Research On Fault Diagnosis For Helicopter Transmission System And Design Of Management System

With the growing role and strengthening position of helicopter in military and civilfields, the reliability and safety of helicopter is more and more respected. Therefore ithas practical significance for research on the fault prediction, diagnosis and automaticmanagement of helicopter. This paper studied fault diagnosis method for thetransmission system of helicopter, and then designed the fault diagnosis and predictionmanagement system. The main research works and achievements of this paper are asfollows:(1) This paper researched the design of system of flow and structure and thedivision of function module for the software. It finished the outline design of the systemon the basis of understanding the user s detail requirements. By using the modular,hierarchical and modularization designed method, it constructed the system frameworkand completed the system solution design.(2) According to the requirements of user, the design specification of software andthe design of flow for database, this paper designed the system database and realized byprogramming based on the platform of VB.NET and SQL Server2005. The system canmanage the data as follows: helicopter fleet, equipments of helicopter, faulty equipments,configuration information of helicopters, maintenance information of helicopters, flightmissions, flight data and the analysis results, etc.(3) Choosing the transmission system of helicopter as the research object, thispaper studied the fault diagnosis method for the key parts of helicopter transmissionsystem by using signal analysis and processing methods and achieved throughprogramming on the platform combined VB.NET with MATLAB. Peak amplitude,mean value, waveform factor, crest factor and kurtosis factor is applied to the researchon fault diagnosis of transmission system based on indexes of time domain; Fast FourierTransform (FFT) is applied to the research on frequency analysis for vibration signals;Time-domain average and wavelet analysis is applied to the research on vibration signaldenoising and fault feature extraction.(4) This paper managed the information of helicopter fleet, in order to validate theeffectiveness of this system and fault diagnosis methods. The results indicated that the system can implement well management of helicopter information, and has stabilizedquality and kindly man-machine interface. Meanwhile, we did some experiments aboutsignal denoising and feature frequency extraction with some simulated signal and someexperiments about fault diagnosis with a series of vibration signals of bearing. Theexperiments indicated that the solution, which applied time-domain average, FFT andwavelet technology to vibration signal denoising, fault feature extraction and faultdiagnosis, is validity, feasibility and practicability. The system can be used as a benigntool for the fault diagnosis, prediction and management of helicopter.