矢双谱分析及其在机械故障诊断中的应用

Vector-bispectrum Analysis and Its Application in Machinery Fault Diagnosis

双谱分析由于可以有效提取信号中的非线性特征被广泛应用于转子故障诊断。但常规双谱分析是以单通道信号为研究对象,不能全面地反映转子系统的非线性特征,存在着信息遗漏的问题,而且由同一截面的两个通道信号得出的分析结论会不一致。为解决这个问题,以全矢谱分析方法为基础提出矢双谱信号分析的新方法。矢双谱是融合了同一截面上双通道信号的幅值信息而保留了各自的相位信息的全矢双谱分析方法,能够真实地反映转子运转所包含的各种信息,且能满足分析结论的一致性要求。给出矢双谱的定义与算法,通过仿真和齿轮箱故障试验,研究结果表明,该方法能够更加全面地反映信号中所包含的非线性特征信息,分析结论具有一致性和可信性,从而提高智能故障诊断的准确性。

Bispectrum analysis method is wildly used in the rotor fault diagnosis because it can distill the nonlinear characters of the signals.But the general bispectrum analysis is used to take the single channel signals as the studied objects,it cannot embody the nonlinear properties of the rotor systems integrally and the problems of the information omission exist,and furthermore the analysis conclusions obtained may be different because of the difference of the information coming from the two-channel signals at the same cross section.In order to solve the problem,the new method named as the vector-bispectrum signal analysis is put forward based on the full vector-spectrum analysis method.Vector-bispectrum is the full vector-bispectrum analysis method that the amplitude information is fused coming from the two-channel signals at the same cross section and each phase information is retained,which can really reflect all kinds of information of the rotor running and satisfy the agreement demands of the analysis conclusions.The definition and algorithms of the vector-bispectrum are given.The simulation and the fault diagnosis experiment of the gearbox are studied.The results show that the nonlinear properties contained by the signals can be more completely reflected,the analysis conclusions are of agreement and reliability,and thus the accuracy of the intelligent fault diagnosis is also improved.