Vehicle yaw control using a robust H∞ observer-based fuzzy controller design

A vehicle dynamics control system has been developed in this study for improving vehicle yaw rate dynamics under critical motions. The system consists of a fuzzy robust H_infin estimated state feedback controller. The variation of the road adhesion conditions is considered and represented by additive parametric uncertainties in the vehicle Takagi-Sugeno fuzzy model. The vehicle lateral velocity is unavailable for measurement and it is estimated by a fuzzy observer. The gains of the fuzzy controller and fuzzy observer are determined in terms of linear matrix inequality (LMI). Simulations have been conducted to evaluate the performance of the closed loop system under various driving conditions and results are presented in this paper.