CN117561355A - Work machine and method for controlling a work machine - Google Patents
Work machine and method for controlling a work machine Download PDFInfo
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- CN117561355A CN117561355A CN202280045461.3A CN202280045461A CN117561355A CN 117561355 A CN117561355 A CN 117561355A CN 202280045461 A CN202280045461 A CN 202280045461A CN 117561355 A CN117561355 A CN 117561355A
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- work machine
- vehicle body
- height
- posture
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- 238000000034 method Methods 0.000 title claims description 17
- 230000005484 gravity Effects 0.000 claims abstract description 13
- 230000008859 change Effects 0.000 description 9
- 230000005540 biological transmission Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 4
- 230000008602 contraction Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000010720 hydraulic oil Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
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Classifications
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
- E02F3/80—Component parts
- E02F3/84—Drives or control devices therefor, e.g. hydraulic drive systems
- E02F3/841—Devices for controlling and guiding the whole machine, e.g. by feeler elements and reference lines placed exteriorly of the machine
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Operation Control Of Excavators (AREA)
Abstract
The controller obtains vehicle body posture data. The controller obtains work machine attitude data. The controller calculates the height of the working machine in the gravity direction from a reference point of the vehicle body based on the vehicle body posture data and the working machine posture data. The controller controls the actuator so that the height of the work machine in the gravitational direction is maintained even if the posture of the vehicle body changes.
Description
Technical Field
The present invention relates to a work machine and a method of controlling the work machine.
Background
The work machine includes a vehicle body, a work machine, and an actuator. The actuator is, for example, a hydraulic cylinder. The actuator is driven in response to an operation by an operator to actuate the work implement. For example, a motor grader is provided with a blade as a work implement. The motor grader is provided with a series drive and a frame as a vehicle body. The blade is supported on the frame. The frame rotatably supports the front wheel. The tandem drive supports the rear wheels. The operator operates the lever of the work machine to move the blade up and down.
In the motor grader described above, the height of the blade changes when the front wheel passes over the heave due to the change in the posture of the frame. Patent document 1 discloses a technique corresponding to this problem. In patent document 1, a controller calculates a change in blade height from the relative rotation angle of the frame and the tandem drive. The controller moves the blade up and down in response to changes in blade height. Thereby, the blade is maintained at a predetermined height.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2001-193095
Disclosure of Invention
Problems to be solved by the invention
However, in the motor grader of patent document 1, when the posture of the entire vehicle body including the tandem drive is changed, the height direction of the blade relative to the vehicle body is also changed. For example, when the tandem drive is tilted from the horizontal, the controller calculates the blade height as a different value than the actual blade height. Therefore, it is difficult to maintain the blade at a predetermined height with high accuracy relative to the ground. In the present invention, even when the working machine is traveling on a rough ground, the working machine can be held at a target height with high accuracy.
Means for solving the problems
One embodiment of the present invention is a work machine including: the system comprises a vehicle body, a working machine, an actuator, a vehicle body sensor, a working machine sensor and a controller. The work machine is supported so as to be movable with respect to the vehicle body. The actuator is connected to the work machine. The actuator actuates the work machine. The vehicle body sensor detects vehicle body posture data indicating a posture of the vehicle body. Work implement sensors detect work implement attitude data indicative of a work implement attitude.
The controller obtains vehicle body posture data. The controller obtains work machine attitude data. The controller calculates a work machine height in a gravity direction from a reference point of the vehicle body based on the vehicle body posture data and the work machine posture data. The controller controls the actuator to maintain the height of the work machine in the gravity direction even if the posture of the vehicle body changes.
Another aspect of the present invention is a method for controlling a work machine including a vehicle body, a work machine, and an actuator. The work machine is supported so as to be movable with respect to the vehicle body. The actuator is connected to the work machine. The actuator actuates the work machine.
The method comprises the following steps: acquiring vehicle body posture data indicating a vehicle body posture; acquiring work machine attitude data indicating a posture of the work machine; calculating a height of the working machine in a gravity direction from a reference point of the vehicle body based on the vehicle body posture data and the working machine posture data; the control actuator can maintain the height of the working machine in the gravity direction even if the posture of the vehicle body changes.
Effects of the invention
According to the present invention, even if the posture of the vehicle body changes, the height of the working machine in the gravity direction is maintained. Therefore, even when the working machine is traveling on a rough ground, the height of the working machine can be maintained with high accuracy.
Drawings
Fig. 1 is a side view of a work machine according to an embodiment.
