Research On The Fault Diagnosis Of Aero-engine Based On The AHP-SDG Method

There are many problems in fault diagnosis process of Aero-engine, because the structure of Aero-engine is very complicated, the airways and plane maintain corporation always do the maintenance according to the AMM (aircraft maintain manual). However, the air failure is always fatal once it happens. The deep knowledge model of Signed Directed Graph (SDG) can express complicated cause-effect relationship, has the capacity of containing large-scale potential information and good applicability on the Aero-engine. In order to make use of the advantage of SDG, on the basis of summarizing the existing literatures of fault diagnosis based on SDG method ,This paper dissect how to establish the whole SDG model of Aero-engine, and use it in the engine's fault diagnosis.This paper propose an analytic hierarchy process ( AHP ) -SDG method, analyze the model-building process of fuel distribute system ,then build the whole SDG model of the Aero-engine. To improve the diagnostic speed of SDG diagnosis process, the idea of combining SDG with expert system and the way to produce the diagnostic rules from SDG are described. Furthermore , we analyze the expression of expert system's knowledge, the realization of inducing equipment and draw up the inducing strategy. Finally realize the SDG fault diagnosis expert system prototype development.We put the example data of airways distribute system failure into the expert system, the result shows that the expert system can find the exact root fault with quick speed.