Track Following of a Single-Stage Actuator

Abstract

The prevalent trend in hard disk design is towards smaller hard disks with increasingly larger capacities. This implies that the track width has to be smaller, leading to lower error tolerance in the positioning of the head. The controller for track following has to achieve tighter regulation in the control of the servomechanism. Current HDDs use a combination of classical control techniques, such as lead-lag compensators, PID compensators, and notch filters. These classical methods can no longer meet the demand for HDDs of higher performance. Thus, many control approaches have been tried, such as LQG and/or LTR approach (see e.g., [18, 19]), and adaptive control (see e.g., [27]) and so on.