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Summary: This article studies the memory‐based dynamic event‐triggered (MBDET) robust adaptive fuzzy control problem for a class of uncertain nonlinear MASs subject to Backlash‐Like Hysteresis. The considered MASs are modeled as a class of nonlinear leader‐following multiagent systems with multiple inputs for each subsystem, which can be used to model multiple multi‐rotor unmanned aerial vehicle (Multi‐UAV) attitude systems. In the framework of backstepping recursive design, the fuzzy approximation technology, the parameter estimation technology, and the first‐order filtering technology are integrated, and an effective fuzzy adaptive control method is proposed, which solves the problems of Backlash‐Like Hysteresis and external disturbances in the system while avoiding the "explosion of complexity". In order to relieve the communication pressure of Multi‐UAV attitude systems, a novel dynamic memory‐event‐triggered mechanism (DMETM) based on user‐set parameters is developed. Compared with the traditional event‐triggered mechanism, this DMETM has larger triggering time intervals, effectively reduces communication frequency, and has greater flexibility in balancing system performance and communication bandwidth resource constraints. The closed‐loop stability analysis scheme for Multi‐UAV attitude systems is presented by combining the backstepping recursive design technique and Lyapunov stability theory, which proves that closed‐loop stability and tracking performance can be ensured. Finally, the design method is successfully applied to show the effectiveness of the proposed method to solve the dynamic memory‐event‐triggered attitude control problem for nonlinear Multi‐UAVs. [ABSTRACT FROM AUTHOR]

This article concentrates on security issues of stochastic event‐based (SEB) sensor scheduling in cyber‐physical systems (CPSs). An SEB attack mechanism is proposed to compromise remote state estimation, in which the attacker can jam the feedback channel and inject false acknowledgments. Based on the Gaussian assumption, the minimum mean square error estimator under the SEB attack is obtained utilizing Bayes' theorem. In this article, the SEB attack stealthiness is composed of communication ratio invariance and anomaly detection invisibility with the forward channel. Furthermore, a double stealthy attack condition is given to complete persistent attacks from the perspective of the attacker. Aiming at maximizing average error covariances on the remote estimator, we design a generation algorithm of optimal SEB stealthy attack sequence and prove its optimality by rearrangement inequality and mathematical induction. Finally, the scalar and networked dc motor vector system simulations illustrate the corresponding theoretical results. [ABSTRACT FROM AUTHOR]

This article studies the problem of event‐triggered consensus for linear multiagent systems. Leaderless and leader‐following cases are considered here. By adopting adaptive technology and utilizing the relationship between parameters, novel fully distributed control schemes are proposed. Both the control updates and the communication consumption between agents can be declined under the designed hybrid event‐triggered controller. Meanwhile, different from some existing event‐based control schemes, the projection operator is avoided so that the developed controllers use only local signal, which relies on neither the minimum nonzero eigenvalue of the Laplacian matrix nor the total number of agents. The designed control schemes can ensure that leaderless and leader‐following consensus to be achieved asymptotically, and Zeno behavior is excluded by presenting a hybrid event‐triggered mechanism. Simulation examples are provided to demonstrate the effectiveness of the presented control protocols. [ABSTRACT FROM AUTHOR]

Summary: This article studies the static output feedback (SOF) secure control issue for cyber‐physical systems against replay attacks. The fundamental purpose focuses on how to stabilize the closed‐loop system regardless of whether the replay attacks occur. First, a detection scheme is presented that can find the behavior of the adversary and recognize which sensor suffers from the attacks. Then, the SOF controller is designed and the adverse influence induced by the replay attacks can be eliminated through the detection information. Thereafter, a sufficient condition has been established which guarantees the closed‐loop system is stable and satisfies a prescribed H∞ performance. Finally, simulation results verify the effectiveness and superiority of the presented design and detection scheme. [ABSTRACT FROM AUTHOR]

