COMPARISON OF OPTICAL AND GPS BASED TIRE SLIP ANGLE ESTIMATION

In order to improve the lateral behavior modeling of a road vehicle, an accurate determination of tire slip angle is needed (typically an accuracy close to 0.1°). In this paper, first, we compare two industrial sensors delivering information of sideslip angle: an optical sensor and a GPS/INS sensor. For this purpose, a specific test bench was developed. The limits of both sensors with regard to the above mentioned precision requirement, are studied, as well for static as for dynamic vehicle maneuvres. Secondly, for the GPS/INS sensor giving better results, we investigate the possibility of direct tire slip angle measurement by mounting this sensor in a plane parallel to the wheel rim. The developed mechanical adapter suffers from an inherent drawback for this kind of mounting, in terms of additional movements, compared to commonly used optical sensors. In spite of this supplementary perturbation, we show that the GPS/INS sensor precision is still better than the optical sensor's.