Design of HDD Servo Controller with Adaptive IMC Structure

A robust controller design method with adaptive internal model control (IMC) structure for hard disk drive (HDD) servo is presented in this paper. To handle the unmodeled dynamics, the internal model control method is adopted to guarantee the robust stability. The model reference adaptive control (MRAC) technique is further incorporated into the IMC structure to deal with the gain variations of the VCM motor. The proposed method is applied to a HDD servo control system, and the experimental results show the effectiveness of the method