Work machine control method, work machine, and system including work machine

Abstract

To suitably operate a working machine during turning of a turning body.SOLUTION: A control command for increasing an operation speed of a work machine as a remaining swing angle to a target position of a swing body decreases is output during a start period of an operation of the work machine during swing of the swing body to which the work machine is attached so as to be operable. A control command is output so that the operation speed of the work machine is reduced as the remaining turning angle is reduced in the end period of the operation of the work machine during the turning of the turning body.SELECTED DRAWING: Figure 15

Description

[Technical Field]

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

[0002] Japanese Patent Application Publication No. 2019-148147 (Patent Document 1) discloses a control device for a loading machine that generates an operation signal to control the pressure of hydraulic oil in the hydraulic device downstream of the swing motor based on the orientation of the swing body, the swing speed, and the target stopping orientation while the swing motor is braking. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-148147 Summary of the Invention [Problem to be solved by the invention]

[0004] In a work machine that includes a rotating body and a work implement movably attached to the rotating body, work is sometimes performed in which the work implement is operated while the rotating body is rotating. The above document describes swing control, but does not describe the operation of the work implement during swing.

[0005] The present disclosure proposes a technique for suitably operating a work machine while a rotating body is rotating. [Means for solving the problem]

[0006] A method for controlling a work machine according to one aspect of the present disclosure includes a first step and a second step. In the first step, a control command is output to increase the operating speed of the work machine as the remaining rotation angle of the rotating body to a target position decreases during a start period of operation of the work machine while the rotating body is rotating, and in the second step, a control command is output to decrease the operating speed of the work machine as the remaining rotation angle decreases during a termination period of operation of the work machine while the rotating body is rotating.

[0007] A work machine according to one aspect of the present disclosure includes a rotating body, a work implement operably attached to the rotating body, a work implement actuator that drives the work implement, a control valve that controls the work implement actuator, and a controller. The controller outputs a control command to the control valve during a start period of operation of the work implement while the rotating body is rotating, such that the operating speed of the work implement increases as the remaining swing angle until the target position of the rotating body decreases. The controller outputs a control command to the control valve during a end period of operation of the work implement while the rotating body is rotating, such that the operating speed of the work implement decreases as the remaining swing angle decreases.

[0008] According to one aspect of the present disclosure, a system including a work machine includes a rotating body, a work machine operably attached to the rotating body, a work machine actuator that drives the work machine, a control valve that controls the work machine actuator, and a controller. The controller outputs a control command to the control valve during a start period of operation of the work machine while the rotating body is rotating, such that the operating speed of the work machine increases as the remaining swing angle until the target position of the rotating body decreases. The controller outputs a control command to the control valve during a end period of operation of the work machine while the rotating body is rotating, such that the operating speed of the work machine decreases as the remaining swing angle decreases.

[0009] A method for controlling a work machine according to one aspect of the present disclosure includes a step of adjusting a control command for increasing the operating speed of the work machine as the remaining rotation angle of the rotating body to which the work machine is operably attached to the target position decreases, based on at least one of the rotation angle of the rotating body from the position when the rotating body starts to rotate to the target position and the movement angle of the work machine from the start of operation to the end of operation, and a step of outputting the adjusted control command.

[0010] A work machine according to one aspect of the present disclosure includes a rotating body, a work implement operably attached to the rotating body, and a controller. The controller adjusts a control command to increase the operating speed of the work implement as the remaining rotation angle of the rotating body to a target position decreases, based on at least one of the rotation angle of the rotating body from the position when the rotating body starts to rotate to the target position and the movement angle of the work implement from the start of operation to the end of operation.

[0011] A control method for a work machine according to one aspect of the present disclosure includes a step of adjusting, based on the weight of the work machine, a control command that reduces the operating speed of the work machine as the remaining movement angle from the current attitude of the work machine to the target attitude becomes smaller, and a step of outputting the adjusted control command.

[0012] A work machine according to one aspect of the present disclosure includes a work implement and a controller. The controller adjusts a control command, based on the weight of the work implement, to reduce the operating speed of the work implement as the remaining angle of movement from the current attitude of the work implement to a target attitude decreases. [Effects of the Invention]

[0013] According to the present disclosure, the work machine can be operated appropriately while the rotating body is rotating. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a hydraulic excavator. [Figure 2]FIG. 10 is a diagram showing an operation flow of excavation and loading by a hydraulic excavator. [Figure 3] FIG. 2 is a perspective view showing a control target point in automatic turning control. [Figure 4] FIG. 10 is a schematic diagram showing the progress of return turning control divided into a plurality of sections. [Figure 5] FIG. 10 is a diagram showing the start and end points of each section of the return swing control, and the operation of the hydraulic excavator in each section. [Figure 6] FIG. 1 is a block diagram showing an automatic turning control system for a return turn. [Figure 7] FIG. 10 is a block diagram showing a process for generating a boom speed command. [Figure 8] FIG. 10 is a diagram showing a boom lowering reference first speed. [Figure 9] FIG. 10 is a diagram illustrating adjustment of a boom lowering speed command value based on a rotation amount. [Figure 10] FIG. 10 is a diagram illustrating adjustment of a boom lowering speed command value according to a boom lowering amount. [Figure 11] FIG. 10 is a virtual diagram in which the sigmoid portion of the boom lowering reference first speed is changed based on the rotation amount and the boom lowering amount. [Figure 12] FIG. 10 is a diagram showing a second boom lowering reference speed. [Figure 13] FIG. 10 is a diagram illustrating adjustment of a boom lowering speed command value based on bucket weight. [Figure 14] FIG. 10 is a virtual diagram in which a boom lowering reference second speed is changed based on a bucket weight. [Figure 15] FIG. 10 is a hypothetical diagram illustrating a comparison and selection of an adjusted first speed command value and an adjusted second speed command value. [Figure 16] FIG. 10 is a block diagram showing a process for generating an arm speed command. [Figure 17] FIG. 10 is a diagram showing an arm operation reference speed. [Figure 18] FIG. 10 is a virtual diagram in which the arm operation reference speed is changed based on the bucket weight. [Figure 19] FIG. 10 is a block diagram showing a process for generating a bucket velocity command. [Figure 20]FIG. 10 is a diagram illustrating a bucket operation reference speed. [Figure 21] FIG. 10 is a virtual diagram in which the bucket operation reference speed is changed based on the bucket weight. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, the embodiments will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. In the drawings, configurations may be omitted or simplified for the sake of convenience. It is also intended from the beginning that any configurations may be extracted from the embodiments and arbitrarily combined.

[0016] In the following description, the terms "up," "down," "front," "rear," "left," and "right" refer to directions relative to an operator seated in the operator's seat 4S in the operator's cab 4 shown in Fig. 1. In this specification, a top view refers to a viewpoint from which the work machine (hydraulic excavator 100) is viewed from above.

[0017] <Work machine configuration> The configuration of a hydraulic excavator as an example of a work machine of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a diagram schematically showing the configuration of a hydraulic excavator 100 as an example of a work machine in one 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 has a revolving body 3 and a traveling body 5.

[0018] The running body 5 has a pair of crawler tracks 5Cr and a traveling motor 5M. The hydraulic excavator 100 is capable of traveling by rotation of the crawler tracks 5Cr. The traveling motor 5M is provided as a drive source for the running body 5. The traveling motor 5M is a hydraulic motor that is hydraulically operated. The running body 5 may have wheels (tires).

[0019] 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.

[0020] The rotating unit 3 has a driver's cab 4. Inside the driver's cab 4, there is provided a driver's seat 4S where an operator sits. The operator (crew member) sits in the driver's cab 4 and can operate the work equipment 2, rotate the rotating unit 3 relative to the traveling unit 5, and travel the hydraulic excavator 100 using the traveling unit 5. The rotating unit 3 has an exterior cover 9. The exterior cover 9 covers the machine room. The hydraulic excavator 100 may be remotely operated.

[0021] The work implement 2 is supported by the rotating unit 3. The work implement 2 is attached to the rotating unit 3 so as to be movable relative to the rotating 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.

[0022] 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 work tool such as a grapple.

[0023] 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 move relative to the main body 1 by the boom cylinder 10. By the operation of the boom cylinder 10, the boom 6 can rotate up and down relative to the revolving unit 3, with the boom foot pin 13 as a fulcrum.

[0024] 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 move relative to the boom 6 by the arm cylinder 11. By operation of the arm cylinder 11, the arm 7 can rotate up and down or back and forth relative to the boom 6, with the boom top pin 14 as a fulcrum.

[0025] 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 can move relative to the arm 7 by the bucket cylinder 12. By the operation of the bucket cylinder 12, the bucket 8 can rotate up and down relative to the arm 7, with the arm top pin 15 as a fulcrum.

[0026] Each of the boom cylinder 10, the arm cylinder 11 and the bucket cylinder 12 is a hydraulic cylinder that is driven by hydraulic pressure, but may be another actuator such as an electric cylinder.

[0027] The hydraulic excavator 100 further has a work implement attitude sensor 20 ( FIG. 6 ) and a position and orientation sensor 21. The work implement attitude sensor 20 detects the attitude of the work implement 2 and outputs an attitude signal indicating 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.

[0028] The position and orientation sensor 21 is, for example, a GNSS (Global Navigation Satellite Systems) receiver. The position and orientation sensor 21 includes two GNSS receivers 21a and 21b. Each of the two GNSS receivers 21a and 21b is installed at a different position on the rotating unit 3. Each of the GNSS receivers 21a and 21b receives a satellite positioning signal from a satellite indicating the position of the rotating unit 3 in a global coordinate system. The position and orientation sensor 21 outputs the received satellite positioning signal indicating the position of the rotating unit 3 in the global coordinate system. The controller 50 (FIG. 6) 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 signal.