Fig. 2 is a perspective view of the front of the work machine.
Fig. 3 is a schematic diagram showing a drive system and a control system of the work machine.
Fig. 4 is a schematic rear view showing the posture of the work machine.
Fig. 5 is a schematic plan view of the work machine showing the posture of the work machine.
Fig. 6 is a schematic enlarged side view of a work machine showing the attitude of the work machine.
Fig. 7 is a schematic plan view of a work machine showing the posture of the work machine.
Fig. 8 is a schematic plan view of the work machine showing the posture of the work machine.
Fig. 9 is a schematic side view showing a vehicle body coordinate system of the work machine.
Fig. 10 is a schematic rear view showing a vehicle body coordinate system of the work machine.
Fig. 11 is a flowchart showing a process of automatic control of the work implement.
Fig. 12 is a schematic side view showing a vehicle body coordinate system of the work machine.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a work machine 1 according to an embodiment. Fig. 2 is a perspective view of the front portion of the work machine 1. The work machine 1 in the present embodiment is a motor grader. As shown in fig. 1, a work machine 1 includes a vehicle body 2 and a work implement 3. Work implement 3 is supported to be movable with respect to vehicle body 2. The vehicle body 2 includes a body frame 4, a tandem drive 5, front wheels 6, and rear wheels 7a,7b.
The body frame 4 supports the front wheels 6 and the work implement 3. The body frame 4 includes a front frame 11 and a rear frame 12. The rear frame 12 is connected to the front frame 11. The front frame 11 can be hinged to the rear frame 12. In the following description, the front-rear-left-right directions refer to the front-rear-left-right directions of the vehicle body 2 in which the hinge angle is 0, that is, the front frame 11 and the rear frame 12 are perpendicular.
The rear frame 12 is provided with a driving unit 13 and a power chamber 14. The driver 13 is provided with a driver seat, not shown. The power chamber 14 is provided with a drive system described later. The front frame 11 extends forward from the rear frame 12. The front wheel 6 is mounted to a front frame 11.
The tandem drive 5 is connected to the rear frame 12. The tandem drive 5 supports the rear wheels 7a,7b and drives the rear wheels 7a,7b. The tandem drive 5 includes a rear shaft 10 extending in the left-right direction. The tandem actuator 5 swingably supports a rear frame 12 of the body frame 4 about a rear shaft 10. When the front wheels 6 move up and down due to the undulation of the road surface not covered by the work implement 3, the body frame 4 swings about the rear axle 10 (see fig. 9).
The rear wheels 7A,7B include a pair of first rear wheels 7A and a pair of second rear wheels 7B. In fig. 1, only the first rear wheel 7A on the left side and the second rear wheel 7B on the left side are shown. The second rear wheel 7B is disposed rearward of the first rear wheel 7A. The rear axle 10 is disposed between the first rear wheel 7A and the second rear wheel 7B. The rear axle 10 serves as a swing center of the vehicle body frame 4 with respect to the tandem actuator 5.
Work implement 3 is movably connected to vehicle body 2. Work implement 3 includes a support member 15 and a blade 16. The support member 15 is movably connected to the vehicle body 2. The support member 15 supports a blade 16. The support member 15 includes a traction lever 17 and a rotating disk 18. The traction lever 17 and the rotating disk 18 are arranged below the front frame 11.
As shown in fig. 2, the traction lever 17 is connected to the shaft support portion 19 of the front frame 11. The shaft support portion 19 is disposed at the front of the front frame 11. The traction lever 17 extends rearward from the front of the front frame 11. The traction lever 17 is supported swingably with respect to the front frame 11 at least in the up-down direction and the left-right direction of the vehicle body 2. For example, the shaft support 19 comprises a ball joint. The drawbar 17 is rotatably connected with respect to the front frame 11 via a ball joint.
The rotary disk 18 is connected to the rear of the drawbar 17. The rotary disk 18 is rotatably supported with respect to the traction lever 17. Blade 16 is connected to rotating disk 18. Blade 16 is supported by a drawbar 17 via a rotating disc 18. Blade 16 is rotatably supported on rotary disk 18 about tilt axis 21. The tilt shaft 21 extends in the left-right direction. The blade 16 is supported slidably in the left-right direction on the rotary disk 18.
