Design, dynamic analysis and control of milliactuator embedded suspension for dual-stage actuator system in hard disk drives

To achieve higher track density of HDDs, a new dual-stage actuator system, based on suspension, is proposed, with a design parameter study and sensitivity analysis through FEM. Based on simulation results, the prototype milliactuator embedded suspension is fabricated and experiments are carried out to identify the dynamic characteristics. It is confirmed that the suggested suspension has the structural qualifications for fine tracking as a secondary actuator, high-shock resistance and flying stability. Using the new dual-stage actuator, the attenuation related to disturbances is examined by a classical control scheme with a systematic approach. In the decoupled master-slave control structures, the attenuation is increased at all frequencies under the servo bandwidth compared with the single-stage control.