[0029] 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 which is represented by axes extending in the front-to-back direction, axes extending in the left-to-right direction, and axes extending in the up-to-down direction (rotation axis RX).

[0030] The hydraulic excavator 100 further has an instruction unit 24 (FIG. 6). The instruction unit 24 is disposed in the operator's cab 4. The instruction unit 24 accepts manual operations by an operator. The instruction unit 24 is manually operated by an operator seated in the operator's cab 4, and outputs operation commands for manual operation.

[0031] The instruction unit 24 is operated by an operator to set a control target point for automatic swing control. A control target point for automatic swing control is a point through which the control target point of the swinging bucket 8 passes while the automatic swing control is being executed. The control target point of the bucket 8 may be, for example, a point where the center of the arm top pin 15 in the left-right direction is located, or may be the cutting edge 8T of the bucket 8 or the bottom surface of the bucket 8. The control target points include a loading swing control end point, an interference avoidance control point, and a return swing control end point. Details of the control target points will be described later.

[0032] <Excavation and loading operation flow and automatic swing control> FIG. 2 is a diagram showing an operation flow of excavation and loading by a hydraulic excavator 100 as an example of a work machine.

[0033] As shown in Fig. 2, in excavation and loading by hydraulic excavator 100, excavation is first performed (step SA). As a result of this excavation, a load such as earth and sand is loaded into bucket 8. After excavation, with the load loaded in bucket 8, rotating body 3 rotates while raising work implement 2 (step SB). This rotation is what is known as loading rotation (hoist rotation).

[0034] When the bucket 8 reaches the point where the load in the bucket 8 is to be discharged due to the loading swing, the swing of the swing unit 3 is stopped. After this, the load in the bucket 8 is discharged (discharged) (step SC). After the load is discharged, the swing unit 3 swings while lowering the work implement 2 to excavate again (step SD). This swing is the so-called return swing (down swing).

[0035] The automatic swing control of the work machine in this embodiment is carried out during the return swing (step SD) during the above-mentioned excavation and loading.

[0036] 3 is a perspective view showing a control target point in automatic swing control of a work machine. In the above-mentioned excavation and loading work, the loading target 200 onto which the load in the bucket 8 is unloaded is, for example, a dump truck. The dump truck 200 has a vessel 200A for loading the load in the bucket 8. The load in the bucket 8 is unloaded into the vessel 200A of the dump truck 200.

[0037] In automatic swing control, the swing unit 3 automatically swings so that the control target point of the bucket 8 moves from the swing start point toward the swing end point. To automate the return swing and perform automatic swing control, it is necessary to set points (control target points) through which the control target point of the bucket 8 passes during the return swing. To set the control target points, three teaching target points are set. The teaching target points are set in advance, for example, by the operator operating the indicator 24. The teaching target points include the loading swing end point TP2, the interference avoidance point TP3, and the return swing end point TP1.

[0038] The loading swing end point TP2 is the swing end point when loading swing control is performed to load the load in the bucket 8 into the vessel 200A of the dump truck 200. The loading swing end point TP2 is, for example, a point above the vessel 200A. The interference avoidance point TP3 is a point that is set so that the bucket 8, which is the work implement, does not interfere with the loading target 200 when automatic swing control is performed. The interference avoidance point TP3 is, for example, a point at the rear end of the side edge of the vessel 200A. The return swing end point TP1 is the swing end point when return swing control is performed to make the work machine swing back to perform the next excavation.

[0039] A control target point for automatic swing control is set based on these teaching target points. A point obtained by offsetting the interference avoidance point TP3 in a direction away from the vessel 200A of the dump truck 200 so that the bucket 8 does not interfere with the dump truck 200 during automatic swing control is set as an interference avoidance control point P3. A point that is the same position as the interference avoidance control point P3 in the vertical direction and directly above the loading swing end point TP2 is set as the loading swing control end point P2. In a top view, the loading swing control end point P2 and the loading swing end point TP2 overlap. The loading swing control end point P2 is directly above the vessel 200A. A point that is the same as the return swing end point TP1, which is a teaching target point, is set as the return swing control end point P1, which is a control target point.

[0040] The instruction unit 24 (FIG. 6) includes a swing control start switch. Automatic swing control is started, with the position of the control target point of the bucket 8 when the swing control start switch is operated as the start position. In loading swing control, the work implement 2 and the rotating unit 3 are controlled so that the control target point of the bucket 8 passes through the start position (the position when the swing control start switch is operated), the interference avoidance control point P3, and the loading swing control end point P2, in that order. In return swing control, the work implement 2 and the rotating unit 3 are controlled so that the control target point of the bucket 8 passes through the start position (the position when the swing control start switch is operated), the interference avoidance control point P3, and the return swing control end point P1, in that order.

[0041] The loading swing control and the return swing control are separate controls, and each is started by being triggered by the operation of the swing control start switch. After the operator manually performs excavation work, the loading swing control starts when the operator operates the swing control start switch. After the control target point of the bucket 8 reaches the loading swing control end point P2 above the vessel 200A, the operator manually discharges the load in the bucket 8 above the vessel 200A. After the discharge is completed, the operator operates the swing control start switch to start the return swing control.

[0042] Fig. 4 is a schematic diagram showing the progress of return swing control divided into multiple sections. Fig. 5 is a diagram showing the start and end points of each section of return swing control and the operation of the hydraulic excavator 100 in each section. Numbers 1, 2, and 3 shown in Fig. 5 correspond to sections S1, S2, and S3 shown in Fig. 4, respectively.

[0043] 4 and 5, the section from the position where the control point of the bucket 8 starts swing control to return after unloading soil to the position at the same height as the interference avoidance control point P3 is defined as section S1. When the control point of the bucket 8 moves within section S1, the work implement 2 is raising and the swing unit 3 is stopped. The control point of the bucket 8 moves straight upward within section S1.

[0044] The section from the end point of section S1 until the control target point of bucket 8 reaches interference avoidance control point P3 is defined as section S2. When the control target point of bucket 8 moves within section S2, the rotating body 3 rotates and the work implement 2 is stopped. The control target point of bucket 8 moves horizontally within section S2.

[0045] The section from the interference avoidance control point P3 until the control target point of the bucket 8 reaches the return swing control end point P1 is defined as section S3. When the control target point of the bucket 8 moves within section S3, the work implement 2 performs a lowering operation and the rotating body 3 performs a swing operation. The control target point of the bucket 8 moves along a curved trajectory through at least a portion of section S3. The return swing control end point P1 may be on the ground G.

[0046] The interference avoidance control point P3 is a point through which the control target point of the bucket 8 passes during the return swing control. The return swing control end point P1 is a point at which the control target point of the bucket 8 is located when the return swing control ends.

[0047] The attitude of the work implement 2 and the position of the rotating unit 3 when the control target point of the bucket 8 is located at each control target point in the automatic swing control are stored in advance. For example, the operator may operate the rotating unit 3 and the work implement 2 to position the control target point of the bucket 8 at each control target point, and in this state operate the indicator 24 to store the attitude of the work implement 2 and the position of the rotating unit 3 at this time. Through this operator operation, the position of the rotating unit 3 and the attitude of the work implement 2 are linked to each control target point and stored in advance.

[0048] In the following embodiment, setting of a control command value for the speed at which the work implement 2 operates while the rotating unit 3 is swinging (specifically, the lowering speed of the boom 6) in section S3 shown in Fig. 4 will be described. The position of the rotating unit 3 when the control target point of the bucket 8 is located at interference avoidance control point P3, which is the start point of section S3, corresponds to the "position when the rotating unit 3 starts swinging." The position of the rotating unit 3 when the control target point of the bucket 8 is located at return swing control end point P1, which is the end point of section S3, corresponds to the "target position of the rotating unit 3." The attitude of the work implement 2 when the control target point of the bucket 8 is located at return swing control end point P1, which is the end point of section S3, corresponds to the "target attitude."

[0049] <Automatic turning control system for work machines> Fig. 6 is a block diagram showing an automatic swing control system for a return swing of a work machine according to the present disclosure. As shown in Fig. 6, the automatic swing control system has a controller 50. The controller 50 includes a processor, a main memory, and a storage unit 54. 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 out a program stored in the storage unit 54, loads it into the main memory, and executes predetermined processing in accordance with the program.

[0050] The controller 50 has a return swing control setting unit 51 and a command signal output unit 55 .

[0051] The return swing control setting unit 51 acquires the attitude signal of the work machine 2 output from the work machine attitude sensor 20. The return swing control setting unit 51 acquires the satellite positioning signal and the swing angle signal output from the position and orientation sensor 21. The return swing control setting unit 51 acquires the instruction signal output from the instruction unit 24.

[0052] The return swing control setting unit 51 sets the operating speed of the work implement 2 and the swing speed of the swing body 3 in automatic swing control. The return swing control setting unit 51 has a boom speed command generating unit 51A, an arm speed command generating unit 51B, a bucket speed command generating unit 51C, and a swing speed command generating unit 51D.

[0053] The boom speed command generation unit 51A generates a control command for the operating speed of the boom 6. The arm speed command generation unit 51B generates a control command for the operating speed of the arm 7. The bucket speed command generation unit 51C generates a control command for the operating speed of the bucket 8. The swing speed command generation unit 51D generates a control command for the swing speed of the swing unit 3.

