Robust Stability Analysis For A Class Of The Network Systems With Time-Delay

As a huge closed-loop control system network system is composed of many modular small closed loop control systems and connected together through a large number of sensors,controllers and actuators.When the network is busy,networks delay,blocking and data loss would happen if data packets to the nodes can not be transmitted effectively,so a method of network control system came up,which allocate data packets to different nodes through channel data traffic to realize remote control to resolve the above problems.Based on the improved Wirting inequality and Lyapunov control theory,the problem of robust stability of a class of networked control systems is discussed in our paper,many controllers with different performance are also designed.The main research is as followings:1.Discussion on stability of a class of simple delay network systems and establishment of a closed-loop system model.According to the second method of Lyapunov stability we construct functions and guarantee the positive definite of unknown matrix,then derive the constructed function in the direction of the system,scale the system by limiting the time delay range,increasing control parameters with time delay splitting and the improved Wirting inequality to obtain the proofs for asymptotic stability of the closed-loop system.The calculation results are expressed in the form of LMI,the feasibility of the proposed method is verified by an example.2.To discuss the stability of a class of uncertain time delay network systems and design the closed-loop system state feedback stabilizer.By adding uncertainty items to the above conditions,according to the second method of Lyapunov stability,we construct the function and assure its unknown matrix positive definite.Then derive the function in direction of the system,scale the system by limiting the delay range,adding control parameters and combining with the delay splitting method,Schur lemma,integral inequality and the improved Wirting inequality,finally obtain the asymptotic stability of the system of uncertain system and design the closed-loop system state feedback stabilizer.The results are expressed in LMI,the feasibility of the proposed method is verified by an example.3.Aiming the existing problems for robust guaranteed cost controller of a class of network closed-loop systems and design a robust guaranteed cost controller.Firstly,we define a robust guaranteed cost controller;according to Lyapunov stability the second method construct the function and assure its unknown matrix positive definite.Then derive the constructed function in the direction of the system,scale the system by limiting the time delay,combining with time delay splitting,the improved Wirting inequality get the existing proof for the robust guaranteedcost controller of networked system.By using the same method to study the performance of uncertain network closed loop system,with integral inequality and Schur lemma to have the existing criterion for robust guaranteed cost controller of the uncertain time delay system and design the robust guaranteed cost controller.The results are expressed in LMI,the feasibility of the proposed method is verified by an example.4.For a class of uncertain network system external anti-disturbance controller is considered with a robust H?controller designed.Firstly,the definition of disturbance suppression inequality is given,then according to Lyapunov stability the second method,the function is constructed with its unknown matrix positive definite;the constructed function is derived in the direction of the system,by limiting the delay range,combining with the delay division method,Schur lemma,integral inequality and improved Wirting inequality to scale the system,the existence criterion of the closed-loop system robust H?controller is obtained,the closed-loop system robust H?controller is also designed.Finally the results are expressed in the form of LMI and the method is verified by an example.