LMD, spectral kurtosis and smooth iterative envelope analysis methods of rolling bearing

Abstract

The invention discloses LMD, spectral kurtosis and smooth iterative envelope analysis methods of a rolling bearing. According to the method, firstly, a local mean value decomposition method is used to decompose an original signal, then the rearrangement and substitution operations of the data are used to eliminate the noise component and trend component in a decomposition result, a spectral kurtosis method is used to analyze the signal which is subjected to the first time of filtering, the central frequency and bandwidth of an optimal filter are obtained, then the filter is used to carry out the second time of filtering of the signal which is subjected to the first time of filtering, then a smooth iterative envelope analysis method is used to carry out envelope analysis of the signal which is subjected to the second time of filtering, and finally the fault type of the rolling bearing is determined according to an envelope spectrum. The methods are suitable for processing a complex rolling bearing fault signal, have good anti-noise performance and robustness, and are 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 LMD, spectrum kurtosis and smooth iterative envelope analysis method of a rolling bearing. 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 th...

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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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