Hardware And Software System Integration Of Fault Diagnosis On Aero-engine Whole Body Vibration

Whole body vibration of modern aero-engines has great impact on the navigability and structural integrity. Represented by excessive vibration of rotor system, whole body vibration will lead to serious vibration damage of key parts, the engine performance degradation, and even a major plane crash accident. In recent years, during different stages as new machine development, maintenance in service and equipment rebuilding, requirements of whole body vibration become increasingly strict.Whole body vibration faults of aero-engine are usually characterized by abnormal vibration. Fault diagnosis technique based on vibration is an important way of solving the problem. Considering the specific structural features and operating characteristics of the rotor-bearing system, researching on the fault diagnosis technique of whole body vibration plays an important role in judging the occurrence of failure quickly, recognizing the failure types correctly, tracing the cause of failure and correspondingly recovering the failure if necessary and proposing recommendations for troubleshooting.Taking the rotor system model test-bed and faults simulation tester as the physical object, this paper analyzes some frequently occurred whole body vibration faults and investigate the constitution of testing system, analysis methods and feature extraction methods of vibration signals. Learning from the supervisor’s model-based quantitative diagnosis theory, a mass of research work on the aero-engine vibration machine quantitative diagnosis was done. It performs the quantitative diagnosis on the failure type, position and severity based on the system dynamic performance analysis and simulation, and eventually forms a fault diagnosis system of aero-engine whole body vibration.The fault diagnosis system of aero-engine whole body vibration mainly consists two parts, one is the vibration monitoring hardware system; the other is the analysis and diagnosis algorithm package based on the MATLAB platform. The former contains sensors that are suitable independently to the specific circumstances on the model level, component level and running-test for the whole aero-engine; it also contains the acquisition system that is reasonably configured and the data processing system. The software package consists the follows:(1) Inherent characteristic analysis software package, which is used to calculate the inherent characteristic of the rotor system considering different critical speed and mode shapes under different support conditions;(2) signal analysis package, which can perform time domain analysis, Fast Fourier transform (FFT), Wavelet transform (WT) and Hilbert-huang transform (HHT) on the vibration faults signals;(3) quantitative diagnosis software package, which can used for quantitative fault diagnosis based on the定性diagnosis and faults dynamic simulation of the whole body vibration, such as the determination of the rubbing location, identification of unbalanced mass and the relationship between the rubbing force and location).Based on the research of the aero-engine whole body vibration faults, a scheme of the hardware and software system for aero-engine whole body vibration fault diagnosis is presented in this paper. The key technological works have been accomplished. Its research results have been utilized by domestic aero-engine design and manufacturing units and can meet the real requirements. The application of the system is able to improve the researching and maintaining efficiency of aero-engines and enhance the economic and social benefit.