Adaptive pole-assignment speed control of ultrasonic motor

The obviously time-varying nonlinearity of ultrasonic motor makes the good performance of speed control difficult to be obtained. Aiming at the nonlinear problem of ultrasonic motor's speed control, a kind of adaptive pole assignment speed control strategy is proposed in this paper. The parameters of motor system are identified online, and then the controller is designed online according to the identified parameters of motor. Novel method for determining initial value of parameters of online identification algorithm is investigated, that realized efficient self-tuning control using a small amount of data. The proposed strategy is robust and relatively simple, and the excellent performance of the proposed control scheme is examined through experimental results.