Fault Diagnosis Technology Research And System Development Of Aircraft Engine

Aircraft engine operate in high temperature,high speed,high volume environment,and has high requirements of the stability and safety of the aircraft engine.Any malfunctions of aircraft engines could cause aircraft accidents,and even lead to disastrous consequences.With the development of technology and modern industry,not only the speed and propulsion of aircraft engines but also the vibration accident are increasing,for example aircraft crash occurred in Taiwan this year is due to an engine malfunction,so the condition monitor and fault diagnosis technology of aircraft engines is becoming a hot research.The most common failure of aircraft engine is structural failure,vibration fault diagnosis method of aircraft engines is the most effective method for the structural failure,and the main research objects are shaft member composed by rotor and bearing.This paper focus on two types of shaft component failure: rotor unbalance and rolling bearing fault.By studying the rotor balancing test methods and how to get rotor vibration amplitude and phase,I get an effective rotor balancing test procedure.By studying bearing defect models and conventional signal processing method,balancing the accuracy of diagnosis and simplicity of calculations,I get a bearing practical diagnostic method based on a combination of filtering and spectrum demodulation.On this basis,continue studying of the intrinsic time scale decomposition(ITD)method and fuzzy entropy algorithm.As a new timefrequency analysis method,ITD method has high computational efficiency and small end effect problem.Fuzzy entropy algorithm combines fuzzy set theory and entropy theory and it is more stable and has less data length dependence,this two methods have very good results analyzing nonstationary signals,this paper combines two methods and support vector machine,then finish an intelligent bearing diagnostic method which can identify the type of bearing failure adaptively.Finally,the author based on research,with VB.Net as a platform to prepare one aircraft engine condition monitoring and fault diagnosis software system,complete set of aircraft engine shaft member troubleshooting processes,including data collection and storage,common signal processing and targeted fault diagnosis and identification of several parts of the module,with a strong engineering significance.