H∞ robust observer-based control for vehicle rollover

In this paper, we propose an Hoc robust observer-based control to prevent rollover of the vehicle when road adhesion and other conditions change. In this work, we take into account that roll rate and yaw rate can be measured easily by sensors, but roll angle and lateral velocity are not measured. After giving the nonlinear model of the vehicle, its representation by a Takagi-Sugeno (T-S) fuzzy model is first discussed. Next, a fuzzy observer and a fuzzy controller which guarantee desired control performances are synthesized. The proposed TS observer is designed with measurable premise variables and the conditions of stability are given in terms of Linear Matrix Inequality (LMI). The simulation results show effectiveness and robustness of the proposed method.