| Title |
Dual-Stage Servo System using Electrostatic Microactuator for Super-High Density HDD |
| Authors |
김승한(Kim, Seung-Han) ; 성우경(Seong, U-Gyeong) ; 이효정(Lee, Hyo-Jeong) ; 이종원(Lee, Jong-Won) ; 최정훈(Choe, Jeong-Hun) ; 안영재(An, Yeong-Jae) ; 전국진(Jeon, Guk-Jin) ; 김봉환(Kim, Bong-Hwan) |
| Keywords |
MEMS(micro-electro-mechanical systems) ; hard disk drive ; servo-bandwidth ; dual-stage servo system ; feedback nonlinear compensator |
| Abstract |
Dual-stage servo system for super-high density HDD has the chances of being composed of the coarse actuator(VCM) for track-seeking control and the fine actuator(microactuator) for-following control in near future. This paper presents the concept design of dual-stage servo system and the track-following control using an electrostatic microactuator for super-high density HDD. The electrostatic microactuator is designed and fabricated by MEMS(micro-electro-mechanical system) process. Both the nonlinear plant(voltage/displacement-to-electrostatic force) and the linear plant(electrostatic force-to-displacement) of the microactuator are established. Inverse function of the nonlinear plant is employed for a feedforward nonlinear compensator design. And feedforward control effect of this compensator is shown by time-domain experiments. A track-following feedback controller is designed using the feedback nonlinear compensator which is derived from the feedforward nonlinear compensator. The track-following control experiment is done to show the control efficiency of the proposed control system. And, excellent track-following control performance(2.21kHz servo-bandwidth, 7.51dB gain margin, 50.98°phase margin) is achieved by the proposed control system. |