ABSTRACT
ABSTRACT: In recent years, expressway authorities in Japan require an effective method for monitoring and measuring surface characteristics of their pavements. Against this background, we have introduced a mobile profiling system enabling real-time roughness data collection. The system uses two accelerometers fixed to a suspension system of any passenger and commercial vehicles to measure the International Roughness Index (IRI) based on a back-calculated profile. One of the advantages of this system is to capture the information of longitudinal profile features. However, since the measurement algorithm is optimized to compute the IRI in real-time, the back-calculated profile is distorted by the natural frequencies of suspension components. This study examines an estimation technique of a longitudinal true profile using the mobile profiling system by developing a reconstruction filter to attenuate the distortion in the spatial frequency domain by the Fast Fourier Transform (FFT) method. As the result of a validation experiment, the mobile profiling system using the reconstruction filter satisfies practical requirements as a profiler compared with a Class 1 measures. The result also indicates that the system basically has a capacity to measure the IRI in real-time, and the back-calculated profile is appropriate for the purpose.
