Automatic rotation control system for a work machine, work machine, and method for automatic rotation control of a work machine

Abstract

The present invention provides an automatic rotation control system for a work machine capable of stopping precisely at the end point of rotation, a work machine, and an automatic rotation control method for a work machine. [Solution] The work machine 2 is attached to the slewing body 3. The controller 50 performs automatic slewing control to control the slewing of the slewing body 3. The controller 50 decelerates the slewing speed of the slewing body 3 based on a second target slewing angle C that is before the first target slewing angle B, which is the target stop angle for the automatic slewing control.

Description

[Technical Field]

[0001] This disclosure relates to an automatic slewing control system for a work machine, a work machine, and a method for automatic slewing control of a work machine. [Background technology]

[0002] Automatic loading control for loading machines is disclosed, for example, in Japanese Patent Publication No. 2019-148147 (Patent Document 1). Patent Document 1 discloses a technique for controlling a slewing body to stop facing the target stopping direction by controlling the pressure of the hydraulic fluid downstream of the slewing motor based on the azimuth of the slewing body, the slewing speed, and the target stopping direction, while the slewing motor is braking. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-148147 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the technology described in Patent Document 1, if deceleration control is performed with the target of the rotation end point located in the target stopping direction, the deceleration may not be sufficient, and the work tool may pass the position of the rotation end point.

[0005] The purpose of this disclosure is to provide an automatic rotation control system for a work machine capable of stopping precisely at the rotation end point, a work machine, and an automatic rotation control method for a work machine. [Means for solving the problem]

[0006] Each of the automatic turning control system and the working machine in the present disclosure includes a revolving body, a working device, and a controller. The working device is attached to the revolving body. The controller executes automatic turning control for controlling the turning of the revolving body. The controller decelerates the turning speed of the revolving body based on a second target turning angle in front of a first target turning angle that is the target stop angle of the automatic turning control.

[0007] The automatic turning control method of the working machine in the present disclosure is an automatic turning control method of a working machine having a revolving body and a working device attached to the revolving body, and includes the following steps.

[0008] A first target turning angle that is the target stop angle of the automatic turning control for controlling the turning of the revolving body is set. A second target turning angle in front of the first target turning angle is set. The turning speed of the revolving body is decelerated based on the second target turning angle.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to realize an automatic turning control system of a working machine, a working machine, and an automatic turning control method of a working machine that can accurately stop at the turning end point.

Brief Description of the Drawings

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

[0011] Hereinafter, embodiments of the present disclosure will be described based on the drawings.

[0012] In the specification and drawings, the same components or corresponding components are denoted by the same reference numerals, and redundant explanations are not repeated. Also, in the drawings, for convenience of explanation, the configuration may be omitted or simplified.

[0013] In the following description, "up", "down", "front", "back", "left", and "right" are directions based on an operator sitting on the driver's seat 4S in the cab 4 shown in FIG. 1.

[0014] [Configuration of Working Machine]

[0015] As an example of the working machine of the present disclosure, the configuration of a hydraulic excavator will be described using FIG. 1.

[0016] Figure 1 is a schematic diagram showing the configuration of a hydraulic excavator as an example of a work machine in one embodiment of the present disclosure. As shown in Figure 1, the hydraulic excavator 100 of this embodiment has a main body 1 and a work machine 2 that is operated by hydraulics. The main body 1 corresponds to an example of a vehicle body of the present disclosure. The main body 1 has a slewing body 3 and a traveling body 5.

[0017] The vehicle 5 has a pair of tracks 5Cr and a drive motor 5M. The hydraulic excavator 100 can move by the rotation of the tracks 5Cr. The drive motor 5M is provided as the drive source for the vehicle 5. The drive motor 5M is a hydraulic motor that is operated by hydraulics. The vehicle 5 may also have wheels (tires).

[0018] The slewing body 3 is positioned on and supported by the traveling body 5. The slewing body 3 is capable of rotating relative to the traveling body 5 about a pivot axis RX by a slewing motor (not shown). The pivot axis RX is the pivot center of the slewing body 3. The slewing motor is a hydraulic motor that operates by hydraulics. The pivot axis RX is a virtual straight line that serves as the pivot center of the slewing body 3. Note that the traveling motor 5M or the slewing motor may be electric motors.

[0019] The slewing body 3 has a cab 4. Inside the cab 4 is a driver's seat 4S where the operator sits. The operator (crew) can sit in the cab 4 and operate the work equipment 2, rotate the slewing body 3 relative to the vehicle 5, and operate the hydraulic excavator 100 by the vehicle 5. The slewing body 3 has an exterior cover 9. The exterior cover 9 covers the machine room. The hydraulic excavator 100 may be remotely controlled.

[0020] The work implement 2 is attached to the slewing body 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 the attachment of this disclosure.

[0021] The boom 6 is rotatably connected to the main body 1. Specifically, the base end of the boom 6 is rotatably connected to the slewing body 3 with the boom foot pin 13 as the pivot point. 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 the boom top pin 14 as the pivot point. 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 the arm top pin 15 as the pivot point. The bucket 8 may be another attachment such as a grapple.

[0022] One end of the boom cylinder 10 is connected to the slewing body 3, and the other end is connected to the boom 6. The boom 6 is movable relative to the main body 1 by the boom cylinder 10. Due to the movement of the boom cylinder 10, the boom 6 can rotate vertically relative to the slewing body 3 with the boom foot pin 13 as the pivot point.

[0023] 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 is movable relative to the boom 6 by the arm cylinder 11. The movement of the arm cylinder 11 allows the arm 7 to rotate in the digging direction or the dumping direction, with the boom top pin 14 as the pivot point.

[0024] One end of the bucket cylinder 12 is connected to the arm 7, and the other end is connected to the bucket link 17. The bucket 8 is movable relative to the arm 7 by the bucket cylinder 12. The movement of the bucket cylinder 12 allows the bucket 8 to rotate in the digging direction or the dumping direction, with the arm top pin 15 as the pivot point.

[0025] Each of the boom cylinder 10, arm cylinder 11, and bucket cylinder 12 is a hydraulic cylinder driven by hydraulic pressure, but other actuators such as electric cylinders may also be used.

