Observer-based leader-following consensus of uncertain nonlinear multi-agent systems

In this paper, the leader-following consensus problem of uncertain high-order nonlinear multi-agent systems on directed graph with a fixed topology is studied, where it is assumed that the relative states of a follower and its neighbors are immeasurable and only the relative outputs are available. Nonlinear adaptive observers are firstly proposed for each follower to estimate the states of it and its neighbors, and an observer-based distributed adaptive control scheme is constructed to guarantee that all followers asymptotically synchronize to a leader with tracking errors being semi-globally uniform ultimate bounded. On the basis of algebraic graph theory and Lyapunov theory, the closed-loop system stability analysis is conducted. Finally, numerical simulations are presented to illustrate the effectiveness and potential of the proposed new design techniques. Copyright (C) 2017 John Wiley & Sons, Ltd.