Design And Implementation Of Compound Drive And Control For Ultrasonic Motor Systems

Ultrasonic motors have attracted wide attention due to their characteristics of low speed and high torque,quick start-stop response,and no electromagnetic interference.Different from the traditional electromagnetic motor,the ultrasonic motor utilizes the inverse piezoelectric effect of the piezoelectric ceramic to convert the electrical energy into the mechanical energy,and the contact friction of the stator and the rotor drives the rotor to rotate.This process leads to the accumulation of heat and changes the operating characteristics of the motor.In addition,there are still dead zones in the speed regulating characteristics of ultrasonic motors.The existence of temperature drift characteristics and dead zone characteristics greatly limits the application of ultrasonic motors in the field of servo control.The main research of this paper is as follows:Firstly,the parameters of the equivalent circuit model of the ultrasonic motor were determined based on the frequency sweep results of the impedance analyzer.A parameter correction method based on the amplitude and phase information of voltage and current was proposed.Based on the modified equivalent circuit model,the design of the ultrasonic motor driver was completed.Secondly,the push-pull drive and the computer constitute the ultrasonic motor drive control platform.Based on this platform,the speed regulating characteristics and the temperature drift characteristics experiment were performed.A temperature drift compensation method based on the admittance tracking is proposed,the speed stability of the ultrasonic motor was achieved.The speed regulating characteristics and speed control methods were summarized through these experiments,and speed servo of the ultrasonic motor was achieved.Last,the stepping response experiment was performed.By setting the PWM pulse interval and pulse count reasonably,the open loop step-by-step control of the ultrasonic motor was achieved.