Research On Active Fault Tolerant/Intrusion Tolerant Cooperative Control Of Discrete NCS Under DETCS

Network Control System(NCS)is a complex network feedback control system that integrates information space and physical system.In the event of a physical failure or a network attack,ensuring the security of the network system is worthy of the scholars' investment in exploration and research,including theoretical basis and practical applications.So far,judging from the articles about NCS published by researchers,it has been explored mainly from the direction of establishing the mathematical model of the system,the safety estimation of the state,and the safety control.Although great progress has been made in the research of fault tolerance or intrusion tolerance alone,there are not many references for the design method of fault-tolerant and intrusion-tolerant coordinated control.However,the possibility of both faults and attacks in actual NCS is particularly high.Therefore,The design of fault-tolerant/intrusion-tolerant cooperative controller makes discrete NCS have high safety and reliability research and has great development prospects and practical application value.In view of this,thesis aims at discrete NCS under network attacks.In order to avoid the waste of network resources,the trigger communication mechanism is introduced to study the controller design problems when actuators and sensors fail,so as to achieve the goal of balancing the control quality of the system and the communication service quality.The general outline is as follows:1)For discrete NCS with both time-varying delay and external interference,based on the constraint conditions of the discrete event triggered communication mechanism(DETCS),the idea of computing(edge computing,CA)on the edge of the network close to the source of the object or data is used to construct Aiming at the system structure of NCS fault tolerance and attack intrusion tolerance,in the sensing unit that meets the uniform sampling condition and the control unit that meets the trigger condition,the online detection,estimation,and estimation of attacks and faults are completed in sequence based on the established system structure.Feedback compensation.Pave the way for the next goal of safety control.2)According to the gradual design plan of single-sided fault tolerance/attack intrusion tolerance,single-sided fault tolerance/double-sided attack tolerance and double-sided fault tolerance/attack intrusion tolerance control,analogy fault tolerance control concepts and distinguishing standards,respectively establish a closed-loop discrete NCS model that integrates actuator faults and same-side cyber attacks,sensor faults and same-side cyber attacks,and DETCS,and draws on the idea of state augmentation,and uses an improved adaptive Kalman filter estimator to evaluate the system state,Actuator or sensor faults and network attack information are tracked and estimated at the same time,laying a solid foundation for the design of fault-tolerant/intrusion-tolerant cooperative controllers.3)Design issues for three types of cooperative controllers:single-sided active fault tolerance/intrusion tolerance,single-sided active fault tolerance/double-sided active intrusion tolerance,and dual-sided active fault tolerance/intrusion tolerance,according to the different characteristics of network attacks and physical faults.In the thesis,the state feedback control strategy based on the sliding mode variable structure control idea and the dynamic output feedback control strategy based on the improved adaptive Kalman filter estimator are used respectively to prove that the discrete NCS can produce physics under the limited energy disturbance of the system.Sufficient conditions for stable operation during failures and network attacks,and the design method of fault-tolerant/intrusion-tolerant cooperative controllers.