Abstract
Ultrasonic motors have large and non-linear parameter space in geometry design. So it is difficult to optimize the geometry of the vibrator. In the present study, a new geometric design method for designing a linear ultrasonic motor is proposed. It is based on a contact analysis between slider and vibrator, finite element method and genetic algorithms. As a fitness function, only an output power of the vibrator obtained by contact analysis is evaluated. In this process, design parameters concerned with driving characteristics such as natural frequencies, amplitude of vibration, direction of displacement at contact points, arrangement of PZTs and factor of electro-mechanical transmission are taken into account. The proposed method is applied to a design problem in which designer might have difficulty in estimating the ideal condition of design parameters. Results of analysis show that the geometry of the vibrator having high output power is designed.