Summary: This paper is concerned with the frequency‐dependent fault detection scheme for networked systems under uniform quantization and try‐once‐discard protocol scheduling. By considering the communication constraint and the data node scheduling, a switched system is firstly modeled to characterize the dynamic features of the whole system. The switching function of the derived system is determined by the try‐once‐discard protocol. For this class of system, a sufficient condition to ensure the exponentially ultimately boundedness is established. With the aid of some novel analysis processes, sufficient conditions to characterize the desired finite frequency performances, which transform the frequency‐domain restrictions into time‐domain conditions, are subsequently developed. Then, the fault detection filters corresponding to the transmission nodes are synthesized by solving an optimization problem. Finally, an application to VTOL aircraft is presented to illustrate the effectiveness of the proposed fault detection strategy. [ABSTRACT FROM AUTHOR]

Summary: This paper investigates the static output feedback control problem for Markov jump systems subject to asynchronous mode information and deception attacks. A hidden Markov model is employed to observe the unmeasurable system mode. In this case, the asynchronous phenomenon between the controller and the original system is depicted. By using the mode‐dependent Lyapunov function, a sufficient condition is established such that the resulting closed‐loop system is stochastically mean square exponentially ultimately bounded under randomly occurring deception attacks and external disturbance. Based on this condition, the asynchronous static output feedback controller is designed in view of linear matrix inequalities. Finally, the effectiveness and superiority of the presented method are elaborated via a numerical example and a practical example. [ABSTRACT FROM AUTHOR]

Summary: This paper concerns the fixed‐time stabilization problem for uncertain strict‐feedback nonlinear systems. Generally, the so‐called fixed‐time stabilization is an extended concept of global finite‐time stabilization. By using fixed‐time controller, the convergence time of the closed‐loop system can be pre‐set by adjusting design parameters, which has more practical application values. The idea of bi‐limit homogeneity has been introduced to design the fixed‐time controller with two terms, whose orders are tuning by a bi‐limit–like strategy. That is the orders of the two terms are less than 1 and more than 1, respectively. Meanwhile, by utilizing power integral terms in the controller, the problem arising from the growth rates of uncertain nonlinear functions can also be solved. Based on appropriate Lyapunov function and backstepping technology, the parameters of the controller are finally determined, and the developed controller ensures the stabilization of system within a fixed time. Stability analysis and simulation results are respectively given to verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper addresses a fault detection strategy in finite frequency domain for networked system with communication constraints and packet loss. The considered communication constraint is that only one data packet can gain into the networks at each time-slot, and the fault detection filters complete the task with only partially available measurements. With consideration of the data packet loss and the stochastic scheduling protocol, a nonhomogeneous Markov jump system is firstly derived to describe the networked systems. For this class of systems, the generalized Kalman-Yakubovic-Popov lemma-based finite frequency fault detection filter design methods are invalid. To tackle this problem, a new mode-dependent lemma is developed to capture the system performance in finite frequency domain. Further, a set of fault detection filters are designed corresponding to the accessed nodes accordingly. Finally, an example is given to show the effectiveness of the proposed fault detection approach. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of adaptive fault-tolerant control for a class of linear systems with time-varying actuator faults. The outage and loss-of-effectiveness fault cases are covered. An active fault compensation control law was designed in two steps. Firstly, the time-varying fault parameters were estimated based on a novel adaptive observer. Compared with the traditional adaptive observer, the actuator fault estimations are faster and the high-frequency oscillations can be attenuated effectively. Such oscillations are usually caused by increasing the gains of adaptive laws to deal with abrupt changes in system dynamics. Then, based on online estimations of the fault parameters, an adaptive fault-tolerant controller was constructed to compensate for the loss of actuator effectiveness and to eliminate the effect of fault estimation error. The asymptotic stability and an adaptive H∞ performance of a closed-loop system can be guaranteed, even in the case of actuator faults and disturbances. Simulation results are given to verify the effectiveness and superiority of the proposed method. [ABSTRACT FROM AUTHOR]