Output Feedback Cooperative-Antagonistic Average Consensus in High-Order Multiagent Systems Over Directed Graphs

Output average consensus of cooperative/ cooperative-antagonistic multiagent systems (MASs) is of great significance in the engineering field, but is rarely addressed for general linear high-order networks interacting over directed graphs. This problem is herein tackled and solved via a novel hierarchical distributed output feedback control architecture, where the higher level embeds a distributed reference generator while the lower one is characterized by a proportional-integral-derivative (PID)-like control structure. The former is responsible for gathering the networked information to compute the output average agreement, which is exploited by the latter for the achievement of the coordination task. Combining the regulator equations and the static output feedback (SOF) procedure, properly extended in the distributed context, a well-defined closed-loop network is derived, and the control gain tuning procedure is provided. The versatility of the proposed approach in also handling the heterogeneous case, arising when agents do not share the same dynamical model, is also proved. Theoretical results establish the stability conditions via the Lyapunov-based analysis and the input-to-state stability (ISS) theory, and prove the accomplishment of the output unsigned/signed average consensus objectives with transient and steady-state performance improvements. Illustrative examples further corroborate the validity of the theoretical results.