Research On Stability Analysis And Control Method Of Networked Control System With Time-delay

With the development and cross penetration of computer technology,network communication technology and control science,the structure of the control system is more and more complex.In order to meet the increasingly enhanced performance requirements and complex functional requirements,network control system arises at the right moment.The combination of network and control system has the advantages of low cost,low power consumption,information resources sharing,simple installation and so on.However,the introduction of network also leads to network delay,sampling period variation,actuator failure and so on.In this paper,the stability and control methods of the system under different conditions are studied.Firstly,a class of networked control systems with short delay is studied.Assuming the sensor is clock driven and single-packet transmission,the uncertainty of delay is parameterized and the corresponding model is established.The stability conditions of the system are given by constructing a reasonable Lyapunov function,and the corresponding control law is obtained by using the property of linear matrix inequality.Secondly,for a class of networked control systems with time-varying sampling period,a more general discrete system model with time-varying sampling period is constructed,and the design scheme of guaranteed performance controller is given.More free variables are introduced in the design process,and the result is less conservative by constructing inequality constraints and equivalent transformation.Through numerical simulation,it is proved that the sampling period in the system can remain stable when the permissible range changes uncertainly and meet the upper bound of the corresponding performance index.Finally,the problem of reliable guaranteed cost control for uncertain systems with time-varying delays and nonlinear perturbations under given quadratic cost function is studied.A reliable guaranteed cost state feedback control law is designed to make the closed-loop system asymptotically stable and the cost function value does not exceed the given upper bound in the case of actuator failure.By using the convexity of the objective function constraint,the design method of the optimal guaranteed performance controller which minimizes the guaranteed performance upper bound of the closed loop system is given.