Hybrid Ultrasonic Actuator for Force-Feedback Interface

There is a great possibility that an ultrasonic motor (USM) can effectively reproduce realistic feelings of hardness and roughness on a virtual object in a haptic virtual reality system, because it has a rapid response characteristic. However, the state following an external force does not exist in an ordinal USM, because a stator vibrator is preloaded to a rotor or a slider and a breaking force always occurs. Moreover, it is hard to arbitrarily change the preload of a USM during operation. In this study, a hybrid ultrasonic actuator that combines a USM function and a clutch one was proposed and examined. Such an actuator can electrically control a preload using piezoelectric actuators and a mechanical amplifier. It can also widely control the generation of driving and braking torques. As an experimental result, the revolution and rapid clutch functions of the hybrid ultrasonic actuator are realized.