherein the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the swing angle of the swing unit reaches the second target swing angle smaller than the absolute value of the negative target swing acceleration before the swing angle of the swing unit reaches the second target swing angle.

9. The work machine according to claim 8, wherein, when a predetermined swing speed is reached before the swing angle of the swing body reaches the second target swing angle, the controller switches to low acceleration control by making the absolute value of the negative target swing acceleration after the predetermined swing speed is reached smaller than the absolute value of the negative target swing acceleration before the predetermined swing speed is reached.

12. The work machine according to claim 10, wherein the controller maintains the rotation speed of the rotating body at a constant speed during the low acceleration control until the rotation speed reaches the first target rotation angle.

9. The work machine according to claim 8, wherein the controller adjusts a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle begins, based on an angle difference between the first target swing angle and the second target swing angle. 　 An automatic swing control method for a work machine having a swing body and a work implement attached to the swing body, comprising: setting a first target swing angle as a target stop angle of automatic swing control for controlling the swing of the swing body; setting a second target turning angle that is shorter than the first target turning angle; and reducing the rotation speed of the rotating body based on the second target rotation angle.

15. The automatic swing control method for a work machine according to claim 14, wherein a negative target swing acceleration of the swing body until the second target swing angle is reached is calculated based on a current swing speed and the second target swing angle.

15. The automatic swing control method for a work machine according to claim 14, wherein switching to low acceleration control is performed by making the absolute value of the negative target swing acceleration after the swing angle of the swing body reaches the second target swing angle smaller than the absolute value of the negative target swing acceleration before the swing angle of the swing body reaches the second target swing angle.

15. The automatic swing control method for a work machine according to claim 14, wherein switching to low acceleration control is performed by making the absolute value of the average negative target swing acceleration after the swing angle of the swing body reaches the second target swing angle smaller than the absolute value of the average negative target swing acceleration before the swing angle of the swing body reaches the second target swing angle.

15. The automatic swing control method for a work machine according to claim 14, wherein, when a predetermined swing speed is reached before the swing angle of the swing body reaches the second target swing angle, control is switched to low acceleration control by making the absolute value of the negative target swing acceleration after the predetermined swing speed is reached smaller than the absolute value of the negative target swing acceleration before the predetermined swing speed is reached.

19. The automatic swing control method for a work machine according to claim 16, wherein the swing speed of the swing body is maintained at a constant speed until the first target swing angle is reached during the low acceleration control.

15. The automatic swing control method for a work machine according to claim 14, wherein a deceleration start swing angle at which deceleration of the swing speed toward the second target swing angle begins is adjusted based on an angle difference between the first target swing angle and the second target swing angle.

Images