Abstract:In order to study on the vibration signal of hydraulic system through EEMD decomposition of main components of order IMF components can represent the decomposition of EEMD signals, analysis of principal component decomposition of EEMD was presented, and the effect of EEMD related principal component was researched. EEMD was applied to decompose the signal to get the IMF component. The correlation coefficient of each component of the original signal was calculated to find the relevant principal component signal. Through the Hilbert envelope spectrum analysis of principal component and comparing with the Hilbert envelope spectrum of the original signal, the analysis effect of EEMD related principal component was validated. The study of the measured signal shows that after the continuous signals of a hydraulic cylinder by EEMD decomposition, with the original signal correlation between the larger of the five order IMF component: IMF1,IMF2,IMF5,IMF6,IMF7 were contained in the original signal components. They were able to represent the major components of the decomposition of EEMD signal, and the first five orders were not able to fully represent the main component of the original signal. It was found by the hydraulic cylinder impact signal analysis that the former two order IMF: IMF1、IMF2 components of the EEMD decomposition had larger correlation with the original signal. The frequency components and the information contained in the original signal were able to be represented to indicate the principal component decomposition of EEMD signal and also to represent the main components of EEMD decomposition. Therefore, EEMD related principal component analysis can highlight the main frequency components of EEMD decomposition, which has good analysis effect to the vibration signals of the hydraulic system.