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In this article, the dynamic output‐feedback H∞ control problem is investigated for discrete‐time state‐delay systems subject to exogenous disturbances and actuator saturations under the round‐robin communication protocol. Using the switched system approach, the Lyapunov–Krasovskii functional and the modified sector condition, sufficient conditions are first obtained under which the closed‐loop systems can achieve some desirable performance indices such as the boundedness, the H∞ performance and the stability in the absence of disturbances. Then, the controller is explicitly characterized by means of the solvability of linear matrix inequalities. For the case without time delays, the corresponding conditions are also presented. Subsequently, the optimization problems about the performance indices are discussed. Finally, the benefit and effectiveness of the proposed results are specifically illustrated via two simulation examples. [ABSTRACT FROM AUTHOR]

This study is concerned with the event‐based security control problem for a class of discrete‐time stochastic systems with multiplicative noises subject to both randomly occurring denial‐of‐service (DoS) attacks and randomly occurring deception attacks. An event‐triggered mechanism is adopted with hope to reduce the communication burden, where the measurement signal is transmitted only when a certain triggering condition is violated. A novel attack model is proposed to reflect the randomly occurring behaviours of the DoS attacks as well as the deception attacks within a unified framework via two sets of Bernoulli distributed white sequences with known conditional probabilities. A new concept of mean‐square security domain is put forward to quantify the security degree. The authors aim to design an output feedback controller such that the closed‐loop system achieves the desired security. By using the stochastic analysis techniques, some sufficient conditions are established to guarantee the desired security requirement and the control gain is obtained by solving some linear matrix inequalities with non‐linear constraints. A simulation example is utilised to illustrate the usefulness of the proposed controller design scheme. [ABSTRACT FROM AUTHOR]