Yorihiko Yano

Approach to speed control using temperature characteristics of ultrasonic motor

Ultrasonic motors have some special unique features, such as high-torque under low-speed operation, compact size, and no electromagnetic noise. Ultrasonic motors would be expected to apply an element of the artificial muscle. The driving principle of the ultrasonic motor is based on friction force between a rotor and a stator. Therefore, it is difficult to drive the ultrasonic motor at a constant speed, because the generation of heat by friction changes the friction force. In this study, we proposed speed controllers of the ultrasonic motor, considering the temperature rise of the ultrasonic motor. From the results, these methods were proved the most effective for the speed control of the ultrasonic motor in experiments.

An EMG control system of ultrasonic motors using PSoC microcomputer

We investigate on development of myoelectric elbow prostheses with ultrasonic motor. Ultrasonic motors have some special unique features, such as high-torque under low-speed operation, compact size, and no electromagnetic noise. On other hand, use of the threshold level or amplitude of EMG (electromyogram) is often adopted as control methods of practical myoelectric prostheses using microcomputer. However, this method is not always suitable for the proposed prostheses. In order to development of an EMG controller for the myoelectric elbow prostheses, we proposed an EMG control system using PSoC microcomputer for ultrasonic motor. In this study, we development an EMG control system for ultrasonic motors using PSoC microcomputer, and it was proved effective in fundamental experiments.

The frequency responses for the physical model construction of the ultrasonic motor

In this study, we built a real-time control system for the ultrasonic motor by RT-Linux to develop the artificial muscle which combined ER fluid and ultrasonic motors. We measured on the frequency responses for the physical model construction of the ultrasonic motor with several load. Then, we discuss the optimal controller for the ultrasonic motor.