Work machine 1 includes a plurality of actuators 22-27 for changing the posture of work machine 3. The plurality of actuators 22-27 includes a plurality of hydraulic cylinders 22-26. A plurality of hydraulic cylinders 22-26 are connected to work machine 3. The plurality of hydraulic cylinders 22-26 are hydraulically telescopic. The plurality of hydraulic cylinders 22 to 26 change the posture of the work implement 3 with respect to the vehicle body 2 by telescoping. In the following description, the expansion and contraction of the hydraulic cylinder will be referred to as "stroke operation".
In detail, the plurality of hydraulic cylinders 22-26 include: left lift cylinder 22, right lift cylinder 23, drawbar shift cylinder 24, blade tilt cylinder 25, and blade shift cylinder 26. The left lift cylinder 22 and the right lift cylinder 23 are disposed apart from each other in the left-right direction. A left lifting hydraulic cylinder 22 is connected to the left part of the drawbar 17. A right lifting hydraulic cylinder 23 is connected to the right part of the drawbar 17. The left and right lift cylinders 22 and 23 are connected swingably to the traction lever 17.
The left and right lift cylinders 22 and 23 are swingably connected left and right with respect to the front frame 11. In detail, the left and right lift cylinders 22 and 23 are connected to the front frame 11 via lifter brackets 29. The lifter bracket 29 is connected to the front frame 11. The lifter bracket 29 supports the left and right lift cylinders 22 and 23 swingably left and right. The traction rod 17 swings up and down around the shaft support portion 19 by the stroke operation of the left and right lift cylinders 22 and 23. Thereby, the blade 16 moves up and down.
The drawbar moving cylinder 24 is connected to the drawbar 17 and the front frame 11. The drawbar shift cylinder 24 is connected to the front frame 11 via a lifter bracket 29. The drawbar shift cylinder 24 is swingably connected with respect to the front frame 11. The drawbar moving cylinder 24 is swingably connected with respect to the drawbar 17. The drawbar moving cylinder 24 extends obliquely downward from the front frame 11 toward the drawbar 17. The drawbar moving cylinder 24 extends from the left and right sides of the front frame 11 to opposite sides. The drawbar 17 swings around the shaft support 19 by the stroke operation of the drawbar moving cylinder 24.
As shown in fig. 1, blade tilt cylinder 25 is connected to rotary disk 18 and blade 16. Blade 16 rotates about tilt axis 21 by the stroke action of blade tilt cylinder 25. Blade travel cylinders 26 are coupled to the rotating disc 18 and blade 16 as shown in FIG. 2. Blade 16 slides laterally relative to rotary disk 18 by the stroke action of blade travel cylinder 26.
The plurality of actuators 22-27 includes a rotary actuator 27. A rotary actuator 27 is connected to the drawbar 17 and the rotary disk 18. The rotary actuator 27 rotates the rotary disk 18 relative to the drawbar 17. Thereby, blade 16 rotates about the rotation axis extending in the up-down direction.
Fig. 3 is a schematic diagram showing a drive system 8 and a control system 9 of the work machine 1. As shown in fig. 3, the work machine 1 includes: a drive source 31, a hydraulic pump 32, a power transmission device 33, and a control valve 34. The drive source 31 is, for example, an internal combustion engine. Alternatively, the drive source 31 may be an electric motor or a hybrid of an internal combustion engine and an electric motor. The hydraulic pump 32 discharges the hydraulic oil by being driven by the driving source 31.
The control valve 34 is connected to the hydraulic pump 32 and the plurality of hydraulic cylinders 22-26 via a hydraulic circuit. Control valve 34 includes a plurality of valves coupled to a plurality of hydraulic cylinders 22-26, respectively. The control valve 34 controls the flow rate of the hydraulic fluid supplied from the hydraulic pump 32 to the plurality of hydraulic cylinders 22-26.
In the present embodiment, the rotary actuator 27 is a hydraulic motor. The control valve 34 is connected to the hydraulic pump 32 and the rotary actuator 27 via a hydraulic circuit. The control valve 34 controls the flow rate of the hydraulic oil supplied from the hydraulic pump 32 to the rotary actuator 27. The rotary actuator 27 may be an electric motor.
The power transmission device 33 transmits the driving force from the driving source 31 to the rear wheels 7a,7b. The power transmission device 33 may also include a torque converter and/or a plurality of speed change gears. Alternatively, the power transmission device 33 may be a transmission such as HST (Hydraulic Static Transmission) or HMT (Hydraulic Mechanical Transmission).
