Path Planning for Cognitive Vehicles using Risk Maps

This paper reports on the behaviour decision and execution unit of AnnieWAY, an autonomous vehicle that is capable of driving through urban scenarios and that has successfully entered the finals of the DARPA Urban Challenge 2007 competition. Starting with a short description of the car and its major hardware components, we outline the underlying software structure and focus on the design of the behavior decision module. The selection of maneuvers necessary to accomplish the mission is conducted online via a concurrent hierarchical state machine that specifically ascertains behavior in accordance with California traffic rules. The states and transitions used to model a adequate behaviour are described. We conclude with a report of the results achieved during the competition.