Research On Event-driven Control And Synchronization For Networked Control Systems With Saturation Constraint

Networked control systems(NCSs)have been widely applied in industrial process control,aerospace,traffic control,smart home and other fields,since they have many advantages such as simple installa-tion,low cost,convenient maintenance,remote operation control and so on.With the complexity of networked control plants and the requirements of control performance improvement,the research of networked control theory and technology has important theoretical significance and application value.Due to the limited network bandwidth,it has become a hot topic that how to reduce the unnecessary signal in the process of control,meanwhile,the performance of the system should be ensured.In addi-tion,the practical physical sensors and actuators cannot provide unlimited amplitude signals in actual control systems.In other words,the saturation is a common nonlinear phenomenon.Saturation may degrade the performance of the control system dramatically and may even result in instability.There-fore,it is of great practical significance to study the control theory,and it is more instructive to use some techniques to counteract the negative effects of saturationIn this dissertation,two types of event-driven problems of network control systems under satu-ration constraints are studied–H_?control problems and synchronous control problems.By using Lyapunov-Krasovskii function method,stochastic analysis theory and linear matrix inequality tech-nique,sufficient conditions of stability have been given,subsequently,controller of the system is de-signed on the basis of the conditions.1)The H_? control problem of the event-based NCSs is studied,which is under the constraint of sensor saturation and actuators stochastic nonlinear.Firstly,a new event-triggered mechanism is introduced–which is an event-triggered mechanism combined with sensor saturation.Secondly,un-der this scheme and actuators stochastic nonlinear,a closed-loop system is modeled as a event-based control system with nonlinear items.Then,based on Lyapunov-Krasovskii function method and the s-tochastic analysis technology,H_?sufficient conditions have gained in the form of LMIs.The controller and the corresponding event-triggered weighted matrix are co-designed on the basis of the stability con-dition.2)The problem of event-triggered dynamic output-feedback H_?control is concerned for net-worked control system with sensor and actuator saturations.The event-triggered scheme combined with sensor saturation is utilized to judge whether the newly sampled signal should be transmitted to the dynamic output-feedback controller or not.Under this scheme,the concurrent closed-loop system is first modeled as a control system with an interval time-varying delay and nonlinear items.Through constructing the Lyapunov-Krasovskii functional and employing linear matrix inequality approach,suf-ficient conditions for H_?asymptotical stability are derived for the networked control system;further-more,under the above stability condition,a dynamic output-feedback controller and the corresponding event-triggered parameters are co-designed through linear matrix inequality approach.3)The problem of event-driven synchronization control is studied for chaotic neural networks with actuator saturation and quantization.Firstly,in order to save bandwidth resources,an event-triggered mechanism is established between the sensor and the quantizer to determine whether the latest sampling signal should be sent to the quantizer.Secondly,A new synchronous error system model is established,which describes the actuator saturation,quantization and event triggering mechanism in a unified framework.Thirdly,by means of Lyapunov function method,sufficient conditions of asymptotic stability are obtained for synchronous error systems in the form of linear matrix inequality,and the expression of the gain matrix is given for the state feedback controller.4)The problem of event-driven resilient synchronization control is researched for chaotic Lur'e system subject to randomly occurred deception attacks and sensor saturation.Firstly,in order to reduce the frequency of signal transmission,an event-triggered mechanism is established between the sensor and the controller.Secondly,the stochastic network attacks are described by nonlinear functions and stochastic variables obeying Bernoulli distribution,and a new synchronization error system model is established,and the joint description of sensor saturation,random spoofing attack and event-triggering mechanism is realized.Thirdly,By using Lyapunov function method and stochastic analysis theory,the asymptotic stability criterion is given for synchronous error system,and a joint design method of controller gain matrix and event trigger matrix is presented.