CN-122013830-A - Control method, device, equipment and medium for lifting bottom fork accessory of loader

CN122013830ACN 122013830 ACN122013830 ACN 122013830ACN-122013830-A

Abstract

The invention discloses a control method, a device, equipment and a medium for lifting of a flat fork of a loader, which are used for obtaining a target flat fork angle of the flat fork of the loader, a movable arm joint angle and a rocker arm joint angle of the loader, calculating the actual length of a movable arm cylinder and the actual length of a rocker arm cylinder according to the movable arm joint angle and the rocker arm joint angle, determining the target length of the movable arm cylinder and the target length of the rocker arm cylinder according to the target flat fork angle, calculating a first deviation value between the target length of the movable arm cylinder and the actual length of the movable arm cylinder and a second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder, and controlling the movable arm cylinder and the rocker arm cylinder of the loader according to the first deviation value and the second deviation value by adopting double-ring serial control logic so as to enable the flat fork to be lifted in parallel. The invention adopts the double-ring serial control logic, thereby improving the gesture maintaining precision of the bottom fork accessory in the lifting process.

Inventors

SHI JIANFENG
GAO PENGFEI
LU YUANSHENG

Assignees

湖州三一重工研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20260330

Claims (11)

1. The method for controlling lifting of the bottom fork attachment of the loader is characterized by comprising the following steps of: acquiring a target bottom fork angle of the bottom fork attachment of the loader, a movable arm joint angle and a rocker arm joint angle of the loader; Calculating the actual length of the movable arm cylinder and the actual length of the rocker arm cylinder according to the movable arm joint angle and the rocker arm joint angle based on the geometric kinematics relation; Determining the target length of the movable arm cylinder and the target length of the rocker arm cylinder according to the target bottom fork angle; Calculating a first deviation value between the target length of the movable arm cylinder and the actual length of the movable arm cylinder, and a second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder; and controlling a movable arm oil cylinder and a rocker arm oil cylinder of the loader according to the first deviation value and the second deviation value by adopting a double-loop serial control logic to enable the bottom fork to lift in parallel, wherein the double-loop serial control logic comprises a position loop control logic and a speed loop control logic.
2. The method of claim 1, comprising, prior to said calculating the boom cylinder actual length and the rocker cylinder actual length: Establishing a coordinate system taking a hinge point of the movable arm and the frame as an origin; And acquiring a first coordinate of a hinge point of the tail part of the movable arm oil cylinder and the frame in the coordinate system and a second coordinate of a hinge point of the tail part of the rocker arm oil cylinder and the frame in the coordinate system.
3. The method of claim 2, wherein calculating the boom cylinder actual length and the rocker cylinder actual length comprises: Calculating a swing arm rotation angle according to the swing arm joint angle and the structure constant angle of the swing arm; calculating a fourth coordinate of the head of the piston rod of the movable arm oil cylinder in the coordinate system based on the movable arm rotation angle; And calculating the Euclidean distance between the fourth coordinate and the first coordinate to obtain the actual length of the movable arm oil cylinder.
4. The method of claim 3, wherein the calculating the boom cylinder actual length and the rocker cylinder actual length further comprises: calculating the coordinates of a swing arm and rocker arm hinge point according to the swing arm rotation angle, wherein the swing arm and rocker arm hinge point is a hinge point between a swing arm and a rocker arm of the loader; Calculating a first included angle formed by the swing arm hinge point, the swing arm connecting rod hinge point and the swing arm bucket hinge point according to the measured swing arm joint angle and the known structure angle of the swing arm, wherein the vertex of the first included angle is the swing arm hinge point; Calculating a first virtual edge length between a movable arm bucket hinge point and a rocker arm connecting rod hinge point by using a cosine law according to the first included angle, the rocker arm structure length and the first hinge distance, wherein the first hinge distance is the distance between the movable arm rocker arm hinge point and the movable arm bucket hinge point; determining a bucket attitude angle based on the first virtual opposite side length; calculating a second virtual edge length between the swing arm and swing arm hinge points and the link bucket hinge points by using a cosine law according to the bucket attitude angle, the bucket structure known angle, the first hinge distance and the link structure length; calculating the rotation angle of the piston rod head of the rocker arm cylinder and the rocker arm hinge point relative to the horizontal line based on the second virtual opposite side length; determining the head hinging point coordinates of the rocker arm cylinder piston rod according to the rotation angle and the coordinates of the swing arm rocker arm hinging point; And calculating the Euclidean distance between the coordinate of the hinging point of the piston rod head of the rocker arm cylinder and the second coordinate to obtain the actual length of the rocker arm cylinder.
5. The method of claim 1, wherein the position loop uses proportional control and the speed loop control logic uses at least one of model predictive control, proportional integral control, and active disturbance rejection control.
6. The method according to any one of claims 1-5, further comprising: when the speed of a movable arm of the loader is in a first gear, a first control mode is adopted to control the movable arm oil cylinder to stretch; When the speed of the movable arm of the loader is in a second gear, a second control mode is adopted to control the movable arm oil cylinder to stretch; and when the speed of the movable arm of the loader is in a third gear, the movable arm oil cylinder is controlled to stretch and retract by adopting a third control mode.
7. The method of claim 1, wherein the acquiring the boom and swing joint angles of the loader comprises: The method comprises the steps of acquiring a swing arm joint angle and a swing arm joint angle of the loader through an angle sensor arranged at a hinge joint position between the swing arm and the swing arm of the loader, or acquiring the swing arm joint angle and the swing arm joint angle of the loader through an IMU inertial measurement unit.
8. A loader fork attachment lifting control device, the device comprising: The information acquisition module is used for acquiring a target bottom fork angle of the bottom fork attachment of the loader, a movable arm joint angle and a rocker arm joint angle of the loader; The actual length calculation module is used for calculating the actual length of the movable arm cylinder and the actual length of the rocker arm cylinder according to the movable arm joint angle and the rocker arm joint angle based on the geometric kinematics relation; the target length determining module is used for determining the target length of the movable arm cylinder and the target length of the rocker arm cylinder according to the target bottom fork angle; The difference value calculation module is used for calculating a first deviation value between the target length of the movable arm oil cylinder and the actual length of the movable arm oil cylinder and a second deviation value between the target length of the rocker arm oil cylinder and the actual length of the rocker arm oil cylinder; the control module is used for controlling a movable arm oil cylinder and a rocker arm oil cylinder of the loader according to the first deviation value and the second deviation value by adopting double-loop serial control logic to enable the bottom fork to lift in parallel, wherein the double-loop serial control logic comprises position loop control logic and speed loop control logic.
9. An electronic device, comprising: a memory and a processor in communication with each other, the memory having stored therein computer instructions which, upon execution, cause the processor to perform the method of any of claims 1 to 7.
10. A computer readable storage medium having stored thereon computer instructions for causing a computer to perform the method of any one of claims 1 to 7.
11. A computer program product comprising computer instructions for causing a computer to perform the method of any one of claims 1 to 7.

