Method and apparatus for measuring velocity in servo systems
US5062064A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1989 |
| Grant date | Oct 29, 1991 |
| Priority date | — |
| Expiry date | Sep 1, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/489
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for measuring the velocity, whether rotary or reciprocating, of a servo shaft driven cyclically by a motor, without employing a tachmometer, while maintaining accuracy despite environmental electrical noise. From movement of the shaft a pair of overlapping square-wave signals in quadrature are produced with transition expressible in Gray Code for each cycle. A clock continuously produces a large number of evenly spaced clock pulses constituting a series of consecutive sample intervals. A signed value representing the algebraic sum of all the quadrature transitions occurring during a sample interval is determined and stored. The number of clock pulses between two quadrature transitions, each transition being the last qualified transition of the two most recent sample intervals having transitions is determined. A computer divides the sample intervals by the number of clock pulses which occurred between the selected quadrature transitions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.