Wavelet packet decomposition valve inner leakage signal noise reduction method, device and system

Abstract

The invention provides a wavelet packet decomposition valve inner leakage signal noise reduction method. The method comprises the steps: acquiring a pipeline valve inner leakage signal containing noise; carrying out wavelet packet decomposition on the pipeline valve inner leakage signal containing the noise to obtain a plurality of wavelet packet coefficients; establishing different wavelet packet coefficient threshold models according to the parity of wavelet packet decomposition layers, wherein specifically, when the number j of decomposition layers is an odd number and when the number j of decomposition layers is an even number, T is a wavelet packet coefficient set threshold, sigma n is the standard deviation of noise, and N is the number of signal samples; reconstructing the valve inner leakage signal according to the thresholded wavelet packet coefficient. The invention further provides a wavelet packet decomposition valve inner leakage signal noise reduction device and system, the stability of valve inner leakage signal noise reduction is effectively improved, and the accuracy and reliability of valve inner leakage signal detection are improved.

Description

technical field [0001] The invention relates to the field of signal noise reduction, in particular to a method, device and system for reducing noise of a valve internal leakage signal by wavelet packet decomposition. Background technique [0002] As an important control part of the pipeline system, the valve plays a huge role in the pipeline transportation process. When the valve is in good condition, the pipeline system can guarantee the normal operation. Once the pipeline valve leaks, it will bring great harm to the normal operation and indication of the equipment and system, especially some key pipeline valves. [0003] At present, the acoustic emission detection technology of internal leakage of valves has gradually become a hot spot, and has achieved good results, but there are still some shortcomings, and the problem of noise reduction is only one of them. The noise reduction of existing valve internal leakage signals generally uses wavelet packet reduction When ther...

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Problems solved by technology

[0004] In order to solve the problems existing in the prior art, the present invention innovatively proposes a wavelet packet decomposition valve internal leakage signal noise reduction method, device and system, which effectively solves the problem that only odd or even layers are considered in the existing wavelet packet noise reduction threshold selection. The distortion of the reconstructed signal after threshold processing and the low accuracy and reliability of the valve internal leakage signal detection have effectively improved the stability of the noise reduction of the valve internal leakage signal and the accuracy of the valve internal leakage signal detection. performance and reliability

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