Research On Some Issues Of Event Triggered Networked Control Systems

Networked control systems have been widely used in remote control opera-tion,aerospace industries,industrial control systems and the medical system due to the advantages of easy maintenance,low cost,high reliability,share of infor-mation resources and so on.Research on networked control systems has broad application prospect and great values both on theory and practice.Because of the restrictions of the network bandwidth,network-induced delay,data packet dropout and disorder,network congestion and stochastic disturbances are in-evitable phenomenons in the process of network transmission,leading to system performance degradation and instability.How to utilize the bandwidth effective-ly,save network resources and avoid network congestion have been a research focus of scholars at home and abroad.This thesis is aimed to deal with some issues of event-triggered networked control systems.The problems of stability analysis and state estimation for linear/nonlinear time-delay systems are discussed.By utilizing the Lyapunov-Krasovskii functionals,linear matrix inequality(LMI)approach and stochastic analysis techniques,several sufficient criteria and state estimator design methods are derived.More specifically the frame and innovation of this thesis are given as follows:1.Reliable control for hybrid-driven T-S fuzzy systems with actu-ator faults and probabilistic nonlinear perturbations.The reliable con-troller design is concerned with hybrid-driven nonlinear systems via T-S fuzzy model with probabilistic actuator faults and probabilistic nonlinear perturbation-s.To reduce unnecessary transmissions in the network,a hybrid-driven scheme is proposed,in which the communication transmission scheme can be selected between time-driven scheme and event-driven scheme.The switch law of the communication scheme is modeled as Bernoulli distributed stochastic variable.Considering the network-induced delay,nonlinear disturbances and the proba-bilistic actuator faults,a new model is constructed under the proposed hybrid-driven scheme.By using Lyapunov-Krasovskii functionals and stochastic analysis techniques,sufficient conditions are established which ensure the asymptotical stability of the augmented system under hybrid-driven scheme.Furthermore,a unified co-design algorithms for the desired controller and the hybrid-driven scheme are developed.Finally,a typical simulation example is used to demon-strate the validity of obtained results.2.Event-based finite-time state estimation for Markovian jump systems with quantizations and randomly occurring nonlinear pertur-bations.Finite-time state estimation is discussed for Markovian jump systems with quantizations and randomly occurring nonlinear perturbations under event-triggered scheme.The event-triggered scheme and the quantization effects are used to reduce the data transmission and ease the network bandwidth burden.The randomly occurring nonlinear perturbations are taken into account,which are governed by a Bernoulli distributed stochastic sequence.Based on stochastic analysis and linear matrix inequality techniques,sufficient conditions of stochas-tic finite-time boundedness and stochastic H? finite-time boundedness are firstly derived for the existence of the desired estimator.Then,the explicit expression of the gain of the desired estimator are developed in terms of a set of linear ma-trix inequalities.Finally,a numerical example is employed to demonstrate the usefulness of the theoretical results.3.Two channel event-triggering communication schemes for net-worked control systems.Event-triggered controller is designed for networked control systems with limited network bandwidth.At first,novel model-based event-triggered transmission strategies for both the sensor-to-controller and the controller-to-actuator channels are proposed,which are capable to reduce the communication bandwidth utilization,while preserving the desired control per-formance.Secondly,considering the effect of the network transmission delay,a newly time-delay system model for the analysis is firstly constructed.Thirdly,based on our newly proposed model,criteria for stability and co-designing both of the feedback gain and the trigger parameters are derived.Finally,a numerical example is given to demonstrate the usefulness of the proposed method.4.Event-triggered output feedback H? control for networked Markovian jump systems with quantizations.H? output feedback control is investigated for event-triggered Markovian jump systems with measured out-put quantizations.An event-triggered mechanism and a quantization scheme are designed to reduce the occupancy of the limited network resources.The mea-sured output is directly transmitted to the event generator,whether the released signal can be sent out to the controller through the quantizer depends on the trig-gering condition.A new Markovian jump time-delay system model with external disturbances is then presented and sufficient conditions are derived to guarantee the stability of the resulting closed-loop system and prescribed performance.Cri-teria for co-designing both the output feedback gain and the trigger parameters are established.Finally,a numerical example confirms the effectiveness of the proposed method.