Analysis for non-stationary road surface roughness regarding four-wheel vehicles using Hilbert-Huang Transform

The paper uses the Hilbert-Huang Transform (HHT) to analyze the non-stationary road surface roughness, pointing at the non-stationary characteristics of the road surface roughness. First, the non-stationary road roughness is obtained by the simulation of the light bus of SY6480 running on the C-class road with variable speed; then it is decomposed using the HHT and the Hilbert marginal spectrum is acquired. The results indicate that the road surface roughness imposed on the four wheels has the rather similar spectrum structure and its energy mostly focus on the several harmonic waves of low frequency, which can guide the design of active suspension, the control of vehicle vibration and the analysis of vehicle ride comfort when vehicles run with variable speed.