Line Of Wave-type Ultrasonic Motor Drive Control System Design

In this paper, the principle of ultrasonic motor is firstly introduced, then a brief reviews of the progress and status quo regarding research on ultrasonic motor control and drive technology are presented. The electric characters of ultrasonic motor are also analyzed. Hereby, the requests of ultrasonic motor control and drive system are put forward. The merit and shortcoming of many typical control systems are analyzed in the paper, especially frequency difference control system and phrase difference control system. On the basis, the way of singlechip control system is presented, which is combined frequency difference control with phrase difference control. The design of system is detailed introduced. The system is consisted of two parts: control module and drive module. The former includes: square wave-producing circuit, frequency-detecting circuit, choosing and displaying circuit, which achieve the functions of frequency and phase difference, frequency tracing etc. The latter includes: push-pull inverter, PWM control circuit, MOSFET drives circuit, overflow of current protecting circuit, which supply the drive voltage needed by ultrasonic motor. The operation principles and design processes of all circuits are detailed analyzed. The experiment indicates that the system not only meets the requirements of functions but also takes on many merits, as follow: 1. The system takes 8051 as the central processing unit, then it achieves the requirements of miniaturization and intelligentization, moreover it advances the digital degree and strengthen the anti-jamming capability of system. 2. The combination of frequency difference control and phase difference control makes many merits of them fully exert, so the system is more ascendant than the system using single control way. 3. The design of driving power adopts the advanced switching power supply technology and has many merits, such as: small volume, high intelligence etc. 4. The control of the system is realized by programming, so all kinds of advanced control methods can apply to this system by changing the program of 8051. The system has the promising application prospect.