Road surface condition detection system
US4690553A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1980 |
| Grant date | Sep 1, 1987 |
| Priority date | — |
| Expiry date | Jun 12, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F2007/005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Road surface condition detection system comprising light projector means for projecting light including the infrared region of the spectrum to a road surface to sense the condition thereof, the infrared having wavelengths at which the reflectance of snow is smaller than that of the road surface in a dry condition, light receiving means for receiving light reflected from the road surface, comparisons means for comparing the output signals generated from the light receiving means with reference signal levels corresponding to dry, wet, snowy and frozen conditions, and judging means for judging the road surface to be one of the conditions in accordance with results of comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.