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This paper studies an arbitrary convergence time tracking controller design problem for high‐order nonlinear systems. Our aim is to enhance the existing free‐will arbitrary time control (FATC), which cannot track time‐varying reference signals. To do so, a new nonautonomous equation is firstly introduced to enable an arbitrary settling time stability for one‐order systems. Then, a prescribed performance control (PPC) technology is integrated for general high order systems. By a backstepping Lyapunov analysis with iteratively contructed nonautonomous equations, it is proved that the closed‐loop system satisfies the prescribed performance and all signals of the closed‐loop system are arbitrary settling time stable (ASTS). Compared with the existing results, the tracking control problem with arbitrary convergence time is addressed by a continuous control law, which shows a better transient performance also. Simulation results confirm the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

In this paper, the problem of observer‐based finite‐time congestion control for transmission control protocol (TCP)/active queue management (AQM) network systems with time‐varying delay and nonresponsive flows such as UDP is studied. The congestion control problem of TCP/AQM network system with time delay and external disturbances observer‐based finite‐time control is solved for the first time, and a theorem proved by the Lyapunov function of TCP/AQM network systems finite‐time bounded is given to ensure that the closed‐loop system is finite‐time bounded. Finally, the control gain and observer gain are obtained by linear matrix inequality (LMI) technique. Simulation results show the effectiveness and superiority 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]

In this paper, the finite time tracking control issue of the TCP/AQM system with input saturation and non-response flows such as UDP is studied. A novel AQM control algorithm is proposed by combining finite time control, prescribed performance control and fuzzy logic system. In order to obtain better disturbance suppression performance, the fuzzy logic system is adopted to deal with the external disturbance and the error disturbance generated by approximate input saturation function. The controller is designed to ensure that the queue tracking error converges to a specific region and achieve the practical finite time stability of all signals in the closed-loop system. The simulation results demonstrate the feasibility and superiority of the proposed method. [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 article focuses on an annular domain finite-time connectively bounded (ADFTCB) problem for a large-scale system with expanding construction (LSWEC). The LSWEC is built via adding new subsystems into the original system which is operating. Inspired by the notion of finite-time annular domain stability (FTADS), a new concept, ADFTCB, is presented in this article, and it is extended to LSWEC for the first time. First of all, the mathematical models of LSWEC and LSWEC with observer are built, and then the corresponding decentralized state-feedback stabilizers and output-feedback stabilizers with observers are designed with the aid of finite-time Lyapunov theory and linear matrix inequality (LMI) method which can make the closed-loop system ADFTCB. A simulation study is provided to demonstrate the feasibility and effectiveness of the presented strategy. [ABSTRACT FROM AUTHOR]