Modling And Simulating For The Drving And Controlling System Of Ultrasonic Motor

The ultrasonic motor (USM) is a new kind of micro-motor. Because of its novel princple and the especial structure, the ultrasonic motor owns many advantages that the electromagnetic motor does not have. The essential mathematic model and the simulation analysis on the model are important for the reasonable design and realization of the driving and controlling system of ultrasonic motors in the course of researching ultrasonic motors. In this paper the traveling wave ultrasonic motor was reserched for it's good application prospect. Firstly the main methods developed in modeling and Simulating for the driving and controlling system of ultrasonic motors are reviewed. Then the parameters value of the ultrasonic motor's equivalent circuit model were calculated by admittance circle method and identified by nonlinear least squares optimization method (Levenberg-Marquardt algorithm) based on the admittance-frequency property experiment of USM's stator. Thirdly a MATLAB/Simulink model of ultrasonic motor was set up, the rotational speed corresponding to the amplitude and frequency of driving voltage was simulated and a BP neural network is set up to simulate the ultrasonic motor's speed characteristics. Finally the push-pull driving circuit model of the traveling wave ultrasonic motor was established and the drive performance of this circuit is simulated, The results show that the square-wave voltage as driving source is feasible and an appropriate matching inductance is not only affects the resonant state of the motor but also plays an important role in optimizing the voltage waveform and boosting voltage amplitude.