Team Gator Nation's Autonomous Vehicle Development for the 2007 DARPA Urban Challenge

Abstract

This paper describes the system design developed for Team Gator Nation’s submission to the 2007 DARPA Urban Challenge. A hybrid Toyota Highlander has been automated and instrumented with pose estimation (GPS and inertial) and object detection (vision and ladar) sensors. The control architecture consists of four primary elements, i.e. Planning Element, Perception Element, Intelligence Element, and Control Element. The Intelligence Element implements the Adaptive Planning Framework developed by researchers at the University of Florida. This framework provides a means for situation assessment, behavior mode evaluation, and behavior selection and execution. The architecture is implemented on a system distributed over ten dual-core computers that intercommunicate via the Joint Architecture for Unmanned Systems (JAUS) version 3.2 protocol. This work’s primary contribution addresses the technical challenges of (a) the reconciliation of differences in estimated global pose, a priori data, and sensed information, (b) the determination of the appropriate behavior mode, and (c) the smooth transition of vehicle control between behavior modes. The processes that perform these tasks as well as the other necessary processes that perform perception, data integration, planning, and control are described in detail together with their design rationale. Finally, testing results accomplished to date are presented.