一种改进的转子振动信号消噪方法研究

Research on an improved de-noising method for rotor vibration signals

为提高转子振动信号消噪方法的性能,通过分析噪声成分和对应消噪方法的特点,提出了一种基于改进中值滤波与小波包消噪技术相结合的信号降噪新方法。该方法首先根据信号采样频率计算中值滤波器的窗口宽度,从而可以有效滤除含噪信号中的脉冲噪声和部分白噪声;然后再用阈值及其处理函数都经过改进的自适应小波包消噪方法去除残留在信号中的白噪声,最终得到信噪比提高的振动信号。通过仿真信号和转子实验振动信号的降噪处理,对新方法的性能进行了验证。降噪结果表明,该方法在有效消除混合复杂噪声对振动信号干扰的同时,保留了故障信号的细节特征,比一般的小波域中值滤波降噪方法更为有效。

In order to improve the performance of de-noising method for rotor vibration signals, a new de-noising method based on improved median filter and wavelet packet technique is proposed through analyzing respective properties of different noise components and relevant de-noising methods. At first, the method calculates the window width of median filter according to sampling frequency to eliminate impulse noise and partial white noise. And then, an improved self-adaptive wavelet packet de-noising technique is used to remove the residual white noise. Subse- quently, useful vibration signals are obtained after the previous processing. Simulation signals and rotor experimental vibration signals were used to verify the performance of the method. Experiment results show that the method can not only effectively eliminate the mixed complex noises, but also preserve the fault character details, which demonstrates that the proposed method outperforms the method based on wavelet domain median filter.