To improve extraction accuracy of bearing fault feature, a novel index named weighted characteristic energy ratio (WCER) is proposed in this article. In WCER, the fault feature in squared envelope spectrum is enhanced through a square operation, and a series of decreasing weights are imposed on the increasing fault harmonics to highlight the low-order fault feature and suppress the noise around the high-order harmonics. For unknown fault types, including single and compound faults, another index named compound WCER (CWCER) is proposed on the basis of WCER. The optimal resonant frequency band is determined via maximizing WCER and CWCER, and the fault feature can be effectively extracted. WCER is applied to diagnose two single faults, whereas CWCER is employed to detect two single faults and a compound fault. Their superiority to traditional indices is demonstrated; they can be better applied to bearing fault diagnosis, especially for unknown faults.

中文翻译：

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滚动轴承故障诊断新指标：复合加权特征能量比


为了提高轴承故障特征提取的准确性，本文提出了一种新的指标——加权特征能量比（WCER）。在WCER中，通过平方运算增强平方包络谱中的故障特征，并对增加的故障谐波施加一系列递减的权重，以突出低次故障特征并抑制高次谐波周围的噪声。针对未知故障类型，包括单一故障和复合故障，在WCER的基础上提出了复合WCER（CWCER）指标。通过最大化WCER和CWCER来确定最佳谐振频段，可以有效地提取故障特征。 WCER用于诊断两个单一故障，而CWCER用于检测两个单一故障和一个复合故障。证明了它们相对于传统指数的优越性；可以更好地应用于轴承故障诊断，特别是未知故障。