Research On Robust Control And Filtering For Nonlinear Networked Control Systems With Quantizations

With the rapid development of computer technology and communication technology,the network is becoming widely used around the world and has penetrated into all fields of daily life.Networked control systems(NCSs)refer to the closed-loop feedback control system composed of real-time network.Compared with the traditional point-topoint control,the networked control system has the advantages of high flexibility,resource sharing and remote operation.However,the network is not a reliable communication medium.Due to the physical limitation of network bandwidth,signal quantization is an inevitable problem in the transmission process.Therefore,based on the existing results,this paper studies the control and filtering of nonlinear networked control systems under the influence of quantization.The main work of this paper is as follows:Firstly,the problem of robust peak-to-peak control for a class of discrete-time nonlinear networked control systems with static quantization is studied.Takagi-Sugeno(T-S)fuzzy model is used to approximate the nonlinear networked control system and the disturbance in the system is considered.The control input is quantized using a static quantizer.Through the fuzzy basis-dependent Lyapunov function,the sufficient conditions for the asymptotic stability of the quantized closed-loop control system with peak-to-peak performance index are given.Then the step-by-step method is used to remove the uncertainty and decouple.Finally,the linear matrix inequality(LMI)form of the robust peak-to-peak controller with quantization is obtained.Next,this paper investigates the problem of nonfragile peak-to-peak filtering for a class of discrete-time nonlinear networked control systems with dynamic quantizations.The Takagi-Sugeno fuzzy model is applied to approximate the considered discrete-time nonlinear networked control systems.The perturbations have also been considered in the peak-to-peak filter to be designed.Unlike most work about the peak-to-peak filtering for dynamic systems with quantization,both the performance output signal and measurement output signal are quantized by two different dynamic quantizers in our work.The main attention is paid to designing the nonfragile peak-to-peak filter which guarantees the filtering error system to be asymptotically stable and possess a peak-to-peak performance index.By employing the fuzzy basis-dependent Lyapunov function approach and the S-procedure,new sufficient conditions about designing the nonfragile peak-to-peak filter has been established,which are expressed in the form of linear matrix inequalities.In the end,a numerical example is offered to verify the effectiveness of the designed nonfragile peak-to-peak filter.Finally,this paper summarizes the research on robust control and filtering of nonlinear networked control systems with quantization,and puts forward the prospect of the next research direction.