LMD时频分析方法的端点效应在旋转机械故障诊断中的影响

摘要

为评估局域均值分解（LMD）受端点效应影响的程度,提出了一种基于能量的端点效应评价指标,并将LMD的端点效应与经验模态分解（EMD）的端点效应进行了比较。因包络线的定义方法不同,LMD在端点附近未定义的包络线较短,端点效应的程度也较轻。提出的端点效应镜像延拓抑制方法经仿真证明效果良好。将LMD应用于提取转子裂纹的故障特征,可获得满意的实验结果。%An index was developed based on energy for evaluating the end effect of LMD.The end effects of LMD and EMD（empirical mode decomposition） were compared.Because the envelop definition was different,in LMD the undefined envelop near border was shorter than that in EMD.LMD end effect is not as seriously as EMD.A mirror extension method was developed to reduce the end effect.The simulation results are quite good.LMD is applied in cracked rotor diagnosis,and the experimental results are also quite good.