Decentralized formation control for small-scale robot teams with anonymity

This paper presents decentralized formation controls for a team of anonymous mobile robots performing a task through cooperation. Robot teams are required to generate and maintain various geometric patterns adapting to environmental changes in many cooperative robotics applications. In particular, all robots must continue to strive toward achieving the team’s mission even if some members fail to perform their role. Toward this end, formation control approaches are proposed under the conditions that robot teams are initially not allowed to have individual identification numbers (IDs), a predetermined leader, and agreement on coordinate systems. Therefore, all members are required first to reach agreement on their coordinate system and obtain unique IDs for role allocations in a self-organizing way. Then, employing IDs within a common coordinate system, two formation control approaches can be realized: leader-referenced and neighbor-referenced formations. Both approaches are verified using an in-house simulator and physical mobile robots. We detail and evaluate each formation control approach, whose common features include self-organization, robustness, and flexibility.