Estimation of Tire-Road Friction Based on Tire Torsional Resonance

摘要

The friction between tire and road is the most important information for vehicle safety systems. Most of the conventional friction estimation methods, however, work only unstable region. In this paper, a friction estimation method using a tire torsional vibration model is proposed. It is based on the frequency characteristics of the wheel speed vibration which are related to the friction. The instrumental variable method is applied for on-line estimation. The experimental result shows that the proposed method applied to free rolling tire detects friction change from dry asphalt to iced road at constant speed, as well as a hydroplaning phenomenon.