Research On Trajectory Planning And Tracking Control Of Six Axis Manipulator

With the continuous development of intelligent manufacturing in China,industrial robots have stood out in the development wave of manufacturing in China due to their advantages such as efficiency and intelligence,and are widely used in industrial fields such as manufacturing and processing.The universal robot in industrial robots is a six axis series type robotic arm.This article takes the six axis robotic arm as the control object and conducts research on how to shorten the trajectory running time of the robotic arm and improve the tracking control accuracy.Firstly,the modified DH method is used to model the manipulator,and the coordinate system and kinematics model of the manipulator are established.At the same time,the forward and inverse kinematics are deduced based on the knowledge of kinematics,and the workspace of the manipulator is analyzed.Subsequently,the Newton Euler and Lagrange modeling methods were introduced,with a focus on deriving the expressions for the total kinetic energy and potential energy of the robotic arm.The Lagrange method was selected to establish the dynamic model.Then,a Simscape physical model of the robotic arm was built and dynamic simulations were conducted to verify the effectiveness of the dynamic model.Kinematics experiments were carried out on the experimental platform.Then,on the basis of the established kinematics and dynamics models,the path planning of free curves is carried out in joint space and Cartesian space respectively by using cubic polynomial interpolation,quintic polynomial interpolation,S-curve,B-spline curve,and arc interpolation and line interpolation methods.A simulation platform was built using the App Designer toolbox,and was used to simulate polynomial interpolation,line interpolation,and arc interpolation.The above trajectory planning methods were experimentally verified on the experimental platform.Secondly,in order to minimize the time of the point-to-point motion trajectory,combined with the speed and acceleration conditions of the robotic arm itself,the optimization objective is to minimize the motion time of each joint of the six axis robotic arm.A 3-5-3 combination polynomial is used to plan the motion trajectory,and an improved particle swarm optimization algorithm is combined to optimize the motion trajectory,greatly reducing the operating time of the robotic arm,which has been verified in experiments.Finally,the algorithm was applied to the study of obstacle avoidance trajectory planning for robotic arms,which not only completed obstacle avoidance but also shortened the trajectory running time.Finally,this paper studies the trajectory tracking control algorithm of the manipulator,proposes a PD feedback Robust control algorithm based on the dynamic model,proves the stability of the controller and simulates the algorithm.By controlling the output torque value of each joint of the manipulator,the angular displacement,angular velocity and other state variables of each joint of the manipulator can track the given expected trajectory quickly and accurately,The accuracy of the algorithm has been verified through experiments,resulting in higher tracking accuracy and more stable operation of industrial robots.