High-precision Tracking Control of Magnetic Head Positioning Mechanism : 1st Report : Comparison of Minor-Loop Analog Feedback with In-phase Design

Abstract

This paper describes two types of head positioning mechanism of hard disk drive. Stabilized positioning mechanism consists of a conventional swing-arm positioning mechanism and a minor-loop analog feedback controller. This controller utilizes estimated velocity of main out-of-phase vibration mode and the estimator needs only VCM voltage and current signal which are easily measured in the circuit. In-phase positioning mechanism consists of an in-phase swing-arm positioning mechanism that was proposed by us. Characteristics of proposed positionig mechanisms are shown by simulation and experimental results.