Stability Analysis And Controller Design For A Class Of Networked Control System Based On Input Delay Approach

Networked control systems(NCSs)have been increasing research interests due to their advantages in low cost,high reliability and wide applications in the field of industrial control.The introduction of network bus architectures will inevitably lead to network-induced delay and data-packet dropout,which will have an impact on the stability of networked control systems.In the actual networked control systems,due to intermal structural changes and environmental influences,there exist uncertainties in the system,which will have an impact on the stability of the system.At the same time,in the process of signal transmission,due to the limitation of bandwidth with large transmitted signal data,these factors often cause adverse effects such as long transmission time and data loss.The quantization of the transmission signal is a feasible method for solving this problem,but adding quantizer to the control systems will affect the stability of the systems.This paper studies the system with quantizer.At present,many research results on networked control systems have been achieved,but further research is still needed in many aspects.In this paper,the input delay approach is used to process the networked control system,and networked control system is transformed into a continuous system with input time delay,and then the stability analysis and controller design are carried out.The research of this paper can divide into the following several parts:(1)Based on the Lyapunov stability theory,the stability analysis of the networked control systems is carried out.By the input delay approach,the networked control system is transformed into a continuous system with an input delay,then a Lyapunov-Krasovskii functional is constructed,and then the functional is taken the derivative,using Wirtinger inequality to deal with single integral terms generated in the derivation process.Sufficient conditions for asymptotic stability of the systems are obtained and the validity of the stability criterion is verified.(2)Robust H? stability analysis of networked control systems with parameter uncertainties is carried out.On the basis of the stability analysis in the previous chapter,the stability of networked control systems with parameter uncertainties is analyzed,and the conditions for robust H.stability criteria of the system are given.Through literature comparison,the system has the stronger anti-interference capability.(3)Robust H? controllers are designed for networked control systems with parameter uncertainties.Based on the robust H? stability analysis of networked control systems with parameter uncertainties in the previous chapter,the robust Hx controller is designed,and the design method of the system controller is given in the form of linear matrix inequalities.Finally,the feasibility of the proposed controller is verified.(4)Stability analysis and controller design of networked control systems with quantizer are carried out.The systems with logarithmic quantizer and dynamic quantizer are analyzed,respectively.In order to facilitate the comparison,we select the same L-K functional as the previous chapters.Using Wirtinger inequality and free weight matrix to deal with the results of functional derivation,and the stability eriteria in the form of linear matrix inequality are obtained.The numerical examples show that the results obtained in this paper are less conservative.On the basis of stability criteria,the controller design of networked control systems with logarithmic quantizer and dynamic quantizer is solved,and the effectiveness of the controller is verified by Simulink simulation.