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This work addresses a finite-time tracking control issue for a class of nonlinear systems with asymmetric time-varying output constraints and input nonlinearities. To guarantee the finite-time convergence of tracking errors, a novel finite-time command filtered backstepping approach is presented by using the command filtered backstepping technique, finite-time theory, and barrier Lyapunov functions. The newly proposed method can not only reduce the complexity of computation of the conventional backstepping control and compensate filtered errors caused by dynamic surface control but also can ensure that the output variables are restricted in compact bounding sets. Moreover, the proposed controller is applied to robot manipulator systems, which guarantees the practical boundedness of all the signals in the closed-loop system. Finally, the effectiveness and practicability of the developed control strategy are validated by a simulation example. [ABSTRACT FROM AUTHOR]

This paper addresses the tracking control problem of TCP/AWM network systems in presence of nonresponsive data flows of category user datagram protocol (UDP) flows. Firstly, a modified network system model is established by a certain suitable variable transformation, and then a fuzzy logic system (FLS) emulator is used to approximate the nonlinear terms in the network dynamics representation system. Secondly, inspired by the idea of the prescribed performance control (PPC), a novel finite-time performance function (NFTPF) is proposed. In turn, an adaptive finite-time congestion control strategy is designed by compatible usage as appropriate of a barrier Lyapunov function (BLF), the backstepping control synthesis, and an event-triggered mechanism. The proposed control strategy can not only make the tracking error to satisfy the pre-assigned transient and steady-state performance, but also ensure that all the closed-loop signals remain semi-globally uniformly ultimately bounded (SGUUB). In addition, the designed congestion control strategy eliminates potential occurrence of Zeno behavior. A set of simulation results are presented to clarify the feasibility and effectiveness of proposed methodological approach and the designed congestion controller. [ABSTRACT FROM AUTHOR]

This paper deals with the synchronization control of power complex networks with switching parameters. In the meantime, the node state constraints are considered during the synchronization process. Admittedly, synchronization problem encountered in power complex networks is becoming progressively important due to the increasing connection and disconnection operations resulting from sustainable energy and controllable load. Hereon, the network model considering switching parameters of each node is established to describe the topology variation of power systems that may be confronted in practical terms. Then, by utilizing the adaptive backstepping technique with a barrier Lyapunov function (BLF), a novel synchronization controller is constructed recursively which accomplishes the nodes full states tracking within the predefined transient behavior. Owing to the characteristic of BLF, the designed controller as well as its adaptive law could guarantee both the constrained state of each node restricted by a prescribed range and the synchronization performance. Meanwhile, the bounded output of the system could track the desired trajectory. Finally, scenario simulations are performed to demonstrate the effectiveness and superiority of the proposed method. [ABSTRACT FROM AUTHOR]

• To avoid explosion of complexity and compensate filtered errors, a finite-time command filtered backstepping approach is proposed for nonlinear systems with external disturbances. • To satisfy the transient and steady-state performance of tracking errors, the BLF method is applied to dynamic nonlinear systems, which can guarantee that the full states are constrained. • To verify the effectiveness of the proposed method, it is applied to TCP/AQM network systems for the first time to avoid network congestion in finite time. This work studies the issue of finite-time tracking control for a class of nonlinear systems with state constraints. By means of command filtered backstepping technique, finite-time theory and Barrier Lyapunov Functions (BLF), a novel finite-time command filtered backstepping approach is presented to guarantee the finite-time convergence of tracking errors. The new proposed method can not only reduce the complexity of computation of the conventional backstepping control and compensate filtered errors by Dynamic Surface Control (DSC), but also can guarantee that the state variables are restricted in compact bounding sets. Moreover, the proposed controller is designed and applied to Transmission Control Protocol/Active Queue Management (TCP/AQM) network systems, which guarantees the practical boundedness of all the signals in the closed-loop system. Finally, the effectiveness and practicability of the developed control strategy are validated by a TCP network simulation example. [ABSTRACT FROM AUTHOR]