Enveloping analyzing method based on variation mode decomposition and spectral kurtosis

Abstract

The invention discloses an enveloping analyzing method based on variation mode decomposition and spectral kurtosis. The method comprises the steps that firstly, an original signal is decomposed with a variation mode decomposition method; then, noise components and trend items in a decomposition result are excluded through data rearrangement and substitution operation; then, the signal obtained after first-time filtering is analyzed with a spectral kurtosis method, and the central frequency and bandwidth of an optimal filter are obtained; then, the filter is used for carrying out second-time filtering on the signal obtained after first-time filtering; then, the signal obtained after second-time filtering is subjected to enveloping analysis with a cubic spline iteration smooth enveloping analyzing method; finally, a fault type of a rotating machine is determined according to an enveloping spectrum. The method is suitable for processing complex rotating machine fault signals, the fault type of the rotating machine can be accurately judged, high noise immunity and robustness are achieved, and engineering application is convenient.

Description

technical field [0001] The invention relates to the field of state monitoring and fault diagnosis of rotating machinery, in particular to an envelope analysis method based on variational mode decomposition and spectral kurtosis. 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 a...

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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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