Tightly-coupled navigation assistance in heterogeneous multi-robot teams

This paper presents the design and results of autonomous behaviors for tightly-coupled cooperation in heterogeneous robot teams, specifically for the task of navigation assistance. These cooperative behaviors enable capable, sensor rich ("leader") robots to assist in the navigation of sensor-limited ("simple") robots that have no onboard capabilities for obstacle avoidance or localization, and only minimal capabilities for kin recognition. The simple robots must be dispersed throughout a known, indoor environment to serve as a sensor network. However, because of their navigation limitations, they are unable to autonomously disperse themselves or move to planned sensor deployment positions independently. To address this challenge, we present cooperative behaviors for heterogeneous robots that enable the successful deployment of sensor-limited robots by assistance from more capable leader robots. These heterogeneous cooperative behaviors are quite complex, and involve the combination of several behavior components, including vision-based marker detection, autonomous teleoperation, color marker following in robot chains, laser-based localization, map-based path planning, and ad hoc mobile networking. We present the results of the implementation and extensive testing of these behaviors for deployment in a rigorous test environment. To our knowledge, this is the most complex heterogeneous robot team cooperative task ever attempted on physical robots. We consider it a significant success to have achieved such a high degree of system effectiveness, given the complexity of the overall heterogeneous system.