Analysis of the time-frequency characteristics of internal combustion engine vibration signal based on Hilbert-Huang transform

In order to investigate the engine vibration generation causes and control its vibration intensity, Hilbert-Huang transform was adopted to analyze the vibration signal of engine cylinder head in time-frequency domain. According to the structural characteristics and working mechanism of engine, the vibration characteristics were discussed. The research results show that the vibration signal mainly consists of two kinds of components. The higher frequency components behave themselves with obvious features of non-stationary periodic and localized impact, and mainly caused by the outbreak of cylinder gas pressure and valve train transient impact incentives. The lower frequency components exhibit the characteristics of frequency and magnitude modulation, and mainly arise from the inertia force and moment of the engine moving parts. The higher frequency components play an important role in the cylinder head vibration signal.