Fully Distributed Adaptive Formation Tracking for Directed Heterogeneous Multi-Agent Systems With Unknown Input

In this brief, the time-varying output formation tracking (TVOFT) problem for directed multi-agent systems is studied, where the leader has unknown input and each follower has nonidentical dynamics. The main object of this brief is to construct fully distributed controller so that the outputs of followers track the leader's output and realize the expected formation simultaneously. Firstly, by exploiting the neighboring information and local estimation, two kinds of adaptive observers are, respectively, constructed to estimate the states of the leader and followers, which do not require the bound of leader's unknown input. Then, by using the distributed observers and the expected time-varying formation vector, a TVOFT control protocol is developed in a fully distributed form, and the parameters of the controller are designed by an algorithm including three steps. Furthermore, on the basis of the Lyapunov stability theory and output regulation method, the TVOFT criteria for the considered closed-loop multi-agent systems are obtained on the basis of the presented control protocol. At last, in order to illustrate the theoretical results, a simulation example is given.