Nonfragile Fault-Tolerant Fuzzy Observer-Based Controller Design for Nonlinear Systems

The problem of actuator fault estimation and fault-tolerant control for a class of uncertain nonlinear systems using Takagi-Sugeno fuzzy models is investigated. A design procedure for nonfragile proportional-integral (PI) observer is proposed to estimate the states of the nonlinear system and reconstruct the abrupt (modeled as step-like faults) and incipient fault signals. Subsequently, a nonfragile fault-tolerant controller is constructed, which is informed by the PI observer. Sufficient conditions of the existence of the PI observer and the fault-tolerant controller are provided in the form of linear matrix inequalities. The proposed fault-tolerant control architecture is tested on two numerical examples.