Reduced-order observer based fault estimation and dynamic output feedback fault-tolerant control for switched fuzzy stochastic systems

In this paper, the fault estimation (FE) and fault-tolerant control (FTC) problems are studied for switched fuzzy stochastic systems subjected to multiple faults and nonlinear exogenous disturbance. The reduced-order FE observer and the nonlinear disturbance observer are used to reconstruct the system state, faults and nonlinear disturbance simultaneously. Furthermore, the dynamic output feedback (DOF) controller is designed to compensate the actuator fault and disturbances. The Root-Mean-Square (RMS) gain is applied to reduce the impact of disturbance, and the limitation of zero initial condition is removed, which means that the initial values of the system and faults do not need to be known. At last, two examples are given to verify the effectiveness of the proposed method.