[0026] <Excavation and loading operation flow and automatic rotation control>

[0027] Next, the operation flow of the excavation and loading of the work machine and the automatic rotation control will be explained using Figures 2 and 3.

[0028] Figure 2 shows the operation flow of excavation and loading by a hydraulic excavator as an example of a work machine. Figure 3 is a perspective view showing automated excavation and loading as an example of an operation in which automatic rotation control of the work machine is performed.

[0029] As shown in Figures 2 and 3, in excavation and loading by the hydraulic excavator 100, excavation is performed first (step SA). This excavation loads soil and other materials into the bucket 8. After excavation, with the load loaded into the bucket 8, the slewing 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 implement 2 is controlled so as not to interfere with the loading target 200. The loading target 200 is, for example, a dump truck. The dump truck 200 has a vessel 200A for loading the load from the bucket 8.

[0030] When the bucket 8 reaches the point where it will discharge the load into the vessel 200A via the loading rotation, the rotation of the rotating body 3 stops. After this, the load in the bucket 8 is discharged (soil removed) into the vessel 200A of the dump truck 200 (step SC). In order to excavate again after soil removal, the rotating body 3 rotates back as shown by the dashed arrow in Figure 3 (step SD).

[0031] The automatic rotation control of the work machine in this embodiment is performed, for example, during the excavation and loading process described above. The automatic rotation control of the work machine in this embodiment is performed, for example, during at least one of the loading rotation (step SB) and the return rotation (step SD) during the excavation and loading process described above. The automatic rotation control of the hydraulic excavator 100 in this embodiment may be performed, for example, during the loading rotation during the excavation and loading process described above, or during the return rotation, or during both the loading rotation and the return rotation.

[0032] As shown in Figure 3, for example, in order to automate the excavation and loading operation and implement automatic rotation control, it is necessary to set points (control target points) through which the bucket 8 passes during the excavation and loading operation. For this reason, when automatic rotation control is performed during loading rotation (solid arrow), at least the soil removal point P2 is set as the control target point. When automatic rotation control is performed during return rotation (dashed arrow), at least the return point (excavation point) P1 is set as the control target point. In addition, in both loading rotation and return rotation, 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.

[0033] The return point P1 is, for example, a point located above the area where excavation is performed. The soil discharge point P2 is, for example, a point located directly above the loading object 200 (for example, the vessel 200A). The passing point P3 is, for example, a point located above the side edge SE of the loading object 200 (for example, the side edge of the vessel 200A). Each of the control target points P1, P2, and P3 is, for example, a point through which the left-right center of the arm top pin 15 passes during automatic rotation control. Note that each of the control target points P1, P2, and P3 may also be set as, for example, a point on the cutting edge 8T of the bucket 8 or a point on the bottom surface of the bucket 8 passes.

[0034] <Automatic slewing control system and automatic slewing control method for industrial machinery>

[0035] Next, the automatic rotation control system and automatic rotation control method for the work machine in this embodiment will be described with reference to Figures 1 and 4.

[0036] Figure 4 is a first block diagram showing the configuration of the automatic slewing control system for the work machine shown in Figure 1. As shown in Figure 4, the hydraulic excavator 100 or its automatic slewing control system includes a work machine attitude sensor 20, a position and orientation sensor 21, a tilt sensor 22, and a detection sensor 23. The work machine attitude sensor 20 detects the attitude of the work machine 2 and outputs an attitude signal indicating the attitude of the work machine 2. The work machine attitude sensor 20 can detect the attitude of the boom 6, arm 7, and bucket 8. The work machine attitude sensor 20 includes sensors located on each of the boom 6, arm 7, and bucket 8. The work machine attitude sensor 20 may be an IMU (Inertial Measurement Unit), a stroke sensor, a potentiometer, an imaging device, or any combination thereof.

[0037] The position and orientation sensor 21 is, for example, a GNSS (Global Navigation Satellite Systems) receiver and a GNSS antenna. The position and orientation sensor 21 includes two GNSS antennas 21a and 21b (Figure 1). Each of the two GNSS antennas 21a and 21b is installed at a different position on the rotating body 3. The GNSS receiver (not shown) calculates the position of the rotating body 3 in the global coordinate system and the direction in which the rotating body 3 is facing from the satellite positioning signals received from the satellite by each of the GNSS antennas 21a and 21b. The GNSS receiver outputs a position signal indicating the position of the rotating body 3 and an orientation signal indicating the direction in which the rotating body 3 is facing.

[0038] The position and orientation sensor 21 may also have a rotation angle sensor. The rotation angle sensor is fixed to the rotating body 3, for example. The rotation angle sensor detects the rotation angle of the rotating body 3 relative to the traveling body 5 and outputs a rotation angle signal indicating the rotation angle of the rotating body 3. The rotation angle sensor can detect the rotation angle in the machine coordinate system (local coordinate system). The rotation angle sensor may be an IMU, a potentiometer, an imaging device, or any combination thereof. The machine coordinate system is a Cartesian coordinate system with the rotation center of the rotating body 3 as the origin, and represented by axes extending in the front-rear direction, the left-right direction, and the up-down direction (rotation axis RX: Figure 1).

[0039] The tilt sensor 22 measures the acceleration and rotational angular velocity (rotation speed) of the rotating body 3 and detects the attitude of the rotating body 3 (e.g., roll angle, pitch angle, yaw angle) based on the measurement results. The tilt sensor 22 is installed, for example, on the underside of the rotating body 3. The tilt sensor 22 is, for example, an IMU. The tilt sensor 22 outputs a tilt signal obtained from the measurement.

[0040] The detection sensor 23 detects terrain or objects around the work site of the hydraulic excavator 100. The detection sensor 23 may be mounted on the operator's cab 4, for example, as shown in Figure 1, on the exterior cover 9, or elsewhere. The detection sensor 23 outputs a detection signal.

[0041] The detection sensor 23 may be, 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 be, for example, a millimeter-wave radar that detects the reflection of millimeter-wave radio waves emitted from a transmitting antenna back from the surface of an object using a receiving antenna. The detection sensor 23 may also be a vision sensor including a camera. The detection sensor 23 may also have a function to detect the attitude of the work machine 2, similar to the work machine attitude sensor 20. For example, the attitude of the work machine 2 may be detected by emitting laser light towards the work machine 2 using the LiDAR described above.

