Envelope analysis method based on non-linear mode decomposition filtering

Abstract

The invention discloses an envelope analysis method based on non-linear mode decomposition filtering. The method includes that, firstly, the original signal is decomposed by the non-linear mode decomposition method, and then the noise component and the trend item in the decomposition result are eliminated by the data rearrangement and substitution operation, the signal after the primary filtering is analyzed by the spectral kurtosis method to obtain the center frequency and bandwidth of an optimal filter, the filter filters the signal after the primary filtering secondarily, the signal after the secondary filtering is subjected to envelope analysis by means of the rational spline iteration smoothing envelope analysis method, and at the end, the fault type of a rotary machine can be determined based on the spectrum envelope. The method is suitable for dealing with complex rotary machine fault signals, can accurately determine the fault type of the rotary machine, 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 envelope analysis method based on nonlinear mode decomposition filtering. 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 amplitude envel...

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; ③ The envelope spectrum obtained by traditional methods has endpoint effects

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