基于循环双谱的滚动轴承故障诊断

当滚动轴承发生早期点蚀故障时，其振动信号表现出循环平稳特性。由于故障特征频率处能量比较小，特征信息容易被噪声淹没，仅仅利用二阶循环平稳已经不能有效提取故障特征。而循环双谱（即三阶循环累积量谱）这一最低阶的高阶统计量谱对噪声具有较好的免疫力，且计算量也相对来说比较其它高阶统计量分析方法来说最小。本文将尝试用循环双谱的中心频率切片谱，对滚动轴承早期故障做特征提取。仿真和实验结果证明了方法的有效性。

Fault diagnosis of rolling element bearing based on cyclic bispectrum

The vibration signals of rolling element bearings are random and cyclostationary when they are with faults.However,because of the relatively strong background noise in early fault stage,it is difficult to disclose the latent periodic components successfully even using the second order cyclostationary analysis.To overcome this difficulty,the method of central frequency spectrum of cyclic bispectrum(CBS),an alternative approach for defecting localized faults in the outer race of a rolling element bearing based on higher-order cyclic statistics analysis,was discussed.The results of simulation and experiment indicate the feasibility and validity of CBS analysis in rolling element bearing early fault diagnosis.