Servo-free velocity estimator for coil driven actuator arm in a data storage drive
US5963393A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1998 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Feb 26, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for determining the velocity and/or position of a coil driven actuator arm without the aid of servo signals. A sample-hold unit is used to measure no-motion coil voltage in the voice motor coil while applying a predetermined coil current. Then, while the same magnitude (opposite direction) current is applied to move the actuator arm, the coil voltage is measured. The coil voltage is reduced by the measured no-motion coil voltage, producing a measurement of back-emf. The back-emf may be amplified by a predetermined factor to yield an estimation of velocity, and this amount may be integrated to provide a gauge of relative actuator arm position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.