Optical disc drive comprising switching gains for forcing phase states to follow a sliding line trajectory in a servo system
US5982721A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0908
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc storage system comprises a sliding mode controller for actuating an optical read head assembly over an optical disc during focus capture, focus tracking, track seeking and centerline tracking. The sliding mode controller is a non-linear control system which operates by switching between positive and negative feedback in order to force certain phase states (such as the read head's position error and velocity) to follow a predetermined phase state trajectory. Sliding mode control provides improved compensation to parametric variations, external load disturbances and other transients such as, for example, the focus capture transient. Furthermore, the sliding mode positive and negative feedback gains need only be within a predetermined range, thereby allowing gain values of 2.sup.n which significantly reduces the complexity and cost of the gain multipliers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.