[0042] The hydraulic excavator 100 or its automatic slewing control system further includes a control unit 24. The control unit 24 is located inside the operator's cab 4. The control unit 24 receives manual operations from the operator and outputs commands based on those manual operations.

[0043] The instruction unit 24 is an operating part (switch, button, touch panel, etc.) for teaching a specific point in order to set the control target point in automatic swing control. The specific point in automatic swing control is a point taught by the operator. The control target point in automatic swing control is the target point that the working point of the swinging bucket 8 passes through during the execution of automatic swing control. The control target point is set at a position offset in the safe direction from the specific point.

[0044] The control target point includes a passing point and a turning end point. The passing point is the point through which the working point of the bucket 8 passes during the turning. The turning end point is the point where the working point of the bucket 8 is located at the end of the turning. The working point of the bucket 8 may be, for example, the point where the left-right center of the arm top pin 15 is located, or it may be the cutting edge 8T of the bucket 8, or the bottom surface of the bucket 8, etc.

[0045] If the automatic rotation control is, for example, the automatic rotation control during automatic loading rotation, the rotation end point is, for example, the soil removal point P2, and the passing point P3 is, for example, the interference avoidance point. The interference avoidance point is, for example, a point set to avoid interference between the work machine 2 and the loading object 200 (Figure 3). Similarly, if the automatic rotation control is, for example, the automatic rotation control during automatic return rotation, the rotation end point is, for example, the return point P1, and the passing point P3 is, for example, the interference avoidance point. The interference avoidance point is, as above, a point set to avoid interference between the work machine 2 and the loading object 200 (Figure 3).

[0046] The automatic rotation control system includes a controller 50. The controller 50 performs automatic rotation control of the rotating body 3 based on target information. The controller 50 includes a control target setting unit 51, an operation information acquisition unit 52, and an EPC (Electric Proportional Valve) valve control unit 53.

[0047] The control target setting unit 51 acquires the attitude signal of the work equipment 2 output from the work equipment attitude sensor 20. The control target setting unit 51 acquires the position signal and direction signal output from the position and direction sensor 21. The control target setting unit 51 acquires the tilt signal indicating the tilt state of the hydraulic excavator 100, output from the tilt sensor 22. The control target setting unit 51 acquires the detection signal output from the detection sensor 23. The control target setting unit 51 acquires the instruction signal output from the instruction unit 24.

[0048] The control target setting unit 51 sets the coordinates of the target point (control target point) that the working point of the rotating bucket 8 will pass through during the execution of automatic rotation control. The control target setting unit 51 sets the coordinates of at least the soil discharge point P2 during loading rotation (solid arrow in Figure 3) and sets the coordinates of at least the return point P1 during return rotation (dashed arrow in Figure 3). In addition, regardless of whether automatic rotation control is performed during loading rotation or return rotation, a passing point (interference avoidance point) P3 may be set so that the bucket 8 does not interfere with the loading target 200.

[0049] The control target setting unit 51 sets control target points (return point P1, soil removal point P2, and passing point P3) based on specific points. The control target setting unit 51 teaches specific points from the coordinates of the left-right center position of the arm top pin 15 at the time it receives an instruction signal from the instruction unit 24. The control target setting unit 51 teaches specific points corresponding to each of the return point P1, soil removal point P2, and passing point P3. Teaching of each specific point is performed, for example, during the first loading rotation after excavation. The control target setting unit 51 sets the return point P1, soil removal point P2, and passing point P3 based on each of the taught specific points.

[0050] The control target setting unit 51 includes a return point setting unit 51A, a soil discharge point setting unit 51B, and a waypoint setting unit 51C. The return point setting unit 51A sets the return point P1. Specifically, the operator operates the instruction unit 24 when they visually determine that the bucket 8 is positioned above the area to be excavated during the rotation of the slewing body 3. Based on the posture of the work machine 2 and the rotation angle of the slewing body 3 at the time the operator operates the instruction unit 24, 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 calculated coordinates of the specific point corresponding to the return point P1 and the shape, dimensions, and posture of the bucket 8, the return point setting unit 51A sets the coordinates of the return point P1 to a point offset in the safe direction from the specific point corresponding to the return point P1.

[0051] The soil discharge point setting unit 51B sets the soil discharge point P2. Specifically, the operator operates the indicator unit 24 when they visually determine that the bucket 8 is positioned above the area where the load in the bucket 8 should be discharged during the rotation of the rotating body 3. Based on the posture of the work machine 2 and the rotation angle of the rotating body 3 at the time the operator operates the indicator unit 24, the soil discharge point setting unit 51B calculates the coordinates in the machine coordinate system of a specific point corresponding to the soil discharge point P2. Based on the calculated coordinates of the specific point corresponding to the soil discharge point P2 and the shape, dimensions, and posture of the bucket 8, the soil discharge point setting unit 51B sets the coordinates of the soil discharge point P2 at a point offset in the safe direction from the specific point corresponding to the soil discharge point P2.

[0052] The waypoint setting unit 51C sets the waypoint P3. Specifically, the operator operates the indicator unit 24 when they visually determine that the bucket 8 is positioned above the side edge SE of the loading object 200 (for example, the side edge of the vessel 200A) during the rotation of the slewing body 3. Based on the posture of the work machine 2 and the rotation angle of the slewing body 3 at the time the operator operates the indicator unit 24, the waypoint setting unit 51C calculates the coordinates in the machine coordinate system of a specific point corresponding to the waypoint P3. Based on the calculated coordinates of the specific point corresponding to the waypoint P3 and the shape, dimensions, and posture of the bucket 8, the waypoint setting unit 51C sets the coordinates of the waypoint P3 at a point offset in the safe direction from the specific point corresponding to the waypoint P3.

