Research On Trajectory Tracking And Vibration Suppression Of Flexible Manipulator

With the development of science and technology,the flexible manipulator has been used widely in various field such as the industry field,military filed,aerospace field and so on.The flexible manipulator has strong rigid-flexible coupling characteristics and it generates elastic vibration easily in motion,such that the position location cannot be achieved accurately and the service life of the manipulator may be reduced.Therefore,it is necessary to suppress the vibration of the flexible manipulator,while completing the motion control of the flexible manipulator.This paper mainly focuses on the dynamic modeling,vibration suppression trajectory planning,trajectory tracking control and vibration suppression control of the flexible manipulator system.Firstly,according to the dynamic characteristics of single-link flexible manipulator system,the Assumed Modes Method and the Lagrange principle are used to establish the dynamic model of the system.The validity and accuracy of the model are verified by modal analysis and numerical simulation.Secondly,for the vibration suppression trajectory planning of flexible manipulator system,the Cloud Adaptive Differential Evolution(CADE)algorithm is employed to optimize the vibration-suppressed trajectory and the optimal vibration suppression trajectory with the minimum of the vibration suppression index is obtained.According to the simulation results,CADE is better than the planning of Differential Evolution(DE).Moreover,the flexible manipulator system has a smaller residual vibration when it moves under the optimal vibration suppression trajectory.Thirdly,for the trajectory tracking control of flexible manipulator system,the Full-order Terminal Sliding Mode Controller(FOTSMC)is proposed.In order to make the system have a small residual vibration when it reaches the target position,control the joint to track the optimal vibration suppressing trajectory.Moreover,in order to use the inertia moment of the system to suppress the residual vibration,control the end position of the flexible manipulator to track the target position after the motion.According to the simulation results,the controller has better trajectory tracking effect and anti-interference performance,and further suppresses the residual vibration of the system under this control strategy.Finally,the piezoelectric actuator is added to the flexible manipulator system,and the singular perturbation theory is employed to decompose the system into a slow subsystem and a fast subsystem.The FOTSMC and BP Neural Network PID controllers are proposed for the trajectory tracking control of the slow subsystems and the vibration suppression control of the fast subsystems,respectively.According to the simulation results,this control strategy has better trajectory tracking and vibration suppression control effects.