焊接电弧声信号降噪技术  

Reducing noise techniques of arc sound signal

作　　者：刘立君[1,2] 兰虎[2] 于忠伟[2] 周滨涛[2] 

机构地区：[1]浙江大学宁波理工学院,浙江宁波315100 [2]哈尔滨理工大学材料科学与工程学院,哈尔滨150080

出　　处：《焊接学报》2009年第12期13-16,共4页Transactions of The China Welding Institution

基　　金：宁波自然基金重点资助项目(2008A610031);黑龙江省自然基金资助项目(E2007-01);黑龙江省青年骨干教师支持项目(1153G009);哈尔滨市科技创新人才基金资助项目(2007RFQXG055)

摘　　要：焊接电弧声作为焊接过程质量监控潜在的源信号之一,在传感、转换以及传输等过程极易受到设备、环境噪声的污染,从硬件、软件两个方面分别对其进行降噪处理.硬件方面包括低噪声传声器、接地装置、消除直流偏移的交流耦合、采用仪器放大器、抗混叠滤波以及屏蔽电缆等措施;软件方面运用基于多尺度分析理论的Mallat算法,实现了基于LabVIEW的电弧声小波分解重构降噪处理.结果表明,电弧声信号经硬件、软件降噪后,不仅"毛刺"得到有效滤除,而且波形突变部分更加清晰,信噪比大幅度提高,为后续电弧声信号特征分析提取以及利用电弧声来监控焊接质量提供技术基础.Arc sound is well known as one of the potential source signals for controlling of welding process quality,which is vulnerable to noise pollution by equipment and environment in sensing,conversing and transmission.Therefore,it is necessary to reduce arc sound noise by hardware and software.Hardware measures include low-noise microphone,grounding devices,eliminating the DC offset exchange coupling,equipment amplifiers,anti-alias filtering and shielding cables,etc.In terms of software,by using Mallat algorithm based on principle of multi-resolution,the noise of arc sound signal is reduced via wavelet decomposition and reconstruction based on LabVIEW.The results show that the burr of arc sound is effectively filtered out,the mutations of waveform are clearer and the noise ratio is obviously increased.The reducing noise means provide technical basis for extracting characteristics of arc signal and monitoring welding quality via arc signal.

关 键 词：焊接电弧声 图形化编程语言 小波变换 降噪 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]