Ultrasonic motors are driven by the friction force between the rotor and the vibrator, which often induces speed fluctuations synchronizing with the rotor position periodically, namely, speed ripples. This paper employs the plug-in type repetitive control for rejecting the position-dependent periodic speed ripple and presents an implementation technique based on rotor position information. A mathematical description for characterizing the speed ripple is introduced using the Fourier series. A position-dependent repetitive controller design and an interpolation scheme to manipulate the delayed data based on the acquired rotor position are developed to improve control performance in speed ripple reduction. Simulation and experimental results are given to confirm the validity of the proposed repetitive control design and implementation.