A Noise Reduction Method for Acoustic Emission Signals Based on Correlation Coefficient and EMD Filtering

Abstract

The present invention discloses a correlation coefficient and EMD (Empirical Mode Decomposition) filtering characteristic-based rub-impact acoustic emission signal noise reduction method. The method enables an excellent noise reduction effect for rub-impact acoustic emission signals containing white noises and pink noises, is not influenced by subjective parameters, can obtain stable results and is adaptive. According to the method of the invention, white noises and the pink noises with different signal-to-noise ratios are added to acoustic emission signals collected by a rub-impact acoustic emission test device; EMD is performed on the noise-containing signals, the correlation coefficients of intrinsic mode functions of each order obtained through the decomposition and the noise-containing signals are solved; the change rule of correlation coefficients corresponding to the intrinsic mode functions of each order is searched out based on the filtering characteristics of the EMD; and an intrinsic mode function of which the rub-impact acoustic emission signal energy is large relatively is reconstructed, so that noise-reduced signals can be obtained.

Description

technical field [0001] The invention relates to a method for reducing noise of acoustic emission signals, in particular to a method for reducing noise of rubbing acoustic emission signals based on correlation coefficient and EMD filter characteristics. Background technique [0002] Dynamic and static rubbing is an important research topic of large rotating machinery. Acoustic Emission (AE) provides a new way for rubbing detection and identification with its unique advantages. Compared with commonly used vibration signals, AE signals have unique advantages in early detection of rubbing faults in rotating machinery due to their sensitive response, wide frequency range, and rich frequency components. However, in the detection of rubbing AE signals of rotating machinery, AE signals are often interfered by actual noise, or even obliterated, making it difficult to identify useful rubbing AE signals. Therefore, when analyzing the collected AE signals, it is necessary To reduce noi...

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