[0054] The return swing control setting unit 51 outputs signals indicating the operating speeds of the boom 6, the arm 7, and the bucket 8, and a signal indicating the swing speed of the swing unit 3, to the command signal output unit 55. The command signal output unit 55 outputs a command signal to the EPC (electromagnetic proportional control) valve 28 based on the input signal indicating the speeds, thereby controlling the EPC valve 28.

[0055] The EPC valve 28 controls the hydraulic valve 30 based on a command current from a command signal output unit 55 of the controller 50. 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.

[0056] The boom cylinder 10 is hydraulically driven to operate the boom 6. The boom speed command generation unit 51A generates a control command for operating the boom cylinder 10. The arm cylinder 11 is hydraulically driven to operate the arm 7. The arm speed command generation unit 51B generates a control command for operating the arm cylinder 11. The bucket cylinder 12 is hydraulically driven to operate the bucket 8. The bucket speed command generation unit 51C generates a control command for operating the bucket cylinder 12. The swing motor is hydraulically driven to rotate the swing body 3. The swing speed command generation unit 51D generates a control command for operating the swing motor.

[0057] By controlling the EPC valve 28 by the command signal output unit 55, each hydraulic actuator is controlled so that the control target point of the bucket 8 during automatic swing control for return swing reaches the return swing control end point P1 via the interference avoidance control point P3. This enables automatic swing control of the work machine during return swing.

[0058] The hydraulic valve 30 may be an electric valve. The hydraulic valve 30 does not have to be controlled by the EPC valve 28. A command current may be directly input from the command signal output unit 55 of the controller 50 to the hydraulic valve 30, and the hydraulic valve 30 may be controlled based on this command current. In this configuration, the automatic swing control system does not need to include the EPC valve 28.

[0059] Various types of information may be input to the memory unit 54 from the input device 26. The input device 26 may be a touch panel, a keyboard, or the like. The input device 26 may be mounted on the hydraulic excavator 100, or may be located remotely from the hydraulic excavator 100 and connected to the controller 50 by wire or wirelessly. Various types of data such as the weight of the bucket 8 (work tool) may be stored in the memory unit 54, and this various data may be transmitted wirelessly from the outside to the memory unit 54 by the input device 26.

[0060] The controller 50, the instruction unit 24, and the input device 26 may each be mounted on the hydraulic excavator 100, or may be disposed remotely outside the hydraulic excavator 100. When the controller 50, the instruction unit 24, and the input device 26 are disposed remotely outside the hydraulic excavator 100, the controller 50, the instruction unit 24, and the input device 26 may each be wirelessly connected to the various sensors 20, 21, the EPC valve 28, etc. The controller 50 may be stored in a server remote from the hydraulic excavator 100. An operator may operate the hydraulic excavator 100 remotely without being seated in the driver's seat 4 of the hydraulic excavator 100. The hydraulic excavator 100, the controller 50, the instruction unit 24, and the input device 26 disposed outside the hydraulic excavator 100 may constitute a control system for the hydraulic excavator 100.

[0061] <Boom speed command generation> During the return swing, in section S3 after the control point of the bucket 8 passes the interference avoidance control point P3, the rotating unit 3 swings and the boom 6 performs a lowering operation to move the control point of the bucket 8 toward the return swing control end point P1. If the lowering operation of the boom 6 ends before the rotating unit 3 swings to the target position of the rotating unit 3, the rotating unit 3 will swing with the bucket 8 positioned close to the ground G. This could result in unnecessary contact of the bucket 8 with the ground G and damage to the bucket 8, so it is necessary to avoid this occurrence. On the other hand, if the lowering operation of the boom 6 is not completed by the time the rotating unit 3 swings to the target position, a wait time for the boom 6 to move will occur, which is undesirable. During the return swing, it is preferable that the rotation of the rotating unit 3 and the lowering operation of the boom 6 be completed at the same time.

[0062] It is also necessary to suppress shocks caused by the lowering operation of the boom 6 during the return swing. In particular, it is necessary to operate the boom 6 smoothly while suppressing shocks when stopping the operation of the boom 6.

[0063] By appropriately setting the operating speed of the work implement 2 while the revolving unit 3 is rotating, it becomes possible to suitably operate the revolving unit 3 and the work implement 2. Setting the operating speed of the work implement 2 according to an embodiment of the present disclosure will be described below.

[0064] 7 is a block diagram showing a process for generating a boom speed command, which is a control command for the operating speed of the boom 6. The boom speed command generating unit 51A reads out a boom lowering reference first speed from the storage unit 54. The boom lowering reference first speed is set in advance and stored in the storage unit 54 in advance.

[0065] FIG. 8 is a diagram showing the boom lowering reference first speed. The horizontal axis of the graph shown in FIG. 8 is the remaining swing angle ratio. Here, the remaining swing angle refers to the swing angle of the swing unit 3 from the current position of the swing unit 3 to the target position. The remaining swing angle ratio refers to the ratio of the remaining swing angle to the swing angle of the swing unit 3 from the position of the swing unit 3 when the swing unit 3 starts to swing to the target position of the swing unit 3. It can be said that the swing angle of the swing unit 3 from the position of the swing unit 3 when the swing unit 3 starts to swing to the target position is the maximum value of the remaining swing angle (maximum remaining swing angle). The remaining swing angle ratio indicates the ratio of the remaining swing angle to the maximum remaining swing angle.

[0066] When the control target point of the bucket 8 is located at the interference avoidance control point P3, the remaining swing angle ratio is 1. When the control target point of the bucket 8 is located at the return swing control end point P1, the remaining swing angle ratio is 0. As the control target point of the bucket 8 moves within section S3 from the interference avoidance control point P3 toward the return swing control end point P1, the remaining swing angle decreases and the remaining swing angle ratio also decreases and approaches 0.

[0067] 8 is the boom lowering speed command value. The boom lowering speed command value is a control command for the operating speed of the boom 6 related to the lowering operation of the boom 6. It should be noted that the boom lowering speed command value is a control signal output from the controller 50 (command signal output unit 55) to the EPC valve 28, and may not necessarily coincide with the actual speed of the boom 6.

[0068] As shown in FIG. 8 , the boom lowering reference first speed is determined by a constant portion and a sigmoid portion. The constant portion is provided during the start period of the swing operation of the rotating unit 3. Here, the start period of the swing operation refers to a certain period of time that continues to an early stage of the swing operation, including the time when the swing unit 3 starts swinging within section S3. In the constant portion, the boom lowering speed command value is set to a constant value. The boom lowering speed command value in the constant portion is a constant low-speed boom lowering speed constant. In the early stage of the swing operation of the rotating unit 3, a control command that keeps the operating speed of the boom 6 constant is output to the EPC valve 28. The low-speed boom lowering speed constant can be changed as a parameter.

[0069] The slow boom lowering speed constant may be a value that sets the operating speed of the boom 6 to zero. In the initial step of the period when the rotating unit 3 starts to rotate, a control command that sets the operating speed of the boom 6 to zero may be output to the EPC valve 28. In the period when the rotating unit 3 starts to rotate, the boom 6 may be lowered at a constant slow speed, or the boom 6 may be kept stopped.

[0070] As the rotating body 3 rotates toward the return rotation control end point P1, the remaining rotation angle decreases, and the remaining rotation angle ratio decreases. The constant portion shifts to the sigmoid portion, and the operating speed of the boom 6 increases.

[0071] In the sigmoid portion, the boom lowering speed command value increases as the remaining rotation angle percentage decreases. In the sigmoid portion, the increase in the boom lowering speed command value relative to the decrease in the remaining rotation angle percentage is not constant. In the sigmoid portion, the graph of the boom lowering speed command value relative to the remaining rotation angle percentage is typically a sigmoid curve. In the sigmoid portion, the increase in the boom lowering speed command value relative to the remaining rotation angle percentage follows a sigmoid function. The slope of the graph of the boom lowering speed command value relative to the remaining rotation angle percentage can be adjusted with the sigmoid coefficient. The sigmoid coefficient can be changed as a parameter. When the sigmoid coefficient is large, the change in the sigmoid function becomes steeper.

[0072] Immediately after transitioning to the sigmoid portion, the increase in the boom lowering speed command value is small, and the boom lowering speed command value is slightly greater than the slow boom lowering speed constant. As the remaining rotation angle percentage decreases, the increase in the boom lowering speed command value per unit decrease in the remaining rotation angle percentage gradually increases. When the remaining rotation angle percentage becomes smaller than a certain value, the increase in the boom lowering speed command value per unit decrease in the remaining rotation angle percentage gradually decreases. As the remaining rotation angle percentage approaches zero, the boom lowering speed command value becomes approximately constant.

[0073] As shown in FIG. 7, the boom speed command generator 51A (FIG. 6) reads out the target position of the revolving unit 3 from the memory unit 54. The boom speed command generator 51A acquires the current position of the revolving unit 3 based on the satellite positioning signal and the rotation angle signal output from the position and orientation sensor 21. The boom speed command generator 51A calculates the remaining rotation angle of the revolving unit 3 from the current position of the revolving unit 3 to the target position. The boom speed command generator 51A calculates the remaining rotation angle rate using the calculated remaining rotation angle and the reciprocal of the required rotation amount of the revolving unit 3. The required rotation amount of the revolving unit 3 is the rotation angle of the revolving unit 3 about the rotation axis RX from the position of the revolving unit 3 when the revolving unit 3 starts to rotate to the target position. The required rotation amount of the revolving unit 3 is the maximum remaining rotation angle described above.

[0074] Boom speed command generating unit 51A applies the calculated remaining swing angle percentage to the graph shown in FIG. 8, and calculates a boom lowering speed command value based on the remaining swing angle percentage.

