Multi Faults Detection Method for Flight Control System Based on Observers

This paper focuses on the flight control system where actuator and sensor faults occur at the same time, uses an unknown input observer and a sliding mode observer to detect faults by constructing an augmented system that regards sensor faults as auxiliary states. SMO is designed to estimate the value of the actuator faults that occurred in subsystem, and a nonlinear UIO observer is proposed for augmented system, which can completely eliminate sensor faults. The impact of system uncertainty on estimation error is minimized by suppressing uncertain factors through <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$H_{\infty}$</tex> method. The simulation results indicate that this scheme can effectively reconstruct multiple faults simultaneously.