Active disturbance rejection consensus control of uncertain high-order nonlinear multi-agent systems

In this paper, we consider the consensus control problem for uncertain high-order nonlinear multi-agent systems in a leader-follower scheme. Each follower node is modeled by a high-order integrator incorporating with unmeasurable states and unknown nonlinear dynamics. First, the total uncertainty that lumps the unknown nonlinear dynamics and the mismatch of control is viewed as an extended state of the agent. By using local information from neighborhood set, a distributed extended state observer (ESO) is designed to estimate not only the unmeasurable agent states but also its total uncertainty. Then, based on the output of the ESO, a novel consensus control law is proposed, in which the total uncertainty is canceled out in the feedback loop in real time. We show that, with the application of the proposed approach, the ESO estimation errors and the disagreement error vectors between the leader and the followers can be made arbitrarily small. A simulation example is given to illustrate the effectiveness of the proposed consensus control method.