Modeling and Analysis for in-Plane Modal Standing Wave Ultrasonic Motor Excited by Quarter-Phase Voltage

An accurate dynamic model which can represent the performance of standing wave ultrasonic motor (SWUSM) is useful for motion control. To analyze the characteristics of in-plane modal SWUSM, this paper proposes a dynamic model excited by quarter-phase voltage. Firstly, the electromechanical coupling model of stator is presented based on the assumed modal energy method. Then the spring stiffness model is applied to replace the nonlinear contact between the stator and mover. In addition, the stick-slip state has been taken into account when the mover and stator remain relatively stationary, and the model of mover is implemented according to dynamic law. Fourth order Runge-Kutta method is adopted to solve the equations, and the characteristics of SWUSM have been simulated. The proposed model provides a basis for the performance evaluation of the SWUSM excited by quarter-phase voltage. Admittance is potential to be a velocity observer, which is profitable for motion control.