局部特征尺度与小波阈值协同下密封摩擦面AE信号降噪研究  

A study on noise reduction of AE signal of sealing friction surface under the synergy of local characteristic-scale decomposition and wavelet threshold

作　　者：陆俊杰 刘柱 丁雪兴[2] 丁俊华 高德 LU Junjie;LIU Zhu;DING Xuexing;DING Junhua;GAO De(Ningbo Key Laboratory of Advanced Seal Technology,Ningbo Tech University,Ningbo 315010,China;School of Petrochemical Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]浙大宁波理工学院宁波市极端密封重点实验室,宁波315010 [2]兰州理工大学石油化工学院,兰州730050

出　　处：《振动与冲击》2023年第12期205-211,219,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51905480);浙江省自然科学基金(LY22E050010);宁波市自然科学基金-青年博士创新研究项目(2022J152);宁波市“科技创新2025”重大专项(2020Z112,2022Z007,2022Z054)。

摘　　要：针对机械密封低速阶段存在信号内源耦合与外部干扰因素的共性问题,提出了信号局部特征尺度分解(local characteristic-scale decomposition,LCD)与小波阈值协同降噪方法。基于局部特征尺度分解结合小波阈值方法与声发射信号降噪的信息映射关系,建立了互相关系数对含噪分量识别机制,将纯净分量和降噪后的含噪分量进行重构,实现信号降噪,并搭建了机械密封声发射测试台,试验结果表明,LCD-新阈值降噪方法降噪效果优于LCD强制降噪和小波阈值降噪,LCD-新阈值降噪的信噪比分别比LCD强制降噪和小波阈值降噪高出20%和23%。从而证明基于局部特征尺度下密封声发射信号协同小波阈值的降噪技术维持了信号的可用性,保障信号故障特征,为进行机械密封全生命周期管理奠定了理论基础。According to the common problem of internal signal coupling and external interference factors,a synergistic noise reduction method was proposed,which is based on local characteristic-scale decomposition(local characteristic-scale decomposition)and wavelet threshold in the low-speed stage of mechanical seals.Based on the information mapping relationship between local feature scale decomposition combined with the wavelet threshold method and acoustic emission signal noise reduction,a cross-correlation coefficient,which is for identification mechanism of noisy components,was established,and the pure components and the denoised noise components were reconstructed to achieve signal reduction.A mechanical seal acoustic emission test bench was built.Test results show that the noise reduction effect of the LCD-new threshold noise reduction method is better than LCD forced noise reduction and wavelet threshold noise reduction,and the signal-to-noise ratio of LCD-new threshold noise reduction is 20%and 23%higher than LCD forced noise reduction and wavelet threshold noise reduction,respectively.Therefore,it is proved that the noise reduction technology based on the acoustic emission signal of the seal in conjunction with the wavelet threshold at the local characteristic scale maintains the availability of the signal,guarantees the fault characteristics of the signal,and lays a theoretical foundation for the full life cycle management of the mechanical seal.

关 键 词：机械密封 启停 信号降噪 声发射 局部特征尺度分解(LCD)-小波阈值 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3