基于复值过程高阶累积量谱的轴心轨迹分析的研究

STUDY OF ORBIT ANALYSIS BASED ON COMPLEX PROCESS HIGH ORDER CUMULANT SPECTRUM

用复值过程表示轴心轨迹,将复值过程高阶累积量理论引入轴心轨迹分析这一研究领域。结合轴心轨迹的形状讨论了轴心轨迹复值过程的频域特点。证明了混杂在轴心轨迹中的高斯复噪声和实虚部非相关随机噪声的高阶累积量为零,定性说明了该理论亦可有效抑制宽带和窄带噪声。定义了双谱的工频切片和半工频切片。给出了利用双谱幅值谱及其工频切片分析轴心轨迹的计算方法,并将该方法用于转子不对中故障轴心轨迹的分析,验证了该方法同时具有对轴心轨迹的提纯和特征提取的功能。利用工频切片方法对多种故障的轴心轨迹进行了特征提取,其结果表明该方法可将不同故障的轴心轨迹转化为量值的组合,符合机械故障智能诊断的需要。

The orbit is expressed as complex process, the theory of complex process high-order cumulant is used in analysis of orbit. The frequency domain characteristic of orbit complex process is discussed combining with shape of orbit. It's proved that the high-order cumulant of gauss complex noise and noncorrelative noise between Re-part and Im-part is zero, and it is explained that this theory can depress broad noise and narrow band noise. The operating frequency slicing and half operating frequency slicing of bispectrum are defined. The numerical value calculating method of analyzing orbit using bispectrum and slicing of bispectrum is put forward. This method is introduced in the identification of orbit of non-concentric rotor, the analysis result show that this method has two function at the same time, which are orbit purifying and fault signature extracting. The operating slicing of bispectrum is used to analysis the orbit of several faults, the results show that different orbit can be transformed into different value or vectors.