Global Localization Robust to GPS Outages using a Vertical Ladar

This paper presents a localization strategy for vehicles in urban environments by mapping and updating natural landmarks provided by a 2D ladar (laser range scanner) when GPS data is unavailable or has a too poor quality because of multi-tracks or bad satellite visibility. The method relies on an approach that takes profit of successive passages in the same area. From the modelling point of view, a particularity of the method is due to the use of linear landmarks - sidewalk edges - which implies the management of topological connections. Real experiments carried out in real conditions prove the feasibility of this approach