Measurement of tire-road friction coefficient from strains induced on side surfaces of a tire

Abstract

Measurement of tire-road friction coefficient is indispensable for automobile safety technology and also for automatic driving technology. Generally, these technologies use information obtained from wheel speed sensors, acceleration sensors, etc. However, it is difficult to accurately measure tire-road friction coefficient with these sensors. Therefore, various studies on intelligent tires capable of measuring the tire-road friction coefficient have been conducted so far. However almost of the proposed intelligent tire systems have problems in terms of high cost or complicated structures and have not been practical use. This study proposes a method to measure tire-road coefficients from strains induced on the side of the tire, which is easy to detect by strain gauges. We clarify the relationship between strains on the tire side face and loads acting on the tire at grounding surface using an experimental apparatus that can simulate perfect slip condition of the tire, and propose a simple method of measuring tire-road friction coefficient from the above results.