Research On Sliding Mode Security Control Of Cyber-physical Systems Under False Data Injection Attack

With the continuous advancement of the intellectualization of physical networks,advanced sensing,computing,and control technologies have been deeply applied in cyber-physical system.At the same time,the amount of data in physical networks has increased dramatically,and the scale of cyber-physical system is gradually tending to modernization,industrialization,and networking.However,due to the vulnerability brought about by high integration and accelerated integration,the network infrastructure of information systems has become a potential target of network attacks.As a network attack that destroys the integrity of information,false data injection attacks have strong accessibility,concealment,and interference,and pose a high degree of threat to cyber-physical system.They have become the focus of network security research.Attackers tamper with the original data by injecting false data into the network layer,interfering with normal state estimation,causing the control center to misjudge the system state and make incorrect decisions,resulting in failures or even paralysis of the entire cyber-physical system.Therefore,it is of great practical significance to study new and effective security control strategies for cyber-physical system under false data injection attacks.Based on the above background,aiming at the security problem of the serious threat to the actuator data caused by the false data injection attack,the observer-based sliding mode control algorithm and the sliding mode control algorithm based on the optimal L₂-gain performance are thought in the thesis respectively,and reliable theoretical support is provided for the defense of the deep fusion cyber-physical system against the false data injection attack.The main research contents of this thesis are as follows:（1）An adaptive integral sliding mode control method based on extended observer is studied for the cyber-physical system with mismatched quantization parameters under false data injection attack.Firstly,the false data injection attack is regarded as a special kind of external disturbance,and the system is dynamically linearized by combining the quantization mismatch,nonlinear term and external disturbance,and an extended state observer is constructed and the convergence analysis of the observation error is carried out.Secondly,the sliding surface is designed so that the system state trajectory can be asymptotically stable after entering the sliding mode.Then,the exponential reaching law is introduced and an adaptive integral sliding mode controller is proposed to ensure the accessibility of the sliding surface.Finally,a simulation example verifies the effectiveness of the control algorithm.（2）Based on the research on the securing control of a single cyber-physical system in（1）,research is conducted on large-scale cyber-physical system.Firstly,the system is dynamically linearized,an extended state observer is constructed,and the convergence conditions of the observation errors are analyzed.Secondly,an integral sliding surface is designed,and the asymptotic stability criterion of the sliding mode system is given in the form of linear matrix inequalities,and the sliding mode vector satisfying the L₂-gain performance of the system is obtained.Then,based on the exponential reaching law,an adaptive integral sliding mode controller is proposed to eliminate quantization errors and generalized disturbances,and enable the system to reach the sliding surface.Finally,a simulation example verifies the effectiveness of the control algorithm.（3）Continuing with the research object in（2）,the adaptive integral sliding mode control problem based on optimal L₂-gain performance is studied.Firstly,the large-scale system under false data injection attacks is modeled.Secondly,a sliding mode surface is designed so that the system state trajectory can achieve asymptotic stability after entering the sliding mode.Sufficient conditions for achieving optimal L₂-gain performance of the system are given using Lyapunov theory and linear matrix inequality techniques.Then,an adaptive integral reaching sliding mode control law is proposed to ensure the reachability of the sliding mode surface.Finally,simulation verifies the effectiveness of the algorithm.