基于HHT的液压缸动态特性分析新方法

摘要

A new method based on HHT to analyze dynamic characteristics of a hydraulic cylinder was proposed. The oil pressure fluctuation signal under periodic excitation was decomposed into IMFs by using EMD. Then, IMFs were classified using the Hilbert marginal spectrum of each IMF and the frequency of the free vibration and forced vibration. The signal was reconstructed after the classification, the free vibration component reflecting the dynamic characteristics of the hydraulic cylinder was extracted. The result showed that the proposed method has good performance to analyze the dynamic characteristics of a hydraulic cylinder, and the free vibration component extraced can be a basis to evaluate the dynamic characteristics of a hydraulic cylinder.%提出了一种基于Hilbert-Huang变换的液压缸动态特性分析的新方法:运用经验模态分解,把周期激励下液压缸油液压力波动信号分解为多个从高频到低频的本征模态函数分量,依据各分量的Hilbert边际谱以及自由振动频率信息,对各分量分类并以此为基础重构信号,提取出反映液压缸动态特性的自由振动分量.此方法在某试验台液压缸动态特性分析中,取得了良好的效果,提取出的自由振动分量,可以作为评价液压缸动态特性好坏的依据.