The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 27, 2006
Filed:
Nov. 16, 2004
Disk drive estimating a sinusoidal error in a wedge time period due to eccentricity in disk rotation
Zhi Wang, San Jose, CA (US);
Jenghung Chen, Cupertino, CA (US);
David Dung Tien Nguyen, Fountain Valley, CA (US);
Zhi Wang, San Jose, CA (US);
Jenghung Chen, Cupertino, CA (US);
David Dung Tien Nguyen, Fountain Valley, CA (US);
Western Digital Technologies, Inc., Lake Forest, CA (US);
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+*cos(2π)+*sin(2π)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:(+1)=()−()*cos(2π){circumflex over (b)}(k+1)={circumflex over (b)}(k)−G*e(k)*sin(2πk/N)wherein G is a predetermined gain.