局域均值分解中PF获取方法的改进

摘要

Fault vibration signal of aero - engine is multi - component signals and local mean decomposition can analyse it.After studying the original method, this paper discovers that mode confusion exists between adjacent Production Function (PF).The higher- frequency PF contains signal of lower- frequency PF.To solve this problem,an improved PF is defined and this way can filter the mode confusion signal.The analyse of artificial signal showed that the improved LMD is better than the original LMD in signal separation.The application results of test- data showed that the improved LMD can extract characteristics of aero - engine fault vibration signal effectively.%航空发动机故障振动信号为典型的多分量信号,局域均值分解方法可以对其分离.在研究了经典的局域均值分解方法后,发现相邻的两个乘积函数( Production Function,PF)中存在模态混淆现象,表现为较高频PF中包含较低频PF的频率成分.针对这一问题,对PF的定义进行了改进,滤除了混淆在其中的低频信号,使信号分离更加充分.仿真信号的分析表明,改进后的算法分离效果优于原算法.试验信号的分析表明,方法可以用于航空发动机故障特征提取.