Research On Resilient Control With Event Trigger Mechanism Against ICPS Cyber Attack

Industrial Cyber Physical System(ICPS)is the integration of physical process,computing,efficient communication and effective control.ICPS is widely used in industrial infrastructure due to advances in computing,communication and related hardware technologies.The openness and vulnerability of wireless network make ICPS vulnerable to cyber attack,causing significant degradation or even collapse of the operational performance of industrial infrastructure.ICPS has limited communication storage in industrial environment,then,the problem of limited communication resource when defending against cyber attack need to be considered.Therefore,this paper studies resilient defense strategies to defend cyber attack with event trigger mechanism to ensure the stability of ICPS under attack and minimize communication resource.The main contents are as follows:(1)In ICPS with interference and noise,the attack compensation resilient strategy when the sensor-to-controller(S-C)channel suffers from data injection attack with the event trigger mechanism is studied.To reduce communication resource and adapt to the changes of the system under interference and attack,the adaptive event trigger mechanism with real-time optimization of the threshold value is introduced,and a closed-loop feedback ICPS model including the H∞ observer and estimator is established with the event trigger mechanism.In order to mitigate the impact of data injection attack,the attack estimator module is designed to compensate for the attack,and the estimator gain matrix is solved by the asymptotic stability criterion.Lyapunov-Krasovskii(L-K)functional is constructed to derive the quantitative relationship among event trigger,data injection attack,network delay,and resilient controller to ensure system stability and H∞ performance.(2)In ICPS with interference,noise and two-channel network delay,the state reconstruction resilient strategy for sensor-to-controller(S-C)channel and controller-toactuator(C-A)channel subject to asynchronous data injection attack with event trigger mechanism is studied.The dual-channel adaptive event trigger mechanism is introduced,the network delay of dual-channel is considered,also,the dual-channel asynchronous event trigger timing model is established;the attack reconstructor reconstructs the state and the attack signal under data injection attack simultaneously,which tracks the system information in real time,and gives correction signals to the controller;the constructed L-K functional considers the system changes caused by the attack,network delay,and the real-time change of the trigger threshold,analyzes the stability and H∞ performance of the system,and derives sufficient conditions for the jointly designed correction-based resilient controller and event trigger threshold.(3)In ICPS with interference,noise and network delay,the resilient strategy for distributed hybrid attack on S-C channel and C-A channel with distributed event trigger mechanism is studied.To improve control accuracy,reduce communication resource and network bandwidth,pairwise quantifiers are introduced at the sensor side and controller side.the distributed hybrid attack model is established,the system information is tracked in real time by an observer.Then,an observer-based controller is designed to construct a quantized ICPS closed-loop system model subjected to distributed hybrid attack with distributed event trigger.Finally,the stability and l∞ performance of the system is analyzed by constructing L-K functional considering the real-time network delay at both ends.To verify the effectiveness of the resilience strategy for the object subject to the data injection attack or hybrid attack under the event trigger mechanism given in this paper,MATLAB simulation is used to control the mass block displacement with a two-degree-offreedom mass-spring-damped tandem system as the controlled object.The experimental results show that the event triggered resilience strategy designed in this paper is effective in defending single-channel or dual-channel data injection attack and distributed hybrid attack,and can further reduce communication resource.