STATE INITIALIZATION OF PEAK FILTER DESIGN IN HDD DUAL-STAGE SERVO CONTROL FOR SMOOTH SETTLING RESPONSE

摘要

Narrow-band disturbance caused by high speed disk rotation is one of the significant contributors to the track misregistration (TMR) in HDD track following. The peak filter design is an effective control method to suppress the narrow-band disturbance, but the activation of peak filter may produce some oscillations in the output response, which would prolong the settling time of HDD servo system. This paper presents a scheme of state initialization to deal with the undesirable transient response caused by control component. The proposed method is applied to an HDD dual-stage servo system with peak filter design. Testing results demonstrate that the settling performance would not be deteriorated when the high-gain filter is properly initialized. This technique would enhance the disturbance attenuation of HDD dual-stage servo system without the degradation of settling performance.