Track following servo system for a disk file
US4594622A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 2, 1984 |
| Grant date | Jun 10, 1986 |
| Priority date | — |
| Expiry date | May 2, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/106
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The performance of a track-following servo system for a disk file is improved by the feeding forward of a prediction of track eccentricity into the normal feedback control loop. The eccentricity related function is derived by combining functions of the position error signal and of the input signal to the head position actuator during at least one revolution of the disk. The eccentricity function is stored and then fed forward to the actuator during a subsequent revolution of the disk. The eccentricity function may be a track shape position signal formed from the difference of the PES and the double time integral of the actuator current. Alternatively it may be an actuator current profile formed from the difference between the actual current and the double time derivative of the PES.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.