Robot Formations Using Only Local Sensing and Control

Jakob Fredslund and Maja J. Mataric

We study the problem of achieving global behavior in a group of robots using only local sensing and interaction, in the context of formations. The goal is to have N mobile robots establish and maintain some predetermined geometric shape. We report results from extensive simulation experiments, and 40+ experiments with four physical robots, showing the viability of our approach. The key idea is that each robot keeps a single `friend' at a desired angle, theta, using some appropriate sensor. By panning the sensor theta degrees, the goal becomes simply to center the friend in the sensor's field of view, for all formations. We also present a general analytical measure for evaluating formations and apply it to the position data from both simulated and real-world experiments. We used two surveillance lasers to track the physical robots to obtain real-world position data.