[0053] The coordinates of the control target points P1, P2, and P3 are calculated based on signals obtained from the work machine attitude sensor 20, the position and orientation sensor 21, and the tilt sensor 22. However, the signal obtained from the position and orientation sensor 21 is not mandatory, and the coordinates of the control target points P1, P2, and P3 may be calculated based on signals obtained from the work machine attitude sensor 20 and the tilt 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.

[0054] The control target setting unit 51 acquires a specific point through teaching as described above, and sets control target points P1, P2, and P3 based on that specific point. The control target setting unit 51 outputs the coordinate signals of the set return point P1, soil removal point P2, and passing point P3 to the operation information acquisition unit 52.

[0055] In Figure 4, the return point setting section 51A, the soil removal point setting section 51B, and the waypoint setting section 51C are shown separately, but the return point setting section 51A, the soil removal point setting section 51B, and the waypoint setting section 51C are not separate and may be the same part. In other words, each of the control target points P1, P2, and P3 may be set by the same part of the control target setting section 51.

[0056] The operation information acquisition unit 52 outputs operation commands for automatic rotation control, such as the operation of the work machine 2 and the rotation of the rotating body 3, based on the coordinate signals of the return point P1, the soil removal 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.

[0057] The EPC valve 28 controls the hydraulic valve 30 based on a command current from the EPC valve control unit 53 of the controller 50. This controls the supply of oil pumped from an oil tank (not shown) by the hydraulic pump 27 to the actuator 29 via the hydraulic valve 30. The actuator 29 is, for example, a hydraulic actuator, such as a boom cylinder 10, an arm cylinder 11, a bucket cylinder 12, or a slewing motor.

[0058] The EPC valve control unit 53 controls the EPC valve 28 so that, in the automatic rotation control for loading, the working point of the bucket 8 reaches the soil discharge point P2, passing through the passing point P3 from the position at the start of the automatic rotation control, as shown in Figure 3. Similarly, the EPC valve control unit 53 controls the EPC valve 28 so that, in the automatic rotation control for returning, the working point of the bucket 8 reaches the return point P1, passing through the passing point P3 from the position at the start of the automatic rotation control, as shown in Figure 3. This enables automatic rotation control.

[0059] In the automatic turning control described above, as shown by the solid line L1a in Figure 5, the turning speed is reduced with the turning end point B as the target in order to complete the turn at turning end point B. In Figure 5, the horizontal axis represents the turning angle, and the vertical axis represents the turning speed (angular velocity).

[0060] However, in this case, as shown by the dashed line L2a, there is a possibility that the deceleration during the turn will not be sufficient, and the stopping position of the turn will exceed the position of the turn termination point B, resulting in what is known as an overshoot.

[0061] Therefore, in this embodiment, in order to solve the above problem, as shown by the solid line L1 in Figure 6, the rotation speed of the rotating body 3 is reduced based on a second target rotation angle C that is before the first target rotation angle B, which is the target stop angle for automatic rotation control. In other words, the rotation speed is reduced with the goal of stopping at the second target rotation angle C, which is before the first target rotation angle B. However, in this case, there is a possibility that it 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, a low-speed control or low-acceleration control, which will be described later, is implemented. The predetermined rotation speed ωp is adjustable, and the adjusted predetermined rotation speed ωp is stored in advance in the storage unit 504 (Figure 7). The predetermined rotation speed ωp may be a speed small enough that it can stop immediately when rotation stop control is performed. Furthermore, if the rotation angle of the rotating body 3 reaches the second target rotation angle C before the rotation speed of the rotating body 3 reaches the predetermined rotation speed ωp, the low-speed control or low-acceleration control described later will be implemented.

[0062] The case where the turning angle of the turning body 3 reaches the second target turning angle C without the turning speed of the turning body 3 reaching the predetermined turning speed ωp will be explained in detail. After the turning angle reaches the second target turning angle C, the turning body 3 turns at a low speed until it reaches the first target turning angle B. The turning speed of the turning body 3 from the second target turning angle C to the first target turning angle B is slower than the turning speed from the turning angle at the deceleration start point A to reaching the second target turning angle C. In this way, low-speed control is implemented, in which the turning body 3 turns at a low speed in the turning angle from the second target turning angle C to the first target turning angle B.

[0063] 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 before reaching 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. Thus, for the turning angle from the second target turning angle C to the first target turning angle B, low-acceleration control is performed in which the degree of deceleration of the turning body 3 is smaller than the degree of deceleration of the turning body 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 deceleration. As will be described later using Figure 10, in low-acceleration control, the absolute value of the negative target turning acceleration after reaching the second target turning angle C may be set to 0 (zero). Therefore, the low-speed control described above can be described as low-acceleration control when the absolute value of the negative target turning acceleration is 0 (zero). In other words, low-speed control is an example of low-acceleration control.

[0064] The following describes an automatic rotation control system and method for reducing the rotation speed of the rotating body 3 based on the second target rotation angle C.

[0065] As shown in Figure 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.

[0066] The rotation angle determination unit 501 acquires a signal indicating the rotation angle detected by the rotation angle sensor 32. The rotation angle sensor 32 may be the same as the position and orientation sensor 21 (Figure 4). Based on the acquired signal indicating the rotation angle, the rotation angle determination unit 501 determines the rotation angle of the rotating body 3.

[0067] The target turning acceleration determination unit 502 acquires the turning angle of the turning body 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 body 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 C (rad / s 2 ) of the turning body 3, the target turning angle θ1 (rad), the offset angle θ O (rad), and the current turning angle θ C (rad), and calculates a negative target turning acceleration α G (rad / s 2 ) based on the following formula (1).

[0068] In the following formula (1), the current turning angle θ C is the current turning angle of the turning body 3 and is detected by the turning angle sensor 32. For example, when the controller 50 defines north as 0°, east as 90°, south as 180°, and west as 270°, the angle of the orientation of the turning body 3 is calculated as the current turning angle. The same applies to other turning angles. The current turning speed ω C is the current turning speed of the turning body 3 and is detected by the turning speed sensor 33. The target turning angle θ1 is the turning angle at the first target turning angle B. The target turning angle θ1 is calculated by the above-described calculation method in the same manner as the current turning angle θ C . The offset angle θ O is the turning angle from the second target turning angle C to the first target turning angle B in FIG. 6. Each of the target turning angle θ1 and the offset angle θ O is stored in the storage unit 504 in advance. Therefore, when calculating the target turning acceleration α G , the target turning angle θ1 and the offset angle θ O stored in the storage unit 504 are referred to.

