Comparative design of dual-stage actuator control systems for hard disk drives

This paper presents a comparative design of dual-stage actuator (DSA) control systems. Three design techniques-discrete-time sliding mode control, robust control using structured singular values, maximum bandwidth design with slew-rate control-are considered, which can be accomplished using almost the same control structures. A design strategy is first introduced. Then, each DSA control system is designed to realize it. Time and frequency responses of each control system are presented. Each DSA control system was compared from the view point of design, performance, and practical implementation.