Method and apparatus for gain calibration in a disk drive servo control system and disk drive recording apparatus with gain calibration function

摘要

A method of gain calibration capable of providing the better performance and stability in a servo control system of a disk drive recording apparatus (hard disk drive) by the measurement and calibration of its gain. The method includes the steps of performing a track seek operation for a given target track, applying the maximum current to the actuator thereby to repeatedly measure moving velocity of the actuator and store the measured values, calculating an average moving velocity from the stored measured values in case that a number of measurement repetition for the moving velocity of the actuator exceeds a given number of times, calculating a scaling factor according to a gain difference of the calculated average moving velocity with respect to a reference velocity stored in a memory, and generating a gain parameter by calculating a reciprocal value of the scaling factor. The reference velocity represents a moving velocity of the actuator obtained upon application of the maximum current thereto during seeking of a sample track in the manufacturing stage of the disk drive recording apparatus. The target track selected to measure the moving velocity of the actuator is adapted to be provided with an accelerating stage, a uniform velocity stage and a decelerating stage during velocity control for servo control.