Inventors:
Ronald James Kadlec - Colorado Springs CO
Paul Henry Kelley - Boca Raton FL
Thomas James Frederick - Coconut Creek FL
International Classification:
G11B 555
Abstract:
In a servo controller for controlling the position of a read/write head of a disk drive, a calibrated controller is dedicated to fixed-distance seeks, especially for "single-track seeks" (seeks to an immediately-adjacent track). The controller is first calibrated during a calibration period that precedes an operational period. The purpose of the calibration period is to determine an optimum combination of "calibrated values" for the fixed-distance seeks. "Calibrated values" may include: acceleration pulse magnitude, acceleration pulse duration, deceleration pulse magnitude, and deceleration pulse duration. During the calibration period, various combinations of possible calibrated values are tested during a series of test seeks of the predetermined fixed distance. During each test seek conducted in the calibration period, a cost function is calculated, and the combination of possible calibrated values with the best cost function is chosen for use as the optimum combination of calibrated values during the subsequent operational period. If, during the operational period, the cost function exceeds the cost function of the optimum combination of calibrated values by a predetermined amount, the controller is re-calibrated to maintain optimum performance of the disk drive during fixed-distance seeks.