Output-feedback consensus control for fractional nonlinear multi-agent systems via a distributed dynamic event-triggered observer strategy.

This paper considers the output-feedback consensus problem (OFCP) for nonlinear fractional multi-agent systems (FMASs) by dynamic event-triggered control, where the nonlinear term is modeled to satisfy the quadratic (QUAD) condition. Firstly, to estimate the states of leader and followers, a new distributed dynamic event-triggered observer (DDETO) and a fractional Luenberger-like observer are developed, respectively. Secondly, a distributed dynamic event-triggered mechanism (D-DETM) is proposed, where the additional internal dynamic variable is subject to the nonlinear fractional dynamical systems. Meanwhile, a computational algorithm is designed to generate continuous combinational output required by the D-DETM. Thirdly, on the bases of the observed state, a distributed dynamic event-triggered output-feedback controller is designed for each follower. It is shown that, under the designed control scheme, the leader-follower OFCP is solved through intermittent communication in a fully distributed way, and no global information is used. Moreover, the Zeno behavior is ruled out for the proposed D-DETM. Finally, a simulation example is given to validate the effectiveness of the proposed scheme.