A robust nonlinear observer-based approach for distributed fault detection of input-output interconnected systems

This paper develops a nonlinear observer-based approach for distributed fault detection of a class of interconnected input output nonlinear systems, which is robust to modeling uncertainty and measurement noise. First, a nonlinear observer design is used to generate the residual signals required for fault detection. Then, a distributed fault detection scheme and the corresponding adaptive thresholds are designed based on the observer characteristics and, at the same time, filtering is used in order to attenuate the effect of measurement noise, which facilitates less conservative thresholds and enhanced robustness. Finally, a fault detectability condition characterizing quantitatively the class of detectable faults is derived. (C) 2015 Elsevier Ltd. All rights reserved.