Multi-track position encoder system
US5774074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/30
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A position encoder system is provided, such system including a code wheel, a pair of sensors, a counter, and a processor capable of identifying the correlation between separately identified markings of the code wheel. The identified correlation is indicative of code wheel accuracy, and thus is used to correct error in any angular position determined using the code wheel. A method of identifying position of the code wheel thus includes: (1) providing a disc including a first track having incremental markings of a first resolution and a second track having incremental markings of a second resolution; (2) providing a first sensor to identify markings along the first track; (3) providing a second sensor to identify markings along the second track; (4) quantifying markings of the second track during a predetermined movement of the disc; (5) identifying eccentricity by determining a difference between the quantified number of markings and a predetermined desired quantity of markings; and (6) adjusting the identified relative angular position based on the corresponding identified eccentricity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.