LAUSR

ABSTRACT This paper studiesthe cooperative tracking control problem for multi-agent systems with unknown external disturbances under a directed graph. The leader's input is nonzero and unavailable to the followers. Based on the relative output measurements of neighbouring agents, a novel observer-based cooperative tracking protocol is presented, where the a group of intermediate estimators are constructed to estimate the tracking errors and the combined signal of the disturbances and the leader's input simultaneously, then decentralised tracking protocols are designed based on the obtained estimates. The states of the global tracking error system are proved to be uniformly ultimately bounded. A numerical example of aircraft illustrates the effectiveness of the cooperative tracking protocol.