基于变采样长度相关滤波的不平衡信号提取法

根据相关滤波提取信号幅值和相位的原理，定义了不平衡信号的近频噪声干扰度的概念，并构建了近频噪声干扰度模型，揭示了干扰度随频率差变化的分布规律；进而提出了一种基于变采样长度相关滤波的不平衡信号提取法，在短数据情况下根据MUSIC谱确定幅值最大的近频干扰信号频率，结合近频干扰度分布规律合理选择采样长度提取不平衡信号幅值和相位。电主轴动平衡测量实验和仿真结果表明：与传统定采样长度相关滤波相比，所提方法受信噪比波动影响小,抗近频干扰能力强,在采样长度更短时提取的不平衡信号幅值和相位的方差更小。

Extraction of Unbalance Signals Based on Correlation Analysis in Adjustable Sampling Length

According to the principles of correlation analysis method for extracting amplitude and phase of signals,this paper defined a concept, interference degree of noise near unbalanced signals in frequency, and established a model about interference degree, revealed its distribution law. Then the method for extraction of unbalance vibration signals was  proposed  based on correlation analysis in adjustable sampling length.It obtained the frequency of nearby interference signal of large amplitude from pseudo spectrum under short data acquisition time calculated by MUSIC,and  reasonable sampling time length  was  selected  based on distribution law of interference degree for extraction of unbalance signals.The results of simulation and experiments show that,compared with the traditional fixed sampling length correlation filtering method, this method obtains smaller variance of amplitude and phase under shorter sampling time, being free from signal-to-noise ratio fluctuation and nosie at the frequency near that of signal.