Multirate adaptive feedforward FIR filter for suppressing disturbances to the Nyquist frequency and beyond

Abstract

In this paper, an add-on multirate adaptive feedforward finite impulse response (FIR) filter is incorporated into the existing slow single-rate track-following control in the hard disk drive (HDD) servo mechanism to suppress the disturbance to the Nyquist frequency and beyond. A multirate least mean square (LMS) algorithm is applied to adjust the parameters in the multirate FIR filter to cancel the effects caused by the disturbance. Our simulation results on the model of the voice coil motor (VCM) in a hard disk drive (HDD) demonstrate that the proposed scheme is able to suppress the disturbances to the Nyquist frequency and beyond.