Road bank angle considerations for detection of impending vehicle rollover*

Safety restraint systems greatly reduce the potential injury risk during vehicle accidents. One major type of accident still remains without adequate occupant protection: Vehicle Rollover. Preventing this kind of accident requires the knowledge of the rollover index which depends on the vehicle dynamic states and other parameters. In this paper we estimate vehicle dynamic states in presence of the road bank angle as disturbance in the vehicle model. Roll angle and roll rate are used to compute the rollover index which is based on the prediction of the lateral load transfer. The used nonlinear model deduced from the vehicle lateral and roll dynamics is represented by a T-S fuzzy model. Stability conditions of such observers are given in terms of Linear Matrix Inequalities (LMI). The estimated states and computed rollover index are illustrated through simulation results.