ROAD SURFACE FRICTION STATE ESTIMATING METHOD, ROAD SURFACE FRICTION STATE ESTIMATING DEVICE, AND TIRE FOR ESTIMATING ROAD SURFACE FRICTION STATE

摘要

PPROBLEM TO BE SOLVED: To provide a method and device for accurately estimating a friction state between a tire and a road surface, and a tire for estimating a road surface friction state for use in estimating a road surface friction state. PSOLUTION: A vertical stress detecting means 11a and a shearing stress detecting means 11b embedded in a land part located at the center in the width direction of a tire tread detect vertical stress σSBZ/SBapplied to tread rubber in the land part, and shearing stress τSBX/SBin the circumferential direction of the tire. A stress ratio computing means 12 then computes a stress ratio rSBX/SB=(τSBX/SB/σSBZ/SB). Data of the stress ratio rSBX/SBand vertical stress σSBZ/SBare transmitted to a road surface friction state estimating device 20 on the vehicle body side. A maximum value rSBb/SBin a region between a grounding center position and a road surface kick-out point is extracted, and a road surface friction coefficient μ between the road surface and the tire is estimated based on the extracted maximum value rSBb/SBand an r-μ map 24M stored in a storage means 24. PCOPYRIGHT: (C)2008,JPO&INPIT