A Chattering-Free Approach to Consensus Tracking of Nonlinear Multiagent Systems With a Dynamic Exogenous Leader and Input Saturation

This article solves the problem of semi-global zero-error consensus tracking (ZECT) of a class of nonlinear multiagent systems (MASs) with a dynamic leader and input saturation under digraph. Different from some existing results that account for a dynamic leader, the upper bound of the dynamic leader's input is allowed to be unknown. To address the challenges of such an unknown upper bound, a hierarchical clustered network design is presented for the MASs consisting of a single dynamic exogenous leader and multiple clusters of agents. Then, with the help of the preset saturation threshold and low-gain feedback technique, some distributed chattering-free adaptive controllers, which do not rely on the global parameters of the network topologies and the upper bound of the dynamic exogenous leader's input, are proposed for the leaders and followers in each cluster, respectively. Moreover, it is proved that the MASs driven by the proposed controllers can achieve semi-global ZECT. Finally, some simulation results confirm the validity of the proposed control approach.