| Network Control Systems(NCSs)have received the attention of the majority of scholars,owing to the significance in theory and application.However,NCSs is a complex large system,in practice,a few of plants and processes are highly nonlinear.If we take the usual linear control methods,the performance can not be satisfied for the actual systems.At the same time,because the network induced factors will inevitably bring the time delay,the data packet dropout and other problems,the serious impact of the system even to be unavailable.Dissipative theory is important in the research of nonlinear systems,and the passive and QSR-dissipation are an important special case of dissipation.Taking the passive control methods will make it more easy,which is analyzes the system from the perspective of energy and does not need to explicitly request system specific state,and under certain conditions,the problem of stability of the system can be summed up in the system of passivity problem.However,it does not enough only to know the passivity of the system.The thesis proposed to define passivity in the L2 signal space and use two passivity indexs v an ρ quantitatively to describe the "deficiency" or "excess" of the passivity of the system to provide more information about the system.This make it convenient to the analysis and design controller for actual systems.With the development of computer network technology,using the traditional timetriggered control will waste communication source,so we can consider the event-triggered control.Besides,the study of the Network control systems deserves investigation for great theoretical development as well as for practical applications.Therefore,in this thesis,the study of NCSs with a class of special nonlinear non-passive controllers and time-delay problem in network links in s discussed,which involves the design of variable time-delay,passive index,event-generator,QSR-dissipation,L2 stability,compensator,and local controller.The main contents of this thesis are as follows:Firstly,for a class of non-passive controllers in nonlinear control systems,a compensator is designed based on the passive index of the system to make the controller system passive.Meanwhile,the passive controller can keep the non-passive controlled objects passive and obtain the expected passive index.At the same time,the passive controller can passivate the controlled plant system with non-passive phase.Besides,from the perspective of resource utilization,the event-trigger device was added to jointly design the event generator and the compensator based on the event trigger mechanism,and sufficient conditions for the QSRdissipation and L2 stability of the closed-loop system were obtained.In addition,we also give the proof that the lower bound of time interval in which two consecutive triggers occur is strictly positive,which avoids the Zeno phenomenon and has theoretical and practical significance.The simulation results verify the feasibility and effectiveness of the theoretical results.Secondly,for the time-varying delay problem of two-channel NCSs link,a local controller is designed under the premise that the rate of change of delay is bounded,and sufficient conditions for the system dissipation and finite gain stability are obtained-Then,based on the passive index,the joint design of the event generator and the local controller of the time-delay NCSs is carried out to obtain sufficient conditions for the QSR-dissipation and stability of the time-delay NCSs under the event triggering mechanism.Then,the joint design of the event generator and the local control of the network control system based on the event trigger mechanism is carried out to obtain sufficient conditions for the QSR-dissipation and stability of the network control system under the event trigger mechanism.In addition,the estimation of the passive index(ε,δ)of two-channel NCSs is discussed,and the quantitative relationship between the event trigger threshold and the passive index is analyzed.Finally,the simulation results verify the feasibility and validity of the theoretical results.Simulation results verify the feasibility and validity of the theoretical results.Lastly,the conclusions and perspectives are presented at the end of the thesis. |
