基于改进阈值自适应冗余小波的振动信号去噪

Denoising Method of Vibration Signal Based on Improved Threshold and Adaptive Redundant Second Generation Wavelet

由电主轴动不平衡引起的振动信号在采集的过程中会混入大量强干扰噪声,引起机床主轴系统稳定性差。自适应冗余第二代小波的降噪方法可有效的去除噪声。针对上述方法中存在的传统阈值函数造成小波系数不连续或恒定偏差的问题,引入双变量改进阈值函数,提出了一种改进的自适应冗余第二代小波的振动信号消噪方法。将改进的方法应用于仿真信号及实际采集的电主轴动不平衡振动信号消噪中,结果表明,改进方法融合了自适应冗余第二代小波信号和双变量改进阈值函数的优点,在低信噪比的仿真信号和振动信号消噪中,能很好的保留原信号的特征并且有效的去除噪声,消噪效果更优。

The method of signal denoising based on adaptive redundant second generation wavelet can eliminate noise effectively from imbalance-causing vibration caused by the dynamic unbalance of spindle which is polluted by strong interference noises on data acquisition process. A new method on signal denoising which introduces the improved bivariate threshold function into the method on signal denoising based on adaptive redundant second generation wavelet was put forward to overcome the shortcomings of soft and hard threshold functions. The new method was applied to the analysis of simulation signal from Matlab and imbalance-causing vibration from the actual collection. The test shows that the new method combines the advantages of adaptive redundant second generation wavelet and the improved bivariate threshold function and can reserve original signal characteristics and eliminate noise effectively, especially for low SNR signal denoising.