Robust cluster consensus of general fractionalorder nonlinear multi agent systems via adaptive sliding mode controller Abstract   In this paper robust cluster consensus is investigated for general fractionalorder multi agent systems with nonlinear dynamics with dynamic uncertainty and external disturbances via adaptive sliding mode controller. First, robust cluster consensus for general fractionalorder nonlinear multi agent systems is investigated with dynamic uncertainty and external disturbances in which multi agent systems are weakly heterogeneous because they have identical nominal dynamics with different normbounded parameter uncertainties. Then, robust cluster consensus for the fractionalorder nonlinear multi agent systems with general form dynamics is investigated by using adaptive sliding mode controller. Robust cluster consensus for general fractionalorder nonlinear multi agent systems is achieved asymptotically without disturbance. It is shown that the errors between agents can converge to a small region in the presence of disturbances based on the linear matrix inequality (LMI) and MittagLeffler stability theory. Finally, simulation examples are presented for general form multi agent systems, i.e. a singlelink flexible joint manipulator which demonstrates the efficiency of the proposed adaptive controller.

Designing an H_infinity Fuzzy LMIBased Consensus Protocol for Nonlinear Multiagent Systems consensus problem of multi agent systems catch great attention in recent years. It is mainly due to its vast applications. Designing an appropriate control protocol that guarantees the desired agreement between the agents is the main purpose of the consensus problem. A linear matrix inequality (LMI)based approach for the H_xe2x88x9e consensus of leaderfollower nonlinear multiagent system (MAS) is proposed in this paper. In the proposed framework, fuzzy Lyuponov function (FLF) is chosen. Some slack matrices are introduced to decouple the Lyapunov matrices from the systemsu0027 one which provide more degrees of freedom to the consensus problem and leads to decrease the conservativeness. As a result, sufficient conditions for consensus problem are presented in terms of LMIs. Finally, In order to evaluate the validity and effectiveness of the proposed approach, a numerical example for consensus of nonlinear MAS with thirteen followers is solved and simulation results are provided. Obtained results demonstrate the solid validity and great effectiveness of the proposed approach.