Isolation of process and sensor faults for a class of nonlinear uncertain systems

This paper presents a unified fault isolation scheme for process faults and sensor faults in a class of nonlinear uncertain systems. The proposed fault diagnosis architecture consists of a fault detection estimator and a bank of isolation estimators, each corresponding to a particular fault type. Based on the class of nonlinear systems and fault types under consideration, adaptive thresholds are derived for the isolation estimators, and fault isolability conditions are rigorously investigated, characterizing the class of process faults and sensor faults that are isolable by the proposed scheme.