Research On Secure Control For Industrial Control System Subject To Actuator Attacks

As the core of national critical infrastructures,Industrial Control Systems(ICSs)form the basis of future smart services.However,ICSs are suffering from cyber-attacks due to their increasing connections to the Internet.At the same time,cyber-attack will permeate into the physical world and cause significant physical damage because of the close interaction between physical process and cyber network.Therefore,protecting the physical process security is an important and indispensable component of cyber security protection of ICSs.As the core of physical process security protection,secure control has been highly valued by researchers.Based on the secure control requirements of ICSs for actuator attack,the research is carried out from the two aspects of known physical system model and unknown physical system model after conducting a systematic study of existed method.For linear physical system with known model,an unbiased state estimator is proposed to obtain the unbiased estimation of the system state.On this basis,to ensure bounded stability and better control performance of the system when actuator attacks are in presence,a one-step delay attack estimation is introduced to design an attack-resilient sliding mode controller.At the same time,the control compensation signal is designed by predictive control theory,which makes the final control algorithm fulfills the input and state constraints.For nonlinear physical system with unknown model,a knowledge and data driven process behavior model is first trained offline.On this basis,a strong robust output feedback control algorithm is constructed by combining sliding mode control and predictive control.By using feedback correction and adaptive control as optimization methods,the process behavior model and control algorithm are updated online with real-time data,so as to improve the performance of the control algorithm.In the thesis,the validity of the proposed secure control framework is verified from theoretical derivation and numerical simulation experiments.The result shows that the proposed secure control framework can effectively deal with the problem of ICSs secure control when actuator attacks are in presence,and can solve the deficiency of the existing methods.