DEVELOPMENT OF SUMMARY INDEX OF RUTTED PROFILE FOR VEHICLE RIDE QUALITY ESTIMATION

The objective of this study is to develop a summary index of a rutted profile for the estimation of ride quality of road vehicles in a rutted road. First, the spatial frequency analysis of the rutted profiles by the continuous wavelet transform is conducted to comprehend the wavy characteristics of the profiles associated with the vehicle motion caused by the lane-change maneuver in the rutting. The result shows that the wavy characteristics in the wavelength of 0.4m affect the vehicle dynamics with respect to the ride quality deterioration. Second, a difference filter is designed to detect the wavelength of 0.4m from a rutted profile. The filtering manipulation enhances the wavy characteristics of the profile corresponding to the ride quality of the vehicle. Finally, we develop a summary index of the profile that is the difference between maximum and minimum elevation of the filtered profile. The result of regression analysis shows that the developed index highly correlates with the ride quality rating value based on the vehicle dynamics. The index enables road administrators to directly estimate the ride quality from rutted profile data of road surfaces in the pavement monitoring activity