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This paper is concerned with the event-triggered $ \mathcal {L}_2-\mathcal {L}_\infty $ L 2 − L ∞ control problem for discrete-time Markov jump systems with DoS attacks and exogenous disturbance. Instead of one common event-triggering scheme, multiple triggering schemes are introduced to sample system signals and the event-triggered Markov closed-loop jump systems are further obtained under the full state feedback controller. Generally, mode information of subsystems is not completely available for the modules of trigger and controller such that asynchronous jump behaviour may occur among the modes of subsystems, triggering scheme and controller. Thus, a hidden Markov model (HMM) is developed to describe such asynchronous behaviour. Meanwhile, security issues of networks are widely studied in recent many literature. For discrete-time Markov jump systems, few works consider cyber attacks, especially periodic Denial-of-Service (DoS) attacks. Based on the HMM, the DoS attacks are taken into account and a set of sufficient conditions are further presented to guarantee the $ \mathcal {L}_2-\mathcal {L}_\infty $ L 2 − L ∞ control performance of the resulting Markov closed-loop jump systems. Subsequently, the design of controller and event-triggering parameters are provided by using matrix inequality method. Finally, an example is given to show the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In this paper, the boundary stabilisation of a coupled time fractional hyperbolic equation system is investigated by both state and output feedback. A target system is first introduced, which, by the semigroup method and the Lyapunov one, is proved to admit a unique solution and is Mittag–Leffler stable. A boundary state feedback controller and state observer are designed via the backstepping technique, with explicit formulae for the gain functions. An observer-based output feedback stabilising controller is then proposed for the controlled system. Some rigorous theoretical proofs are given to demonstrate that the resulting closed-loop system under the state and output feedback controllers has a unique solution and is Mittag–Leffler stable. Some numerical simulations are performed to validate the effectiveness of the proposed control approach. [ABSTRACT FROM AUTHOR]

In this paper, we apply the active disturbance rejection control, an emerging control technology, to output-feedback stabilisation for a class of uncertain multi-input multi-output nonlinear systems with vast stochastic uncertainties. Two types of extended state observers (ESO) are designed to estimate both unmeasured states and stochastic total disturbance which includes unknown system dynamics, unknown stochastic inverse dynamics, external stochastic disturbance without requiring the statistical characteristics, uncertain nonlinear interactions between subsystems, and uncertainties caused by the deviation of control parameters from their nominal values. The estimations decouple approximately the system after cancelling stochastic total disturbance in the feedback loop. As a result, we are able to design an ESO-based stabilising output-feedback and prove the practical mean square stability for the closed-loop system with constant gain ESO and the asymptotic mean square stability with time-varying gain ESO, respectively. Some numerical simulations are presented to demonstrate the effectiveness of the proposed output-feedback control scheme. [ABSTRACT FROM AUTHOR]

In this paper, both linear extended state observer (ESO) and nonlinear ESO with homogeneous weighted functions are proposed for a class of multi-input multi-output (MIMO) nonlinear systems composed of coupled subsystems with large stochastic uncertainties. The stochastic uncertainties in each subsystem including internal coupled unmodelled dynamics and external stochastic disturbance without known statistical characteristics are lumped together as the stochastic total disturbance (extended state) of each subsystem. The linear ESO and nonlinear ESO are designed separately for real-time estimation of not only the unmeasured state but also the stochastic total disturbance of each subsystem. The practical mean square convergence of these two classes of ESOs are developed. Some numerical simulations are presented to demonstrate the effectiveness of the ESOs with the advantages of smaller peaking values and more accurate estimation by the nonlinear ESO. [ABSTRACT FROM AUTHOR]

In this paper, the practical mean-square convergence of active disturbance rejection control for a class of uncertain stochastic nonlinear systems modelled by the Itô-type stochastic differential equations with vast stochastic uncertainties is developed. We first design an extended state observer (ESO) to estimate both the unmeasured states and the stochastic total disturbance which includes unknown internal system dynamics, external stochastic disturbance without known statistical characteristics, unknown stochastic inverse dynamics, and uncertainty caused by the deviation of control parameter from its nominal value. The stochastic total disturbance is then cancelled (compensated) in the feedback loop. An ESO-based output-feedback control is finally designed analogously as for the system without uncertainties. The practical mean-square reference tracking and practical mean-square stability of the resulting closed-loop system are achieved. The numerical experiments are carried out to illustrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In this paper, we apply the active disturbance rejection control approach to output-feedback stabilization for uncertain lower triangular nonlinear systems with stochastic inverse dynamics and stochastic disturbance. We first design an extended state observer (ESO) to estimate both unmeasured states and stochastic total disturbance that includes unknown system dynamics, unknown stochastic inverse dynamics, external stochastic disturbance, and uncertainty caused by the deviation of control parameter from its nominal value. The stochastic total disturbance is then compensated in the feedback loop. The constant gain and the time-varying gain are used in ESO design separately. The mean square practical stability for the closed-loop system with constant gain ESO and the mean square asymptotic stability with time-varying gain ESO are developed, respectively. Some numerical simulations are presented to demonstrate the effectiveness of the proposed output-feedback control scheme. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]