On the simulation of mechanical behaviour of travelling wave ultrasonic motors

Travelling wave ultrasonic motors, TWUM, are based on the friction transmission of mechanical travelling waves excited on the stator by using high Q piezoelectric ceramics, When reducing the analysis to the optimal design of the motor stator, the electromechanical coupling factor can be defined as one of the objective function in the optimisation process. The present paper describes the work carried out in the process of optimising TWUM operation. First, the paper describes a novel modelling suitable for parametric optimisation of the motor performance, secondly, parameters having the most relevant influence on motor performance are identified as optimisation parameters. Finally, the proposed objective functions and the optimisation results are discussed.