Structural controllability of higher-order multi-agent systems under absolute and relative protocols

The paper investigates the structural controllability of leader-follower multi-agent systems under absolute and relative protocols. Three models of agents: double integrator, high-order integrator, and generic linear are analyzed. Some necessary and sufficient graphical conditions are provided for structural controllability based on information communication graph of the system. In particular, linear absolute and relative protocols are designed for generic linear agents under which structural controllability is proved to be uniquely determined by information communication graph.