As shown in fig. 3, the work machine 1 includes an operation device 35 and a controller 36. The operating device 35 is operable by an operator so as to change the posture of the work implement 3. The attitude of work implement 3 indicates the position and orientation of blade 16 relative to body 2. Fig. 4 is a schematic rear view of work machine 1 showing the posture of work implement 3. As shown in fig. 4, the height of the left end portion 161 and the height of the right end portion 162 of the blade 16 can be changed according to the operation of the operating device 35.
According to the operation of the operation device 35, the yaw angle θ1, the pitch angle θ2, and the slip angle θ3 of the drawbar 17 are changed. Fig. 5 is a schematic plan view of work machine 1 showing the posture of work implement 3. As shown in fig. 5, the yaw angle θ1 of the drawbar 17 is an inclination angle of the drawbar 17 in the left-right direction with respect to the front-rear direction of the vehicle body 2. The yaw angle θ1 of the drawbar 17 may be an inclination angle of the drawbar 17 in the left-right direction with respect to the front-rear direction of the front frame 11. The position of the blade 16 in the left-right direction varies according to the yaw angle θ1 of the drawbar 17.
Fig. 6 is a schematic side view of work machine 1 showing the posture of work machine 3. As shown in fig. 6, the pitch angle θ2 of the drawbar 17 is an inclination angle in the up-down direction of the drawbar 17 with respect to the front-rear direction of the vehicle body 2. As shown in fig. 4, the slip angle θ3 of the drawbar 17 is an inclination angle of the drawbar 17 about a slip axis A1 extending in the front-rear direction of the vehicle body 2.
In addition, according to the operation of the operation device 35, the rotation angle θ4 of the rotating disk 18, the tilt angle θ5 of the blade 16, and the movement amount W1 of the blade 16 can be changed. Fig. 7 is a schematic plan view of work machine 1 showing the posture of work implement 3. As shown in fig. 7, the rotation angle θ4 of the rotating disk 18 is the rotation angle θ4 of the rotating disk 18 with respect to the front-rear direction of the vehicle body 2. As shown in fig. 6, the inclination angle θ5 of the blade 16 is the inclination angle of the blade 16 about the inclination axis 21 extending in the left-right direction. Fig. 8 is a schematic plan view of work machine 1 showing the posture of work implement 3. As shown in fig. 8, the movement amount W1 of the blade 16 is the amount of sliding of the blade 16 in the right-left direction with respect to the rotating disk 18.
The operating device 35 comprises a plurality of operating members 41-46. A plurality of operating members 41-46 are provided corresponding to left lifting hydraulic cylinder 22, right lifting hydraulic cylinder 23, drawbar shifting cylinder 24, blade tilting hydraulic cylinder 25, blade shifting cylinder 26 and rotary actuator 27, respectively.
The plurality of operating members 41-46 include a left lift lever 41, a right lift lever 42, a traction lever shift lever 43, a rotating lever 44, a blade tilt lever 45, and a blade shift lever 46. The left lift cylinder 22 expands and contracts according to the operation of the left lift lever 41. The right lift cylinder 23 expands and contracts according to the operation of the right lift lever 42.
The traction lever moving cylinder 24 expands and contracts according to the operation of the traction lever shift lever 43. The rotary actuator 27 rotates according to the operation of the rotary lever 44. Blade tilt cylinder 25 expands and contracts in accordance with the operation of blade tilt lever 45. Blade travel cylinder 26 expands and contracts in response to the operation of blade shift lever 46. The plurality of operation members 41 to 46 output signals indicating operations of the operation members 41 to 46 by the operator, respectively.
The controller 36 controls the drive source 31 and the power transmission device 33 to drive the work machine 1. The controller 36 controls the hydraulic pump 32 and the control valve 34 to operate the work implement 3. The controller 36 includes a processor 37 and a memory device 38. The processor 37 is, for example, a CPU, and executes a program for controlling the work machine 1. The storage device 38 includes a memory such as a RAM and a ROM, and an auxiliary storage device such as an SSD or an HDD. The storage device 38 stores programs and data for controlling the work machine 1.
As shown in fig. 3, the work machine 1 includes a work machine sensor 48 for detecting the posture of the work machine 3. Work implement sensor 48 includes a plurality of sensors S1-S8. The plurality of sensors S1-S8 are, for example, magnetic sensors. However, the plurality of sensors S1 to S8 may be other types of sensors such as optical sensors. The plurality of sensors S1 to S5 detect the stroke lengths of the plurality of hydraulic cylinders 22 to 26. The plurality of sensors S1-S5 includes a left lift sensor S1, a right lift sensor S2, a tow bar movement sensor S3, a blade tilt sensor S4, and a blade movement sensor S5.
