ROAD SURFACE FRICTION COEFFICIENT DECISION DEVICE AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a road surface friction coefficient decision device capable of detecting with precision a friction coefficient between a tire and a road surface only through a wheel speed as an information source obtained from a vehicle. SOLUTION: This device comprises a wheel speed detecting means for detecting a wheel speed of each wheel of vehicle; calculating means for obtaining a mean wheel speed of four wheels or of driving wheels based on a detected wheel speed; calculating means for obtaining a mean wheel adjustable-speed from the mean wheel speed; calculating means for obtaining temporal variation of the mean wheel adjustable-speed; and a road surface friction coefficient decision means for deciding a friction coefficient between a road surface and a tire based on a value of the temporal variation of the wheel acceleration/deceleration.