Multirate vibration suppression control of hard disk drives

In this paper, a novel vibration suppression perfect tracking control (PTC) method is proposed for short-span seeking mode of hard disk drives based on multirate feedforward control. In the proposed method, it is assumed that plant is modeled as the rigid and primary vibration modes. By using this model, a feedforward PTC is designed with a modified controllable canonical realization in order to control the transient response of position, velocity, acceleration, and jerk of the proposed virtual plant. Simulations and experiments are carried out to show that the proposed system can suppress the primary vibration mode in short-span seeking control. Finally, the proposed method is applied to a benchmark problem of hard disk drive control which is made by a technical committee of IEE of Japan. The robustness of the proposed feedforward method is improved by a multirate feedback controller against the variation of primary vibration frequency