Dual-stage servo controller for HDD using MEMS microactuator

A MEMS microactuator provides a low-cost and high-performance solution to realize high track densities of HDD, because of the batch fabrication process and its clean mechanical characteristics. However, the servo system to control such a dual-stage system tends to be more complicated than a conventional HDD system. In this paper, a simple and efficient design method of a dual-stage servo controller for HDD applications is described. The experimental results of the track following control with the dual-stage actuator using a conventional VCM and a MEMS microactuator showed that the fourth-order servo controller can achieve a high bandwidth of more than 2 kHz.