The left lift sensor S1 detects the stroke length of the left lift cylinder 22. The right lift sensor S2 detects the stroke length of the right lift cylinder 23. The drawbar movement sensor S3 detects a stroke length of the drawbar movement cylinder 24. Blade tilt sensor S4 detects the stroke length of blade tilt cylinder 25. Blade movement sensor S5 detects the stroke length of blade movement cylinder 26.
The plurality of sensors S1-S8 includes a rotation sensor S6. The rotation sensor S6 detects a rotation angle θ4 of the rotating disk 18. The plurality of sensors S1 to S8 output signals indicating the detected stroke length and rotation angle θ4. The plurality of sensors S1-8 includes a left cylinder angle sensor S7 and a right cylinder angle sensor S8. The left cylinder angle sensor S7 detects the swing angle of the left lift cylinder 22 with respect to the lifter bracket 29 in the left-right direction. The right cylinder angle sensor S8 detects the swing angle of the right lifting hydraulic cylinder 23 in the left-right direction with respect to the lifter bracket 29. By these sensors S1 to S8, the posture of the drawbar 17 with respect to the vehicle body 2 can be detected, and the posture of the blade 16 with respect to the drawbar 17 can be detected. That is, the attitude of blade 16 with respect to vehicle body 2 can be detected by these sensors S1 to S8.
Work machine 1 includes a body sensor 49. The vehicle body sensor 49 is, for example, an IMU (inertial measurement unit). The vehicle body sensor 49 detects vehicle body posture data indicating the posture of the vehicle body 2. The vehicle body posture data includes a yaw angle and a yaw angle of the vehicle body 2. The vehicle body sensor 49 is not limited to the IMU. The body sensor 49 may be, for example, an inclinometer as long as it is a means for measuring the yaw angle and the yaw angle of the body 2.
The body sensor 49 is mounted to the body frame 4. Therefore, as shown in fig. 9, the pitch angle θ6 of the vehicle body 2 is an inclination angle in the up-down direction with respect to the vehicle body frame 4 in the horizontal direction. As shown in fig. 10, the yaw angle θ7 of the vehicle body 2 is an inclination angle in the left-right direction with respect to the vehicle body frame 4 in the horizontal direction. The vehicle body sensor 49 is not limited to the vehicle body frame 4, and may be mounted at another position of the vehicle body 2 where the relative position to the vehicle body frame 4 is not changed. For example, the vehicle body sensor 49 may be disposed at a position other than the position where the relative position of the tandem actuator 5 and the traction lever 17 with respect to the vehicle body frame 4 is changed.
Based on the signal from the work implement sensor 48, the controller 36 acquires work implement posture data indicating the posture of the work implement 3 with respect to the vehicle body 2. The work implement attitude data includes the height of the left end portion 161 of the blade 16, the height of the right end portion 162, the yaw angle θ1, the pitch angle θ2, the yaw angle θ3, the rotation angle θ4 of the rotating disk 18, the tilt angle θ5 of the blade 16, and the movement amount W1 of the blade 16. The controller 36 acquires vehicle body posture data based on a signal from the vehicle body sensor 49. The controller 36 changes the posture of the work machine 3 by controlling the plurality of actuators 22 to 27 in accordance with the operations of the plurality of operation members 41 to 46.
The controller 36 also executes automatic control of the work implement 3 based on the vehicle body posture data and the work implement posture data. In the automatic control of the work implement 3, the controller 36 controls the left and right lift cylinders 22 and 23 so as to maintain the work implement 3 at the target height. The following describes a process of automatically controlling the work implement 3. Fig. 11 is a flowchart showing a process of automatic control of the work implement 3.
As shown in fig. 11, in step S101, the controller 36 determines whether there is an operation of the operation device 35. The controller 36 may determine that the operation of the operation device 35 is not performed when there is no operation input of the operation device 35 for a predetermined period of time. When at least one of the above-described operation members 41 to 46 is operated, the controller 36 does not perform automatic control of the work machine 3. Therefore, the controller 36 changes the posture of the work machine 3 by controlling the plurality of actuators 22 to 27 in accordance with the operations of the plurality of operation members 41 to 46. When the operation members 41 to 46 are not operated, the process advances to step S102.
