UIO based robust fault diagnosis approach for aero-engine fiber-optic sensor

The purpose of this study is to develop a model-based method for detecting optical fiber sensor fault in aero-engine linear discrete time invariant (LDTI) system considering both disturbances and uncertainties. Firstly, the fiber-optic sensors are analyzed and utilized to measure the aero-engine compressor output and aero-engine compressor is reduced to a 4-input 3-output single-spool state space linear model. Secondly, the discrete robust unknown input observer (DRUIO) is designed for the fault detection based on a linear matrix inequality (LMI) approach. The performance of the observer is demonstrated by applying the design procedure to a nonlinear gas turbine model. And the result shows that less than 2% sensor fault can be detected with disturbance.