Vehicle Parameter Estimation and Stability Enhancement using the Principles of Sliding Mode

In this paper, tires longitudinal forces, vehicle side slip angle and velocity are identified and estimated using sliding modes (SM) observers. Longitudinal forces are estimated using high order SM observers, while for the estimation of the vehicle side slip angle and vehicle velocity, a SM observer based on the hierarchical super twisting algorithm. Validations with the simulator VE-DYNA pointed out the good performance and the robustness of the proposed observers. After validating these observers, controller design for the braking is accomplished using a reduced state space model representing the movement of the vehicle centre of gravity in the (X, Y) plane. Driver´s reactions are taken into account. The performance of the closed loop system is carried out by means of simulation tests.