In step S102, the controller 36 obtains the current posture of the vehicle body 2. Here, the controller 36 obtains the current posture of the vehicle body 2 from the vehicle body posture data. In step S103, controller 36 obtains the current posture of work implement 3. Here, the controller 36 obtains the current posture of the work implement 3 from the work implement posture data.
In step S104, controller 36 calculates the current height of work implement 3. The controller 36 calculates the height of the work machine 3 based on the vehicle body posture data and the work machine posture data. For example, the height of work implement 3 is the height of left end 161 and the height of right end 162 of blade 16. Here, the height of the work implement 3 is a height in the gravitational direction from the origin O1, with the origin O1 of the vehicle body 2 shown in fig. 12 as a reference point. For example, the height of work implement 3 is a height in the gravitational direction of work implement 3 from a horizontal plane including origin O1 of vehicle body 2.
As shown in fig. 12, when the work machine 1 advances to perform work, the origin O1 of the vehicle body 2 is disposed in the tandem actuator 5. For example, the origin O1 of the vehicle body 2 is arranged at the center in the left-right direction of the rear axle 10. In fig. 12, the Z1 axis shows the direction of gravity. The X1 axis shows the front-rear direction of the vehicle body 2 perpendicular to the gravitational direction. In fig. 4, the Y1 axis shows the left-right direction of the vehicle body 2 perpendicular to the gravitational direction. The posture of the vehicle body 2 changes centering on the origin O1 of the vehicle body 2. For example, as shown in fig. 9, the pitch angle θ6 of the vehicle body 2 changes around the origin O1. As shown in fig. 10, the slip angle θ7 of the vehicle body 2 changes around the origin O1.
In step S105, the controller 36 determines a target attitude of the work implement 3. The controller 36 calculates a target attitude of the work implement 3 so that the height of the work implement 3 becomes the target height. Further, the controller 36 stores the height of the work implement 3 when it is determined that the operation of the operation device 35 is not performed, as the target height. For example, the controller 36 calculates the target yaw angle and the target slip angle of the drawbar 17 so that the height of the work implement 3 becomes the target height.
In step S106, controller 36 controls at least one of actuators 22 to 27 so that the height of work implement 3 becomes the target height. For example, the controller 36 controls the lift cylinders 22 and 23 and the boom moving cylinder 24 so that the pitch angle θ2 of the boom 17 becomes a target pitch angle and the slip angle θ3 of the boom 17 becomes a target slip angle.
In this case, the controller 36 controls the lifting hydraulic cylinders 22, 23 and the boom moving cylinder 24 so that the position of the blade 16 in the left-right direction does not change. That is, in the work machine 1, not only the height direction of the blade 16 but also the position of the blade 16 in the left-right direction changes by the extension and contraction of the lift cylinders 22, 23. Accordingly, the controller 36 controls the boom-moving cylinder 24 to cancel out the change in the position of the blade 16 in the left-right direction due to the expansion and contraction of the lift cylinders 22, 23. Thereby, the height of the work implement 3 is maintained at the target height, and the position of the work implement 3 in the left-right direction is maintained.
Controller 36 controls actuators 22-27 to maintain work implement 3 at the target height by repeating the processing of steps S102 to S106 described above. When the operation device 35 is operated by the automatic control, the controller 36 terminates the automatic control (step S101).
According to the work machine 1 of the present embodiment described above, the work implement 3 is held at the target height of the work implement 3 by automatic control. The target height is a height in the gravity direction from the origin O1 of the vehicle body 2, and even if the posture of the vehicle body 2 changes, the work implement 3 can be maintained at the target height of the work implement 3. Therefore, even when work machine 1 travels on a rough ground, work implement 3 can be held at the target height with high accuracy.
For example, in FIG. 9, blade 16' shown by the dashed line illustrates the position of blade 16 without automatic control. As shown in fig. 9, when the front wheel 6 is in a rolling state without automatic control, the blade 16' is raised above the position of the blade 16 shown in fig. 12. However, in the work machine 1 of the present embodiment, as shown in fig. 9, the blade 16 is maintained at the target height of the work implement 3 in the gravity direction by the automatic control. Therefore, even if the front wheel 6 is in a rough state, the blade 16 can be held at the target height with high accuracy by controlling the actuators 22 to 27 by the controller 36.
While the above description has been given of one embodiment of the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.
