Abstract
A new decoupled track-seeking controller methodoloty is proposed for dual-stage servo systems of magnetic disk drives. The controller is applied to the dual-stage system with a push-pull PZT micro-actuator and enables high speed one track-seeking. The methodology has three steps design procedure : 1) Design a VCM feedforward controller to prevent overshoot in response of VCM actuator. 2) Design a feedforward loop from the VCM reference signal to the PZT actuator, such that an output PES (position error signal) only follows a PES reference signal. The robustness of the seek controller for both gain variation and PZT hysteresis is analyzed by using simulations. Simulations and experiments show that the proposed dual-stage track-seeking controller is a more effective performance than the conventional single VCM servo and can achieve 0.3ms one-track seeking time.
