基于角域四阶累积量切片谱的柴油机连杆轴承故障特征提取

Fault feature extraction of connecting rod bearings of a diesel engine based on angle domain fourth-order cumulant slice spectrum

提出了一种角域四阶累积量切片谱方法,应用于提取连杆轴承微弱故障特征。首先,对升速过程振动信号进行阶比重采样得到角域平稳信号,再计算其四阶累积量对角切片谱,构成角域四阶累积量切片谱,用于分析不同转速区间、不同测试位置下的非稳态信号,提取连杆轴承微弱故障特征。试验结果表明:角域重采样与四阶累积量对角切片谱相结合,既能分析非稳态信号,又能抑制噪声干扰;特定阶比带内的角域四阶累积量对角切片谱的能量和峰值,能有效识别连杆轴承各种技术状态,可以作为连杆轴承磨损故障的特征参数;并得出了敏感测试位置、敏感转速区间和特征阶比带。

A method based on angle domain fourth-order cumulant slice spectrum was proposed to extract weak fault features of connecting rod bearings.Firstly,the unsteady vibration signals in accelerating process were order-re-sampled and the steady signals were obtained in angle domain,then the fourth-order cumulant diagonal slice spectrum was calculated to constitute the angle domain fourth-order cumulant slice spectrum,it was used to analyze unsteady signals in different rotating speed intervals and at different measure positions to extract weak fault features of connecting rod bearings.The test results showed that the combination of angle domain re-sampling and the fourth-order cumulant diagonal slice spectrum can be used not only to analyze unsteady signals,but also to suppress noise interference; the energy and the peaks of the angle domain fourth-order cumulant slice spectrum in a certain order band can be used to distinguish different technical states of connecting rod bearings effectively,it can be taken as the feature parameter of connecting rod bearing faults; the sensitive measuring positions,rotating speed intervals and feature order bands can be obtained.