Tartan Racing: A multi-modal approach to the DARPA Urban Challenge

The Urban Challenge represents a technological leap beyond the previous Grand Challenges. The challenge encompasses three primary behaviors: driving on roads, handling intersections and maneuvering in zones. In implementing urban driving we have decomposed the problem into five components. Mission Planning determines an efficient route through an urban network of roads. A behavioral layer executes the route through the environment, adapting to local traffic and exceptional situations as necessary. A motion planning layer safeguards the robot by considering the feasible trajectories available, and selecting the best option. Perception combines data from lidar, radar and vision systems to estimate the location of other vehicles, static obstacles and the shape of the road. Finally, the robot is a mechatronic system engineered to provide the power, sensing and mobility necessary to navigate an urban course. Rigorous component and system testing evaluates progress using standardized tests. Observations from these experiments shape the design of subsequent development spirals and enable the rapid detection and correction of bugs. The system described in the paper exhibits a majority of the basic navigation and traffic skills required for the Urban Challenge. From these building blocks more advanced capabilities will quickly develop.