HDD servo loop gain calibration based on MRA method

Abstract

An automatic gain calibration method based on model reference adaptation for HDD servo is presented. Variations in VCM gain may cause variations in servo control stability margins and thus need to be compensated. The traditional model reference adaptive method is modified in this paper to generate the compensation gain adaptively. Experimental results show that after the compensation, the DC gain of the open-loop responses can be maintained nearly constant despite the variations in head position and operating temperature