作　　者： ; ; ; ;

机构地区： 华南理工大学机械与汽车工程学院

出　　处： 《焊接学报》 2011年第6期5-8,113,共4页

摘　　要： 提出了一种新的指数衰减型自适应阈值消噪法,采用此法对交流方波信号进行了消噪处理,能较好地还原出原始信号,得到了清晰的电弧电流和电压信号,较好地保留了信号中的高频突变分量,准确地判断出过零点时电流和电压的上升和下降过程.与传统阈值消噪法相比,指数阈值法消噪具有误差小,连续性好,且在阈值点有任意阶导数的特点.结果表明,采用新方法在滤出了信号中的大部分噪声同时,较好地保留了信号的突变部分不失真,减小了电弧信号中的高频信号细节的损失,改善了信号局部特征提取的效果. A novel denoising method with exponential decay threshold is proposed in this paper,by using this method the original signals can be well recovered and the clear arc current and voltage waveforms are obtained,the high frequency components of electric signals are reserved perfectly,and the rising or falling edge of current or voltage waveforms crossing the zero point are evaluated precisely.Comparing with the traditional wavelet denoising method,this method has the characteristics of little error,good continuity,and random rank derivative at the threshold point.The experiment results show that the majority of noise in the electric signals is eliminated while the distortion-free status of transient components of the electric signals is maintained perfectly,the loss of high frequency detail components is reduced and the effect of the local character extraction from welding arc signals is improved.

关 键 词： 小波变换 消噪 方波信号

领　　域： [金属学及工艺]