Optimally designed parsimonious repetitive learning compensator for hard disc drives having high track density
US6574067B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2001 |
| Grant date | Jun 3, 2003 |
| Priority date | — |
| Expiry date | Sep 15, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5521
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A repetitive learning compensator for a servo system of a disc drive includes a memory buffer having a length N/m where N is the number of servo sectors in a track, m is a parsing factor greater than 1 and N/m is an integer. A down sampler supplies servo signals containing error signals to the repetitive learning compensator at a frequency of fs/m, where fs is a sampling frequency based on N and a fundamental frequency f0 of the spindle motor. An up sampler supplies filtered signals from the repetitive learning compensator to the actuator assembly at the sampling frequency fs. One aspect of the disclosure includes tuning the repetitive learning compensator with a phase advance represented by NPA and a cutoff frequency fc, where NPA and fc are selected as a pair to provide the greatest transfer function amplitude at the harmonic frequencies for the repetitive learning compensator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.