局部费歇尔判别分值在滚动轴承故障诊断中的应用

摘要

为精确、高效地识别出滚动轴承不同程度、不同类型的故障,提出一种基于局部费歇尔判别分值(Localized fisher discriminant score,LFDS)的故障诊断方法.该方法首先从时域、频域及时频域构造原始故障特征集;然后运用LFDS选择出其中最能反映故障本质的敏感特征子集;最后将选择出的特征子集输入到最小二乘支持向量机进行模式识别.用滚动轴承一组故障特征数据集进行验证.结果表明,经LFDS选择出的特征能显著表现出不同故障类别间的差异.%In order to precisely and efficiently identify different types with different degree of fault rolling bearing.An intelligent fault diagnosis method based on localized fisher discriminant score (LFDS) is put forward.At first,the feature extractions of time domain,frequency domain and time-frequency from vibration signal are prepared;then use LFDS to select the most sensitive feature subset from the original feature set;finally,the sensitive low dimension feature data set is fed into least squares support vector machine algorithm to recognize the fault type.The proposed method was verified by the typical fault vibration signal of rolling bearing.According to the example result,the feature subset selected by LFDS can reveal the differences among the different types with different degree.