Data storage device with real time fly height predictor for different servo seek sequences and other drive operations
AssigneeWestern Digital Technologies, Inc.
InventorsSandy Xianghui Xiao, Noureddine Kermiche
Life of this patent
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Abstract
Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: store heater power history data defining historic levels of heater power applied to the heater in the selected head; based on the heater power history data, select one or more calibrations from plural calibrations that define relationships between the fly height of the selected head and different levels of heater power change; and determine a predicted fly height of the selected head over a target sector of the one or more disks using the selected one or more calibrations and the heater power history data.
Claims22
A data storage device, comprising:
- one or more disks;
- an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface of a corresponding disk among the one or more disks, the selected head including a heater associated with adjusting a fly height of the selected head;
- and
- one or more processing devices, individually or in combination, configured to:
- store heater power history data defining historic levels of heater power applied to the heater in the selected head;
- based on the heater power history data, select one or more calibrations from plural calibrations that define relationships between the fly height of the selected head and different levels of heater power change;
- and
- determine a predicted fly height of the selected head over a target sector of the one or more disks using the selected one or more calibrations and the heater power history data,
- wherein the selecting and the determining are performed during a seek operation in which an ending point of the seek operation is changed after the seek operation has commenced.
A method comprising:
- determining plural calibrations that define relationships between a fly height of a selected head and different levels of heater power change in a data storage device, wherein the plural calibrations are determined using measured values of the fly height of the selected head that occur over time as a result of applying respective ones of the levels of heater power change from a respective first value to a respective second value;
- storing heater power history data defining historic levels of heater power applied to a heater in the selected head;
- based on the heater power history data, selecting one or more calibrations from the plural calibrations;
- determining a predicted fly height of the selected head over a target sector of one or more disks using the selected one or more calibrations and the heater power history data,
- wherein the determining the plural calibrations, the storing, the selecting, and the determining the predicted fly height are performed by one or more processing devices individually or in combination.
One or more processing devices comprising, individually or in combination:
- means for storing heater power history data defining historic levels of heater power applied to a heater in a selected head in a data storage device;
- means for selecting, based on one or more changes in levels of heater power in the heater power history data, one or more calibrations from plural calibrations that define relationships between the fly height of the selected head and different levels of heater power change;
- and
- means for determining a predicted fly height of the selected head over a target sector of one or more disks using the selected one or more calibrations and the heater power history data.
Dependencies are inferred from the claim text.