Method and apparatus for evaluating quadrature encoders
US4901255A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Mar 21, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R25/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for evaluating the performance of a device, such as a quadrature encoder, which generates at least two electrical wave train signals, each varying between first and second states and the two normally being out of phase one with the other. In the invention, four types of change of phase relation between the signals are distinguished from a succession of changes, the interval required for each type of phase change is timed and recorded, and a predetermined plurality of sets of records are accumulated. The mean time interval for a change of phase relation between the two wave train signals is computed from the accumulated plurality of sets of records and compared with the accumulated sets of records of timed intervals for determining the one type of phase change for which the difference from the mean time interval is the greatest. A number indicative of the phase duration of that type of change of phase which has the greatest difference from the mean time interval is then computed and used in deriving an encoder quality signal representative of the performance of the quadrature encoder generating the wave train signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.