A New Approach For Measuring Terrain Profiles

This paper presents a new approach for measuring terrain profiles. The proposed approach uses RGB-D sensors to measure terrain surface relative to the vehicle. Since the RGB-D sensor is an area scanner, a feature matching technique called the grid-based feature-to-map matching technique, developed by the authors, matches objects seen in consecutive images and constructs a terrain profile in a global coordinate system. The RGB-D sensor are mounted inside a box to shield natural light and provide consistent LED lighting. As it constructs a terrain profile by matching scanned data regardless of the vehicle movement, the proposed approach is not affected by the vehicle movement as much as conventional techniques and achieves high accuracy. Preliminary experimental work indicates that the proposed approach could measure terrain profiles in sub-centimeter accuracy of all dimensions. The potential applicability of the proposed approach to the maintenance and inspection of railroads has also been demonstrated.