Almost Output Consensus of Nonlinear Multi-Agent Systems in the Presence of External Disturbances

In this paper, we investigate the almost output consensus problem for nonlinear multi-agent systems under the influence of external disturbances. The concept of almost output consensus of nonlinear multi-agent systems is defined. Conditions on the nonlinear systems are established under which distributed consensus protocols are designed in a re-cursive manner. These protocols are shown to achieve almost output consensus, that is, output consensus of the system is achieved in the absence of disturbances and the L
₂
-gain from the disturbances to the output consensus error of agents with the same initial condition can be made arbitrarily small. A numerical example is shown to verify the theoretical results.