Aircraft Engine Fault Detection Using Dynamic/Adaptive Threshold Approach

Fault detection plays a critical role in aircraft engines and the performance of their control systems. A real challenge in fault detection applications is the design of a scheme which can distinguish between model uncertainties and occurrence of faults. Therefore, a technique to accommodate uncertainties in the model, help in reducing false alarms and missed detections is essential for the enhancement of engine operations. In this paper, a dynamic/adaptive threshold algorithm is developed for aircraft engine fault detection based on both ‘unstructured’ time-varying perturbations in the model parameters as well as external disturbances. The residuals are errors between estimated and measured variables of the outputs. With this design approach, the residual crossing the dynamic/adaptive threshold indicates the occurrence of fault. By this method of ‘dynamic/adaptive threshold’, model uncertainties do not trigger a false alarm as in normal case with a constant threshold. Simulation results based on an engine Component Level Model (CLM) are shown to demonstrate the effectiveness of the proposed method.Copyright © 2007 by ASME