The aim of presented work consists in developing an active steering assistance system to avoid the rollover of heavy vehicle. Single body model of heavy vehicle is developed and presented in this paper. An estimator based on the high order sliding mode observer is developed in order to estimate the vehicle dynamics. The lateral acceleration limit is then estimated and lateral position and lateral speed are controlled using twisting algorithm in order to avoid the rollover of the vehicle. In the same time, an identification of some parameters of the model has been done in order to increase the robustness of the method. Some simulation results are given to show the quality of the proposed approach.
