Consensus control of feedforward nonlinear multi-agent systems: a time-varying gain method

In this paper, the leader–follower consensus of feedforward nonlinear multi-agent systems is achieved by designing the distributed output feedback controllers with a time-varying gain. The agents dynamics are assumed to be in upper triangular structure and satisfy Lipschitz conditions with an unknown constant multiplied by a time-varying function. A time-varying gain, which increases monotonously and tends to infinity, is proposed to construct a compensator for each follower agent. Based on a directed communication topology, the distributed output feedback controller with a time-varying gain is designed for each follower agent by only using the output information of the follower and its neighbors. It is proved by the Lyapunov theorem that the leader–follower consensus of the multi-agent system is achieved by the proposed consensus protocol. The effectiveness of the proposed time-varying gain method is demonstrated by a circuit system.