Equation

[0069] Furthermore, the control target point (earth removal point) is determined through teaching, and the first target turning angle B at the control target point (earth removal point) is determined. This target turning angle θ1, which is the first target turning angle B, is stored in the memory unit 504. The offset angle θ0 can be freely adjusted and is pre-adjusted and stored in the memory unit 504. The second target turning angle C is determined by the first target turning angle B and the offset angle θ O It is calculated from and stored in the memory unit 504.

[0070] Furthermore, equation (1) is derived from equations (2) and (3) below. Equations (2) and (3) are obtained from the relationship between the turning speed ω and time t, as shown in Figure 8. Time t is the elapsed time from the present until the turning stops. In Figure 8, the area enclosed by the vertical axis showing the turning speed, the horizontal axis showing time, and the diagonal line IL represents the turning angle that the turning body 3 will turn until it stops. Therefore, the current turning angle θ C Turn angle from (θ1-θ0-θ) to the second target turning angle C C ) is expressed by the following equation (2). Also, the slope of the shaded line IL in Figure 8 represents negative acceleration. Therefore, the target turning acceleration α G This is expressed by equation (3) below. Equation (1) is obtained by eliminating time t from equations (2) and (3).

number

number

[0071] Furthermore, the turning brake torque T is determined by the turning inertia J and the target turning acceleration α. G It is defined as the value obtained by multiplying by (T = -J × α G ). From equation (1), the offset angle θ is used to calculate the turning brake torque T. O It can be seen that it is used.

[0072] The EPC valve control unit 503 determines the final turning speed command value (rad / s) based on the calculated turning brake torque T and other factors, and according to the actual turning speed. If the actual turning speed is less than the threshold, or if (target turning angle θ1 - current turning angle θ) C -Offset angle θ O If () ≤ 0, the turning speed command is set to the angular velocity before turning stops (predetermined turning speed ωp). Here, if the actual turning speed is less than the threshold, for example, if the turning speed drops too low before the turning angle reaches the second target turning angle C, it means that instead of continuing to decrease the turning speed, it is set to the angular velocity before stopping (predetermined turning speed ωp). For this reason, the above 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 The condition )≦0 means that when the turning angle reaches the second target turning angle C, which is before the first target turning angle B, the turning speed is set to the angular velocity before stopping (predetermined turning speed ωp). The angular velocity before stopping may be small enough to stop the turn immediately after the automatic turning control is completed.

[0073] The EPC valve control unit 503 controls the EPC valve 28 by outputting the final rotation speed command value determined above to the EPC valve 28. As a result, the EPC valve 28 is controlled so that in automatic rotation control, the rotation speed of the rotating body 3 is reduced based on a second target rotation angle C that is offset in front of the first target rotation angle B.

[0074] Here, the offset angle θ is used to calculate the turning brake torque T. O The reason for its use will be explained using Figures 9(A) to (C).

[0075] Figures 9(A) to (C) show the offset angle θ used to calculate the turning brake torque T. O This diagram explains the reason for its use. Figures 9(A) to (C) schematically show the command signals output to the EPC valve 28. In each of Figures 9(A) to (C), the horizontal axis represents the rotation angle, and the vertical axis represents the rotation speed.

[0076] In the command signal shown in Figure 9(B), the vehicle is decelerated so that the turning speed stops at the second target turning angle C, which is before the first target turning angle B. Therefore, the degree of deceleration (slope T2) from the deceleration start angle A1 to the second target turning angle C shown in Figure 9(B) is greater than the degree of deceleration (slope T1) from the deceleration start angle A1 to the first target turning angle B shown in Figure 9(A). Consequently, with the actual braking force under the control shown in Figure 9(B), there may be cases where the vehicle cannot stop suddenly.

[0077] Therefore, as shown in Figure 9(C), by providing an offset to the deceleration start angle A1, deceleration begins from a turning angle A2 that is earlier than the deceleration start angle A1. As a result, the degree of deceleration (inclination T3) from turning angle A2 to reaching the second target turning angle C becomes smaller than in the case of Figure 9(B), and the turn can be stopped with the actual braking force. In this way, an offset angle θ is used in the calculation of the turning brake torque T in order to reliably stop the turn. O This is used.

[0078] Offset angle θ O This is adjusted by the controller 50. Specifically, the controller 50 adjusts the deceleration start turning angle, which is the angle at which the turning speed begins to decrease 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.

[0079] The controller 50 may also control negative acceleration to 0 (zero) during low-acceleration control after reaching the second target turning angle C. In this case, as shown in Figure 10, whether the turning angle of the rotating body 3 reaches the second target turning angle C (L1) or the turning speed of the rotating body 3 reaches a predetermined turning speed ωp at a predetermined angle D (L2), the turning speed of the rotating body 3 is maintained at the predetermined turning speed ωp until it reaches the first target turning angle B, and is controlled to a constant speed. In this case, when the turning angle of the rotating body 3 reaches the first target turning angle B, the turning speed is instantly reduced to 0 (zero) by applying the brakes, and the turning of the rotating body 3 is stopped.

[0080] The controller 50 described above includes a processor, main memory, and a storage unit 504. The processor is, for example, a CPU (Central Processing Unit). The main memory includes, for example, non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory). The controller 50 reads the program stored in the storage unit 504, loads it into the main memory, and executes predetermined processing according to the program. The storage unit 504 may be provided separately from the controller 50.

[0081] In the above, we described the case where the control switches to low acceleration control after the rotation angle of the rotating body 3 reaches the second target rotation angle C. However, as shown by the dashed line L2 in Figure 6, if the rotation speed ωp is reached at a predetermined angle D before the rotation angle of the rotating body 3 reaches the second target rotation angle C, the control may be switched to low acceleration control after reaching the predetermined angle D. In other words, the controller 50 may be set so that the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body 3 reaches the predetermined angle D is smaller than the absolute value of the negative target rotation acceleration before the rotation angle of the rotating body 3 reaches the predetermined angle D. To put it another way, the controller 50 may be set so that the absolute value of the negative target rotation acceleration from the predetermined angle D to the first target rotation angle B is smaller than the absolute value of the negative target rotation acceleration from the rotation angle at the deceleration start point A to the predetermined angle D.

