Fully distributed consensus control for a class of disturbed second-order multi-agent systems with directed networks

In this paper, the distributed consensus control problem is considered for a class of disturbed second-order multi-agent systems (MASs) with directed networks. Both leaderless and tracking cases are investigated. For the leaderless consensus problem, each agent is assumed to be affected by local disturbances generated by exosystems. Modeling error is assumed to exist in each local exosystem model. Different from existing works, a local composite disturbance observer is proposed, with which the exact states of the local disturbances can be well estimated asymptotically. Accordingly, the fully distributed leaderless consensus problem can be solved. For the tracking problem, the dynamics of the leader is assumed to be linear with respect to its state variables and the coefficient matrices are unknown to all the followers. Each follower is affected by disturbances generated by exosystems. A class of distributed parameter estimation algorithms is proposed to handle the unknown coefficient matrices in the dynamics of the leader, with which, the fully distributed tracking problem can be further solved. Finally, some simulation examples are given to verify correctness of the theoretical results.