Servo control apparatus and method using absolute value input signals
US6545836B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1999 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Nov 12, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/41369
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A servo control apparatus and method controls systems at least partially on the basis of an observable variable that has an absolute value functional relationship with the controlled variable and does not change sign for positive and negative variations from a nominal value. When applied to the positional control of an object, the control system observes a value of a position error signal and maps that signal to two different potentially correct displacement values. Two estimators within the control system are initiated, one using the positive displacement and the other using the negative displacement, and the two estimators each predict the future position of the object and the corresponding position error signal for each estimated position. A new position error signal is detected and compared to the two estimated position error signals. After sufficient system evolution, the control system can select one or the other of the estimators as being correct and the associated displacement is identified as correct and is used for future positioning applications, preferably until the sign of the displacement of the head again becomes ambiguous. The control system can be used in combinati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.