Measurement of friction coefficient between a tire and grounding surface with the deformation of inner of the tread

Abstract

Previously, in order to measure friction coefficients of tire grounding surface in car slipping, a cantilever-type sensor that can detect the vertical load and friction force as well as the direction of the friction force simultaneously has been proposed. The sensing part, which contacts grounding surface, of the proposed sensor is pulled out of the tire tread through a hole. However, penetrating the hole through tire tread part has some problems: leakage of air from the tire, weakening of the rigidity etc. Therefore this study proposes a sensor that can be installed on the inner surface of a tire without penetrating hole through the tire tread by filling the detecting part of the sensor in the inner part of the tire tread. If the detecting part filled in the inner surface has sufficient airtight structure from the integral manufacturing, the durability of the sensor as well as retaining air pressure are expected. This study measured the deformation of the inner part of the tread through the detecting part under high-load at tire slipping state. Furthermore, relation between the measurement values and the force applied to the tire from grounding surface was clarified. As a result, the study confirmed that the proposed method can detect the friction coefficients between the tire and tire grounding surface.