Abstract: The developed test system for ultrasonic motors (USM) in-plane vibration modal testing is introduced. The system realizes auto-positioning the measurement points array through the X-Y digital control slider. Only utilizing a one-dimensional laser measurement head, through decomposition measurement way, realizes measuring the two-dimensional in-plane vibration with a 90° angular positioning equipment. The system can measure the in-plane vibration modal frequencies of the object and its vibration shape when stirred up by sine wave. The system can measure the shape of the USM faces including rectangle and circle. It also can measure the in-plane vibration modal of the linear alignment points on the USM faces. The development work fills up the blank of the world.

Key words: In-plane vibra-tion, Modal, Modal test, Ultrasonic motor, Vibration shape