In-Vehicle Roundabout Perception Supported by A Priori Map Data

In order to drive through a roundabout an automated vehicle needs to know the roundabout's geometry relative to the vehicle itself. In this work we present a model describing the geometry of a roundabout and a perception system that computes the parameters of this model relative to the ego vehicle before the ego vehicle enters the roundabout. Only a part of the model's parameters are estimated using on-board sensor observations. The complete roundabout geometry is computed by aligning a detailed geometrical description from an a priori digital map with the estimated parameters. For this purpose a regular navigation map is extended with geometric information about roundabouts. This extended map data is not georeferenced and the presented approach does not require high accuracy global localization or any additional landmarks to be stored in the map. The system's performance has been evaluated based on ground truth data.