EEMD and cubic spline smoothing envelope analysis method for rotary machine

Abstract

The invention discloses an EEMD (Ensemble Empirical Mode Decomposition) and cubic spline smoothing envelope analysis method for a rotary machine. The method includes the steps that firstly, the EEMD method is utilized to decompose an original signal, then, data rearrangement and replacement operation are utilized to exclude the noise component and a trend term in the decomposition result, next, a spectral kurtosis method is adopted to analyze the signal obtained after preliminary filtering, center frequency and bandwidth of an optimal filter are obtained, then, the filter is utilized to conduct secondary filtering on the signal obtained after the preliminary filtering, then, the cubic spline iteration smoothing envelope analysis method is adopted to conduct envelope analysis on the signal obtained after secondary filtering, and finally, the fault type of the rotary machine is determined according to an envelope spectrum. The method is suitable for processing complex rotary machine fault signals, the fault type of the rotary machine can be judged accurately, good noise resistance 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 EEMD and cubic 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 amplitude...

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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