| 摘要 |
A misposition correction system for correcting misposition errors due to spindle runout and other slowly varying errors in a servo positioning system of a magnetic disk storage device. The system includes means for dynamically measuring misposition error with respect to a data track centerline using an anti-aliasing analog filter, means for digitizing the measured analog signal and for removing selected harmonics of the fundamental-frequency of the resulting cyclic error signal, means for transforming the digitized error signal by a matched digital filter whose transfer function contains independently adjustable DC gain, fundamental-frequency gain, and phase lead components thereby to generate a misposition error correction signal that matches the electrical and mechanical response characteristics of the servo system. Further, the system includes means to iteratively refine the correction signal by re-applying it to the servo controller when measuring misposition errors with respect to the data track centerline. The system stores separate misposition correction signals for each transducer on the disk so that one of several correction signals can be selected depending on which transducer in the device is selected. The system further includes means for generating a bias force correction signal to correct for non-linear position errors resulting from variations in bias forces acting on the transducer carriage over its range of radial displacement.
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