Fault Detection and Isolation for a Class of Uncertain State-Feedback Fuzzy Control Systems

This paper investigates the fault detection and isolation (FDI) problem for a class of nonlinear state-feedback control systems with parameter uncertainties. First, the considered nonlinear systems are described by multiple T–S fuzzy models with uncertain grades of membership and local nonlinear parts in normal case and faulty cases. Then, a switching technique is introduced to address the uncertain grades of membership, external disturbances, local nonlinear parts, faults, and the coupling of them. In a multiple-model scheme, a bank of FDI observers are constructed, each of which is based on the T–S model that describes the system in the presence of a particular fault, such that one of them can track the current system state, and the corresponding observer estimate error can converge exponentially to zero. Finally, two examples are given to illustrate the effectiveness and advantages of the new results.