Development of an Integrated Mobile Robot System at Carnegie Mellon University: December 1989 Final Report

This report describes progress in development of an integrated mobile robot system at the Robotics Institute of Carnegie Mellon University from July 1988 to December 1989. This research was sponsored by the Defense Advanced Research Projects Agency and monitored by the U.S. Army Engineer Topographic Laboratories under contract OACA76-86-C-0019. In this program, we pursued a broad agenda of research in the development of mobile robot vehicles, focused on the NAVLAB computercontrolled van. In the period covered by this report, July 1988 to December 1989, we addressed major software issues for mobile mbot vehicles: Evolution of the CODGER Blackboard and the Driving Plpellne Archltecture. * CODGER is the blackboard system for the NAVLAB that synchronizes and passes data among the various processing modules. The Driving Pipeline is a set of modules that operate in parallel to implement continuous motion control, mad-following, and obstacle avoidance. In this reporting period. our extensions to CODGER and the Driving Pipeline include adaptive adjustment of planning parameters to give desired robot responsiveness and control parameters to ensure smooth operation. We developed a new method for vehicle path planning designed to handle off-road scenarios rather than traditional "flat-world" scenarios. In the past, most path planning algorithms have assumed that the entire world is flat, with polygonal obstacles clearly identified. However, the terrain encountered in cross-country driving presents more subtle problems in vehicle tilt and clearance; these interact with vehicle constraints such as minimum turning radius. Our new path planner can explicitly model and account for such aspects of the problem, and has been optimized to work fast enough for use on the NAVLAB driving cross-country. Kinematic Path Plannlng for Wheeled Vehlcies. This software is central to the New Generation System (NGS) for robot vision and navigation, which combines many independent technologies to produce an integrated mobile robot system.