[0075] As shown in Fig. 7, the boom lowering speed command value based on the remaining rotation angle ratio is adjusted according to the rotation amount of the rotating unit 3. Fig. 9 is a diagram showing the adjustment of the boom lowering speed command value according to the rotation amount. The horizontal axis of the graph shown in Fig. 9 represents the rotation amount of the rotating unit 3, and the vertical axis of the graph represents the adjustment coefficient.

[0076] When the rotation amount of the rotating unit 3 is the reference rotation amount, the adjustment coefficient based on the rotation amount of the rotating unit 3 is set to 1. When the rotation amount of the rotating unit 3 is greater than the reference rotation amount, the rotation time increases, so the boom lowering speed per unit time is decreased, and the boom lowering time is increased. Therefore, when the rotation amount of the rotating unit 3 is greater than the reference rotation amount, the adjustment coefficient based on the rotation amount of the rotating unit 3 is set to a value smaller than 1. When the rotation amount of the rotating unit 3 is smaller than the reference rotation amount, the rotation time decreases, so the boom lowering speed per unit time is increased, and the boom lowering time is decreased. Therefore, when the rotation amount of the rotating unit 3 is smaller than the reference rotation amount, the adjustment coefficient based on the rotation amount of the rotating unit 3 is set to a value larger than 1.

[0077] 7, boom speed command generation unit 51A acquires the position of the rotating unit 3 when the control point of the bucket 8 is located at interference avoidance control point P3, and the position of the rotating unit 3 when the control point of the bucket 8 is located at return swing control end point P1. Boom speed command generation unit 51A uses the acquired position of the rotating unit 3 to calculate the required amount of rotation of the rotating unit 3. Boom speed command generation unit 51A applies the required amount of rotation of the rotating unit 3 to FIG. 9 to obtain an adjustment coefficient based on the amount of rotation of the rotating unit 3.

[0078] As shown in Fig. 7, the boom lowering speed command value based on the remaining swing angle ratio is adjusted according to the amount of lowering of the boom 6. Fig. 10 is a diagram showing adjustment of the boom lowering speed command value according to the amount of boom lowering. The horizontal axis of the graph shown in Fig. 10 represents the amount of lowering of the boom 6, and the vertical axis of the graph represents the adjustment coefficient.

[0079] When the amount of lowering of the boom 6 is the reference boom lowering amount, the adjustment coefficient for the amount of lowering of the boom 6 is set to 1. When the amount of lowering of the boom 6 increases, an adjustment is made to increase the amount of boom lowering per unit time, i.e., the boom lowering speed, so that the boom lowering time does not change. Therefore, when the amount of lowering of the boom 6 is greater than the reference boom lowering amount, the adjustment coefficient for the amount of lowering of the boom 6 is set to a value greater than 1. When the amount of lowering of the boom 6 decreases, an adjustment is made to decrease the amount of boom lowering per unit time, i.e., the boom lowering speed, so that the boom lowering time does not change. Therefore, when the amount of lowering of the boom 6 is smaller than the reference boom lowering amount, the adjustment coefficient for the amount of lowering of the boom 6 is set to a value less than 1.

[0080] 7, boom speed command generation unit 51A acquires the attitude of boom 6 when the control point of bucket 8 is located at interference avoidance control point P3, and the attitude of boom 6 when the control point of bucket 8 is located at return swing control end point P1. Boom speed command generation unit 51A calculates the required boom lowering amount using the acquired attitude of boom 6. The required boom lowering amount is the amount of lowering of boom 6 from the attitude of boom 6 when boom 6 starts the lowering operation to the target attitude of boom 6. Boom speed command generation unit 51A applies the required boom lowering amount to FIG. 10 to determine an adjustment coefficient based on the lowering amount of boom 6.

[0081] The boom speed command generation unit 51A calculates an adjusted first speed command value by multiplying the boom lowering speed command value based on the remaining rotation angle ratio by an adjustment coefficient based on the rotation amount of the rotating body 3 and an adjustment coefficient based on the boom lowering amount.

[0082] FIG. 11 is a virtual diagram in which the sigmoid portion of the boom lowering reference first speed shown in FIG. 8 is changed based on the rotation amount of the revolving unit 3 and the lowering amount of the boom 6. In the graph shown in FIG. 11, as in FIG. 8, the horizontal axis represents the remaining rotation angle percentage and the vertical axis represents the boom lowering speed command value. When the required rotation amount of the revolving unit 3 is smaller than the reference rotation amount, or when the lowering amount of the boom 6 is larger than the reference boom lowering amount, boom speed command generator 51A increases the boom lowering speed command value above the reference speed. When the required rotation amount of the revolving unit 3 is larger than the reference rotation amount, or when the lowering amount of the boom 6 is smaller than the reference boom lowering amount, boom speed command generator 51A decreases the boom lowering speed command value below the reference speed.

[0083] The boom lowering speed command value in the sigmoid portion is adjusted based on the rotation amount and boom lowering amount of the rotating unit 3. On the other hand, the boom lowering speed command value in the constant portion is not adjusted based on the rotation amount and boom lowering amount of the rotating unit 3. Even if the rotation amount or boom lowering amount of the rotating unit 3 differs from the reference amount, the boom lowering speed command value in the constant portion is a fixed low-speed boom lowering speed constant.

[0084] 7, boom speed command generating unit 51A reads out the boom lowering reference second speed from storage unit 54. The boom lowering reference second speed is set in advance and stored in storage unit 54 in advance.

[0085] FIG. 12 is a diagram showing the boom lowering reference second speed. The horizontal axis of the graph shown in FIG. 12 represents the remaining boom angle. The remaining boom angle refers to the rotation angle of the boom 6, which rotates vertically relative to the revolving unit 3 around the boom foot pin 13 as a fulcrum, when the boom 6 moves from its current position to its target position. The remaining boom angle is maximum when the control target point of the bucket 8 is located at the interference avoidance control point P3. The remaining boom angle is zero when the control target point of the bucket 8 is located at the return swing control end point P1. As the control target point of the bucket 8 moves within section S3 from the interference avoidance control point P3 toward the return swing control end point P1, the remaining boom angle decreases and approaches zero. As in FIG. 8, the vertical axis of the graph shown in FIG. 12 represents the boom lowering speed command value.

[0086] As shown in Figure 12, the boom lowering speed command value decreases as the remaining boom angle decreases. When the remaining boom angle is relatively large, the boom lowering speed command value is set to a relatively large value. When the remaining boom angle is relatively large, the amount of decrease in the boom lowering speed command value for a given decrease in the remaining boom angle is small. When the remaining boom angle decreases and becomes smaller than a certain value, the boom lowering speed command value decreases sharply. When the remaining boom angle is smaller than a certain value, the boom lowering speed command value decreases linearly in proportion to the remaining boom angle.

[0087] As shown in FIG. 7, boom speed command generation unit 51A (FIG. 6) reads out the target attitude of boom 6 from memory unit 54. Boom speed command generation unit 51A calculates the current attitude of boom 6 based on the attitude signal of work implement 2 output from work implement attitude sensor 20. Boom speed command generation unit 51A calculates the remaining boom angle using the current attitude and target attitude of boom 6. The remaining boom angle is the rotation angle of boom 6 relative to revolving unit 3 when boom 6 moves from the angle of boom 6 relative to revolving unit 3 when the boom 6 is in the current attitude (current boom angle) to the angle of boom 6 relative to revolving unit 3 when the boom 6 is in the target attitude (target boom angle).

[0088] Boom speed command generating unit 51A applies the calculated remaining boom angle to the graph shown in FIG. 12, and calculates a boom lowering speed command value based on the remaining boom angle.

[0089] As shown in Fig. 7, the boom lowering speed command value based on the remaining boom angle is adjusted according to the weight of the bucket 8. Fig. 13 is a diagram showing adjustment of the boom lowering speed command value according to the bucket weight. The horizontal axis of the graph shown in Fig. 13 represents the weight of the bucket 8, and the vertical axis of the graph represents the adjustment coefficient.

[0090] When the weight of the bucket 8 is the reference bucket weight, the adjustment coefficient for the weight of the bucket 8 is set to 1. If the weight of the bucket 8 is large, even a small boom lowering speed command value will result in a large speed at which the boom 6 actually lowers, so the boom lowering speed command value is decreased to adjust the actual speed of the boom 6 to be equivalent to the reference speed. Therefore, when the weight of the bucket 8 is larger than the reference bucket weight, the adjustment coefficient for the weight of the bucket 8 is set to a value smaller than 1. If the weight of the bucket 8 is small, the required boom lowering speed cannot be obtained with the boom lowering speed command value under the reference conditions, so the boom lowering speed command value is increased to adjust the actual speed of the boom 6 to be equivalent to the reference speed. Therefore, when the weight of the bucket 8 is smaller than the reference bucket weight, the adjustment coefficient for the weight of the bucket 8 is set to a value larger than 1.

[0091] 7, boom speed command generating unit 51A obtains the weight of bucket 8. The weight of bucket 8 is input to controller 50 by the operator operating input device 26, and is stored in advance in memory unit 54. Boom speed command generating unit 51A reads out the weight of bucket 8 from memory unit 54. Boom speed command generating unit 51A applies the weight of bucket 8 to FIG. 13 to determine an adjustment coefficient based on the weight of bucket 8.

[0092] The type and weight of the bucket 8 may be stored in association with each other in the storage unit 54. When the operator operates the input device 26 to input the type of bucket 8 to the controller 50, the controller 50 may acquire the weight of the bucket 8 that is associated with the input type of bucket 8.

