Abstract: By considering the random natures of the failure events and the failure detection and isolation(FDI)decisions in real active fault tolerant control(FTC)systems, two Markov processes are introduced to describe the random failures and the FDI decision behavior separately. The TakagiSugeno(T-S) fuzzy model is employed to represent a nonlinear active FTC system. Based on the parallel distributed compensation(PDC) scheme and linear matrix inequality(LMI) optimization technique, an approach to the design of a fuzzy FTC law such that the closed-loop fuzzy system is stochastically stable and a given level of H_∞ disturbance attenuation is satisfied, is provided. Moreover, a suboptimal H_∞ FTC design problem is also addressed. Finally, trucktrailer simulation results show the effectiveness of the proposed method.

Key words: active fault tolerant control, Markov process, fuzzy control, H_∞ control