Patent ID: 6195157
Filing Date: 2001-02-27
Classification: B60T,G01C,G01S

Abstract:
A process for determining an abnormality in the detection of a distance by a vehicle distance sensor including a radar, said vehicle distance sensor detecting the distance from the vehicle to an object ahead of the vehicle, said process comprising the steps of:(a) transmitting a signal from the radar, ahead of the vehicle;(b) receiving a reflected signal reflected by an object ahead of the vehicle;(c) determining the distance between the vehicle and the object based on the time between the transmission of the signal and the receipt of the reflected signal;(d) determining the variation in the magnitude of the reflected signal from the object and determining when the variation becomes equal to or larger than a first reference value prior to the object falling into a non-detected state, wherein a reflected signal which is equal to or larger than the reference value indicates a deterioration in the environment of reception of the signal whereby the abnormality of the detection of the distance is determined;wherein the determination of the abnormality is made when said object is within a predetermined distance from the vehicle and wherein a deviation between a distance from the vehicle to the object which has fallen into a non-detected state in a current detection cycle and a distance from the vehicle to the object which has fallen into the non-detected state in the previous detection cycle is within a predetermined distance.