  This paper deals with suboptimal distributed H2 control by dynamic output
feedback for homogeneous linear multi-agent systems. Given a linear multi-agent
system, together with an associated H2 cost functional, the objective is to
design dynamic output feedback protocols that guarantee the associated cost to
be smaller than an a priori given upper bound while synchronizing the
controlled network. A design method is provided to compute such protocols. The
computation of the two local gains in these protocols involves two Riccati
inequalities, each of dimension equal to the dimension of the state space of
the agents. The largest and smallest nonzero eigenvalue of the Laplacian matrix
of the network graph are also used in the computation of one of the two local
gains.A simulation example is provided to illustrate the performance of the
proposed protocols.
