CN-120395817-B - Mechanical arm path planning method based on passing points

CN120395817BCN 120395817 BCN120395817 BCN 120395817BCN-120395817-B

Abstract

The application relates to a path planning method of a mechanical arm based on a passing point, which comprises the steps of calculating a joint variable value corresponding to each joint in a target mechanical arm at the current passing point, determining the distance between the current passing point and the next passing point, judging whether the distance is not larger than a preset distance value, if not, compiling each joint motion instruction from the current passing point to the next passing point through an joint motion balancing strategy, otherwise, conducting interpolation segmentation between the current passing point and the next passing point, determining the interpolation direction corresponding to the current passing point, compiling each joint motion instruction in each interpolation segment according to the interpolation direction and the joint motion balancing strategy, and controlling the target mechanical arm to execute corresponding motion through each joint motion instruction. Therefore, the problems that the prior method causes unnecessary energy waste in the movement process of the mechanical arm, has higher inverse solution calculation complexity when the degree of freedom is redundant, influences the path planning efficiency of the mechanical arm and the like are solved.

Inventors

CHEN SHANGUANG
LI ZHIZHONG
ZHU CHAO
WANG CHUNHUI

Assignees

清华大学
中国航天员科研训练中心

Dates

Publication Date: 20260512
Application Date: 20250415

Claims (6)

1. The mechanical arm path planning method based on the passing points is characterized by comprising the following steps of: determining all the passing points corresponding to the motion trail of the target mechanical arm, calculating a joint variable value corresponding to each joint in the target mechanical arm at the current passing point based on a preset inverse solution calculation method, determining the distance between the current passing point and the next passing point, and judging whether the distance is not more than a preset interval value; If the distance is not greater than the preset distance value, compiling each joint movement instruction from the current passing point to the next passing point directly through a preset joint movement equalization strategy; If the distance is greater than the preset distance value, performing interpolation segmentation operation between the current passing point and the next passing point to obtain a plurality of interpolation segments between the current passing point and the next passing point, determining an interpolation direction corresponding to the current passing point by the target mechanical arm, and writing each joint motion instruction in each interpolation segment according to the interpolation direction and the joint motion equalization strategy; Traversing each passing point except for the end point in all the passing points to obtain each joint movement instruction from each passing point to the next passing point, and controlling the target mechanical arm to execute corresponding actions based on each joint movement instruction; If the distance is greater than the preset distance value, performing interpolation segmentation operation between the current passing point and the next passing point to obtain a plurality of interpolation segments between the current passing point and the next passing point, determining an interpolation direction corresponding to the current passing point by the target mechanical arm, and writing each joint motion instruction in each interpolation segment according to the interpolation direction and the joint motion equalization strategy, wherein the method comprises the following steps: Calculating the number of interpolation segments between the current passing point and the next passing point based on the preset interval value, and calculating the pose of each interpolation segment point according to a preset interpolation algorithm and the number of interpolation segments; judging whether the inverse solution calculation method considers interpolation direction selection corresponding to the current passing point or not; If the inverse solution calculation method considers the interpolation direction selection, performing inverse solution calculation on two directions from the current passing point to the next passing point and from the next passing point to the current passing point to obtain a joint variable value of each interpolation segmentation point in each direction, calculating a motion curve length of a tail end corresponding to each direction, calculating motion time corresponding to the two directions according to a preset tail end motion linear speed and the motion curve length, and comparing the motion time corresponding to the two directions to select the joint variable value of each interpolation segmentation point in a direction with smaller motion time as a final joint variable value; if the inverse solution calculation method does not consider the interpolation direction selection, taking the pose of the interpolation segmentation point as a final joint variable value; and writing each joint motion instruction of each interpolation segment in the plurality of interpolation segments in turn based on the final joint variable value.
2. The method of claim 1, wherein if the distance is not greater than the preset distance value, writing each articulation command from the current pass point to a next pass point directly through a preset articulation balancing strategy, comprising: Calculating an approximate value of the length of a motion curve of the target mechanical arm from the current passing point to the tail end of the next passing point, and calculating corresponding motion time based on a preset tail end motion linear speed and the approximate value; determining the change amount corresponding to the joint variable value of each joint, and calculating the rotation angular velocity or the translation velocity corresponding to the joint variable value of each joint according to the change amount corresponding to the joint variable value of each joint at the current passing point and the movement time; and writing each joint movement instruction from the current passing point to the next passing point based on the rotation angular velocity or the translation velocity corresponding to the joint variable value of each joint and a preset target value or the change amount by combining with a preset mechanical arm movement instruction specification.
3. The method of claim 2, wherein the calculating the motion profile length approximation of the target manipulator from the current pass point to the end of the next pass point comprises: Calculating the linear distance between the current passing point and the next passing point and the change amount of each joint, and calculating the corresponding approximation segmentation number based on the linear distance and the preset approximation linear length for controlling the calculation precision; Dividing the joint change amount by the approximation segmentation number to obtain an approximation segmentation change amount corresponding to the joint change value of each joint; Based on the approximation segmentation change amount, joint variable values of each joint are sequentially increased to obtain a plurality of approximation segmentation points, linear distances of adjacent approximation segmentation points in the plurality of approximation segmentation points are calculated, and the linear distances of the approximation segmentation points are accumulated to obtain an approximation value of the motion curve length.
4. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the route point based robot path planning method of any one of claims 1-3.
5. A computer readable storage medium having stored thereon a computer program, wherein the program is executed by a processor for implementing a route point based robot arm path planning method according to any one of claims 1-3.
6. A computer program product comprising a computer program, characterized in that the computer program is executed for implementing a route point based robot arm path planning method according to any of claims 1-3.

