Method and system of measurement and optimization of noise in servo systems
AssigneeStorage Technology Corporation
InventorsSteven G. Trabert, Matthew Tucker, Gerald M. Grammens
Life of this patent
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Abstract
Method and system of measuring and optimization of noise in a servo system. The method and system including features to optimize filtering otherwise reducing noise in the system so as to permit improved system operation.
Claims18
A method of measuring noise in a servo system having a media head to read media signals from a media element, the method comprising:
- determining position error signals (PES) as a function of signals collected by two servo readers, the servo readers reading servo patterns included on the media element;
- subtracting the PES of one of the servo readers from the other servo reader to determine PES noise;
- characterizing the PES noise filtering the signals collected by the servo readers prior to determining the position error signals;
- and
- optimizing the PES noise by adjusting the filtering according to a PES noise optimization strategy.
A method of positioning a media head to read media signals from a media element in a servo system, the method comprising:
- determining position error signals (PES) based on signals collected by two servo readers, the servo readers reading servo patterns included on the media element;
- subtracting the PES of one of the servo readers from the other servo reader to isolate PES noise;
- calculating a PES noise value for the PES noise;
- applying a PES noise optimization strategy to optimize the PES noise value;
- and
- positioning the head based on PES determined after implementing the PES noise optimization strategy.
A method of testing servo pattern quality of servo patterns included on a media element, the method comprising:
- providing a tape head having two servo readers;
- providing a benchmarked servo pattern;
- determining a position error signal (PES) for each of the servo readers as a function of signals collected by the servo readers from the benchmarked servo patterns;
- optimizing the servo readers as a function of a noise value associated with a difference in noise between the PES signals of the two servo readers;
- determining a benchmarked PES noise value as a function of signals collected from the benchmarked servo pattern after the optimizing of the servo readers;
- determining a non-benchmarked PES noise value as a function of signals collected from a non-benchmarked servo pattern after the optimizing of the servo readers;
- and
- outputting a servo pattern quality of the non-benchmarked servo pattern as a function of a difference between the benchmarked PES noise value.
Dependencies are inferred from the claim text.