[0093] Boom speed command generating unit 51A multiplies the boom lowering speed command value based on the remaining boom angle by an adjustment coefficient based on the weight of bucket 8, to obtain an adjusted second speed command value.

[0094] FIG. 14 is a hypothetical diagram in which the boom lowering reference second speed shown in FIG. 12 is changed based on the weight of bucket 8. In the graph shown in FIG. 14, as in FIG. 12, the horizontal axis represents the remaining boom angle and the vertical axis represents the boom lowering speed command value. When the weight of bucket 8 is lighter than the reference bucket weight, boom speed command generation unit 51A sets the boom lowering speed command value to be greater than the reference speed. When the weight of bucket 8 is heavier than the reference bucket weight, boom speed command generation unit 51A sets the boom lowering speed command value to be less than the reference speed.

[0095] 7, boom speed command generation unit 51A compares an adjusted first speed command value obtained based on the remaining swing angle ratio with an adjusted second speed command value obtained based on the remaining boom angle, and selects the smaller speed command value. Boom speed command generation unit 51A generates, as a boom speed command, a control command based on the smaller speed command value of the adjusted first speed command value calculated based on the remaining swing angle ratio and the adjusted second speed command value calculated based on the remaining boom angle. The generated boom speed command is output to EPC valve 28.

[0096] FIG. 15 is a virtual diagram showing a comparison and selection between the adjusted first speed command value and the adjusted second speed command value. The horizontal axis of the graph shown in FIG. 15 represents the remaining swing angle percentage or the remaining boom angle, and the vertical axis of the graph represents the boom lowering speed command value. The solid line graph shown in FIG. 15 represents the smaller speed command value of the adjusted first speed command value and the adjusted second speed command value. The dashed line graph shown in FIG. 15 represents the larger speed command value of the adjusted first speed command value and the adjusted second speed command value. The boom lowering speed command value is determined by the solid line graph shown in FIG. 15.

[0097] During the start of rotation of the rotating unit 3, a control command to keep the boom 6 lowering speed constant is output to the EPC valve 28. During the start of rotation of the rotating unit 3, the boom lowering speed command value is set to a constant low-speed boom lowering speed constant, and a control command based on the low-speed boom lowering speed constant is generated. During the start of rotation of the rotating unit 3, the boom 6 is either kept stopped or the boom 6 is lowered at a constant low speed while the rotating unit 3 is rotated.

[0098] During the start of the lowering operation of the boom 6 while the rotating unit 3 is rotating, the adjusted first speed command value is selected, and a control command is generated based on a boom lowering speed command value calculated based on the remaining rotation angle percentage. During the start of the lowering operation of the boom 6 while the rotating unit 3 is rotating, a control command is output to the EPC valve 28 to increase the boom lowering operation command value as the remaining rotation angle becomes smaller. During the start of the lowering operation of the boom 6, a control command is output to the EPC valve 28 to increase the boom lowering operation command value as the remaining rotation angle percentage becomes smaller.

[0099] The increase in the boom lowering speed command value during the start of the lowering operation of the boom 6 is not constant, but increases rapidly as the remaining rotation angle becomes smaller. During the start of the lowering operation of the boom 6, a control command is output to the EPC valve 28 to increase the acceleration of the lowering operation of the boom 6 as the remaining rotation angle becomes smaller.

[0100] During the termination period of the lowering operation of the boom 6 while the revolving unit 3 is rotating, the adjusted second speed command value is selected, and a control command is generated based on the boom lowering speed command value calculated based on the remaining boom angle. During the termination period of the lowering operation of the boom 6 while the revolving unit 3 is rotating, a control command is output to the EPC valve 28 to decrease the boom lowering speed command value as the remaining boom angle decreases. By outputting a control command calculated based on the remaining boom angle, the lowering speed of the boom 6 gradually decreases as the remaining rotation angle decreases. During the termination period of the lowering operation of the boom 6 while the revolving unit 3 is rotating, a control command is output to the EPC valve 28 to decrease the boom lowering operation command value as the remaining rotation angle decreases.

[0101] Here, the start period of the boom 6 lowering operation refers to a period of time that continues to some extent at the beginning of the boom 6 lowering operation within section S3. The start period of the boom 6 lowering operation includes the time point at which the boom lowering speed command value starts to increase from the low-speed boom lowering speed constant. The start period of the boom 6 lowering operation is the time period before the sigmoid portion shown in Figure 15. The start period of the boom 6 lowering operation includes the time point at which the constant portion shown in Figure 15 transitions to the sigmoid portion.

[0102] The period when the rotating unit 3 starts to rotate and the period when the boom 6 starts to lower while the rotating unit 3 is rotating are different periods that are consecutive to each other. If the boom 6 is kept stopped during the period when the rotating unit 3 starts to rotate, the period when the boom lowering starts includes the time when a control command is output to start the boom 6 lowering operation and increase the lowering speed of the boom 6 above zero. If the boom is lowered at a constant low speed during the period when the rotating unit 3 starts to rotate, the period when the boom lowering starts includes the time when a control command is output to increase the lowering speed of the boom 6 above that low speed.

[0103] The end period of the boom 6 lowering operation refers to a certain amount of time that continues towards the end of the boom 6 lowering operation within section S3. The end period of the boom 6 lowering operation includes the time point at which the boom lowering speed command value becomes zero. The end period of the boom 6 lowering operation is the time period after the sigmoid portion shown in Figure 15. The end period of the boom 6 lowering operation includes the time point at which a control command is output to stop the boom 6 lowering operation and set the boom 6 lowering speed to zero.

[0104] There is no temporal overlap between the start period of the lowering operation of the boom 6 and the end period of the lowering operation of the boom 6. The end period of the lowering operation of the boom 6 is a time period after the start period of the lowering operation of the boom 6.

[0105] <Generation of arm speed command> 16 is a block diagram showing the process of generating an arm velocity command, which is a control command for the motion velocity of the arm 7. The arm velocity command generation unit 51B reads out the arm motion reference velocity from the storage unit 54. The arm motion reference velocity is set in advance and stored in the storage unit 54 in advance.

[0106] FIG. 17 is a diagram showing the arm operation reference speed. The horizontal axis of the graph shown in FIG. 17 is the remaining arm angle. The remaining arm angle refers to the rotation angle of the arm 7 when the arm 7, which rotates relative to the boom 6 around the boom top pin 14 as a fulcrum, moves from its current posture to its target posture. The absolute value of the remaining arm angle is maximum when the control target point of the bucket 8 is located at the interference avoidance control point P3. The remaining arm angle is 0 when the control target point of the bucket 8 is located at the return swing control end point P1. As the control target point of the bucket 8 moves within section S3 from the interference avoidance control point P3 toward the return swing control end point P1, the remaining arm angle approaches 0.

[0107] The vertical axis of the graph shown in Fig. 17 is the arm velocity command value. The arm velocity command value is a control command for the motion speed of the arm 7 regarding the motion of the arm 7 relative to the boom 6. It should be noted that the arm velocity command value is a control signal output from the controller 50 (command signal output unit 55) to the EPC valve 28, and may not necessarily coincide with the actual speed of the arm 7.

[0108] When the absolute value of the remaining arm angle is relatively large, the arm speed command value is set to a relatively large value. As the absolute value of the remaining arm angle decreases, the absolute value of the arm speed command value also decreases and approaches 0. As the absolute value of the remaining arm angle decreases, the amount of change in the arm speed command value relative to a constant amount of change in the absolute value of the remaining arm angle gradually becomes smaller. When the absolute value of the arm speed command value is relatively large, the arm speed command value changes rapidly when the remaining arm angle changes. When the remaining arm angle approaches zero, the arm speed command value changes gradually when the remaining arm angle changes.

[0109] As shown in FIG. 16, the arm speed command generation unit 51B (FIG. 6) reads out the target posture of the arm 7 from the memory unit 54. The arm speed command generation unit 51B calculates the current posture of the arm 7 based on the posture signal of the work implement 2 output from the work implement posture sensor 20. The arm speed command generation unit 51B calculates the remaining arm angle using the current posture and target posture of the arm 7. The remaining arm angle is the rotation angle of the arm 7 relative to the boom 6 when the arm 7 moves from the angle of the arm 7 relative to the boom 6 when the arm 7 is in the current posture (current arm angle) to the angle of the arm 7 relative to the boom 6 when the arm 7 is in the target posture (target arm angle).

[0110] The arm speed command generating unit 51B applies the calculated remaining arm angle to the graph shown in FIG. 17 to determine an arm speed command value based on the remaining arm angle.

[0111] As shown in Fig. 16, an arm speed command value based on the remaining arm angle is adjusted according to the weight of the bucket 8. For this adjustment, the graph described with reference to Fig. 13 is used to determine an adjustment coefficient according to the weight of the bucket 8.

[0112] Arm velocity command generation unit 51B obtains the weight of bucket 8. Arm velocity command generation unit 51B applies the weight of bucket 8 to Fig. 13 to determine an adjustment coefficient based on the weight of bucket 8. Arm velocity command generation unit 51B multiplies the arm velocity command value based on the remaining arm angle by the adjustment coefficient based on the weight of bucket 8 to determine a post-adjustment arm operation velocity command value.

[0113] FIG. 18 is a virtual diagram in which the arm operation reference speed shown in FIG. 17 is changed based on the weight of bucket 8. In the graph shown in FIG. 18, as in FIG. 17, the horizontal axis represents the remaining arm angle and the vertical axis represents the arm speed command value. When the weight of bucket 8 is lighter than the reference bucket weight, arm speed command generation unit 51B sets the arm speed command value to be greater than the reference speed. When the weight of bucket 8 is heavier than the reference bucket weight, arm speed command generation unit 51B sets the arm speed command value to be smaller than the reference speed.

