Precise Position Control of a Traveling-Wave Ultrasonic Motor

In this paper, precise position control of a traveling-wave ultrasonic motor is achieved, avoiding the traditional drawbacks attributable to nonlinear torque generation, which are overshoot or slow response time. For that purpose, a behavior model control is proposed and presented. With this control law, a quick and precise response is obtained. In this paper, we present a position-control scheme of an inertial load. The guideline used for this control was a rotation of 90 in a response time of about 200 ms with a position error of 0.6 mrad, targeting a typical application for avionics. In this paper, a Shinsei USR30 is used, but the method can be applied to other ultrasonic motors.