Coordination and Control of Hierarchically Organized Interacting Agents

The coordination and control of hierarchically organized interacting agents is an important issue in many applications, e.g., harbor or warehouse automation. A formalism of agents as hierarchical input/output automata is proposed. A system of interacting agents is modeled as the parallel composition of their automata. We extend the usual parallel composition operation of I/O automata with a hierarchical composition operation for refining abstract tasks into lower-level subtasks. We provide an algorithm to synthesize hierarchically organized controllers to coordinate the agents' interactions in order to drive the system toward desired states. Our main contribution regards the formal definition, the representation, the theorems about its properties (i.e., the parallel and hierarchical composition are distributive operations), and the synthesis algorithm, proved to be complete and correct.