Research On Position Control And Vibration Suppression Technology Of Flexible Joint Manipulator

Industrial manipulators are developing towards lightness and flexibility.The manufacturing field requires higher and higher work efficiency and position accuracy of the manipulator.How to effectively control the manipulator,suppress residual vibration and improve position control accuracy i s very important.Due to the uncertainty of parameters,the uncertainty of joint friction torque parameters and the existence of external disturbances in industrial manipulators,there will be vibration during the motion of the manipulator,and the existen ce of joint flexibility will cause the residual vibration of manipulator after the angle of each joint of the manipulator reach the desired value.We expect that after the manipulator reaches the designated position quickly and steadily,the end of the act uator will accurately stay in the designated pose.Therefore,it is necessary to research the position control and vibration suppression of the flexible joint manipulator.This dissertation will carry out research on this,analyze the advantages and disadv antages of different vibration suppression algorithms by reading the literature,and choose the input shaping method as the solution for the residual vibration suppression of the flexible joint manipulator.Through the analysis of some control methods to i mprove the position control accuracy,choose the friction torque compensation as a scheme to improve the position control accuracy of the manipulator,and joint speed planning issues are taken into consideration.I propose that the input shaping and friction compensation act on the controlled system as a solution to improve the position control progress and residual vibration,and the influence of the position control and vibration suppression effect is researched when considering the load,and the designed control plan is carried out by building a simulink simulation model.Complete the flexible joint modeling.Based on the Lagrange dynamic equation,the dynamic model of the flexible joint manipulator can be obtained through derivation,and the correctness of the established dynamic model is determined based on the consistency of the simulation model results and the numerical solution results.Analyze the vibration characteristics of the flexible joint,derive the vibration expression,and research the factors that determine the resonant frequency of the manipulator.Introduce the basic principle that the input shaper can achieve vibration suppression,build a simulation model to compare the vibration suppression ef fects of different input shaper and analyze their robustness,combine the input shaper with the closed-loop control system of the flexible joint manipulator,and research the stability of closed-loop system when input shaper is considered.In order to improve the accuracy of position control,based on the Lu Gre dynamic friction model,the joint friction torque is identified and compensated,the dual-state observer is designed to observe the bristles shape variables,the adaptive control law of unknown parameters in the friction model is designed,it is proved that using the designed adaptive control law,the parameters in the Lu Gre model can converge quickly.In addition,the joint speed is planned to obtain the joint angle curve under trapezoidal and S-shaped speed planning.Through some comprehensive simulation experiments,verify the researched control algorithm in this dissertation,the results show that using the designed scheme,compared with previous research results,the maximum amplitude attenuation of residual vibration is increased by about 12%,and the maximum amplitude attenuation of position tracking error is increased by about 1 0%.