An ELMD and Smoothing Iterative Envelope Analysis Method for Rotating Machinery

Abstract

The invention discloses an ELMD (ensemble local mean decomposition) and smooth iteration envelope analysis method of rotation machinery. According to the method, first of all, original signals are decomposed by use of an ELMD method, then by use of rearrangement and replacement operation of data, noise components and trend items in a decomposition result are eliminated, next, a center frequency and bandwidth of an optimal filter are obtained by analyzing signals after first filtering by use of a spectrum kurtosis method, then by use of the filter, the signals after the first filtering are filtered for a second time, then by use of a smooth iteration envelope analysis method, envelop analyzing is performed on the signals after second filtering, and finally, a fault type of the rotation machinery is determined according to an envelope spectrum. The method is applied to processing complex rotation machinery fault signals, can accurately determine the fault type of the rotation machinery, has good noise immunity and robustness, and facilitates 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 smooth iterative 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 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; ③The envelope spectrum obtained by traditional methods has endpoint effects

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