Title :
Controller optimization for minimum position error signals of hard disk drives
Author_Institution :
Adv. Technol. Grou, Maxtor Corp., Milpitas, CA, USA
fDate :
10/1/2001 12:00:00 AM
Abstract :
In order to reduce the position error signal (PES) and track misregistration (TMR) of disk drives, it is generally believed that the bandwidth of a disk drive servo system has to be increased. However, increase of the bandwidth is limited by available sampling frequency and mechanical resonances of a head-disk assembly. Hence, for a given servo-mechanical system, optimization of a servo controller is a crucial and economical way to get the best TMR performance. In this paper, optimization of a servo controller that yields minimum PES is presented. The equivalent position-mode disturbance is estimated by the error transfer function inversion method. The estimated disturbance is injected into the servo system to evaluate PES. The optimization process will select the best controller that minimizes PES under the specified constraints. It has been demonstrated that the minimization has been achieved by shaping the error transfer function rather than increase of the servo bandwidth, PES reduction has been confirmed by simulation and experiments
Keywords :
disc drives; hard discs; machine control; motion control; motor drives; servomotors; transfer functions; controller optimization; disk drive servo system bandwidth; equivalent position-mode disturbance; error transfer function inversion method; error transfer function shaping; hard disk drives; head-disk assembly; mechanical resonances; minimum position error signals; motion control; position error signal reduction; sampling frequency; servo controller optimisation; servo-mechanical system; track misregistration; Assembly; Bandwidth; Control systems; Disk drives; Error correction; Resonance; Resonant frequency; Sampling methods; Servomechanisms; Transfer functions;
Journal_Title :
Industrial Electronics, IEEE Transactions on