Patent ID: 7196864
Filing Date: 2007-03-27
Classification: G11B

Abstract:
1. A control system for processing distributed servo position information defining a plurality of circumferential tracks on a disk of a disk drive, and for generating a control signal for positioning a transducer head during a track following operation, each circumferential track exhibiting total runout having a repeatable runout component and a nonrepeatable runout component, the control system comprising: a position error signal (PES) calculator circuit for calculating PES values based on the distributed servo position information read during a track following operation; a first servo-loop compensator for processing the PES values during a normal data access operation, the first servo-loop compensator having a first transfer function that is optimized with respect to a variance of the total runout component resulting in a first ratio of a variance of the repeatable runout component and a variance of the nonrepeatable runout component; and a second servo-loop compensator for processing the PES values during a repeatable runout calibration operation, the second servo-loop compensator having a second transfer function that is optimized with respect to a variance of the nonrepeatable runout component resulting in a second ratio of a variance of the repeatable runout component and the variance of the nonrepeatable runout component, wherein the second ratio is greater than the first ratio.