Hierarchical Control and Subgroup Formation for the Robotic Swarms in Patrol Missions

—Supervision and interventions by operators are essential but restrictive factors for robotic swarm operations, whereas they may also enhance system capability. With the aim of demonstrating this positive effect, this research proposes the hierarchical organization and subgroup forming of robotic swarms for effective use of the interventions. Each robot acts as one of four roles and organizes the swarm hierarchically according to its respective role. The interventions are modelized as instructions to inform the required number of robots to handle a task during patrol missions. The instructions propagate among robots to form a subgroup with the required number of robots and handle the task while the remained robots continue patrolling. The tasks are highly simplified, only requiring the robots to stay nearby each task for a certain period. Simulation results showed that the proposed scheme improved performance regarding the number of completed tasks and required time for each task during patrol missions. The results quantitatively demonstrated that the supervision and interventions on robotic swarms might enhance their capabilities.