[0082] Furthermore, the controller 50 may set the absolute value of the average negative target turning acceleration after the turning angle of the rotating body 3 reaches the second target turning angle C to be smaller than the absolute value of the average negative target turning acceleration before the turning angle of the rotating body 3 reaches the second target turning angle C. In other words, the controller 50 may set the absolute value of the average negative target turning acceleration from the second target turning angle C to the first target turning angle B 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.

[0083] <Automatic turning control method>

[0084] Next, the automatic turning control method in this embodiment will be explained using Figures 7 and 11.

[0085] Figure 11 is a flowchart showing an automatic slewing control method for a work machine in one embodiment of the present disclosure. As shown in Figure 11, automatic slewing control is started (step S1). Automatic slewing control is started, for example, when an operator presses the automatic slewing control start switch and the conditions for starting automatic slewing control are met. When automatic slewing control is started, the slewing body 3 starts to slewing. One of the conditions for starting automatic slewing control is, for example, that the orientation of the slewing body 3 is within a predetermined range. As a result, the bucket 8 slewing toward the set coordinates of the slewing end point.

[0086] The rotation 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 by whether or not the rotation angle has reached the deceleration start point A shown in Figure 6. In this determination, as will be described later, it is determined whether or not the rotation has reached the deceleration start point A based on whether or not the rotation can be stopped at the target rotation angle C when decelerated from the current rotation angle with a predetermined provisional target rotation acceleration. The rotation angle of the rotating body 3 at the deceleration start point A is, for example, the deceleration start angle A1 (Figure 9(B)) or the deceleration start angle A2 (Figure 9(C)). If the rotation angle determination unit 501 determines that the rotation angle has not reached the deceleration start point A (Figure 6), step S2 is repeated.

[0087] On the other hand, if the turning angle determination unit 501 determines that the turning angle has reached the deceleration start point A, deceleration control is started (step S3). During the execution of deceleration control, the negative target turning acceleration α calculated by the target turning acceleration determination unit 502 is used. G The turning speed is reduced based on this.

[0088] During deceleration control, the rotation angle determination unit 501 of the controller 50 determines whether the rotation angle of the rotating body 3 has reached the second target rotation angle C (step S4). In this determination, the rotation angle determination unit 501 refers to the second target rotation angle C that is pre-stored in the storage unit 504. If the rotation angle determination unit 501 determines that the rotation angle has reached the second target rotation angle C, the low acceleration control described later (step S6) is executed.

[0089] On the other hand, if the rotation angle determination unit 501 determines that the rotation angle has not reached the second target rotation angle C, it is determined whether the rotation speed of the rotating body 3 is less than or equal to a predetermined rotation speed ωp (step S5). In this determination, the predetermined rotation speed ωp stored in the memory unit 504 is referenced. Specifically, it is determined whether the current rotation speed obtained from the rotation speed sensor 33 is less than or equal to the predetermined rotation speed ωp stored in the memory unit 504. If it is determined that the current rotation speed of the rotating body 3 is greater than the predetermined rotation speed ωp, the steps from step S3 onward are repeated.

[0090] On the other hand, if it is determined that the current rotation speed of the rotating body 3 is less than or equal to a predetermined rotation speed ωp, low acceleration control (step S6) is executed. Specifically, as shown by the dashed line L2 in Figure 6, if the rotation speed reaches the predetermined rotation speed ωp at a predetermined angle D before the rotation angle of the rotating body 3 reaches the second target rotation angle C, low acceleration control (step S6) is executed. In this low acceleration control, the rotation speed is reduced by a smaller degree of deceleration than the degree of deceleration before the rotation angle reaches the predetermined angle D (Figure 6). Specifically, the absolute value of the negative target rotation acceleration after the rotation angle reaches the predetermined angle D is set to be smaller than the absolute value of the negative target rotation acceleration before the rotation angle reaches the predetermined angle D.

[0091] Furthermore, if it is determined in step S4 that the turning angle has reached the second target turning angle C, low acceleration control (step S6) is also executed. Specifically, as shown by the solid line L1 in Figure 6, when the turning speed reaches a predetermined turning speed ωp at the same time that the turning angle of the turning body 3 reaches the second target turning angle C, low acceleration control (step S6) is executed. In this low acceleration control, the turning speed is reduced by a smaller degree of deceleration than the degree of deceleration before the turning angle reaches the predetermined angle C (Figure 6). Specifically, the absolute value of the negative target turning acceleration after the turning angle reaches the predetermined angle C is set to be smaller than the absolute value of the negative target turning acceleration before the turning angle reaches the predetermined angle C.

[0092] During low-acceleration control, the rotation angle determination unit 501 of the controller 50 determines whether the rotation angle of the rotating body 3 has reached the first target rotation angle B (step S7). In this determination, the rotation angle determination unit 501 refers to the first target rotation angle B that is pre-stored in the storage unit 504. If the rotation angle determination unit 501 determines that the rotation angle has not reached the first target rotation angle B, the steps from step S6 onward are repeated. On the other hand, if the rotation angle determination unit 501 determines that the rotation angle has reached the first target rotation angle B, the automatic rotation control is stopped (step S8).

[0093] The automatic turning control method of this embodiment is implemented as described above.

[0094] The determination of whether or not the rotation angle of the rotating body 3 has reached the deceleration start point A is carried out as follows. First, a predetermined degree of deceleration is set in advance and stored, for example, in the memory unit 504. This becomes a provisional target turning acceleration for determining the deceleration starting point A. Using Figure 9(A) as an example, this is like having the incline of the slope T1 stored in advance.

[0095] From the teaching control target point, the target turning angle B is determined, and the offset angle θ is stored in advance. O The target turning angle C is determined by taking these factors into consideration. The current turning angle and turning speed are constantly monitored.

