Research Of Vibration Suppression Strategy Of Flexible Manipulator Based On Trajectory Planning

Flexible robot has been widely applied in many fields such as aerospace and industrial,due to its simple structure,light weight and high feasibility.However,additional self-excited or external-excited vibration is produced with the inherent low stiffness of flexible component of flexible robot,which will lead to deterioration of positioning and control precision,and low reliability.Flexible arm is a kind of widely used flexible structure,it is particularly important to control the vibration shape and amplitude of the flexible arm in the process of operation.The conventional active or passive mode of vibration control by external controller will cause the damping and the extra mass of the flexible arm system to increase,and the energy consumption will be larger.This project is designed to optimize the motion trajectory of the flexible manipulator system,without changing the structural parameters such as stiffness,damping and mass of the flexible arm,based on the dynamics characteristics of the manipulator,the optimal control of the motor at the joint of the robot arm can effectively reduce vibration in the end of the flexible manipulator system.The dynamic model of the two-link flexible manipulator system is established and its dynamic equation is derived,due to the dynamic model of flexible manipulator and the principle of minimum vibration.The motion trajectory of the flexible manipulator is planned and designed.Based on the above constraint conditions,three kinds of manipulator trajectory planning strategies and kinematics simulation analysis are designed and analyzed in the joint coordinate system.A mathematical model of servo motor in the joint of a mechanical arm is set up,according to the theory of electromagnetic field.A motor control strategy,based on an adaptive PID controller and combined with trajectory planning,is designed.The numerical simulation of the drive and control system of the servo motor is carried out with the MATLAB software.The performance of the vibration control of the manipulator is analyzed.An experimental test platform is built for two-link flexible manipulator,including a joint servo motor,a planetary reducer,a motion controller,a flexible arm and a laser vibration measuring sensor.The three kinds of trajectory planning strategies mentioned are experimentally studied,and combined with theoretical analysis,the influence of trajectory planning on vibration amplitude and its change rule are analyzed.The experimental results are in good agreement with the theoretical analysis,which proves that the proposed method based on trajectory planning is effective for the vibration suppression of flexible manipulators.A useful idea and method for the effective control of the vibration of the flexible manipulator are provided to the subject.