This paper focuses on dynamic output feedback control of Cyber-Physical Systems (CPS) under Denial-of-Service (DoS) attacks. Firstly, by analyzing the different effects of DoS attacks on the sensor-to-controller (S-C) channel and the controller-to-actuator(C-A) channel respectively, a switching system modeling method for the dynamic output feedback CPS is presented. Considering the bandwidth of the two channels is different and the energy limitation of the attacker, it is fair to assume that an attacker can only jam one communication channel at each time step and the maximum number of consecutive DoS attacks is bounded. Secondly, according to a packet-based transmission scheme, a nested switching model considering both the spatial variability and the temporal persistence of DoS attacks is constructed on the basis of the switching system. Then, the exponential stability condition of the dynamic output feedback CPS is obtained, and a controller design method based on linear matrix inequality is proposed. Finally, a simulation example is given to verify the effectiveness of the proposed method.

This paper investigates the bounded filtering problem for two-dimensional (2-D) discrete systems with encryption-decryption mechanism (EDM) and dynamic event-triggered mechanism (ETM). Firstly, considering the potential information leakage, a novel EDM is designed for 2-D systems based on the quantization-based encoding-decoding mechanism. In addition, the dynamic ETM with bidirectional evolutionary characteristics is proposed to alleviate the computational and communication burdens. In such a framework, the filtering error systems (FESs) at the eavesdropper side and the user side are obtained, respectively. Subsequently, the encryption parameters are devised such that the filtering error at the eavesdropper side diverges. Additionally, the boundedness criteria are established to ensure that the client-side FESs are bounded in terms of Lyapunov stability analysis approach. Finally, it is demonstrated that the proposed bounded filtering algorithm is valid for 2-D systems in several types of industrial environments.

This paper is concerned with the set-membership filtering problem for the two-dimensional shift-varying systems subject to the stochastic communication protocol and uniform quantization effects. To prevent the data transmission from collisions, only one sensor can transmit the measured information to the filter at each sampling shift instant, and the selected sensor is determined by the scheduling strategy of the stochastic communication protocol. On the contrary, the uniform quantization mechanism has been employed to mitigate the influence of quantization error on filtering performance. Incorporating the stochastic communication protocol and uniform quantization mechanism, this paper proposes a set-membership filter design framework for the two-dimensional shift-varying systems with unknown-but-bounded noises. Sufficient conditions are derived for the existence of desired set-membership filter by utilizing double mathematical induction, such that the estimation error resides within the ellipsoidal set. Moreover, the optimal filtering algorithm is given by minimizing the ellipsoidal constraints. Finally, several examples are provided to illustrate the effectiveness of the proposed filter design algorithm.

In this paper, we discuss the modeling and control problem for networked systems with access constraints and packet dropouts. Due to the limitation of communication capacity, only the limited number of sensors and actuators are allowed to gain access to network medium according to a stochastic access protocol, and packet dropouts may happen in both backward and forward channels, which can be described by i.i.d Bernoulli processes. Under consideration of the access constraints and packet dropouts, the networked control system can be modelled as a Markov jump system. In such a framework, to solve the controller synthesis problem, the time-varying Kalman filter is first designed. Then, by using the theory of Markovian jump systems and dynamic programming, an optimal controller is designed such that the networked system is exponentially mean-square stable while minimizing the quadratic cost. Finally, two illustrative examples are given to demonstrate the effectiveness of the proposed results.

This paper is concerned with the dynamic output feedback control issue for a class of networked control systems with medium access constraints, network-induced delays and packet dropouts. It is assumed that the medium access constraints at both sides of the controller obey the Markov distribution, the upper bound of the network-induced delays is less than one sampling period, and the packet dropouts of networked channels can be described by i.i.d Bernoulli distribution processes. Then, the networked control systems are modelled as a class of asynchronous dynamic systems. According to Lyapunov stability theory and switching system theory, the dynamic output feedback controller is designed to guarantee the exponential stability of networked systems with the given decay rate. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed method.