Dynamic Leader-following Consensus of Multiple Uncertain Euler-Lagrange Systems with a Switched Exosystem

This paper addresses the leader-following consensus problem of multiple uncertain Euler-Lagrange systems. Different from the existing results, the exosystem considered in this paper is a switched system, which can greatly enrich the reference signals. However, the switched exosystem brings about two technical difficulties. First, due to the switching of the exosystem, asymptotic leader-following consensus cannot be achieved. To address this issue, we define a so-called dynamic leader-following consensus in the sense that the tracking errors are bounded and decay to zero in a piecewise way. Second, the switched exosystem leads to a nonlinear switched closed-loop system. In order to ensure the stability of the closed-loop system, we have given an explicit lower bound on the dwell time of the switching signal.