Dual-stage actuator disk drive with method for secondary-actuator failure detection and recovery while track-following
US7079338B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2005 |
| Grant date | Jul 18, 2006 |
| Priority date | — |
| Expiry date | Jun 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method in a dual-stage actuator disk drive tests if the secondary actuator has failed while the disk drive is in its normal track-following operating mode. The secondary actuator is removed from the control loop and the primary actuator maintains the read/write head on a data track in the track-following mode. The servo control processor generates a test signal to the secondary actuator and receives the position error signal (PES) as the read head detects the PES bursts in the data track being followed. The servo control processor calculates the response of the secondary actuator to the test signal by deconvolving the motion of the primary actuator from the PES. The calculated response is then compared with an expected response to determine if the secondary actuator has failed. The coherence function can be calculated to measure the statistical validity of the calculated secondary-actuator frequency response.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.