Control of a haptic interface actuated by ultrasonic motors

This paper presents a haptic interface actuated by a Traveling Wave Ultrasonic Motor (TWUM). First, we detail a one degree of freedom force-feedback device on which control laws are tested. Then the control strategy is presented. It relies on a modeling of the motor which is inverted in order to reach the control laws. We present a strategy to attain good behavior when the lever rotates at low rotational speed. Moreover, a virtual environment is described. It is is made of a spring and walls. A specific way to simulate walls which takes advantage of TWUM is shown. Finally, experimental results are presented.