The characteristics of compensation on temperature of ultrasonic motor with robot actuator by fuzzy controller

This paper describes the bending traveling-wave type ultrasonic motor (USM) which generates the traveling wave by combining two standing waves with phase difference time and space. In +20/spl deg/C/spl sim/30/spl deg/C, the USM operation character has represented normal condition. But at higher temperatures (as generated by prolonged operation), USM operation characteristic has an abnormal condition; that is, driving frequency, drive current and r.p.m is down. The recent USM has controller without temperature compensation. This study aimed at fuzzy controller which must follow the driving frequency at operation temperature and then r.p.m and torque increase.