PURPOSE: To provide a method and device for detecting the soiling of an optical vehicle sensor whereby a period requiring cleaning is properly judged.
CONSTITUTION: The device is the soiling detecting device of the optical vehicle sensor 11, which is arranged just over a road, permits a road surface to be irradiated with a light beam, detects reflection light and detects presence or absence of a vehicle on the road by the level of the reflection light. The device is provided with a storage part 13 storing the level of the reflection light of a state without soiling in the vehicle sensor 11 by a command from a control part 12 and the control part 12 which judges the soiling state at the point of measurement time by the stored reflection light level and the level of reflection light which is measured at the optional point of time and issues alarm for cleaning and maintenance when it is judged that the soiling state exceeds a fixed limit.
UEDA FUKUMI
MANABE FUMIO
OKADA IWAYA
| JPS6235159A | 1987-02-16 |