Study For Networked Control Systems With Time Delays And Packet Dropets

The analysis and synthesis of Network control systems is one of the main themes in the field of international control research in recent years.Different from the traditional computer controlled,the environmental impact of the network makes network control system has a lot of new features.The direct use of traditional control theory has been unable to design a effective control strategy.So,it is necessary to design new research ideas and research tools based on its characteristics.Both the sensor and control information transmission through the network in Network control systems.Because of information transmission in the way of time-sharing multiplexing,there inevitable exists network latency.The delay is usually time-varying, uncertain.At the same time,the unreliability of network transmission,resulting in data packets loss may occur during transmission,which make the controller and the input not be able to update,impact the performance of the system.The system will lead to serious instability.Therefore,packets loss and time-varying delay of network control system must be addressed.The study of robust control of networked control systems has important theoretical and practical value.In this paper,we mainly investigate robust stability, controller and filter design of several network-based control of uncertain time-delay system from the view of time-domain.The organization of this dissertation is as follows:In chapter two,based on some new fuzzy Lyapunov-Krasovskill functional method and LMI technique,the problem of robust H_∞state feedback control for uncertain fuzzy network control system with quantizer is considered.Considering data packet loss in network environment,a new fuzzy state feedback controller is designed such that resulting closed-loop fuzzy networked control system with time delays is robustly asymptotically stable and satisfies a prescribed H_∞performance level,which is in terms of linear matrix inequalities which can be solved numerically using Matlab Control Toobox.In chapter three,we considered the problem of stability of Delta network-based control system with status and output quantization.The aim is to design state feedback controller which guarantees H_∞performance.Through the suitable Lyapunov functionals in Delta region,we get a new stability criterion.All results are presented in terms of linear matrix inequalities(LMIs) form.Numerical examples are given to illustrate the feasibility and effectiveness of the developed technique.In chapter four.the problem of both robust H_∞filtering and networked control system with Markovian jump parameters and packets lost is considered.A wider class of parameter uncertainties than norm-bounded parameter uncertainties is described in this model.Sufficient conditions for the filter to satisfy prescribed H＿∞performance are given in terms of LMIs,which can stabilize the system and guarantee a prescribed H_∞performance on attenuation of all admissible parameter uncertainties.A numerical example is given to illustrate the feasibility and effectiveness of the developed technique.