Sideslip angle, lateral tire force and road friction estimation in simulations and experiments

Transversal tire forces and sideslip angle are essential data for improving vehicle safety, handling, steerability, comfort and performance. This paper proposes and compares four observers designed to calculate vehicle sideslip angle and lateral tire forces. The different observers are derived from the Extended Kalman filter (EKF), the single-track model, and use different on tire-force models. The first three tire-force models are the linear model, the Burckhardt model and the Pacejka model. The remaining tire-force model, the "linear adaptive" model, is proposed in this paper in order to construct an adaptive observer. The "linear adaptive" model is based on the linear model, but with an additional variable used to correct wheel cornering stiffness errors. The paper describes models and observers, along with a, road-friction identification method. Observers are first compared in a simulation context using a professional vehicle simulator. Subsequently, observers are applied to real experimental data acquired on the Heudiasyc Laboratory car.