| 摘要 |
PURPOSE:To permit the control of the angle or the position of a motor with a high accuracy by a method wherein the position or the speed of the motor is detected by a detector and the driving frequency of the ultrasonic motor is counted based on the time or the position of a detecting signal to control the motor by inserting the frequency of the motor externally or internally. CONSTITUTION:An ultrasonic motor is provided with an optical encoder, consisting of light transmission slits and fixed light transmission slits for example, on one part of the same. In this case, the motor is provided with a stator 1, a rotor 2, an encoder rotating unit 3 and a sensor fixing unit 4. The position or the speed of the motor is detected by the encoder and the driving frequency of the ultrasonic motor is counted based on the time or the position of a detecting signal while the frequency of driving of the ultrasonic motor is controlled by inserting the counted frequency externally or internally. According to this method, the ultrasonic motor may be controlled more accurately compared with the control of the same, which is effected only by the encoder. |
