Cooperative robust output regulation of linear uncertain multi-agent systems

The cooperative output regulation of a linear multi-agent system has been studied recently for the case where the system uncertain parameters vary in a sufficiently small neighborhood of their nominal value. This problem is handled by an internal model design which converts the problem into a simultaneously eigenvalue placement problem of an augmented multi-agent system. In this paper, we further consider the cooperative robust output regulation problem for a class of minimum phase linear multi-agent systems in the sense that the controller allows the system uncertain parameters to vary in an arbitrarily prescribed compact subset. For this purpose, we introduce a new type of internal model that allows the cooperative robust output regulation problem of the given plant to be converted into a robust stabilization problem of an augmented multi-agent system. We then solve our problem by combining a simultaneous high gain state feedback control technique and a distributed high gain observer technique. A special case of our result leads to the solution of the leader-following robust consensus problem for a large class of uncertain multi-agent systems.