ROAD SURFACE STATE IDENTIFICATION DEVICE FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To discriminate between a sandy road and a pressurized snow road. SOLUTION: An estimation valueθ-hat of a pseudo maximum friction coefficient equivalent to an inclination ofμ-s characteristic curve in the periphery of a slip ratio O based on a wheel speed estimation error ew and a car body speed estimation error ev and an estimation valueμr-hat of a rolling resistance coefficient is calculated based on the car body speed estimation error ev so that the road surface state is estimated based on the pseudo maximum friction coefficient estimation valueθ-hat and the rolling resistance coefficient estimation valueμr-hat. The sandy road and the pressurized snow road having the similar road friction coefficients can be thus discriminated.