Description

Control method, device, equipment and medium for lifting bottom fork accessory of loader Technical Field The invention relates to the technical field of loader control, in particular to a method, a device, equipment and a medium for controlling lifting of a bottom fork of a loader. Background The loader is a shovel transporting machine widely applied to projects such as highways, railways, ports, wharfs, coal, mines, water conservancy, national defense and the like, urban construction and the like. In the process of lifting the goods by the loader, if the posture of the bottom fork attachment cannot be kept stable, the change of the front and back inclination angle occurs, so that the goods slide down, are damaged and even cause safety accidents. Therefore, the parallel control of the bottom fork attachment in the whole lifting process is realized, and the method has important significance for improving the operation safety, efficiency and operation comfort. In the related art, control modes of the bottom fork attachment of the loader are mainly divided into three categories. The manual control device is a traditional manual control with pure hydraulic pressure, and an operator controls the movable arm and the rotating bucket control rod simultaneously according to experience so as to maintain the posture of an accessory. One type is to modify a mechanical structure for driving a bottom fork mechanism to lift in a loader, and set the mechanical structure as a parallelogram-shaped connecting rod structure, but the modification of the mechanical structure is relatively complex, and the loader is applicable to a plurality of working devices, so that the modification of the mechanical structure is generally difficult to adapt to the use of other working devices. The other type is that the angle of the movable arm and the rocker arm is measured by an angle sensor, then a target angle value is calculated in real time, and the rotation of the movable arm and the rocker arm is directly controlled according to the angle deviation, but the phenomenon of shaking or hysteresis control occurs in the lifting process. Whether the mechanical structure is manually controlled or modified or the regulation and control mode is modified, it is difficult to ensure that the real-time inclination angle during parallel lifting is consistent with the inclination angle which is adjusted in advance. Disclosure of Invention The invention provides a control method, a device, equipment and a medium for lifting a flat fork of a loader, which are used for solving the problem that the inclination angle of the flat fork of the loader cannot be ensured to be consistent with the target inclination angle when the flat fork of the loader is lifted in parallel. In a first aspect, the invention provides a control method for lifting a bottom fork attachment of a loader, which comprises the following steps: acquiring a target bottom fork angle of the bottom fork attachment of the loader, a movable arm joint angle and a rocker arm joint angle of the loader; Calculating the actual length of the movable arm cylinder and the actual length of the rocker arm cylinder according to the movable arm joint angle and the rocker arm joint angle based on the geometric kinematics relation; Determining the target length of the movable arm cylinder and the target length of the rocker arm cylinder according to the target bottom fork angle; Calculating a first deviation value between the target length of the movable arm cylinder and the actual length of the movable arm cylinder, and a second deviation value between the target length of the rocker arm cylinder and the actual length of the rocker arm cylinder; and controlling a movable arm oil cylinder and a rocker arm oil cylinder of the loader according to the first deviation value and the second deviation value by adopting a double-loop serial control logic to enable the bottom fork to lift in parallel, wherein the double-loop serial control logic comprises a position loop control logic and a speed loop control logic. According to the invention, the difference value between the target length and the actual length of the movable arm cylinder and the rocker arm cylinder is calculated in real time, and the position speed double-loop serial control logic is adopted, so that the gesture maintaining precision of the bottom fork attachment in the lifting process is improved, and the control burden of operators is reduced. In an alternative embodiment, before the calculating the actual length of the boom cylinder and the actual length of the rocker arm cylinder, the method includes: Establishing a coordinate system taking a hinge point of the movable arm and the frame as an origin; And acquiring a first coordinate of a hinge point of the tail part of the movable arm oil cylinder and the frame in the coordinate system and a second coordinate of a hinge point of the tail part of the rocker arm oil cylinder and the frame in the