Development of an ultra-precision stage control system using nonresonant ultrasonic motor

This paper presents the development of an ultra-precision stage control system by introducing the nonresonant ultrasonic motor (NRUSM). System identification experiments are carried out considering the fundamental characteristic of NRUSM. The friction, which affects the accuracy of the positioning, is evaluated. Then the relation between the friction and the control bandwidth is experimentally examined. Using the frictional property as well as the identified model, the position control system with friction compensation is designed. Moreover, for its design the anti-windup-based wide band control is performed. Thus, the effectiveness of the identified model and the designed control system is verified by simulations and experiments.