Systematic Filter Design by Convex Optimization for Disturbance Rejection in Dual-Stage Actuated Hard Disk Drives

Abstract

To enhance storage capacity in hard disk drive systems (HDDs), dual-stage actuated systems employing both piezoelectric and voice coil motors (VCMs) are utilized in the positioning of magnetic heads. However, external disturbances, such as rotational vibrations and cooling fan vibrations, necessitate the design of controllers with robust disturbance rejection performance to further improve positioning precision. In this paper, we propose an auto-tuning method for a fixed-structure filter in a dual-stage actuated HDD system. The filter parameters are determined using our proposed frequency response data-based convex optimization process. Furthermore, the initial guess for the optimization is selected from the Robust Bode (RBode) plot which is a visible tool in designing robust controllers. Simulation results confirm the effectiveness of our proposed method.