Frequency Tracking of Ultrasonic Motor Using Fuzzy Controller

This paper describes a fuzzy control system and simulation for ultrasonic motors. Although ultrasonic motor has much merit, such as small size, light weight, high precision, fast control dynamics and large driving force when low speed, etc. However, the nonlinear dynamic characteristic and the accurate mathematical model is difficult to obtain. So the traditional control method is almost no effect on the USM control. To tackle the problem, intelligent control is proposed as a good candicate to the control system. This paper presents a fuzzy control system for USM to make it have a good driver operating. This paper propose a method to make the driver system output the frequency of the drive voltage source which follow the frequency of the USM so that the piezoelectric material sets up resonance. Then the USM will operate steady speed. The simulation results show that the fuzzy control system achieve reasonable performance when the frequency change.