基于频域形态滤波的低速滚动轴承声发射信号降噪新方法

声发射检测技术以其灵敏度高、频响范围宽、信息量大等优点，为机械故障诊断提供了一条新的检测途径，但应用于旋转机械设备时，容易混入各种有色噪声。当噪声频率与声发射信号重叠时，传统的降噪方法难以满足要求。将形态滤波应用到信号频域，可以有效消除有色噪声的干扰。根据声发射频响特性，对频谱进行拟合平滑高斯白噪声的影响，最后重构到时域。仿真和实际低速轴承信号表明此方法具有较好的降噪效果，有利于信号后续的处理和分析。

A new de-noising method for acoustic emission signal of rolling bearings with low speed based on morphological filtering in frequency domain

Acoustic emission technique provide a new testing approach to the machinery fault diagnosis because of its characteristics of high sensitivity, wide frequency response range and information. The signal often is mixed with a variety of color noise when applied to the rotation machinery. Traditional noise reduction methods can not meet the requirements when the frequency of noise and acoustic emission are superposed. The morphology filter is applied to the frequency domain to eliminate the color noise. Then, according to the acoustic emission frequency response characteristic can fit the spectrum in order to smooth the white Gaussian noise. Finally, the time domain waveform will be reconstructed. The results of simulation and faulty bearing show that the proposed methodology can achieve good effect of noise reduction, and be beneficial to subsequent process and analysis.