Learning Decentralized Controllers for Robot Swarms with Graph Neural Networks

We consider the problem of finding distributed controllers for large networks of mobile robots with interacting dynamics and sparsely available communications. Our approach is to learn local controllers which require only local information and local communications at test time by imitating the policy of centralized controllers using global information at training time. By extending aggregation graph neural networks to time varying signals and time varying network support, we learn a single common local controller which exploits information from distant teammates using only local communication interchanges. We apply this approach to a decentralized linear quadratic regulator problem and observe how faster communication rates and smaller network degree increase the value of multi-hop information. Separate experiments learning a decentralized flocking controller demonstrate performance on communication graphs that change as the robots move.