A networked control system (NCS), which integrates various physical components by utilising communication networks, is a complex intelligent control system with high flexibility and reliability. It has been widely applied in various areas, such as power grids, intelligent transportation, and smart manufacturing. However, compared with traditional control systems, NCSs expose more extra vulnerabilities with the openness of communication networks, leading to long-term concerns for the security of NCSs against cyber attacks. This paper gives a survey in detail on recent developments on the security of NCSs subject to deception attacks from the two domains of information technology (IT) and system control, respectively. First, several security incidents reported in recent years are reviewed and a couple of prevailing cyber attacks are analysed. Besides, the results on IT security with respect to the protection-detection-reaction model are summarised. Then, from the domain of system control, the security issues on attack design, attack detection, secure state estimation and resilient control are surveyed in depth. Furthermore, several novel security topics from the combination of IT and system control are also discussed. Finally, several future research directions are presented on this topic.

This brief concerns the problem of false data injection (FDI) attacks against partial sensor measurements of a networked stochastic system. For a Kalman filter based output tracking control system with a residual-based anomaly detector, a partial FDI attack strategy is presented to deteriorate the system performance by injecting false signals into the feedback communication channel to tamper partial sensor measurements. The stealthiness condition of the attack as well as its impact on the closed-loop system is derived, which are quite different from those of the FDI attack against all sensor measurements given in the existing work. This may be helpful for guaranteeing the secure control of a networked system by protecting partial critical sensor measurements from FDI attacks. Two numerical examples are included to verify the theoretical results.

This paper addresses the cooperative output tracking control problem for a linear heterogeneous networked multi-agent system with random network-induced delays and packet dropouts in the feedback channel of each agent, which consists of one leader agent and multiple following agents. To compensate for adverse effects of those random communication constraints, an incremental networked predictive control scheme based on state observers is proposed. A necessary and sufficient condition is derived for the stability of the resulting closed-loop system, which is independent of random communication constraints. Experimental results on a networked multi-motor control test rig show the effectiveness and applicability of the proposed scheme, including a feature that zero steady-state output tracking errors can be achieved even for the case with plant-model mismatch.

This brief is concerned with the time-varying formation problem for second-order networked multi-agent systems, which are subject to random communication delays and packet dropouts in the sensor-to-controller and controller-to-actuator channels of each agent. A cloud-based time-varying formation predictive control method with control input quantization is proposed to actively compensate for those random communication constraints. A definition of quantized time-varying formation is given, and then a necessary and sufficient condition to achieve the quantized time-varying formation as well as the stability of the resulting closed-loop system is obtained, which is independent of random communication constraints and quantization errors. Simulation results are provided to verify the effectiveness of the proposed method.