Distributed adaptive consensus protocols for linear multi-agent systems with directed graphs and a leader of unknown control input

This paper is concerned with the distributed adaptive consensus protocol design problem for linear multi-agent systems with directed graphs in the presence of a leader with nonzero but unknown control input. By introducing appropriate nonsmooth functions, a novel adaptive consensus protocol is proposed, under which leader-follower consensus can be achieved for any communication graph containing a directed spanning tree with the leader as the root node. The adaptive consensus protocol is fully distributed, relying on only the agent dynamics and the relative states of neighboring agents.