Singular Networked Systems Research Articles

Adaptive Neural Security Control for Networked Singular Systems Under Deception Attacks

This paper studies the issue of the adaptive neural security controller design for uncertain networked singular systems in the presence of deception attacks. Considering that the attack signal is unknown, the neural networks technique is exploited to approximate the attack signal, which eliminates the assumption that the attack signal has a known upper bound. By combining the state feedback with the estimated information of the attack, the impact of the attack is effectively compensated. Furthermore, a novel Lyapunov function, including the decomposed state vector and the weight matrix estimation error, is established to evaluate the bounded area of the system state. Finally, a numerical example substantiates the validity of the theoretical results.

Periodic event‐triggered and self‐triggered control of singular system under stochastic cyber‐attacks

The periodic event-triggered control (PETC) and self-triggered control (STC) for networked singular systems under denial-of-service (DoS) attack and deception attack are studied. Due to the fact that DoS attack is able to prevent the control input from transmitting and deception attack falsifies the control input as a non-linear disturbance, a closed-loop system is constructed with different control inputs based on the switched system method. Next, the attention is focused on the design of PETC and STC schemes. PETC scheme adopts the input delay approach to transform the closed-loop system into a switched singular time-delay system and adjusts the triggering intervals by the frequency and duration of cyber-attacks. STC scheme relies on a reduced-order system derived from the original singular system and utilises the current sampled information to predict the next triggering instant. Then, exponential stability criteria are derived by codesigning the triggering parameter and controller gain. Finally, a small-signal version of the structure-preserving power network model is given to demonstrate the effectiveness of the proposed methods.

Event-triggered Extended Dissipative Control for Networked Singular Systems

In this paper, an event-triggered extended dissipative control problem for networked singular systems is investigated, where the extended dissipativity analysis unifies the H∞ performance, L2 − L∞ performance, passivity, (Q, S, R)-dissipativity in one framework. Under the event-triggered scheme, the closed-loop system is modeled as a time-delay system. Some sufficient conditions for extended dissipativity are developed and presented in terms of linear matrix inequalities (LMIs). Then the design of the state feedback controller becomes a matter of solving a set of LMIs. Finally, a numerical example is provided to illustrate the effectiveness of the proposed method.

Controllability and observability of networked singular systems

The controllability and observability of networked systems are studied, where the network topology is directed and the nodes are time-invariant singular linear systems. Under the regularity assumption, a specific condition for the R-controllability of the network with single-input single-output node-systems is first established. Furthermore, necessary and sufficient conditions are derived for the R-controllability and C-controllability of the network with multi-input multi-output node systems. It is shown that the controllability of the overall system is an integrated result of the network topology, the subsystem dynamics, the external inputs, and the inner interactions. Additionally, corresponding observability criteria for such systems are also obtained, which indicate that the observability of the whole system depends only on the parameters of its subsystem. Finally, several examples are given to illustrate the proposed results.

Retracted: Event-triggered H ∞ control for networked singular systems

The following article published in IET Control Theory & Applications, Song, Weixu; Sun, Jian; Chen, Jie: ‘Event-triggered H ∞ control for networked singular systems’, IET Control Theory & Applications, 2016, DOI: 10.1049/iet-cta.2016.0861 on 6 December 2016 has been retracted by agreement between the authors, the Editor-in-Chief, James Lam, and the Institution of Engineering & Technology. The retraction has been made at the request of the authors owing to an error in the main results.

Comments on “network-based H∞ control for singular systems with event-triggered sampling scheme [Information Sciences 329 (2016) 540–551

This note addresses that the stability conditions given in Theorem 1 of [1] are incorrect, so the proposed design method for networked singular systems is impracticable.

Network-Based Event-Triggered Control for Singular Systems With Quantizations

This paper investigates the problem of event-triggered $H_{\infty}$ control for a networked singular system with both state and input subject to quantizations. First, a discrete event-triggered scheme, which activates only at each sampling instance, is presented. Next, two new sector bound conditions of quantizers are proposed to provide a more intuitive stability analysis and controller design. Then, network conditions, quantizations, and the event-triggered scheme are modeled as a time-delay system. With this model, the criteria are derived for $H_{\infty}$ performance analysis, and codesigning methods are developed for the event trigger and the quantized state feedback controller. An inverted pendulum controlled through the network is given to demonstrate the effectiveness and potential of the new design techniques.

Network-based H∞ control for singular systems with event-triggered sampling scheme

In this paper, the problem of event-triggered H∞ control is investigated for networked singular systems. To make full use of the characteristics of networked control system, a discrete event-triggered communication scheme, which only needs to supervise the system state in discrete instants, is proposed. The sampling-interval is employed to unify the networked singular system and the event-triggered condition into a new time-delay system. Based on this model, sufficient criteria are derived to guarantee the networked singular system regular, impulse-free and stable with an H∞ norm bound. The corresponding state feedback controller is designed. A practical example is given to show that the proposed event-triggered scheme is more effective and useful than some existing works.

H ∞ filtering for discrete-time singular networked systems with communication delays and data missing

In this article, the problem of H ∞ filter design is investigated for discrete-time singular networked systems with both multiple stochastic time-varying communication delays and probabilistic missing measurements. Two kinds of stochastic time-varying communication delays, namely stochastic discrete delays and stochastic distributed delays, are simultaneously considered. The purpose of the addressed filtering problem is to design a filter such that, for the admissible random measurement missing and communication delays, the filtering error dynamics is asymptotically stable in the mean square with a prescribed H ∞ performance index. In terms of linear matrix inequality (LMI) method, a sufficient condition is established that ensures the asymptotical stability in the mean square with a prescribed H ∞ performance index of the filtering error dynamics and then the filter parameters are characterised by the solution to an LMI. A numerical example is introduced to demonstrate the effectiveness of the proposed design procedures.

Impulsive Controller Design for Complex Nonlinear Singular Networked Systems with Packet Dropouts

Globally exponential stability of Complex (with coupling) Nonlinear Singular Impulsive Networked Control Systems (CNSINCS) with packet dropouts and time-delay is investigated. Firstly, the mathematic model of CNSINCS is established. Then, by employing the method of Lyapunov functional, exponential stability criteria are obtained and the impulsive controller design method is given. Finally, some simulation results are provided to demonstrate the effectiveness of the proposed method.