The work machine 1 is not limited to the motor grader, and may be another work machine such as an excavator. In other work machines such as an excavator, the position of the origin O1 may be set appropriately according to the structural characteristics of the work machine. The configuration of work implement 3 is not limited to the above embodiment, and may be modified. For example, work machine 3 may include a blade and a lift arm. The lift arms may also support the blade and be attached to the body. The parameter indicating the posture of the work implement 3 is not limited to the above embodiment, and may be changed.
The plurality of operation members 41 to 46 are not limited to the above-described embodiment, but may be modified. For example, the operation member is not limited to a lever, and may be another member such as a joystick, a switch, or a touch panel. The plurality of operating members 41-46 may also directly operate the actuators 22-27, respectively.
The sensor for detecting the posture of the work implement 3 is not limited to the above embodiment, and may be modified. The sensors S1 to S5 are not limited to the stroke length, and may directly detect the angle. Work implement sensors 48 may also include an IMU (inertial measurement unit). The IMU may also be mounted to the drawbar 17. The attitude of the drawbar 17 may also be detected by the IMU. Either one of the left cylinder angle sensor S7 and the right cylinder angle sensor S8 may be omitted.
The operating device 35 may also comprise operating means for automatic control. The controller 36 may also start automatic control according to the operation of the operation member for automatic control. The controller 36 may also terminate the automatic control according to the operation of the operation member for the automatic control. The controller 36 may store the height of the work implement 3 at the start of the automatic control as the target height according to the operation of the operation member for the automatic control.
In the above automatic control, in the case where the posture (angle) or the change in posture (angular velocity) of the vehicle body 2 exceeds a predetermined value, there is a possibility that the detection errors of the sensors S1 to S8 become large. In addition, when rapid acceleration or rapid deceleration is performed by a predetermined amount or more, the reaction rates of the sensors S1 to S8 may not be able to catch up. In this case, the controller 36 may temporarily release the automatic control. The controller 36 may temporarily cancel the automatic control when the difference between the target posture and the current posture of the work machine 3 exceeds a predetermined threshold.
In the above embodiment, the automatic control was described in the case where the work machine 1 is advanced to perform work, but the present invention is also applicable to the case where the work machine 1 is advanced to perform work. In this case, the origin O of the vehicle body 2 may be a center position between the left and right front wheels 6.
In the above embodiment, the controller 36 obtains the posture of the work implement 3 when the operation device 35 is not operated for a certain period of time, and obtains the height of the work implement 3 at that time as the current height of the work implement 3. However, the method of obtaining the current height of the work implement 3 is not limited thereto, and may be modified. For example, the controller 36 may acquire the posture of the work implement 3 when the operation device such as a button is operated, and set the current height of the work implement 3 as the height of the work implement 3 at that time. A switch may be provided for increasing or decreasing the height of the obtained work implement 3 by a predetermined amount. The controller 36 may change the target attitude of the work implement 3 according to the operation of the switch. This allows fine adjustment of the target attitude of work implement 3.
Industrial applicability
According to the present invention, the work machine can be held at the target height with high accuracy even when the work machine is traveling on a rough ground.
Description of the reference numerals
2: vehicle body, 3: work machine, 4: body frame, 5: serial driver, 6: front wheels, 7a,7b: rear wheels, 22-27: actuator, 35: operating means, 36: controller, 48: work implement sensor, 49: vehicle body sensor
Claims (10)
1. A working machine is characterized by comprising:
a vehicle body;
a work implement supported to be movable with respect to the vehicle body;
an actuator connected to the work machine and configured to operate the work machine;
a vehicle body sensor that detects vehicle body posture data indicating a posture of the vehicle body;
a work machine sensor that detects work machine attitude data indicating an attitude of the work machine;
the controller is used for controlling the operation of the controller,
the controller performs control such that,
acquiring the vehicle body posture data;
acquiring the attitude data of the working machine;
calculating a height of the work machine in a gravitational direction from a reference point of the vehicle body based on the vehicle body posture data and the work machine posture data;
the actuator is controlled so that the height of the work machine in the gravity direction is maintained even if the posture of the vehicle body changes.
2. The work machine of claim 1 wherein,
the vehicle body includes:
a front wheel;
a body frame supporting the front wheels and the work machine;
a rear wheel;
comprising a rear axle which supports the rear wheel and extends in the left-right direction, and a tandem drive which supports the body frame swingably around the rear axle,
the controller maintains the height of the work machine in the gravitational direction even if the body frame swings about the rear axle relative to the tandem drive.
3. The work machine of claim 2 wherein,
the reference point of the vehicle body is arranged in the serial driver.
