Control and Sensor Fault-Tolerance of Vehicle Lateral Dynamics

In this paper, fault tolerant control (FTC) system is developed for lateral vehicle dynamics by combining static output feedback control and sliding mode observers for improving vehicle handling and stability under sensors faults. The system consists of three blocks: fault detection and isolation (FDI) block, a static output feedback controller block and a switcher block. The nonlinear two degrees of freedom vehicle motion (bicycle model) is described by a Takagi-Sugeno (T-S) fuzzy model. The strategy of the FDI method is based on a bank of observers, each one is constructed using sliding mode design techniques to estimate the system state vector. Thus the diagnostic signal-residuals are generated by the comparison of measured and estimated outputs and the faulty sensor is isolated. Simulations demonstrate that the vehicle maintains acceptable performance after either set of yaw rate sensor and lateral velocity sensor has failed.