Disturbance attenuation with multi-sensing servo systems for high density storage devices

PANG CHEE KHIANG

Publication

Disturbance attenuation with multi-sensing servo systems for high density storage devices

PANG CHEE KHIANG

Abstract

Track densities in magnetic recording demonstrations for future HDDs (Hard-Disk Drives) are projected to exceed 500,000 TPI (Tracks-Per-Inch) in the year 2007 and are still increasing. However due to the renowned superparamagnetic limitation in magnetic recording physics, data storage industries are also looking into probe-based storage systems actuated by MEMS (Micro-Electrical-Mechanical-Systems) for high density nanometer scale recording. In this dissertation, novel control topologies incorporating multi- and self-sensing (employing the actuator as a sensor simultaneously) sampled-data servo systems are proposed with specific considerations on sensor fusion issues for actuator-sensor collocation and high SNR (Signal-to-Noise Ratio). Improved track-following performance in piezoelectric- and MEMS-actuated storage systems are achieved via stronger disturbance rejection capabilities and robustness of proposed control algorithms to fulfill data storage demands in future consumers' mobile electronic devices.