Takahiro Oda

Development of Fast and Fine Position Control System of an Ultrasonic Motor

This paper shows experimentally that an ultrasonic motor has an approximate first-order transfer function between phase shift input and rotational speed output. A position control system which feedbacks position and velocity involving integral control action was developed. A fast response of about 100 msec and fairly high positioning accuracy up to a rotary encoder resolution were both realized in this system.

A study of Sheet Feeding Mechanism Using Ultrasonic Vibration.

This study describes a sheet feeding mechanism which uses ultrasonic vibration generated by a piezoelectric actuator. The actuator vibrates in the sheet feeding direction and normal to the sheet feeding direction. It is an elliptical mode of vibration. In this paper, the motion of the vibrator is defined by the two motions of contact with the sheet and separation from the sheet, and it is determined theoretically that a sheet feeding speed can be controlled by the amplitude of elliptical vibration. As a result of fundamental experiments, it was proved that a sheet, such as paper or a telephone card. could be fed easily, and it was confirmed that the experimental curve of sheet feeding speed was in agreement with the theoretical curve.