Development and Preliminary Evaluation of a Varying-Speed Road Profiler

The International Roughness Index (IRI) has been widely used to characterize the road ride quality in the highway engineering community. IRI is commonly obtained via the longitudinal profile data collected by a high-speed inertial profiler. It is well known that the IRI value based on an inertial profiler can be biased under low-speed or varying-speed conditions. This stems from the inherent limitation of the accelerometer embedded in the measurement system. This study proposes a different approach to solving the problem by employing three-dimension laser scanning technology. Without relying on the accelerometer to offset the vehicle vertical dynamics/vibration, the new approach uses the measurement by a line laser to transfer the elevation along the driving direction. Following this principle, a road profiler was developed and installed on a host vehicle. A preliminary evaluation of the newly developed profiler was conducted on two urban road sections in Beijing. The elevation was focused on wavelength, IRI index, and repeatability analysis. The results showed that the proposed profiler could effectively capture road elevation and accurately characterize ride quality. It was indicated that this new equipment could serve as a useful tool to better accommodate the ride quality measurement under varying-speed data collection conditions, particularly in the urban environment.