梳状滤波阵图及其应用

COMB FILTER ARRAY AND ITS APPLICATION

提出了一般梳状滤波器的设计方法,证明了传统的时域平均只是一般梳状滤波的一个特例。在此基础上提出了一种新的信号分析方法——梳状滤波阵图法:首先粗略估计周期信号基频的取值范围,然后以一定频率间隔离散化该频率区间,以得到的一系列离散化的频率值作为信号基频的估计,逐次对采样信号做梳状滤波处理,将得到的一组时域滤波波形以二维灰度图或三维阵图的形式显示,最后从中挑选出特征明显的若干行做进一步的分析。该方法可以在无同步信号的情况下有效地提取出混杂于强背景噪声中的周期信号,将其应用于滚动轴承故障信号精细特征分析取得了满意的效果。

A methodology for the design of a general comb filter is proposed, and it is demonstrated that the traditional time domain averaging is just a special case of the general comb filtering. On this basis, a novel signal analysis technique capable of extracting the periodic waveform with inexactly known period from noisy discrete-time observationsr is presented. Firstly the region that the signal fundamental frequency may lie in is finely discretized, resulting in an array of candidates of the fundamental frequency estimate. Then the contaminated signal is independently cleaned by an array of comb filters, each with a candidate of the fundamental frequency estimate as the reference frequency. Finally the obtained series of filtered signals axe depicted as a gray image, and the interested waveforms are picked up for further analysis. The validity of the approach is confirmed by analyzing the synthetic signal and the vibration signal produced by multiple point defects in a rolling element bearing.