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A robust super-twisting sliding mode control (SMC) based on a disturbance observer is firstly investigated for transmission control protocol (TCP) network systems with unknown disturbance in this paper. To reject chattering from SMC, a super-twisting algorithm (STA) based on integral SMC is introduced to TCP/AQM systems. Meanwhile, to improve the estimation accuracy of the model, a disturbance observer is designed. By selecting the appropriate sliding surface coefficients, the stability of the closed-loop control system is achieved. At last, simulation comparison results are given to illustrate the feasibility and the superiority of the proposed approach. [ABSTRACT FROM AUTHOR]

For the nonlinear TCP/AWM network congestion control system with external disturbances, under the framework of backstepping control method, an adaptive network congestion control strategy based on event-triggered mechanism is proposed. This strategy reduces the waste of network resources by introducing an event-triggered mechanism and uses RBF neural network to deal with external disturbances. The Lyapunov theory is used to prove that all signals in the closed-loop system are bounded. Finally, the proposed method is verified by simulation and is compared with PID, which further verifies the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

This work investigates a finite-time H ∞ robust congestion control issue for transmission control protocol network systems. By means of the backstepping technique, finite-time control method and H ∞ control theory, a novel robust H ∞ finite-time controller design approach is presented to guarantee the finite-time convergence of the queue tracking error. Furthermore, the closed-loop network system has an L 2 gain less than or equal to a given positive real number. Comparative simulation results show that the proposed control method performs better than the existing control approach. [ABSTRACT FROM AUTHOR]

This work investigates an adaptive finite-time congestion control problem of transmission control protocol/active queue management. By means of the funnel control, neural networks and sliding mode control, a new AQM algorithm is proposed to ensure that the tracking error e 1 t converges to the prescribed boundary in finite time and the transient and steady-state performances of e 1 t can be satisfied. The stability analysis is given to prove that all the signals of the closed-loop system are finite-time bounded. Finally, a comparison example is considered to demonstrate the feasibility and superiority of the presented scheme. [ABSTRACT FROM AUTHOR]

This paper proposes an active queue management (AQM) controller for a class of linearized congestion router network systems in the presence of unknown time-varying link number and disturbances. Based on the idea of MiniMax method in game theory, a novel output feedback controller is specially designed with the improved robustness to the disturbances and parameter variations. By applying the proposed algorithm in the terms of LMIs, the worst effect caused by the disturbance can be evaluated using MiniMax method, and mean while the controller is optimally designed to deal with the system under the worst condition. Finally, the effectiveness of presented AQM method is verified on the software platform of NS2. [ABSTRACT FROM AUTHOR]