Portable Sensor Motes as a Distributed Communication Medium for Large Groups of Mobile Robots

We argue for the use of swarms of distributed portable sensors as a support medium for a large number of autonomous mobile robots. Because of the scaling issues inherent in their multiplicity, and because they may operate in broadcast-denied environments, swarm robot architectures often focus on local and “indirect” communication methods such as breadcrumbs, pheromones, or messages left in the environment. We are interested in how far we can go with these models in real robots. To this end, our research investigates robots capable of deploying, retrieving, moving, and locally communicating with many embedded sensor motes. The mobile agents deploy and optimize the location of the motes, read historic and current sensor data from them, and store useful local information in them for other mobile agents to discover later. We have demonstrated the ability to do robot foraging in environments with significant noise and physical disruption, such as might occur in any deployment of a large sensor network. We have also demonstrated experiments using swarms and sensor motes to collectively build sophisticated, non-trivial swarm behaviors, such as laying out complex shapes using compass/straightedge geometry. In this paper we discuss these results and their limitations, and indicate where we think wireless sensor mote technology can help advance swarm robotics going forward.