[0114] 16, the arm velocity command generator 51B generates a control command based on the obtained adjusted arm velocity command value as an arm velocity command. The generated arm velocity command is output to the EPC valve 28.

[0115] <Bucket speed command generation> 19 is a block diagram showing the process of generating a bucket speed command, which is a control command for the operating speed of the bucket 8. Bucket speed command generating unit 51C reads out the bucket operating reference speed from storage unit 54. The bucket operating reference speed is set in advance and stored in storage unit 54 in advance.

[0116] FIG. 20 is a diagram showing the bucket operation reference speed. The horizontal axis of the graph shown in FIG. 20 is the remaining bucket angle. The remaining bucket angle refers to the rotation angle of the bucket 8 when the bucket 8, which rotates relative to the arm 7 with the arm top pin 15 as the fulcrum, moves from its current posture to its target posture. The absolute value of the remaining bucket angle is maximum when the control target point of the bucket 8 is located at the interference avoidance control point P3. The remaining bucket angle is 0 when the control target point of the bucket 8 is located at the return swing control end point P1. As the control target point of the bucket 8 moves within section S3 from the interference avoidance control point P3 toward the return swing control end point P1, the remaining bucket angle approaches 0.

[0117] The vertical axis of the graph shown in Fig. 20 is the bucket velocity command value. The bucket velocity command value is a control command for the motion speed of the bucket 8 related to the motion of the bucket 8 relative to the arm 7. It should be noted that the bucket velocity command value is a control signal output from the controller 50 (command signal output unit 55) to the EPC valve 28, and may not necessarily coincide with the actual velocity of the bucket 8.

[0118] When the absolute value of the remaining bucket angle is relatively large, the bucket speed command value is set to a relatively large value. As the absolute value of the remaining bucket angle decreases, the absolute value of the bucket speed command value also decreases and approaches zero. As the absolute value of the remaining bucket angle decreases, the amount of change in the bucket speed command value relative to a constant amount of change in the absolute value of the remaining bucket angle gradually decreases. When the absolute value of the bucket speed command value is relatively large, a change in the remaining bucket angle causes a rapid change in the bucket speed command value. When the remaining bucket angle approaches zero, a change in the remaining bucket angle causes a gradual change in the bucket speed command value.

[0119] As shown in FIG. 19, bucket speed command generation unit 51C (FIG. 6) reads out the target attitude of the bucket 8 from memory unit 54. Bucket speed command generation unit 51C calculates the current attitude of the bucket 8 based on the attitude signal of the work machine 2 output from work machine attitude sensor 20. Bucket speed command generation unit 51C calculates the remaining bucket angle using the current attitude and target attitude of the bucket 8. The remaining bucket angle is the rotational angle of the bucket 8 relative to the arm 7 when the bucket 8 moves from the angle of the bucket 8 relative to the arm 7 when the bucket 8 is in the current attitude (current bucket angle) to the angle of the bucket 8 relative to the arm 7 when the bucket 8 is in the target attitude (target bucket angle).

[0120] Bucket speed command generating unit 51C applies the calculated remaining bucket angle to the graph shown in FIG. 20 to determine a bucket speed command value based on the remaining bucket angle.

[0121] As shown in Fig. 19, the bucket speed command value based on the remaining bucket angle is adjusted according to the weight of the bucket 8. For this adjustment, the graph described with reference to Fig. 13 is used to find the adjustment coefficient according to the weight of the bucket 8.

[0122] The bucket speed command generation unit 51C acquires the weight of the bucket 8. The bucket speed command generation unit 51C applies the weight of the bucket 8 to FIG. 13 to determine an adjustment coefficient based on the weight of the bucket 8. The bucket speed command generation unit 51C determines a post-adjustment bucket operation speed command value by multiplying the bucket speed command value based on the remaining bucket angle by the adjustment coefficient based on the weight of the bucket 8.

[0123] FIG. 21 is a hypothetical diagram in which the bucket operation reference speed shown in FIG. 20 is changed based on the weight of bucket 8. In the graph shown in FIG. 21, similar to FIG. 20, the horizontal axis represents the remaining bucket angle and the vertical axis represents the bucket speed command value. When the weight of bucket 8 is lighter than the reference bucket weight, bucket speed command generation unit 51C makes the bucket speed command value larger than the reference speed. When the weight of bucket 8 is heavier than the reference bucket weight, bucket speed command generation unit 51C makes the bucket speed command value smaller than the reference speed.

[0124] 19, bucket velocity command generator 51C generates a control command based on the determined adjusted bucket velocity command value as a bucket velocity command. The generated bucket velocity command is output to EPC valve 28.

[0125] <Action and effect> The characteristic configuration and effects of this embodiment are summarized as follows.

[0126] 15, the controller 50 outputs a control command to the EPC valve 28 to increase the operating speed of the work implement 2 as the remaining rotation angle to the target position of the rotating body 3 decreases during the start period of operation of the work implement 2 while the rotating body 3 is rotating. The controller 50 outputs a control command to the EPC valve 28 to decrease the operating speed of the work implement 2 as the remaining rotation angle decreases during the end period of operation of the work implement 2 while the rotating body 3 is rotating.

[0127] If a large speed command value is output when starting operation of the work implement 2 during a return swing, the work implement 2 may attempt to operate at high speed, which could result in a shock. By outputting a control command that gradually increases the operating speed of the work implement 2 during the start of operation of the work implement 2, the occurrence of such a shock can be suppressed. Furthermore, if the speed command value is suddenly set to zero when stopping operation of the work implement 2, a shock may occur due to the inertia of the work implement 2. By outputting a control command that gradually decreases the operating speed of the work implement 2 during the end of operation of the work implement 2, the occurrence of such a shock can be suppressed. Therefore, it is possible to operate the work implement 2 in an optimal manner while the revolving unit 3 is swinging.

[0128] As shown in FIG. 15 , during the start of operation of the work implement 2 while the rotating unit 3 is rotating, the controller 50 may output a control command to the EPC valve 28 to increase the operating speed of the work implement 2 as the ratio of the remaining swing angle to the rotation angle of the rotating unit 3 from the position at which the rotating unit 3 starts swinging to the target position decreases. Because the required swing amount of the rotating unit 3 during return swing is not constant, determining the control command for the operating speed of the work implement 2 based on the remaining swing angle ratio rather than the remaining swing angle makes it possible to suitably output a control command corresponding to various required swing amounts. Operating the work implement 2 based on the remaining swing angle may result in the rotating unit 3 swinging while maintaining the work implement 2 in a high posture, for example, during the start of swing. Operating the work implement 2 based on the remaining swing angle ratio rather than the remaining swing angle can avoid such a situation and allow the work implement 2 to operate suitably.

[0129] 15, the controller 50 may output to the EPC valve 28 a control command to increase the acceleration of the operation of the work machine 2 as the remaining swing angle decreases during the start of operation of the work machine 2 while the rotating body 3 is swinging. By outputting a control command that gradually increases the increase in the operating speed of the work machine 2 for a constant swing of the rotating body 3, it is possible to reliably suppress the occurrence of shocks due to the operation of the work machine 2, and to operate the work machine 2 appropriately.

[0130] As shown in Fig. 15, the controller 50 may output to the EPC valve 28 a control command to reduce the operating speed of the work machine 2 as the remaining angle of movement from the current attitude of the work machine 2 to the target attitude decreases during the end period of the operation of the work machine 2 while the rotating body 3 is rotating. By gradually reducing the operating speed of the work machine 2 during the end period of the operation of the work machine 2 based on the remaining angle of movement of the work machine 2, it becomes possible to output a control command to reduce the operating speed of the work machine 2 to zero when the work machine 2 stops. This makes it possible to reliably suppress the occurrence of shock due to the inertia of the work machine 2 when the work machine 2 stops.

[0131] During the end period of the operation of the work implement 2 while the rotating body 3 is rotating, a control command is output to reduce the operating speed of the work implement 2 as the remaining movement angle of the work implement 2 becomes smaller, so that the work implement 2 can be operated so that the operating speed of the work implement 2 becomes smaller as the remaining rotation angle of the rotating body 3 becomes smaller.

[0132] As shown in Fig. 15, the controller 50 may output a control command to the EPC valve 28 to keep the operating speed of the work implement 2 constant during the start period of the swing of the swing body 3. If the control command for the operating speed of the work implement 2 is suddenly increased at the timing when the operation of the work implement 2 starts, a shock may occur. By outputting a control command to keep the operating speed of the work implement 2 constant during the start period of the return swing, and then outputting a control command to gradually increase the operating speed of the work implement 2, it is possible to more reliably prevent shock from occurring due to the operation of the work implement 2.

[0133] 15, the controller 50 may output a control command to the EPC valve 28 to set the operating speed of the work implement 2 to zero during the start period of the swing of the swing body 3. During the start period of the return swing, a control command of a magnitude that does not actually cause the work implement 2 to operate is output, and then, at the timing when the operation of the work implement 2 actually starts, the control command for the operating speed of the work implement 2 is increased, thereby more reliably suppressing the occurrence of shocks due to the operation of the work implement 2.

[0134] As shown in FIG. 1, the work machine 2 includes a boom 6 rotatably connected to a rotating bed 3, and as shown in FIG. 15, the operation of the work machine 2 may be an operation to lower the boom 6. When the boom 6, which is a heavy object, is lowered, the speed at which the boom 6 is lowered may be faster than intended due to the influence of gravity, which may result in a shock. The occurrence of such a shock can be suppressed by outputting a control command to gradually increase the lowering speed of the boom 6 during the start of the lowering operation of the boom 6.

