The Research On The Stability Of Networked Control System With Random Long Time Delay And Uncertain Parameters

Networked control systems,namely control systems,are also known as distributed control systems,integrating the technology of sensor,network,computer,electronic and networked communication in one.Compared with the traditional control systems based on point-to-point model,NCSs have a series of advantages,including of the convenient in installation and maintenance,the high degree of information integration,less wire layout for system,the high flexibility and reliability and so on.Even through the added network brings substantial facilitation for control systems,it also leads to many new problems in need of a solution,such as time delay,packet loss and packet disorder,which significantly affect the quality of service and even the stability of system.Therefore,the controller design and stability analysis on NCSs with long time delay,packet dropouts and uncertain parameters are studied in the paper.The specific work is as follows:To illustrate the purpose and significance of the research,the concept of NCSs is described in detail,and the present situation in domestic and foreign research and the development of NCSs are summarized in the paper.Besides,the matrix inequality,robust control,guaranteed cost control,asynchronous dynamic systems and the corresponding definitions and lemmas,involved in this paper,are also presented.According to the anti-interference ability of the system,the NCSs are divided into general continuous systems and control systems with uncertain parameters.In view of the fact that the former requires high control performance,based on Lyapunov function and robust theory,the design of guaranteed cost control and the relative performance indexes are gave,which can ensure system quickly stable with different delay.As for the latter,considering with the ideal system without packet loss,a robust controller with good control performance for system parameters chattering is designed.Then,the system is modeled as asynchronous dynamical system by using the switched network to simulate the packet loss of the system,and the sufficient conditions for the stability of the system are obtained,where the characteristics of long time delay,packet loss and jitter are both considered.Finally,the correctness and validity of the proposed method is verified through several numerical simulations.For the complex multiple input systems,based on the idea of multiple input single output method,the systems are modeled and analyzed as a whole,instead of analyzing each subsystem,which simplifies the analysis process.Then,a method of the corresponding controller design and stability analysis is provided via a series of matrix inequalities.In the end,an application of simulation experiment of wheeled mobile robot shows the feasibility of this approach.The paper summarizes the work and points out the shortcomings and the need for improvement in the future study.