摘要
针对机械密封声发射信号容易受到环境噪声干扰,难以有效地从背景噪声中分离的问题,提出将互补集合经验模态分解(CEEMD)与改进小波阈值降噪方法相结合的声发射信号自适应降噪方法。根据白噪声经经验模态分解(EMD)后其固有模态函数分量的能量密度与其平均周期的乘积为一常数的特性,自适应地判定CEEMD信噪分量的分界点;为避免小波原阈值函数的缺陷,应用改进小波阈值函数对高频IMF分量进行降噪处理,然后同其余的IMF分量进行信号重构,完成降噪过程。对仿真信号和采集的机械密封声发射信号的降噪结果,证明了该降噪方法的有效性和可行性。
Aimed at the problem that the mechanical seal acoustic emission signal is easily interfered by environmental noise and it is difficult to effectively separate from the background noise,the adaptive de-noising method of acoustic emission signal combining the complete ensemble empirical mode decomposition(CEEMD)and the improved wavelet threshold de-noising method was proposed.According to the characteristic that the energy density of the intrinsic mode function component and its average period are constant after the empirical mode decomposition(EMD)of white noise,the boundary point of the CEEMD signal-to-noise component is adaptively determined.In order to effectively avoid the defects of the wavelet original threshold function,the improved wavelet threshold function is used to de-noise the high-frequency IMF component,and then the signal is reconstructed with the rest of IMF component to complete the noise reduction process.The noise reduction results of the simulated signals and the mechanical seal acoustic emission signals collected by experiment show the effectiveness and feasibility of the noise reduction method.
作者
石大磊
高宏力
李克斯
SHI Dalei;GAO Hongli;LI Kesi(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China)
出处
《润滑与密封》
CAS
CSCD
北大核心
2019年第7期131-137,共7页
Lubrication Engineering
基金
中央高校基本科研业务费专项资金资助项目(2682016CX033)
关键词
声发射信号
互补集合经验模态分解
改进阈值函数
降噪方法
acoustic emission signal
complete ensemble empirical mode decomposition
improved threshold function
de-noising method
