True ground speed sensor
US5100230A · kind A · utility
8Cited by
5References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1990 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | Oct 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/366
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A speed sensor for a moving vehicle. A transmissive grating is used in conjunction with an electromagnetic wave source and beam combining waveguide to mix two beams of frequency f and f+.DELTA.f, where .DELTA.f is proportional to the speed of the grating relative to the ground. The source energy is reflected off the road to the grating. The zeroth and first order transmission from the grating are mixed to give the beat frequency .DELTA.f proportional to the ground speed. The sensor has no moving parts, and is independent of any gear ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.