H? fault tolerant control for uncertain state time-delay systems

H_∞ formulation of the robust fault tolerant control problem for uncertain systems with state time-delays is studied in this paper. A robust control law is then designed in order to automatically compensate actuator and sensor faults, based on a performance index as H_∞ model-matching problem. Where, the gain is obtained via Linear Matrix Inequality (LMI) feasibility conditions. Indeed, a new condition is developed to show that the system can be guaranteed to be asymptotically stable in the presence of uncertainties, faults and disturbances based on the Lyapunov-Krasovskii theory. The effectiveness of the design methodology is verified based on a two-stage chemical reactor train with delay recycle streams.