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This article investigates the adaptive fuzzy prescribed time H ∞ congestion control problem for a class of high speed transmission control protocol/active queue management (HSTCP/AQM) systems subject to asymmetric input saturation and external disturbance. Firstly, a saturation-based finite-time performance function (SFTPF) is constructed by introducing a nonnegative modified signal associated with input saturation errors into user-defined performance boundaries, which features the capability of ensuring the user-appointed tracking performance when no saturation exists and degrading it once saturation occurs, thereby effectively increasing the flexibility and reliability of the control scheme. Then, by designing a novel shifting function, the condition that the initial value of the queue tracking error remains within that of SFTPF is relaxed, which avoids the SFTPF being redeveloped for different initial queue tracking errors. Thereafter, an auxiliary system and H ∞ control theory are employed to eliminate the adverse effect caused by input saturation and external disturbance, respectively. Moreover, through the Lyapunov stability analysis, it is proven that, under our proposed adaptive fuzzy congestion control scheme, all the closed-loop signals are bounded, and the connection between input saturation and performance-related constraint is established. Finally, a set of simulation results are presented to demonstrate the feasibility and effectiveness of the designed congestion controller. • A new shifting function is developed to relax the initial condition restriction. • An error transformation function is designed to solve asymmetric constrained issues. • The performance constraint boundaries can be resiliently enlarged and recovered. • An adaptive fuzzy practical prescribed time congestion control scheme is proposed. [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]

Inspired by the prescribed performance control (PPC), a new performance function, called finite-time performance function (FTPF), is first defined in this paper, by which a novel finite-time control design process is introduced. This work is also the first to solve the finite-time control issue for a class of transmission control protocol/active queue management (TCP/AQM) networks. Meanwhile, with the aid of FTPF, PPC and neural networks, a new adaptive practically pre-assigned finite-time controller is designed, which guarantees that the queue length q (t) tracks the desired queue q ref in finite-time and all the signals of the closed-loop system are semi-globally practical finite-time stable (SGPFS). Finally, simulation results are shown to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

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]

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]

A novel network congestion algorithm is introduced for Transmission Control Protocol/Active Queue Management (TCP/AQM) system in this paper. The established TCP/AQM system is more accurate and general. Moreover, an adaptive congestion controller is designed by virtue of the Barrier Lyapunov Function (BLF), backstepping-like and Neural Networks (NNs) approximation techniques, by which the transient and steady-state performances on the tracking error can be pre-given and other signals of the closed-loop system also are verified to be semi-globally, uniformly and ultimately bounded. Finally, a comparison example is considered to demonstrate the feasibility and superiority of the presented scheme. [ABSTRACT FROM AUTHOR]