Abstract
FDI(Fault Detection and Isolation) filters are very important scheme for guaranteeing safety and reliability of realistic active control systems. FDI filters based on the sliding mode observer proposed by Edwards provide desirable performances for detection of faults. This method can effectively estimate the size and the shape of faults. However, this method cannot estimate all faults in spacecraft systems because the systems involve poles at the origin. This paper proposes a method of estimation of faults using virtual sensor outputs to avoid the pole problem. The proposed method provides desirable fault estimation results for a spacecraft system.
