Disk drive estimating a sinusoidal error in a wedge time period due to eccentricity in disk rotation
US7068451B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2004 |
| Grant date | Jun 27, 2006 |
| Priority date | — |
| Expiry date | Nov 16, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1282
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive and method for estimating a sinusoidal error in a wedge time period is disclosed. An estimated WTP is calculated according to:EST_WTP=RTP+â*cos(2πk/N)+{circumflex over (b)}*sin(2πk/N)wherein RTP is a reference time period corresponding to a nominal WTP, k is an index representing a servo wedge, and {â,{circumflex over (b)}} are adjustable coefficients. A wedge time error e(k) is estimated as the difference between the estimated WTP and a detected actual WTP. The coefficients {â,{circumflex over (b)}} for generating the estimated WTP are adjusted according to:â(k+1)=â(k)−G*e(k)*cos(2πk/N){circumflex over (b)}(k+1)={circumflex over (b)}(k)−G*e(k)*sin(2πk/N)wherein G is a predetermined gain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.