Hasegawa Miki

Estimation of road management index using car noise and vibration

Miyaki Yasuyuki

Maintenance methods of road maintenance are mainly MCI and IRI. In Japan, MCI is used as road maintenance method. However, MCI cannot acquire data because it is expensive. Therefore, using the noise and vibration, we compare the actual MCI data and the correlation with road properties. The final goal was to verify the simple and inexpensive road property evaluation method. For this reason, in this fiscal year, the purpose was to verify the relationship between road properties data and the relation of Nagaoka city using vertical vibration acceleration. 
iPad was used for vibration acceleration measurement. Because the effective value of the vertical vibration acceleration changed in a very different road condition, consideration that it is related to MCI. However, even if the effective value of the vertical vibration acceleration is compared with the MCI and each factor data, a clear relationship cannot be obtained.
Considered that the measurement data of the vertical vibration acceleration changes depending on two factors, flatness and crack. Therefore, in order to separate the flatness and the crack, noticed the frequency component. When the measurement data is Fourier transformed, spectral values are large for those with flatness and cracks. It was found that the frequency is flatness at around 5 Hz and crack at 10 Hz or more. It was confirmed that changes in spectral values occur at different frequencies.
After this, vertical vibration acceleration is noticed the frequency component relation of the flatness and cracks. As a problem, the road property data used this time was a 100 m section. Therefore, consideration that there was a difference between the road property of the tire position during driving and the road property data. Therefore, it is necessary to calculate the road properties at the tire position during measurement. Although only vertical vibration acceleration is verified in this fiscal year, it is also necessary to verify noise and horizontal vibration acceleration.