Output Consensus of Heterogeneous Multi-Agent Systems with Mismatched Uncertainties and Measurement Noises: An ADRC Approach

In this paper, the practical output consensus problem for heterogeneous high-order leader-follower multi-agent systems under directed communication topology containing a directed spanning tree and subject to large-scale mismatched disturbances, mismatched uncertainties, and measurement noises is addressed. By introducing a reversible state transformation without changing the output, the actual total disturbance affecting output performance of each agent and matched with the control input of the transformed system is extracted and estimated by extended state observers. Then, the control protocols based on estimates of extended state observers, are designed by combing the output feedback control ones to obtain output consensus and feedforward compensators to attenuating the total disturbance of each agent actively. It is shown with a rigorous proof that the outputs of all followers can track practically the output of the leader, and all the states of the leader-follower multi-agent systems are bounded. Some numerical simulations are performed to verify the validity of the control protocols and theoretical result.