Follow-up control system of ultrasonic motor based on DSP

According to advantages of ultrasonic motor (USM), a follow-up control system based on DSP-TMS320F2810 is presented in this paper. By analyzing output characteristic of USM, velocity of USM is mainly affected by frequency. So frequency is adopted as control variable in PID arithmetic. Time-varying input signal is followed by speed closed loop control, which forms inside loop. And the position of the motor is checked in time which makes outside loop. By experiments it is proved that the follow-up system has quicker speed tracking and exacter orientation compared to traditional analog follow-up system.