Hierarchical Distributed Control for Interconnected Systems

Most approaches concerning distributed control for physically interconnected systems assume a flat controller structure, i.e. the subsystems exchange state information directly and in each timestep. In this paper, ideas from distributed control, network topology optimization and optimal control are combined in order to construct a distributed two-layer state feedback control structure. A decomposition algorithm is proposed which groups the subsystems into distinct clusters. Within each cluster, information is exchanged between the subsystems in every timestep. On the upper layer of the hierarchy, informaton is exchanged between the clusters with a lower frequency. The underlying communication topology is optimized to obtain a compromise between control performance and communication cost. This leads to reduced communication between the subsystems compared to existing hierarchical approaches.