[0096] Based on the above, it is possible to determine whether the rotation can be stopped at the target rotation angle C when decelerated at a predetermined hypothetical target rotation acceleration from the current rotation angle. If, in this determination, the rotation can be stopped at the target rotation angle C, it is determined that the rotation angle of the rotating body 3 has reached the deceleration start point A, and deceleration control is initiated.

[0097] <Effects>

[0098] Next, the effects of this embodiment will be described.

[0099] In this embodiment, as shown in Figures 6 and 7, the controller 50 decelerates the rotation speed of the rotating body 3 based on a second target rotation angle C that is before the first target rotation angle B, which is the target stop angle for automatic rotation control. This suppresses overshoot.

[0100] Furthermore, according to this embodiment, as shown in Figures 6 and 7, the controller 50 calculates the negative target rotational acceleration of the rotating body 3 until it reaches the second target rotational angle C, based on the current rotational speed and the second target rotational angle C. This makes it possible to control the rotation of the rotating body 3 so that it reaches a predetermined rotational speed at the second target rotational angle C.

[0101] Furthermore, according to this embodiment, as shown in Figures 6 and 7, the controller 50 makes the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body 3 reaches the second target rotation angle C smaller than the absolute value of the negative target rotation acceleration before the rotation angle of the rotating body 3 reaches the second target rotation angle C. This makes it possible to suppress overshoot.

[0102] Furthermore, according to this embodiment, as shown in Figures 6 and 7, the controller 50 makes the absolute value of the average negative target rotation acceleration after the rotation angle of the rotating body 3 reaches the second target rotation angle C smaller than the absolute value of the average negative target rotation acceleration before the rotation angle of the rotating body 3 reaches the second target rotation angle C. This makes it possible to suppress overshoot.

[0103] Furthermore, according to this embodiment, as shown in Figures 6 and 7, if the controller 50 reaches a predetermined rotation speed ωp before the rotation angle of the rotating body 3 reaches the second target rotation angle C, it makes the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed ωp smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed ωp. This makes it possible to reliably perform low-acceleration control before the rotation speed of the rotating body 3 becomes 0 (zero).

[0104] Furthermore, according to this embodiment, as shown in Figure 10, the controller 50 maintains the rotation speed of the rotating body 3 at a constant speed until it reaches the first target rotation angle B in low-acceleration control. By controlling the rotation speed of the rotating body 3 to a constant speed of a predetermined rotation speed ωp, it is avoided that the rotation speed becomes 0 (zero) before reaching the first target rotation angle B. In addition, by reducing the predetermined rotation speed ωp to a level that allows for immediate stopping, the shock when stopping the rotation can be suppressed, and the rotation can be stopped immediately once the rotation angle of the rotating body 3 reaches the first target rotation angle B.

[0105] Furthermore, according to this embodiment, as shown in Figure 9(C), the controller 50 adjusts the deceleration start turning angle at which it begins to reduce the turning speed 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 turn with the actual braking force.

[0106] <Note>

[0107] The embodiments described above include the following technical concepts.

[0108] (Note 1) A rotating body and A work machine attached to the aforementioned rotating body, The system includes a controller that performs automatic rotation control to control the rotation of the rotating body, The controller is an automatic rotation control system for a work machine, which reduces the rotation speed of the rotating body based on a second target rotation angle that is before a first target rotation angle which is the target stopping angle for automatic rotation control.

[0109] (Note 2) The automatic rotation control system for a work machine as described in Appendix 1, wherein the controller calculates the negative target rotation acceleration of the rotating body until it reaches the second target rotation angle, based on the current rotation speed and the second target rotation angle.

[0110] (Note 3) An automatic slewing control system for a work machine as described in Appendix 1 or Appendix 2, wherein the controller switches to low-acceleration control by making the absolute value of the negative target slewing acceleration after the slewing angle of the slewing body reaches the second target slewing angle smaller than the absolute value of the negative target slewing acceleration before the slewing angle of the slewing body reaches the second target slewing angle.

[0111] (Note 4) An automatic slewing control system for a work machine as described in Appendix 1 or Appendix 2, wherein the controller switches to low acceleration control by making the absolute value of the average negative target slewing acceleration after the slewing angle of the slewing body reaches the second target slewing angle smaller than the absolute value of the average negative target slewing acceleration before the slewing angle of the slewing body reaches the second target slewing angle.

[0112] (Note 5) An automatic rotation control system for a work machine as described in Appendix 1 or Appendix 2, wherein the controller switches to low-acceleration control by making the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle.

[0113] (Note 6) The controller maintains the rotation speed of the rotating body at a constant speed until the first target rotation angle is reached in the low-acceleration control, an automatic rotation control system for a work machine as described in any one of Appendix 3 to Appendix 5.

[0114] (Note 7) An automatic slewing control system for a work machine according to any one of the appendices 1 to 6, wherein the controller adjusts the deceleration start slewing angle at which the slewing speed begins to decelerate toward the second target slewing angle, based on the angular difference between the first target slewing angle and the second target slewing angle.

[0115] (Note 8) A rotating body and A work machine attached to the aforementioned rotating body, The system includes a controller that performs automatic rotation control to control the rotation of the rotating body, The controller is a working machine that reduces the rotation speed of the rotating body based on a second target rotation angle that is before a first target rotation angle which is the target stop angle for automatic rotation control.

[0116] (Note 9) The work machine as described in Appendix 8, wherein the controller calculates the negative target rotational acceleration of the rotating body until it reaches the second target rotational angle, based on the current rotational speed and the second target rotational angle.

[0117] (Note 10) The work machine according to Appendix 8 or 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.

[0118] (Note 11) The work machine as described in Appendix 8, wherein the controller switches to low acceleration control by making the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle.

[0119] (Note 12) The controller maintains the rotation speed of the rotating body at a constant speed until the first target rotation angle is reached in the low-acceleration control, as described in Appendix 10 or Appendix 11 of the working machine.

[0120] (Note 13) The controller adjusts the deceleration start turning angle at which the turning speed begins to decrease toward the second target turning angle, based on the angle difference between the first target turning angle and the second target turning angle, according to any one of the appendices 8 to 12.