[0135] As shown in FIG. 11, the controller 50 adjusts the control command to increase the operating speed of the work implement 2 as the remaining rotation angle of the rotating body 3 to the target position decreases, based on at least one of the rotation angle of the rotating body 3 from the position when the rotating body 3 starts rotating to the target position, and the movement angle of the work implement 2 from the start of operation to the end of operation.

[0136] If the operating speed of the work unit 2 is high relative to the rotation angle of the rotating unit 3, the movement of the work unit 2 will end before the rotating unit 3 rotates to the target position. On the other hand, if the operating speed of the work unit 2 is low relative to the rotation angle of the rotating unit 3, the movement of the work unit 2 will not have finished when the rotating unit 3 rotates to the target position. By adjusting the operating speed of the work unit 2 based on either or both of the required rotation amount of the rotating unit 3 and the required movement amount of the work unit, the timing at which the rotation of the rotating unit 3 ends and the timing at which the movement of the work unit 2 ends can be made closer, making it possible to operate the work unit 2 appropriately while the rotating unit 3 is rotating.

[0137] If the operating speed of the work unit 2 is not adjusted when the rotation angle of the revolving unit 3 is greater than the reference angle, the movement of the work unit 2 will end before the revolving unit 3 rotates to the target position, so in this case, the operating speed of the work unit 2 may be adjusted to decrease. As shown in Figure 9, when the rotation angle of the revolving unit 3 is greater than the reference angle, the operating speed of the work unit 2 may be adjusted to gradually decrease as the difference between the rotation angle of the revolving unit 3 and the reference angle increases. This ensures that the timing when the revolving unit 3 finishes rotating and the timing when the work unit 2 finishes moving are closer together.

[0138] If the operating speed of the work machine 2 is not adjusted when the movement angle of the work machine 2 is smaller than the reference angle, the movement of the work machine 2 will end before the revolving unit 3 swings to the target position, so in this case, the operating speed of the work machine 2 may be adjusted to be slower. As shown in Fig. 10, when the movement angle of the work machine 2 is smaller than the reference angle, the operating speed of the work machine 2 may be adjusted to gradually decrease as the difference between the movement angle of the work machine 2 and the reference angle increases. This ensures that the timing at which the revolving unit 3 swings and the timing at which the work machine 2 swings end are brought closer together.

[0139] If the operating speed of the work unit 2 is not adjusted when the rotation angle of the revolving unit 3 is smaller than the reference angle, the movement of the work unit 2 will not have finished when the revolving unit 3 has rotated to the target position, so in this case, the operating speed of the work unit 2 may be adjusted to increase. As shown in Figure 9, when the rotation angle of the revolving unit 3 is smaller than the reference angle, the operating speed of the work unit 2 may be adjusted to gradually increase as the difference between the rotation angle of the revolving unit 3 and the reference angle increases. This ensures that the timing when the revolving unit 3 finishes rotating and the timing when the work unit 2 finishes moving are closer together.

[0140] If the operating speed of the work machine 2 is not adjusted when the movement angle of the work machine 2 is greater than the reference angle, the movement of the work machine 2 will not have finished when the revolving unit 3 has rotated to the target position, so in this case, the operating speed of the work machine 2 may be adjusted to be increased. As shown in Fig. 10, when the movement angle of the work machine 2 is greater than the reference angle, the operating speed of the work machine 2 may be adjusted to gradually increase as the difference between the movement angle of the work machine 2 and the reference angle increases. This makes it possible to reliably bring the timing at which the rotation of the revolving unit 3 ends and the timing at which the movement of the work machine 2 ends closer together.

[0141] As shown in FIG. 14, the controller 50 adjusts the control command based on the weight of the work implement 2 to decrease the operating speed of the work implement 2 as the remaining movement angle from the current posture of the work implement 2 to the target posture decreases.

[0142] When the weight of the work implement 2 is large, the inertia of the work implement 2 is large. When the weight of the work implement 2 is small, the inertia of the work implement 2 is small. The weight of the work implement 2 affects the responsiveness of the work implement 2 when reducing its operating speed. By adjusting the operating speed of the work implement 2 based on the weight of the work implement 2, it is possible to operate the work implement 2 at an appropriate speed that corresponds to the responsiveness of the work implement 2 when reducing its operating speed. By appropriately setting the amount of change in the speed of the work implement until the operating work implement 2 is stopped, it becomes easier to stop the work implement 2 in the target attitude.

[0143] When the weight of the work machine 2 is greater than the reference weight, the operating speed of the work machine 2 may be reduced to reduce the amount of speed change until the work machine 2 stops. By making such an adjustment, it becomes easier to stop the work machine 2 in the target posture. Since the slope of the operating speed of the work machine 2 when decelerating a heavy work machine 2 can be made smaller, it is possible to reduce the shock when the work machine 2 stops. As shown in FIG. 13, when the weight of the work machine 2 is greater than the reference weight, the operating speed of the work machine 2 may be adjusted to gradually decrease as the difference between the weight of the work machine 2 and the reference weight increases.

[0144] When the weight of the work machine 2 is smaller than the reference weight, the operating speed of the work machine 2 may be increased. By making such an adjustment, the work machine 2 can be moved to the target posture in a short time. Although the amount of speed change required to stop the work machine 2 increases, the inertia of the work machine 2 is small and the responsiveness during speed changes is high, so it is possible to reliably stop the work machine 2 at the target posture. As shown in FIG. 13, when the weight of the work machine 2 is smaller than the reference weight, the operating speed of the work machine 2 may be adjusted to gradually increase as the difference between the weight of the work machine 2 and the reference weight increases.

[0145] In the above description of the embodiment, an example was described in which the boom lowering reference first speed shown in FIG. 8 is a sigmoid curve in the sigmoid portion. A graph of the boom lowering speed command value versus the remaining swing angle percentage does not necessarily include a sigmoid curve. The boom lowering reference first speed in the sigmoid portion may be a curve according to another type of function, such as a quartic function or a quadratic function. Alternatively, the boom lowering reference first speed may be a straight line according to a linear function. The boom lowering reference first speed may be a graph according to any function that increases the operating speed of the work implement 3 as the remaining swing angle of the rotating unit 3 decreases during the start of operation of the work implement 2 while the rotating unit 3 is rotating.

[0146] In the description of the embodiment, an example has been described in which the boom lowering reference second speed shown in Fig. 12 is a function of the boom lowering speed command value relative to the remaining boom angle. The boom lowering reference second speed may also be a function of the boom lowering speed command value relative to the remaining rotation angle. The boom lowering reference second speed may also be a function of the boom lowering speed command value relative to the remaining rotation angle percentage.

[0147] The process for generating a boom speed command described with reference to Figures 7 to 15 can also be applied to generating an arm speed command and a bucket speed command. By introducing a speed limit based on the remaining swing angle, the operation of the work machine 2 that moves automatically by return swing control can be made to resemble the operation of the work machine 2 in accordance with the operation of a skilled operator.

[0148] In the description of the embodiment, a hydraulic excavator 100 is given as an example of a work machine, but the present invention is not limited to the hydraulic excavator 100 and can also be applied to other types of work machines such as loading shovels, mechanical rope shovels, electric shovels, and bucket cranes.

[0149] <Additional Notes> The above description includes the following additional features.

[0150] (Appendix 1) a first step of outputting a control command to increase the operating speed of the work implement as a remaining rotation angle of the rotating body to a target position of the rotating body decreases during a period during which the work implement starts to operate while the rotating body is rotating; a second step of outputting a control command during a period in which the operation of the work machine is to end while the rotating body is rotating, such that the operating speed of the work machine decreases as the remaining rotation angle decreases.

[0151] (Appendix 2) The control method described in Appendix 1, wherein in the first step, a control command is output to increase the operating speed of the work machine as a ratio of the remaining rotation angle to the rotation angle of the rotating body from the position when the rotating body starts to rotate to the target position decreases.

[0152] (Appendix 3) The control method according to claim 1 or 2, wherein in the first step, a control command is output to increase the acceleration of the operation of the work machine as the remaining swing angle decreases.

[0153] (Appendix 4) 4. The control method according to claim 1, wherein the second step outputs a control command to reduce the operating speed of the work machine as the remaining movement angle from the current attitude of the work machine to the target attitude becomes smaller.

[0154] (Appendix 5) 5. The control method according to any one of claims 1 to 4, further comprising an initial step of outputting a control command to keep the operating speed of the work machine constant during a period when the rotation of the rotating body starts.

[0155] (Appendix 6) 6. The control method according to claim 5, wherein in the initial step, a control command is output to set the operating speed of the work machine to zero.

[0156] (Appendix 7) the work machine includes a boom rotatably connected to the rotating body, 7. The control method according to any one of claims 1 to 6, wherein the operation of the work machine is a lowering operation of the boom.

[0157] (Appendix 8) A rotating body; a work machine operably attached to the rotating body; a work machine actuator that drives the work machine; a control valve for controlling the work machine actuator; a controller that outputs a control command to the control valve during a period in which the operation of the work machine starts while the rotating body is rotating, so as to increase the operating speed of the work machine as the remaining rotation angle to the target position of the rotating body decreases, and that outputs a control command to the control valve during a period in which the operation of the work machine ends while the rotating body is rotating, so as to decrease the operating speed of the work machine as the remaining rotation angle decreases.

