Research On The Design Of Fault Diagnosis System For The Rotating Part Of Civil Aero-engine

Rotor system which undertakes the import task of energy conversion and power output is the main part of aero engine, so the health status of rotor system plays a vital role in the safety and economy of civil aviation operations. While the rotor system is an extremely complex nonlinear time-varying system, it is difficult to discover, locate and eliminate faults in aeroengine. Based on the research of the dynamic characteristics of rotor system with common faults, the fault diagnosis system for the civil aero-engine rotor was designed in order to diagnose faults quickly and accurately.Reference to the rotor system of aeroengine, the dynamical models under four different fault conditions including imbalance, misalignment, rub-impact and the coupling of the latter two was established. The dynamic response of fault models solved by the method of Runge-Kutta was used to extract the fault feature which can provide theoretical guidance to the research of fault diagnosis.In order to diagnose the faults in the rotor system of aeroengine accurately and efficiently, the key technology of fault diagnosis system of rotor system was researched. Several signal analysis methods and pattern recognition methods were compared to each other. The EMD which had the characteristic of self-adaptive was selected as the signal analysis algorithm of the fault diagnosis system, and the SVM method which had high test accuracy was selected as the pattern recognition algorithm of the fault diagnosis system.Based on the above research, a fault diagnosis system for aeroengine rotor system was designed and implemented using object-oriented programming method in VC++ development environment. According to design process of the software, the demand analysis and the design of hardware and software which included data acquisition module, signal analysis module, feature extraction module, pattern recognition module and fault diagnosis database management system was implemented.Finally, the coupled method of black-box testing and white-box testing was adopted to debug the fault diagnosis system of rotor system. And in order to ensure reliability and accuracy, the fault diagnosis system was finally tested on the aeroengine rotor simulator rig, and the result showed that the intelligent and efficient system achieved a high precision for the typical faults. The system can provided practicable idea for research on the design of fault diagnosis system for the rotating part of civil aero-engine.