Observer-Based Robust Process Fauldt Detection and DiAgnosi´s for a Satellite System with Flexible Appendages

This paper presents a novel observer-based robust process fault detection and diagnosis (FDD) scheme in a class of nonlinear dynamic systems. The proposed observer synthesis sliding mode techniques and PID-type iterative learning estimators. The observer inputs, which are designed to isolate and estimate faults, are iteratively computed using the proportional, integral, and derivative information about the output estimation error. An adaptive algorithm is adopted to update the parameters of the observer. Moreover, robustness, sensitivity, and stability or this fault detection and diagnosis scheme are theoretically analyzed. Finally, the proposed algorithm is applied to a satellite system with flexible appendages, and simulation results illustrate its effectiveness