Patent ID: 6650987
Filing Date: 2003-11-18
Classification: B60T,G01N

Abstract:
A road friction coefficient estimating apparatus for a vehicle for estimating a friction coefficient of a road surface on which said vehicle travels comprising:motion parameter detecting means for detecting motion parameters of said vehicle; low friction coefficient road traveling condition detecting means for detecting a traveling condition indicative of a traveling on said road surface having a low friction coefficient; low side road friction coefficient estimating means for estimating a low side road friction coefficient according to an adaptive control theory and to a vehicle motion model based on said motion parameters and said traveling condition indicative of a traveling on said road surface having said low friction coefficient; and road friction coefficient estimating means for estimating said road friction coefficient by comparing an actual yaw rate calculated based on said motion parameters, with a high friction coefficient road reference yaw rate calculated according to said motion parameters and a high road friction coefficient established beforehand, and a low friction coefficient road reference yaw rate calculated according to said motion parameters and said low road friction coefficient established beforehand.