ELECTROMAGNETIC ACTUATOR AND STACKED PIEZOELECTRIC SENSORS FOR CONTROLLING VIBRATIONS OF A MOTOR ON A FLEXIBLE STRUCTURE

This paper presents an actuator with a sensor for controlling vibrations of machines. It consists of a voice coil-type electromagnetic actuator connected to a piezoelectric sensor and a coil spring. The actuator is used for controlling a motor laid on the beam. The sensor detects the disturbance force due to the centrifugal force of the motor, and the force, which is equivalent to the disturbance force, is applied to the motor and the beam by the actuator. This implies that the disturbance force is cancelled. The control technique just mentioned has advantages because it reduces the vibration on the low-frequency region. In addition, the actuator becomes compact, and the control force becomes small. But the control is insufficient for controlling the resonance peak. The PD control is available for reducing the resonance peak, but the displacement and velocity sensors are required. In the present article, a method of vibration control of disturbance cancellation combining the PD control is presented in which both the displacement and velocity sensors are not required. The analytical results for obtaining the control current and the response of both the motor and beam have been obtained. To validate the present actuator–sensor system and the control method, experimental tests are carried out.