Networked Control Under DoS Attacks:Tradeoffs Between Resilience and Data Rate

In this article, we study communication-constrained networked control problems for linear time-invariant systems in the presence of Denial-of-Service (DoS) attacks, namely attacks that prevent transmissions over the communication network. Our article aims at exploring the tradeoffs between system resilience and network bandwidth capacity. Given a class of DoS attacks, we characterize the bit-rate conditions that are dependent on the unstable eigenvalues of the dynamic matrix of the plant and the parameters of DoS attacks, under which exponential stability of the closed-loop system can be guaranteed. Our characterization clearly shows the tradeoffs between the communication bandwidth and resilience against DoS. An example is given to illustrate the proposed approach

Resilient Control under Denial-of-Service Attacks

Cyber-physical systems (CPSs) have attracted much attention due to the advances in automation. By integrating communication and computation technologies, CPSs have a broad spectrum of applications ranging from the control of small local systems to the control of large-scale systems, some of which are safety-critical. This raises the issue of reliability of CPSs to a considerably important level. Among a variety of aspects in reliability problems, the security of CPSs becomes a challenge from both practical and theoretical points of view. This thesis investigates the stabilization problem of networked control systems under Denial-of-Service (DoS) attacks. Intuitively, implementing predictor-based controllers can compensate for the data loss due to DoS attacks by estimating the lost signals, and hence the resilience of control systems can be improved. Following this idea, we have developed the resilient controllers by exploiting the recent results in finite-time observers. It is interesting to see that the resilience of the networked control systems depends on the prediction accuracy and horizon. Besides this, the thesis also investigates the stabilization problem of distributed systems under DoS attacks

Distributed estimation over a low-cost sensor network: a review of state-of-the-art

Proliferation of low-cost, lightweight, and power efficient sensors and advances in networked systems enable the employment of multiple sensors. Distributed estimation provides a scalable and fault-robust fusion framework with a peer-to-peer communication architecture. For this reason, there seems to be a real need for a critical review of existing and, more importantly, recent advances in the domain of distributed estimation over a low-cost sensor network. This paper presents a comprehensive review of the state-of-the-art solutions in this research area, exploring their characteristics, advantages, and challenging issues. Additionally, several open problems and future avenues of research are highlighted

Optimal scheduling and control for constrained multi-agent networked control systems

In this paper, we study optimal control and communication schedule co-design for multi-agent networked control systems, with assuming shared parallel communication channels and uncertain constrained linear time-invariant discrete-time systems. To that end, we specify the communication demand for each system using an associated robust control invariant set and reachability analysis. We use these communication demands and invariant sets to formulate tube-based model predictive control and offline/online communication schedule co-design problems. Since the scheduling part includes an infinite dimension integer problem, we propose heuristics to find suboptimal solutions that guarantee robust constraints satisfaction and recursive feasibility. The effectiveness of our approach is illustrated through numerical simulations