Tire-road friction estimation for enhancing the autonomy of wheel-driven vehicles

For improving the stability of vehicles, especially for autonomous driving, various techniques including vehicle dynamic control, traction control, and anti-lock braking system have been developed and are being adopted. To accomplish these systems, the most important factor is to acquire the tire-road friction characteristics. The majority of tire-road friction estimation algorithms are based on the tire slip ratio and the tracking force obtained by a tire model. However, as the slip ratio and tracking force by a tire model cannot be measured directly and be defined strictly, additional estimation algorithm to get these values are required. Therefore, in this paper, in the view of traditional friction definition, we propose a tire-road friction estimation method that uses the traditional friction model. The real car experimental result shows good performance of the proposed methodology.