Model-based control for ultrasonic motors

A complete model-based control for traveling-wave-type ultrasonic motors is presented in this paper. The control scheme consists of inner control loop s with respect to the oscillation systems, offering all meaningful degrees of freedom for adjusting the traveling bending wave, and outer control loop s for torque and speed. After a brief review on modeling the actuator and p resentation of a parameter identification method, the control scheme is dev eloped and verified by measurements on a prototype drive system, Several me asures for the compensation of nonlinearities and temperature effects are d eveloped and achieved improvements are discussed with respect to the specia l properties of this novel actuator. Finally the developed drive is applied to an "active control stick."