road surface friction coefficient estimating method, vehicle control method, and the road surface friction coefficient estimating device

摘要

The condition of a road surface on which a vehicle is traveling is estimated accurately, using a tire having a general variable-pitch tire pattern for detection of a road surface condition. The tire for detection of a road surface condition has rows of blocks, the total number N of the circumferentially disposed blocks being 10 or more and the number n of lug grooves, each provided with at joining section connecting circumferentially adjacent blocks, being in the range of (N/2) ‰¤ n ‰¤ (N-5). The vibrations of the tire are detected by an acceleration sensor and are subjected to a rotational order ratio analysis by a rotational order ratio analyzing unit. And the road surface condition is estimated by comparing the amplitude P of the rotational order component of the tire vibrations extracted by a rotational order component extracting unit with a predetermined threshold value K.