Study on observer-based robust control of the vehicle lateral dynamics via TS model with unmeasurable premise variables

This paper introduces a fuzzy observer-based control approach for the vehicle lateral dynamics. The Takagi-Sugeno (TS) fuzzy model is utilized to describe the dynamics of a nonlinear time-varying lateral system. Based on the fuzzy model, a fuzzy observer is developed to estimate the side slip angle using the yaw velocity measurement. The objective of this study is twofold: first, the observer-based controller is designed to improve the stability of the vehicle although perturbations related to the nonlinearities of the contact force models, the variations of the adherence coefficients, etc. Second, the proposed strategy takes into account the unmeasurable membership functions of the TS formulation in the design of the observer.