State estimation for a four-wheel-independent-drive electric ground vehicle

The main work of this paper is to estimate the sideslip angle with the measurements of yaw rate based on the vehicle lateral dynamics. The vehicle dynamic model is first established and the parameters are identified with experimental data. Since the dynamic model is nonlinear, in order to facilitate the system analysis and observer design, the nonlinear model is transformed to a linear-parameter-varying (LPV) system. An observer is proposed based on the LPV form. An optimal observer design method is then developed. The sideslip angle observer for a four-wheel-independent-drive electric ground vehicle is designed according to such a method. The performance of the designed observer is illustrated with experimental test data.