Positioning Control of Ultrasonic Motor Using Homogeneous Finite-Time Control

Abstract

Ultrasonic motors are available for the construction of precise positioning servo systems because of having high holding torque. However, deriving their dynamical models are generally difficult due to the complicated physical structures and a specific driving principle. Especially, their transient states in driving at high velocities need higher-order system models that are generally make the problems more difficult. In this paper, we provide a second-order linear system model for a ultrasonic motor by taking nonlinearity of steady-states into account. The modeling errors of transient states are compensated by a finite-time stabilizer based on homogeneous control Lyapunov functions. Then,after tuning the control parameters via computer simulation, we show the effectiveness of our servo system by comparing simulation and experimental results.