ELMD and rational spline smooth envelope analysis method for rotating machinery

Abstract

The invention discloses an ELMD and rational spline smooth envelope analysis method for rotating machinery. According to the method, firstly, an original signal is decomposed through performing the set local mean decomposition method. Secondly, based on the data rearrangement and substitution operation, a noise component and a trend term in the decomposition result are removed. Thirdly, a signal is analyzed after the first filtering process through performing the spectral kurtosis method, so that the center frequency and the bandwidth of an optimal filter are obtained. Fourthly, the signal is subjected to second filtering after the first filtering process by means of the above filter. Fifthly, the signal is subjected to envelope analysis after the second filtering process through performing the rational spline iterative smooth envelope analysis method. Finally, the fault type of the rotating machinery is determined according to an envelope spectrum. According to the technical scheme of the invention, the method can be used for processing the complex fault signals of the rotating machinery and accurately judging the fault type of the rotating machinery. Meanwhile, the method is good in noise resistance and robustness, and is convenient for engineering application.

Description

technical field [0001] The invention relates to the field of state monitoring and fault diagnosis of rotating machinery, in particular to an ELMD and rational spline smoothing envelope analysis method of rotating machinery. Background technique [0002] Envelope analysis technique is widely used in fault diagnosis of gears and rolling bearings. The existing envelope analysis technology has the following three defects: ① The existing envelope analysis technology either directly analyzes the original signal, or only analyzes the original signal after simple filtering, so the existing method It is easily disturbed by noise, trend and other components, resulting in low analysis accuracy of the existing technology; ②The existing envelope analysis technology is based on the Hilbert transform, and the Hilbert transform requires that the signal to be analyzed must be a single component Narrowband signals, otherwise the frequency modulation part of the signal will pollute the amplit...

AI Technical Summary

Problems solved by technology

The existing envelope analysis technology has the following three defects: ① The existing envelope analysis technology either directly analyzes the original signal, or only analyzes the original signal after simple filtering, so the existing method It is easily disturbed by noise, trend and other components, resulting in low analysis accuracy of the existing technology; ②The existing envelope analysis technology is based on the Hilbert transform, and the Hilbert transform requires that the signal to be analyzed must be a single component Narrowband signals, otherwise the frequency modulation part of the signal will pollute the amplitude envelope analysis results of the signal, but the current signals to be analyzed do not strictly meet the conditions of single component and narrowband, which will lead to the existing technology is easy to The problem of misjudgment occurs; ③The envelope spectrum obtained by traditional methods has endpoint effects

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