基于改进EEMD方法的工程机械液压系统冲击振动信号研究

工程机械液压系统发生冲击故障时,振动信号会出现相应的时频特性的变化,准确捕捉液压缸冲击振动信号,提取信号的典型特征是故障诊断的关键。该文首先运用SVM延拓解决EEMD方法的端点效应,然后通过改进的三次样条插值方法拟合包络线,再利用互相关分析与频谱分析对特征模态分量进行筛选,选取出能够代表信号特征的IMF分量。最后使用改进的EEMD方法对液压系统突然换向引起的冲击振动信号进行分析,选取出能够代表信号特征的IMF分量,为以后的智能诊断故障特征提取提供依据。

Study on Impact Vibration Signal of Construction Machinery Hydraulic System Based on Improved EEMD Method

When the hydraulic system has a shock fault,the vibration signal will change with the corresponding time-frequency characteristics.The key to fault diagnosis is to accurately capture the shock vibration signal of the hydraulic cylinder and extract the typical characteristics of the signal.In this paper,SVM extension is applied to solve the endpoint effect of EEMD method,then the envelope is fitted by the improved cubic spline interpolation method,and the characteristic modal components are screened by cross correlation analysis and spectrum analysis to select the IMF components that can represent the signal characteristics.Finally,the improved EEMD method is used to analyze the shock vibration signal caused by the sudden reversal of the hydraulic system,and the IMF component that can represent the signal characteristics is selected to provide the basis for the intelligent fault diagnosis feature extraction in the future.