A novel simulation model for ring type ultrasonic motor

In this paper, a novel mathematical model for a traveling wave ultrasonic motor, developed by Alenia Spazio, now Alcatel Alenia Space Italia S.p.A. (Roma, Italy), within an Italian Space Agency (ASI) program, is described. The dynamic equations for the stator and the rotors of the ultrasonic motor are assembled into a differential system, whose equations are coupled by terms which represent interface generalized forces. Neglecting transient conditions, the complete mathematic model of the system is solved and an iterative process is developed, in order to obtain the motor’s running curves for different operation parameters, geometric dimensions and physical features of the system. The algorithm is implemented in Matlab environment and a graphical user interface is constructed for user-friendly managing. The model, also validated by means of experimental tests, can be used for parametric analyses with respect to different parameters, in order to optimize motor’s configuration. It represents a simple but powerful aid to determine final motor design that can satisfy specifications or to predict motor’s behavior under different working conditions.