Ultra-precision stage control based on friction model of non-resonant ultrasonic motor

This paper presents a friction model-based ultra-precision stage control that introduces the non-resonant ultrasonic motor (NRUSM). At first, the friction characteristic is experimentally evaluated as a function of the stage position. Next, the friction model is adopted for the proposed continuous-pass tracking control design, and then the efficiency of the model-based control is verified by positioning experiments. Finally, measuring the time variation of the static friction characteristics, the on-line identification method for the control system is proposed.