Title :
Speed control of a new disc-type ultrasonic motor by using current controller
Author :
Juang, Puu-An ; Gu, Da-wei
Author_Institution :
Dept. of Eng., Univ. of Leicester, UK
Abstract :
The rotational speed of an ultrasonic motor is related to the vibration speed of its stator. Because drift of the piezostator characteristics will cause variation of the motor speed, a controller is thus necessary in order to produce a constant output speed. Variations of the motor output characteristics will also make it very difficult to obtain the efficiency of the motor. This paper points out the origins of possible drifts in a new disc-type piezoelectric ultrasonic motor which has three nonequal-triangular (120°-90°-150°) fixed points near the edge. The frequency behavior of the proposed motor and its consequences on speed control scheme are discussed. The speed control scheme is implemented by using current modulation, so the rotational speed will be kept constant.
Keywords :
angular velocity control; electric current control; machine control; stators; ultrasonic motors; vibrations; current controller; current modulation; disc-type piezoelectric ultrasonic motor; piezostator characteristics; speed control scheme; stator vibration speed; Adaptive control; Circuits; Control systems; Fuzzy control; Motor drives; Pulse width modulation; Resonant frequency; Stators; Velocity control; Voltage control; Current modulation; motor control; speed control scheme; ultrasonic motor;
Journal_Title :
Power Electronics, IEEE Transactions on
DOI :
10.1109/TPEL.2005.861159