Large-scale implementation of floating car data monitoring road friction

Knowledge about the friction potential could improve several advanced driver-assistance systems. The true friction potential, needed to validate every friction potential estimation method, is normally measured by full braking tests. These are limited to proving grounds and cannot measure the friction potential on public roads due to their potential impact on surrounding traffic. In order to measure the friction potential under real conditions, a new method, which only brakes one wheel for a short time, is developed. By the means of force measurement wheels all forces acting on the wheel are measured. The vehicle reaction is analyzed and it is shown, that the method can be used without endangering other traffic participants. Measurements of the new method are validated by comparing measurement results to full braking tests and first results of measurements on public roads are presented.

Single Wheel Braking - A New Method to Measure Friction Potential on Public Roads

The tyre to road contact friction is one of the most important properties when it comes to manoeuvrability of ground vehicles and information, to driver and vehicle, is of vital importance in critical situations. Different characteristics of different friction estimation methods make it hard to determine and compare performance of estimators. This article is an attempt to define and evaluate the performance of tyre to road friction estimators. The objective of the performance evaluation is to define and grade the performance of estimators based on all sorts of approaches and combinations of these. The result may be used in the context of benchmarking as well as a tool in the development process of the estimator. The test methods and metrics presented are illustrated with a comparative study of three different estimation approaches.

S Yngve

Papers

Evaluation of tyre to road friction estimators, test methods and metrics