Disk drive with adaptive control of periodic disturbances
US7145746B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2006 |
| Grant date | Dec 5, 2006 |
| Priority date | — |
| Expiry date | Apr 14, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59622
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive, such as a magnetic recording hard disk drive, has a head positioning servo control system that includes an improved repetitive controller included with the conventional feedback controller for suppressing periodic disturbances. The repetitive controller includes a low-pass filter (LPF) and a time-delay memory with a time delay matched to the period of the periodic disturbance. In a digital implementation, where the head position error signal (PES) is sampled, the time delay is the time for N samples. A subsequent PES sample is summed with the time-delay input sample from N samples earlier and this summed value is input to the LPF. The output of the LPF is added to the subsequent PES sample and the added value is input to the feedback controller. The value of N is adjustable, so the repetitive controller is adaptable to changes in frequency of the periodic disturbance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.