Estimation of tire slip-angles for vehicle stability control using Kalman filtering approach

The increasing number of accidents worldwide has motivated the need to develop technologically sophisticated automobiles that provide improved vehicle handling, stability, comfort, fuel efficiency and safety. In automotive industry, current focus is on the development of active safety systems, which assist the driver in order to avoid critical situations. But, some key states which are valuable for the vehicle dynamics control system are not measurable or cost prohibitive. Hence, the states are to be estimated. This paper presents the estimation of tire slip-angles, which are among the essential states. A simplified model of the vehicle has been considered during a turning maneuver. Then, the interdependency of lateral and longitudinal velocities w.r.t yaw rate is depicted. Later, the longitudinal velocity is subsequently used for slip angle estimation for the front and the rear wheels using linear Kalman filter approach. Computer simulation have been conducted to verify the proposed approach with results indicating that the proposed approach is very effective and robust in estimating tire slip-angles of a vehicle.