A NOVEL DESIGN FOR THE UNKNOWN INPUT FAULT-DETECTION OBSERVER

Abstract

The unknown input fault detection observer (UIFDO) is one of the most powerful diagnostic approaches for disturbed and uncertain dynamic systems. Normally, the procedure for designing a UIFDO is complicated. This paper presents a novel approach that uses vector projection theory to develop a direct design algorithm with simple matrix calculations for the synthesis of a UIFDO. Some associated existence conditions for the fault detectability of a stable UIFDO are also discussed. In addition to fault detection, we extend the proposed UIFDO Co handle fault isolation by appending a post filter to specify and diagonalize the fault/residual map. Detailed examples reveal the effectiveness of the proposed methodology.