| Compared to the Fourier-based linear and stationary spectral analysis, the empirical mode decomposition (EMD) based time-frequency analysis method was considered a great breakthrough. Based on the "Research on the new method for rotating machine faults diagnosis based on independent component analysis"(National Nature Science Fund Project, No: 50205025) and "Study on the new method of CORBA-based distributed calculation tactics construction in remote condition monitoring and diagnosis"(Zhejiang Province Nature Science Fund Project, No: 501061), this paper aimed to the rotating machinery faults diagnosis oriented time-frequency analysis. The EMD-based basic theories and methods were studied; To weaken the EMD method's end effect, some new data extention means were proposed; To improve the EMD method's precision and efficiency, some new algorithms were proposed; The EMD based time-frequency analysis software was designed and developed; A experiment system at the base of rotor test bed was built to study the rotor faults diagnosis using the new time-frequency analysis method, then studed several typical faults. The study results of the dissertation provide a new way to the faults analysis and diagnosis of rotating machine, especially to non-linear and non-stationary's. The details were studied as follows:Chapter one explained the importance of the rotating machinery faults diagnosis oriented time-frequency analysis study and briefly introduced the general situation of faults diagnosis of the rotating machine. The developing and the current situations of the time-frequecy theories were summarized. At last, the way of study,the main contents, general structure scheme and innovation points of this dissertation were presented.Chapter two introduced the basic ideas of EMD theories briefly, and then discussed the EMD-based time-frequency analysis method's basic agrithom. the conclusion was deduced that the method is valid in the field of signals processing and fault diagnosis in rotating machinery by simulation and real signal analysis.Chapter three discussed the origin of EMD method's end effect, then studied the direct, time-series based and neuron network based data extention technologys to weaken the end effect. At last, compared the three data extention technologys merits.The time-series based and neuron network based data extention methods were proposed.Chapter four studied the improvement of the EMD algorithm al efficiency and precision.Reserthed the effect of spline interpolation's end condition to the EMD algorithm's precision , then discussed the low-order and propoed high-order spline interpolation based EMD algorithm and their effects. Under the study of simple average EMD algorithm.deduced the self-tune time-variety based EMD algorithm and investigated the effect of the algorithm. At last, the valid data based fast EMD algorithm was proposed.Chaper five aimed to the requirement of the EMD based time-frequency analysis in the field of rotating machinery signal analysis and fault diagnosis.studied the method of rotatory speed prediction to improve the precision of complete period sampling of vibration signals in rotating machinery, then, discussed the phenomenon of mode fission in noise signal anlysis by EMD and provided the filter method to weaken the phenomenon. After then, found a process to analysis the signals using EMD-based method in the field of rotating machinery signal analysis and faultdiagnosis. At last, EMD-based filter techonolgy was researched.Chaper six compared the EMD-based time-frequency analysis method to the typical's :short time fourier analysis, Wigner distribution and wavelet anlysis,the result showed that the EMD-based's is better than the others.To weaken the crossing interfere in multi-components signal in Wigner distribution the EMD-based Wigner distribution was proposed and the study result showed that the method is valid.Chapter seven built a experiment system at the base of rotor test bed, discussed characteristics of several typical fault in rotating m...
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