Mechanical arm tail end trajectory tracking algorithm based on null space obstacle avoidance

Abstract

The invention provides a mechanical arm tail end trajectory tracking algorithm based on null space obstacle avoidance. A minimum pseudo-distance in an analytic form is adopted to replace a traditional Euclidean distance to serve as a proximity index of obstacle avoidance, and a null-space obstacle avoidance task of a mechanical arm is completed in combination with a gradient projection method. A self-adaptive positive definite coefficient matrix K and a speed error saturation function sat(e<.>) are designed to feed back a real-time tail end trajectory operation result to a redundant mechanical arm kinematics inverse solution, and the joint angular speed is self-adaptively adjusted according to the feedback result so as to reduce the tail end trajectory tracking error. According to the mechanical arm tail end trajectory tracking algorithm based on the null space obstacle avoidance, the tail end trajectory tracking problem of the redundant mechanical arm is solved, and meanwhile the null-space obstacle avoidance task is completed; obstacle avoidance action can be taken in advance by adopting pseudo-distance, stable space operation of a mechanical arm joint is ensured, the trajectory tracking precision can be remarkably improved by adopting the tail end trajectory tracking algorithm, and a tail end main task is completed to the maximum extent; and the simulation experiment result of the redundant mechanical arm verifies the effectiveness and superiority of the algorithm.

Description

technical field [0001] The invention belongs to the field of motion planning algorithms of manipulators, and in particular relates to a trajectory tracking algorithm at the end of a manipulator based on zero-space obstacle avoidance. Background technique [0002] Redundant manipulators have better flexibility and operability due to the redundancy, and at the same time have great advantages in motion obstacle avoidance, singularity avoidance, joint torque optimization, etc., and have become a research hotspot in the field of robotic frontier technology. one. However, if the robot collides with obstacles during its movement, the robot arm will not be able to complete a given task, or even cause irreversible damage to its own robot arm. Collision-free motion planning has become an important prerequisite for its application in the industrial field. Robotic obstacle avoidance can be divided into zero-space obstacle avoidance and obstacle avoidance where obstacles appear at the e...

AI Technical Summary

Problems solved by technology

[0003] The technical problem of the present invention is: to overcome the deficiencies of the prior art, to provide a trajectory tracking algorithm for the end of the robot arm based on zero-space obstacle avoidance, which solves the problem of large error in the trajectory tracking of the end, and at the same time completes the zero Spatial obstacle avoidance tasks, and each joint angle runs smoothly without sudden changes

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