[0158] (Appendix 9) The work machine described in Appendix 8, wherein the controller outputs a control command to the control valve during a period in which the work machine starts operating to increase the operating speed of the work machine as the ratio of the remaining swing angle to the swing angle of the rotating body from a position at which the rotating body starts rotating to the target position decreases.

[0159] (Appendix 10) The work machine according to claim 8 or 9, wherein the controller outputs a control command to the control valve during a period when the work machine starts to operate, to increase the acceleration of the operation of the work machine as the remaining swing angle becomes smaller.

[0160] (Appendix 11) The work machine according to any one of Supplementary Note 8 to Supplementary Note 10, wherein the controller outputs a control command to the control valve during a period in which the work machine is ending operating to reduce the operating speed of the work machine as a remaining angle of movement from a current attitude of the work machine to a target attitude decreases.

[0161] (Appendix 12) 12. The work machine according to any one of Supplementary Note 8 to Supplementary Note 11, wherein the controller outputs a control command to the control valve to keep the operating speed of the work implement constant during a period when the rotating body starts to rotate.

[0162] (Appendix 13) 13. The work machine according to claim 12, wherein the controller outputs a control command to the control valve to set the operating speed of the work implement to zero during a period when the rotating body starts to rotate.

[0163] (Appendix 14) the work machine includes a boom rotatably connected to the rotating body, 14. The work machine according to any one of Supplementary Note 8 to Supplementary Note 13, wherein the operation of the work implement is an operation of lowering the boom.

[0164] (Appendix 15) a step of adjusting a control command for increasing the operating speed of the work implement as the remaining rotation angle of the rotating body to which the work implement is operably attached to the target position decreases, based on at least one of the rotation angle of the rotating body from the position at which the rotating body starts to rotate to the target position and the movement angle of the work implement from the start of operation to the end of operation; and outputting the adjusted control command.

[0165] (Appendix 16) 16. The control method according to claim 15, wherein when the swing angle is greater than a reference angle, the operating speed of the work machine is adjusted to be slower.

[0166] (Appendix 17) 17. The control method according to claim 16, wherein the operating speed of the work machine is adjusted to gradually decrease as the difference between the swing angle and the reference angle increases.

[0167] (Appendix 18) A rotating body; a work machine operably attached to the rotating body; a controller that adjusts a control command to increase the operating speed of the work implement as the remaining rotation angle of the rotating body to the target position decreases, based on at least one of the rotation angle of the rotating body from the position when the rotating body starts to rotate to the target position, and the movement angle of the work implement from the start of operation to the end of operation.

[0168] (Appendix 19) The work machine according to claim 18, wherein the controller adjusts the operating speed of the work implement to be slower when the swing angle is greater than a reference angle.

[0169] (Appendix 20) The work machine according to claim 19, wherein the controller adjusts the operating speed of the work implement to gradually decrease as the difference between the swing angle and the reference angle increases.

[0170] (Appendix 21) a step of adjusting a control command to reduce the operating speed of the work machine as a remaining movement angle from a current attitude of the work machine to a target attitude becomes smaller, based on the weight of the work machine; and outputting the adjusted control command.

[0171] (Appendix 22) 22. The control method according to claim 21, wherein when the weight of the work machine is greater than a reference weight, the operating speed of the work machine is adjusted to be slower.

[0172] (Appendix 23) 23. The control method according to claim 22, wherein the operating speed of the work machine is adjusted to gradually decrease as the difference between the weight of the work machine and the reference weight increases.

[0173] (Appendix 24) A work machine, a controller that adjusts a control command to reduce the operating speed of the work machine as the remaining movement angle from the current attitude of the work machine to a target attitude becomes smaller, based on the weight of the work machine.

[0174] (Appendix 25) The work machine according to claim 24, wherein the controller adjusts the operating speed of the work machine to be slower when the weight of the work machine is greater than a reference weight.

[0175] (Appendix 26) 26. The work machine according to claim 25, wherein the controller adjusts the operating speed of the work machine to gradually decrease as the difference between the weight of the work machine and the reference weight increases.

[0176] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0177] 1 main body, 2 work equipment, 3 rotating body, 4 operator's cab, 4S operator's seat, 5 running body, 5Cr crawler, 5M running motor, 6 boom, 7 arm, 8 bucket, 10 boom cylinder, 11 arm cylinder, 12 bucket cylinder, 20 work equipment attitude sensor, 21 position and direction sensor, 21a, 21b receiver, 24 instruction unit, 26 input device, 27 hydraulic pump, 28 EPC valve, 29 actuator, 30 hydraulic valve, 50 controller, 51 return swing control setting unit, 51A boom speed command generation unit, 51B arm speed command generation unit, 51C bucket speed command generation unit, 51D swing speed command generation unit, 54 memory unit, 55 command signal output unit, 100 hydraulic excavator, 200 loading object (dump truck), 200A vessel, G ground, P1 Return swing control end point, P2 loading swing control end point, P3 interference avoidance control point, S1, S2, S3 section, RX swing axis swing center, TP1 return swing end point, TP2 loading swing end point, TP3 interference avoidance point.

Claims

1. a first step of outputting a control command to increase the operating speed of the work machine as a remaining rotation angle of the rotating body to a target position decreases during a period during which the work machine starts to operate while the rotating body is rotating, the first step being a control command to increase the operating speed of the work machine as a remaining rotation angle of the rotating body to a target position decreases during a period during which the work machine starts to operate while the rotating body is rotating; a second step of outputting a control command during a period in which the operation of the work machine is to end while the rotating body is rotating, such that the operating speed of the work machine decreases as the remaining rotation angle decreases.

2. 2. The control method according to claim 1, wherein the first step outputs a control command to increase the operating speed of the work machine as a ratio of the remaining swing angle to the swing angle of the swing body from a position at which the swing body starts swinging to the target position decreases.

3. 2. The control method according to claim 1, wherein the first step outputs a control command to increase the acceleration of the operation of the work machine as the remaining swing angle decreases.

4. 2. The control method according to claim 1, wherein the second step outputs a control command to reduce the operating speed of the work machine as a remaining movement angle from the current attitude of the work machine to the target attitude decreases.

5. The control method according to claim 1 , further comprising an initial step of outputting a control command to keep the operating speed of the work machine constant during a period when the rotation of the rotating body starts.

6. The control method according to claim 5, wherein in the initial step, a control command is output to set the operating speed of the work machine to zero.

7. the work machine includes a boom rotatably connected to the rotating body, The control method according to claim 1 , wherein the operation of the work machine is a lowering operation of the boom.

8. A rotating body; a work machine operably attached to the rotating body; a work machine actuator that drives the work machine; a control valve for controlling the work machine actuator; a controller that outputs a control command to the control valve during a period in which the operation of the work machine starts while the rotating body is rotating, so as to increase the operating speed of the work machine as the remaining rotation angle to the target position of the rotating body decreases, and that outputs a control command to the control valve during a period in which the operation of the work machine ends while the rotating body is rotating, so as to decrease the operating speed of the work machine as the remaining rotation angle decreases.

9. 9. The work machine according to claim 8, wherein the controller outputs a control command to the control valve during a period in which the work machine starts to operate, to increase the operating speed of the work machine as a ratio of the remaining swing angle to a swing angle of the rotating body from a position at which the rotating body starts to swing to the target position decreases.

10. The work machine according to claim 8 , wherein the controller outputs a control command to the control valve during a period in which the work machine starts to move, to increase the acceleration of the movement of the work machine as the remaining swing angle decreases.

11. 9. The work machine according to claim 8, wherein the controller outputs a control command to the control valve during a period in which the work machine is ending its operation to reduce the operating speed of the work machine as a remaining angle of movement of the work machine from a current attitude to a target attitude decreases.

12. The work machine according to claim 8 , wherein the controller outputs a control command to the control valve to keep the operating speed of the work implement constant during a period when the swing body starts to swing.

13. The work machine according to claim 12 , wherein the controller outputs a control command to the control valve to set the operating speed of the work implement to zero during a period when the swing body starts to swing.

14. the work machine includes a boom rotatably connected to the rotating body, The work machine according to claim 8 , wherein the operation of the work implement is a lowering operation of the boom.

15. A rotating body; a work machine operably attached to the rotating body; a work machine actuator that drives the work machine; a control valve for controlling the work machine actuator; a controller that outputs a control command to the control valve during a period in which the operation of the work machine starts while the rotating body is rotating, to increase the operating speed of the work machine as the remaining rotation angle to the target position of the rotating body decreases, and outputs a control command to the control valve during a period in which the operation of the work machine ends while the rotating body is rotating, to decrease the operating speed of the work machine as the remaining rotation angle decreases.

16. a step of adjusting a control command for increasing the operating speed of the work implement as the remaining rotation angle of the rotating body to which the work implement is operably attached to the target position decreases, based on at least one of the rotation angle of the rotating body from the position at which the rotating body starts to rotate to the target position and the movement angle of the work implement from the start of operation to the end of operation; and outputting the adjusted control command.

17. A rotating body; a work machine operably attached to the rotating body; a controller that adjusts a control command to increase the operating speed of the work implement as the remaining rotation angle of the rotating body to the target position decreases, based on at least one of the rotation angle of the rotating body from the position when the rotating body starts to rotate to the target position, and the movement angle of the work implement from the start of operation to the end of operation.

18. a step of adjusting a control command to reduce the operating speed of the work machine as a remaining movement angle from a current attitude of the work machine to a target attitude becomes smaller, based on the weight of the work machine; and outputting the adjusted control command.

19. A work machine, a controller that adjusts a control command to reduce the operating speed of the work machine as the remaining movement angle from the current attitude of the work machine to a target attitude becomes smaller, based on the weight of the work machine.

Images