Research on the state observer of the vehicle body slip angle based on the Recursive Least Squares

The estimation of the body slip angle is the key problem in the electronic stability control system design. In this paper a state observer of the vehicle body slip angle is designed by considering the variation of the vehicle model parameters timely, which are effected by the maneuvers. In order to get a better state estimation value, the tire cornering stiffness is identified online based on the Recursive Least Squares (RLS). According to the results of simulation, the state observer with sufficient robustness can be used to overcome the impact of model error and the effectiveness of the observer can be verified by the simulation.