Feed-forward method for repeatable runout cancellation
US7787210B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2009 |
| Grant date | Aug 31, 2010 |
| Priority date | — |
| Expiry date | Mar 17, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic hard disk drive includes a method for eliminating that portion of track following error by a read/write transducer that is caused by repeatable runout of the disk tracks. The repeatable runout is eliminated by application of an iterative algorithm that calculates feed-forward correction terms based on gain coefficients iteratively calculated from the amplitude and phase portions of a Bode plot characterizing the system. The corrective coefficients can be inserted into the hard disk drive at a summing junction that redefines the centerline of the track, or at a summing junction that causes the actuator to follow the repeatable runout and make non-repeatable runout corrections relative thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.