Distributed H_{infinity} Coordination of Multi-agent Systems with Directed Switching Topology and Time-delay

In this paper, we consider multi-agent H_{infinity} consensus control problems with external disturbance under directed switching topologies. Both switching networks with and without time-delay are taken into consideration. By the model transformation, the multi-agent H_{infinity} control problem is converted into the switching linear system H_{infinity} control problem with special structure. Based on graph theory and common Lyapunov function method, we establish LMI sufficient conditions under which all agents can reach consensus with the desired H_{infinity} performance in two cases of zero and nonzero communication delays respectively. Specially, we obtain an explicit estimation expression of H_{infinity} performance index in undirected non-time-delay switching topology case. Finally, two numerical examples are provided to illustrate the effectiveness of the obtained results.