MULTI-SENSOR FAULTDETECTION AND ISOLATION FOR AERO-ENGINE DCS WITH MARKOV TIME DELAY BASED ON H∞UNKNOWN INPUT OBSERVERS

Abstract

In this paper, a novel approach is proposed to design a bank of unknown input observers(UIOs) for aero-engine distribute control system(DCS) with multi-sensor fault. First, considering the system with multi-sensor fault which doesn’t satisfy the observer matching condition, a H ∞ UIO is proposed based on the disturbance decoupling principle of unknown input observer(UIO) and H ∞ control theory. The parameter matrixes of UIO are solved in terms of linear matrix inequality(LMI) toolbox. Second, the fault detection and isolation scheme is proposed for DCS with multi-sensor fault and the UIOs are designed for a bank of fault detection and isolation sets which are obtained by reorganizing the control system. The residual signal generated by each observer is robust to the sensor fault in the matching set, and sensitive to the sensor fault out of the matching set. Finally, the residual signals were simulated and the results show the effectiveness of the proposed method.