Nonlinear Positioning Compensator of a Novel Thin-Disc Ultrasonic Motor Using Fuzzy Sliding-Mode Control

An approach of controller design based on fuzzy set and sliding-mode control theory for positioning purpose of a thin-disc edge-driving ultrasonic motor (USM) is developed in this study. A commercially available thin-disc buzzer used as a novel actuating component of ultra sonicmotor with simple structure has been demonstrated its cost effectiveness and advantage in flexible mechanism design of a stator and rotor separately according to the necessary of applications. The driving mechanism associated with the non-linear phenomena such as dead-zone and hysteresis behaviors were studied too. Through system identification technique, the approximated transfer function of ultrasonic motor was obtained for controller design usingfuzzy sliding-mode (FSMC). It has been successfully applied to position tracking to prove the excellent robust performance in noise rejection.