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In this paper, an event-triggered dynamic surface controller is proposed for strict-feedback nonlinear networked systems with mismatched uncertainties. Towards this aim and first of all, an event-based dynamic surface control law is designed. Then, the closed-loop error dynamics is derived and rewritten as a linear dynamics with nonlinear perturbation terms. Next, these terms are classified into vanishing and nonvanishing perturbations. Finally, by imposing some constraints on the nonvanishing terms, an event-triggering mechanism is constructed. By formulating the imposed constraints in the form of linear matrix inequalities (LMIs) and using the ultimate boundedness theory, the ultimate error boundedness and quadratic tracking objectives are addressed in the framework of convex optimisation. The absence of the Zeno behaviour, which is an important feature of any event-triggered methodology, is also proven. The validity of the theoretical results is illustrated by applying the proposed method to a remotely operated underwater vehicle in a simulation study as well as an experimental implementation on a magnetic levitation system. [ABSTRACT FROM AUTHOR] more...

In this paper, an event‐triggered dynamic surface control technique is proposed for strict‐feedback uncertain nonlinear networked systems in the presence of network‐induced time delays. First, an event‐based dynamic surface control law is designed. Then, by rewriting the control law as a communication‐delay‐distribution‐dependent model, the closed‐loop error dynamics is derived and modeled as a linear time‐delay system with perturbation terms. Next, a periodic event‐triggering condition is designed by imposing some inequality constraints on the perturbations. A theorem related to the H∞$$ {H}_{\infty } $$ ultimate boundedness and quadratic tracking of the closed‐loop system is presented. The proposed technique is utilized to design a decentralized dynamic surface control structure with event‐triggered inter‐vehicle communications for a vehicle platoon. [ABSTRACT FROM AUTHOR] more...

This paper is devoted to investigate the distributed consensus problem for multi-agent systems with uncertain agent models. The uncertainty in the agents' dynamics is considered as granular fuzzy numbers and consequently the consensus error is a granular fuzzy number. It is proven that this error converges to zero asymptotically using the proposed fuzzy consensus protocol. Additionally, the definition of granular fuzzy consensus surface is proposed which determines the robustness of the consensus protocol to changes in the communication topology. Necessary and sufficient conditions are proposed to ensure that an unbounded fuzzy consensus surface can be reached with the proposed consensus protocol. The final consensus value as a fuzzy number is also calculated in presence of uncertainty. Simulation examples corroborate the efficiency of the presented method. [ABSTRACT FROM AUTHOR] more...