Description

Mechanical arm path planning method based on passing points Technical Field The application relates to the technical field of mechanical arm path planning, in particular to a mechanical arm path planning method based on passing points. Background The mechanical arm path planning is a process of calculating the pose of a middle path point of a motion track and the variable value of the corresponding mechanical arm according to the poses of a starting point and a finishing point, the constraints of kinematics, dynamics, environment and the like, and the requirements on the path planning are different according to different purposes of the mechanical arm. For the purposes of mechanical processing, welding and the like, each point of the motion track of the mechanical arm has higher precision requirements, and for the purposes of carrying, loading and unloading, assembling, maintaining and the like, the motion track of the mechanical arm only has certain pose precision requirements on the final point pose, and the middle track generally has no strict requirements, even if a plurality of passing points are required to be designated for the purposes of obstacle avoidance and the like. The existing mechanical arm path planning method is more, and the path planning is required to calculate the values of the joint variables corresponding to each pose besides calculating the pose of each point of the motion trail, namely the inverse solution calculation of the kinematics. If an analytical formula of motion inverse solution is available, interpolation functions such as linear motion and the like can be realized, and after a starting point and an end point are designated, intermediate points are automatically interpolated according to tracks such as a straight line and the like, so that the motion is from the starting point to the end point. The interpolation function can be embedded into the mechanical arm control system, so that the programming of the mechanical arm movement program is simplified. For the scene which is repeatedly used for a long time after planning once, various teaching methods can be used for obtaining the motion trail, namely, the motion process of the mechanical arm in the teaching process is recorded, then the process is reproduced in the use process, and if an interpolation function is provided, the motion process among all adjacent points can be automatically interpolated by a control system after the passing points are interactively set. For an application scene (such as an indefinite maintenance point) in which a starting point, an ending point and a passing point are required to be specified at any time, path planning is required to be performed in real time, a complete motion track is interpolated, simulation confirmation is performed after no danger such as collision occurs, and for a mechanical arm with a higher degree of freedom, inverse solution calculation may be complex and have considerable calculation amount. For mechanical arms with redundant degrees of freedom, the inverse solution calculation of each point of the path track is possibly complex, and the condition of multiple solutions often occurs, and the optimization calculation complexity of the whole path track is higher, the time consumption is longer, and the problem needs to be solved. Disclosure of Invention The application provides a path planning method of a mechanical arm based on passing points, which aims to solve the problems that the prior path planning method of the mechanical arm causes unnecessary energy waste in the motion process of the mechanical arm, has higher inverse solution calculation complexity when having redundancy degrees of freedom, affects the path planning efficiency of the mechanical arm and the like. The embodiment of the first aspect of the application provides a mechanical arm path planning method based on a passing point, which comprises the following steps of determining all passing points corresponding to a motion track of a target mechanical arm, calculating joint variable values corresponding to each joint in the target mechanical arm at the current passing point based on a preset inverse solution calculation strategy, determining the distance between the current passing point and a next passing point, judging whether the distance is not larger than a preset distance value, directly compiling each joint motion instruction from the current passing point to the next passing point through a preset joint motion balancing strategy if the distance is not larger than the preset distance value, performing interpolation segmentation operation between the current passing point and the next passing point if the distance is larger than the preset distance value, obtaining a plurality of interpolation segments between the current passing point and the next passing point, determining the interpolation direction corresponding to the target mechanical arm at the current passing point, compiling each jo