抄録
Dual-stage servo control loops are modeled for hard disk drives (HDDs) with the consideration of time delay which is due to the time taken for position error signal demodulation and controller computing. The time delays are involved in controller design and the closed servo control loop is investigated to show the effects of the time delay on servo control performance. The studied actuation system is a PZT milliactuator based dual-stage servo system. The delay time within and over the sampling interval is separately considered for 62.5kHz sampling rate. To show the effect of sampling rate on servo control performance, 40 kHz sampling rate is considered for comparison. The results tell us that increasing sampling rate gives more marked improvement of servo performance than reducing time delay for HDD dual-stage actuation servo systems.