[0121] (Note 14) An automatic rotation control method for a work machine having a rotating body and a work machine attached to the rotating body, The steps include setting a first target rotation angle which is the target stop angle for the automatic rotation control that controls the rotation of the rotating body, The steps include setting a second target turning angle that is closer than the first target turning angle, An automatic rotation control method for a work machine, comprising the step of reducing the rotation speed of the rotating body based on the second target rotation angle.

[0122] (Note 15) An automatic rotation control method for a work machine as described in Appendix 14, wherein the negative target rotation acceleration of the rotating body until it reaches the second target rotation angle is calculated based on the current rotation speed and the second target rotation angle.

[0123] (Note 16) Automatic rotation control method for a work machine according to Appendix 14 or Appendix 15, wherein the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle is made 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, thereby switching to low acceleration control.

[0124] (Note 17) Automatic rotation control method for a work machine according to Appendix 14 or Appendix 15, wherein the absolute value of the average negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle is made 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, thereby switching to low acceleration control.

[0125] (Note 18) Automatic rotation control method for a work machine as described in Appendix 14, wherein if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle, the method switches to low acceleration control by making the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed.

[0126] (Note 19) An automatic rotation control method for a work machine as described in any one of appendices 16 to 18, wherein in the low-acceleration control, the rotation speed of the rotating body is maintained at a constant speed until the first target rotation angle is reached.

[0127] (Note 20) An automatic slewing control method for a work machine according to any one of appendices 14 to 19, wherein the deceleration start slewing angle at which the slewing speed begins to decelerate toward the second target slewing angle is adjusted based on the angle difference between the first target slewing angle and the second target slewing angle.

[0128] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0129] 1 Main body, 2 Work equipment, 3 Slewing body, 4 Cab, 4S Driver's seat, 5 Running body, 5Cr Tracks, 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 equipment attitude sensor, 21 Position and orientation sensor, 21a, 21b GNSS antenna, 22 Tilt sensor, 23 Detection sensor, 24 Indicator unit, 27 Hydraulic pump, 28 EPC valve, 29 Actuator, 30 Hydraulic valve, 32 Slewing angle sensor, 33 Slewing speed sensor, 50 Controller, 51 Control target setting unit, 51A Return point setting unit, 51B Soil removal point setting unit, 51C Waypoint setting unit, 52 Operation information acquisition unit, 53, 503 EPC valve control unit, 100 hydraulic excavator, 200 loading target, 200A vessel, 501 slewing angle determination unit, 502 target slewing acceleration determination unit, 504 memory unit, B first target slewing angle, C second target slewing angle, RX slewing axis.

Claims

1. A rotating body and A work machine attached to the aforementioned rotating body, The system includes a controller that performs automatic rotation control to control the rotation of the rotating body, The controller is an automatic rotation control system for a work machine, which reduces the rotation speed of the rotating body based on a second target rotation angle that is before a first target rotation angle which is the target stop angle for automatic rotation control.

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

3. Automatic rotation 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 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.

4. Automatic rotation 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 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.

5. Automatic rotation 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 rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle.

6. The automatic slewing control system for a work machine according to any one of claims 3 to 5, wherein the controller maintains the slewing speed of the slewing body at a constant speed until the first target slewing angle is reached in the low-acceleration control.

7. The automatic rotation control system for a work machine according to claim 1, wherein the controller adjusts the rotation start angle at which it begins to reduce the rotation speed toward the second target rotation angle, based on the angle difference between the first target rotation angle and the second target rotation angle.

8. A rotating body and A work machine attached to the aforementioned rotating body, The system includes a controller that performs automatic rotation control to control the rotation of the rotating body, The controller is a working machine that reduces the rotation speed of the rotating body based on a second target rotation angle that is before a first target rotation angle which is the target stop angle for automatic rotation control.

9. The work machine according to claim 8, wherein the controller calculates the negative target rotational acceleration of the rotating body until it reaches the second target rotational angle, based on the current rotational speed and the second target rotational angle.

10. The work machine according to claim 8, 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.

11. The work machine according to claim 8, wherein the controller switches to low acceleration control by making the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle.

12. The working machine according to claim 10 or 11, wherein the controller maintains the rotation speed of the rotating body at a constant speed until the first target rotation angle is reached in the low-acceleration control.

13. The work machine according to claim 8, wherein the controller adjusts the deceleration start turning angle at which the turning speed begins to decrease toward the second target turning angle, based on the angle difference between the first target turning angle and the second target turning angle.

14. An automatic rotation control method for a work machine having a rotating body and a work machine attached to the rotating body, The steps include setting a first target rotation angle which is the target stop angle for the automatic rotation control that controls the rotation of the rotating body, The steps include setting a second target turning angle that is closer than the first target turning angle, An automatic rotation control method for a work machine, comprising the step of reducing the rotation speed of the rotating body based on the second target rotation angle.

15. Automatic rotation control method for a work machine according to claim 14, wherein the negative target rotation acceleration of the rotating body until it reaches the second target rotation angle is calculated based on the current rotation speed and the second target rotation angle.

16. Automatic rotation control method for a work machine according to claim 14, wherein the absolute value of the negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle is made 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, thereby switching to low acceleration control.

17. Automatic rotation control method for a work machine according to claim 14, wherein the absolute value of the average negative target rotation acceleration after the rotation angle of the rotating body reaches the second target rotation angle is made 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, thereby switching to low acceleration control.

18. Automatic rotation control method for a work machine according to claim 14, wherein if the rotation angle of the rotating body reaches a predetermined rotation speed before reaching the second target rotation angle, the method switches to low acceleration control by making the absolute value of the negative target rotation acceleration after reaching the predetermined rotation speed smaller than the absolute value of the negative target rotation acceleration before reaching the predetermined rotation speed.

19. Automatic rotation control method for a work machine according to any one of claims 16 to 18, wherein in the low-acceleration control, the rotation speed of the rotating body is maintained at a constant speed until the first target rotation angle is reached.

20. Automatic rotation control method for a work machine according to claim 14, wherein the deceleration start rotation angle at which the rotation speed starts to decelerate toward the second target rotation angle is adjusted based on the angle difference between the first target rotation angle and the second target rotation angle.

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