Compensation for Position-Dependent Mechanical Resonances in Head-Positioning Control of Hard Disk Drives

We propose a compensation method for position-dependent mechanical resonances in head-positioning control system of hard disk drives (HDDs). To realize high-accuracy head-positioning control, it is important to compensate for the mechanical resonances in the head-positioning control system. The some mechanical resonance characteristics depend on the magnetic head's location. In conventional design method, a notch filter must be designed to compensate for the mechanical resonances at any magnetic head location. The disadvantage is that phase lag caused by the notch filter worsens the stability of the head-positioning control system. To overcome this disadvantage, we propose a magnetic head-position-dependent notch filter to compensate for the position-dependent mechanical resonances in the head-positioning control system. The simulation results in HDD benchmark model show that the proposed method can decrease the phase lag caused by the notch filter. That is, the proposed method can improve the stability compared to the conventional method. (C) 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.