Disturbance Rejection Control based on Adaptive Identification of Transfer Characteristics from Acceleration Sensor for Hard Disk Drive System

In this paper, a new method for disturbance rejection control which is based on adaptive identification of transfer characteristics from acceleration sensor is proposed. For hard disk drive, external disturbance which should be reduced is growing with widespread use of movable computers and other independent machinery. In order to reject the effect of the external disturbance we apply the feedforward controller which is designed by the adaptive identification algorithm. In adaptive identification, the proposed method uses Disturbance Observer to get the estimated disturbance as a substitute for the system disturbance which can't be observed. By this, the proposed method can identify the transfer characteristics directly which was impossible before and can design the feedforward input easily. Some experimental results in which a hard disk drive is shaken in the vertical direction arc shown to verify the effectiveness of the proposed method.