Comprehensive treated sections in a trajectory planner for realizing autonomous driving in Braunschweig'S urban traffic

With the announcement of the “Stadtpilot”- Project the Technische Universität Braunschweig has accepted the challenge of guiding a vehicle fully autonomously in the complex environment of Braunschweig's entire ring road. Autonomous driving on this two-lane urban road includes interaction with traffic, behavior at intersections, lane change maneuvers at speeds up to 60 km/h as well as merging into moving traffic. The demanding terms of the surroundings require an extremely high precision of all modules. Compared to former research activities in autonomous driving, the width of the ring road's roadway varies significantly and has both narrow curves close to the turn radius of the vehicle and straight roads. Therefore, a new approach for trajectory planning having the comprehensive treatment of path-planned sections as its distinctive feature has been realized and the first major success within the context of the “Stadtpilot”-Project. Curvature optimized trajectories are generated over the whole roadway that are independent from the way driving decision are found, resulting in a safe, smooth and comfortable driving behavior. This paper introduces the algorithm and shows its potential on the basis of a typical driving maneuver on the ring road.