A navigation framework for multiple mobile robots and its application at the Expo.02 exhibition

This paper presents a navigation framework which enables multiple mobile robots to attain individual goals, coordinate their actions and work safely and reliably in a highly dynamic environment. We give an overview of the framework architecture, its layering and the subsystems reactive obstacle avoidance, local path planning, global path planning, multi-robot planning and localization. The latter receives particular attention as the localization problem is a key issue for navigation in unmodified and difficult environments. The framework permits a lightweight implementation on a fully autonomous robot. This is the result of a design effort striving for compact representations and computational efficiency. The experimental testbed was the "Robotics" pavilion at the Swiss National Exhibition Expo.02 where ten fully autonomous robots were interacting with more than half a million visitors during a five-month period on 3316 km.