EXPERIMENTAL STUDIES OF USING STEERING TORQUE UNDER VARIOUS ROAD CONDITIONS FOR SIDESLIP AND FRICTION ESTIMATION

Recent work shows that steering torque, a measurement already available in some production vehicles, is a promising source of information for estimating sideslip and friction. By modeling steering torque and lateral force, preliminary studies have demonstrated the ability to estimate friction at half the peak tire force and sideslip angle up to the limits of handling using steering torque and other available measurements. In order to explore the issues and limitations associated with this method, this paper investigates the accuracy of these models during experimental test conditions that include flat and banked roads, road grade, and transient maneuvers. The experimental results demonstrate that the models perform well on flat and banked roads and during transient maneuvers, but a more sophisticated load transfer model is required to capture the effect of road grade.