4. A working machine as claimed in any one of claims 1 to 3, characterized in that,
further comprises an operating device operable by an operator,
the controller performs control such that,
acquiring an operation signal indicating an operation of the operation device;
controlling the actuator to cause the work machine to operate according to the operation of the operation device;
storing a height of the work machine at the time of termination of the operation device as a target height;
the actuator is controlled so that the height of the work machine in the gravity direction is maintained at the target height even if the posture of the vehicle body changes.
5. The working machine as claimed in any one of claims 1 to 4, characterized in that,
the controller controls the actuator so that the position of the work machine in the left-right direction is maintained even if the posture of the vehicle body changes.
6. A method for controlling a work machine, the work machine comprising: a vehicle body; a work implement supported to be movable with respect to the vehicle body; an actuator connected to the work machine and configured to operate the work machine; the method is characterized by comprising the following steps:
acquiring vehicle body posture data indicating a posture of the vehicle body;
acquiring work machine attitude data indicating an attitude of the work machine;
calculating a height of the work machine in a gravitational direction from a reference point of the vehicle body based on the vehicle body posture data and the work machine posture data;
the actuator is controlled so that the height of the work machine in the gravity direction is maintained even if the posture of the vehicle body changes.
7. The method of claim 6, wherein,
the vehicle body includes:
a front wheel;
a body frame supporting the front wheels and the work machine;
a rear wheel;
a tandem drive including a rear axle supporting the rear wheel and extending in a left-right direction, and swingably supporting the body frame about the rear axle;
the height of the work machine in the gravitational direction is maintained even if the body frame swings about the rear axle relative to the tandem drive.
8. The method of claim 7, wherein,
the reference point of the vehicle body is arranged in the serial driver.
9. The method according to any one of claims 6 to 8, further comprising:
acquiring an operation signal indicating an operation of an operation device operable by an operator;
controlling the actuator to cause the work machine to operate according to the operation of the operation device;
storing a height of the work machine at the time of termination of the operation device as a target height;
the actuator is controlled so that the height of the work machine in the gravity direction is maintained at the target height even if the posture of the vehicle body changes.
10. The method according to any one of claims 6 to 9, further comprising:
the actuator is controlled so that the position of the work machine in the left-right direction is maintained even if the posture of the vehicle body changes.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021-173205 | 2021-10-22 | ||
| JP2021173205 | 2021-10-22 | ||
| PCT/JP2022/032445 WO2023067898A1 (en) | 2021-10-22 | 2022-08-29 | Work machine and method for controlling work machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117561355A true CN117561355A (en) | 2024-02-13 |
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ID=86059007
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280045461.3A Pending CN117561355A (en) | 2021-10-22 | 2022-08-29 | Work machine and method for controlling a work machine |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPWO2023067898A1 (en) |
| CN (1) | CN117561355A (en) |
| WO (1) | WO2023067898A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2024060716A (en) * | 2022-10-20 | 2024-05-07 | 株式会社小松製作所 | Work machine, and method to control work machine |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS557506B2 (en) * | 1972-05-12 | 1980-02-26 | ||
| JPS5282803A (en) * | 1975-12-29 | 1977-07-11 | Komatsu Mfg Co Ltd | Device for automatically controlling blade of construction machine |
| JPH08165677A (en) * | 1994-12-13 | 1996-06-25 | Tamagawa Seiki Co Ltd | Bucket position control method and device of power shovel |
| US6269885B1 (en) * | 1999-12-15 | 2001-08-07 | Husco International, Inc. | Blade height control system for a motorized grader |
| JP4669499B2 (en) * | 2007-08-10 | 2011-04-13 | 日本中央競馬会 | Blade control device |
| US8141650B2 (en) * | 2008-06-24 | 2012-03-27 | Deere & Company | Automatic depth correction based on blade pitch |
| JP6689638B2 (en) * | 2016-03-23 | 2020-04-28 | 株式会社小松製作所 | Motor grader control method and motor grader |
-
2022
- 2022-08-29 WO PCT/JP2022/032445 patent/WO2023067898A1/en active Application Filing
- 2022-08-29 JP JP2023554968A patent/JPWO2023067898A1/ja active Pending
- 2022-08-29 CN CN202280045461.3A patent/CN117561355A/en active Pending
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| Publication number | Publication date |
|---|---|
| JPWO2023067898A1 (en) | 2023-04-27 |
| WO2023067898A1 (en) | 2023-04-27 |
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