Four-wheeled vehicle modelling toward on board dynamics observer

This paper applies the step by step algorithm based on sliding mode observer to estimate tire forces. To define an observer, a model of a four-wheeled vehicle has been developed. The model is a rigid-body model with 10 degrees-of-freedom, including individual wheel speeds. Then a vehicle dynamic state is defined with the tire forces treated as vehicle variables with unknown dynamics. A field of test results is used to demonstrate the validity of this technique.