Active control on flow-induced vibration of the head gimbals assembly in hard disk drives

Abstract

An active control method has been applied for the flow-induced vibration (FIV) of the head gimbals assembly (HGA) in working hard disk drives (HDDs) through suppressing the pressure fluctuations around the HGA. Firstly, the HGA off-track vibrations and the pressure fluctuations around the HGA are measured. The results show a high correspondence between the pressure fluctuations and the HGA off-track vibration. Secondly, a feedback control architecture, based on numerical simulations, is proposed for the FIV of the HGA by introducing virtual pressure sensors into the airflow regions around the HGA. The numerical results show that the FIV of the HGA can be successfully controlled when the pressure fluctuations are actively suppressed around the HGA. Finally, an experiment has been conducted to demonstrate the proposed feedback control method for the FIV of the HGA, in which the FIV on the HGA was detected by a laser Doppler vibrometer and used as the feedback error signals.