Research On Stability Of Time-delay Models For Networked Control Systems

With the improvement of science and technology and the development of technology integration,networked control system has gradually entered the field of vision of people in recent years,and more and more people pay attention to.Because of its advantages of resource sharing,simple system,easy construction and strong flexibility,it is widely used in various fields such as the Internet,communication field,transportation field,intelligent manufacturing field,aerospace and even military.However,in the actual control,the stability of the system is often affected and the working efficiency of the system is adversely affected because of the different situations faced by each node of the networked system and the communication delay between different nodes.Because of the wide application of networked control system and its high research value,many researchers at home and abroad have been attracted to study it,and further exploration has been made in the direction of the research on the consistency of networked control system.In this thesis,the consistency problem of networked control systems with nonlinear terms under sampled data control is studied by using the method of Lyapunov-Klosov theorem.An aperiodic sampling controller is used to reconstruct the sampled data system by using the input time-delay method,and the original system is transformed into a continuous system with time-varying delay controlling the input.Then,a new time-varying Lyapunov functional is constructed by using matrix analysis,algebraic graph theory and vector generalization of Wirtinger's inequality.This function can simplify the mathematical calculation and optimize the stability conditions.According to the proposed conditions,the results of the upper bound of the sampling interval can be further obtained.The results show the effectiveness of the design method and the advantages of the method compared with the existing research conclusions.Then,the sampling controller is selected,and the MATLAB simulation tool is used to simulate it by using the NENMF optimization method,and the feasibility of the method is verified.The main parts of this thesis are summarized as follows:1.Introduced the research background of networked control system,the significance of its research,and the research status at home and abroad.Discussed the characteristics of the system,and led to the research topic of this thesis.At the same time,the mathematical tools used in the thesis and the existing achievements and research methods related to control are described.2.Aiming at the problems of networked control system such as time delay and actuator saturation,by using control theories such as Lyapunov-Krosovsky theorem and mathematical methods such as linear matrix inequality,this thesis obtains sufficient conditions for the state of each node in the system to achieve uniform stability under such conditions.Then a sampling controller is designed,and it is proved that the networked control system can reach the synchronous state under appropriate initial conditions.At the end of the theory part,the superposition algorithm is introduced,and the maximum sampling upper bound of the sampling controller is estimated by using the superposition algorithm.Then,the simulation of an example is carried out by using MATLAB programming software to further verify the feasibility of the proposed conclusion.3.This thesis gives an example and proves that the control strategy has practical value and broad application prospect.At last,this thesis of control summarizes the content of the research,with the development prospect and future research direction of this field are prospected.