DETECTION OF INCIPIENT FAULTS IN POST-FAULT SYSTEMS SUBJECT TO ADAPTIVE FAULT-TOLERANT CONTROL

摘要

This paper is concerned with designing a detection scheme of incipient faults in Post-Fault Systems (PFS) subject to Adaptive Fault-Tolerant Control (AFTC). The difficulty lies in the adaptivity of the AFTC that simultaneously counteracts the effect of new incipient faults on system performance. This makes some of conventional fault-detection strategies ineffective. Three existing fault-detection schemes are investigated to find which one is the best tool for detection of incipient faults. It turns out that the Unknown Input Observer (UIO) is the most suitable tool to achieve this tough task where the UIO is designed to decouple the incipient faults from the AFTC such that the residual is sensitive only to the incipient faults. Simulation study is presented using an aircraft example to test the three fault detection approaches. It is verified that the UIO is the most effective tool in detecting incipient faults in PFS subject to AFTC.