Seagate Technology Incorporated

Maxtor Corporation

Jihao Luo

Jim Fitzpatrick

Travis Lee Hein

Mirmehdi L Abrishamchian

Barry J Henry

Jesse Speckhard

Baoliang Zhang

Write commands through a read/write head are regulated in response to head fly height. The head fly height is determined, and the rate at which the write command is carried out is regulated in response to the determined fly height. The rate may be regulated by inserting write inhibit gaps between writing data segments of the write command so as to allow the head to cool and, thereby, control fly height.

Regulating data writes responsive to head fly height

A method of providing a control output by selecting a controller to an actuator is discussed. A first controller having an estimator-compensator architecture is selected if the actuator is in a settle stage. A second controller having an architecture other than that of the first controller is selected when the actuator is in a track follow stage. The control output is provided from the selected controller to the actuator. The control output is indicative of the control signal.

High-order hybrid actuator controller

Various embodiments are disclosed that control head fly height based on estimates of head fly height. The fly height clearance between the head and a data storage media is estimated. Heating of the head by a heater element is then regulated in response to the estimated fly height.

Estimation and control of head fly height

Methods of estimating a flying height of a read/write head include determining an idle period of the head since a last selection of the head as a working head, estimating the residual temperature of the head in response to the idle period, and estimating the flying height of the head in response to the estimated residual temperature of the head.

Estimating residual temperature for flying height adjustment of read/write heads

A disk drive and related methods are provided for tuning the control of an actuator for position mode seeking of a head between tracks on a disk based on a measured open loop response of the actuator. The disk drive includes a rotatable data storage disk, a head, an actuator, and a servo controller. The actuator positions the head relative to the disk responsive to a current command signal. The servo controller carries out a position mode seek of the head between tracks on the disk by generating the current command signal which is varied in response to a current feedforward signal that defines a head position profile during the seek, varied in response to a position response signal that defines an expected actuator movement response of the head to the current feedforward signal, and varied in response to a current feedback signal. The servo controller measures an open loop response of the actuator to an open loop test current signal, and uses the measured position mode seek performance to vary contributions of the current feedforward signal and the position response signal to the current command signal to improve the position mode seek performance.

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Shrewsbury, MA, United States of America

Jihao Luo