Research On Control Technology Of Electromechanical Integrated Harmonic Piezodrive

The electromechanical integrated piezoelectric harmonic drive system is a new type of piezoelectric motor. This motor is mainly composed of piezoelectric ceramics, two-stage amplification of sleeve and movable teeth transmission system. Under the four phase voltage, using the inverse piezoelectric effect of piezoelectric ceramics, electrical energy is converted into mechanical energy to output to the two-stage amplification sleeve, and the movable teeth transmission system converts mechanical energy into the output power. Compared with traditional piezoelectric motors, its significant advantage is rolling contact, less friction, high torque at low speed, etc.For the electromechanical integrated piezoelectric harmonic drive system, its driving principle is analyzed. The output torque equation is set up, and the effects of mechanical parameters on the torque are analyzed. Using Laplace transform, the Output torque transfer function and the speed transfer function are set up, and the effects of the system parameters on the gain and time constant of the speed transfer function are analyzed.Considering changes of mesh tooth number, the angular velocity disturbance expression is set up, and the effects of mechanical parameters on the disturbance are analyzed, the practical speed responses are obtained. The PI regulator is designed, the robust of control system for parameters is investigated. The response equation caused by disturbance is solved, then the compensating voltage and ideal output response are presented.The control model of the electromechanical integrated piezoelectric harmonic drive system is set up and the simulink model is set up in Matlab/simulink. Tracking response characteristics to typical signals and sine voltage signal are analyzed, and the influence of PI controller parameters on tracking response characteristics is discussed. PD controller of feedforward compensation is designed, and based on PI controller and PD controller, tracking and anti-interference characteristics are analyzed, and the influence of anti-interference characteristics of PI controller parameters on the system is analyzed.Based on the control model of the system, the influence of mechanical parameters, PI controller and PD controller parameters on step response, tracking and anti-interference characteristics of the system are analyzed, and a set of optimal parameters is presented.The Lab VIEW control experiment system of electrical integrated piezoelectric harmonic drive system is designed, The control experiment of the system is completed, the experiment results and the theoretical analysis results are compared. It verifies that the theoretical analysis is correct.