Simultaneous Observation of the Wheel Torque and Tire Force as well as the Vehicle Speeds

Individual torques at each vehicle wheel are important intermediate variables for the design of Advanced Driver Assistance Systems, and their knowledge stays an interesting research problem. In this study, a nonlinear high-gain unknown inputs state observer is designed to compute simultaneously longitudinal and transversal tire forces, resultant torques applied to wheels and the vehicle speeds. The necessary measurements are the usual rotation speed. Having validated the model of knowledge using a realistic vehicle simulator, the observer is tested under the same conditions and shows good performances for the vehicle state, tire forces and the unknown torques reconstruction.