  In this paper, an optimal output consensus problem is studied for
discrete-time linear multiagent systems subject to external disturbances. Each
agent is assigned with a local cost function which is known only to itself.
Distributed protocols are to be designed to guarantee an output consensus for
these high-order agents and meanwhile minimize the aggregate cost as the sum of
these local costs. To overcome the difficulties brought by high-order dynamics
and external disturbances, we develop an embedded design and constructively
present a distributed rule to solve this problem. The proposed control includes
three terms: an optimal signal generator under a directed information graph, an
observer-based compensator to reject these disturbances, and a reference
tracking controller for these linear agents. It is shown to solve the
formulated problem with some mild assumptions. A numerical example is also
provided to illustrate the effectiveness of our proposed distributed control
laws.
