Stability Analysis And Controller Design For A Class Of Networked Control Systems With Stochastic Delay

Compared with traditional control systems,the networked control systems(NCSs)have better interactivity,expansibility and convenience.However,due to the rapid increase of data and the limited network resources,there exist some inevitable problems such as network induced delay and data packet dropout from data transmission,and these problems have certain probability characteristics.At the same time,because of the noise and uncertain factors in the system operation environment,the system parameters are generally uncertainty.Therefore,this paper studies network induced delay,data packet dropout,randomness,uncertainty from NCSs.Based on Lyapunov second method,robust control,integral inequality and other methods,the stability of the system is analyzed and the controller is designed.The main research contents of this paper are as follows:(1)The stability of NCSs with network induced delay and data packet dropout is studied.Firstly,an input delay is constructed,and the augmented matrix and triple integral term are introduced into the constructed Lyapunov functional for making full use of the delay information.Secondly,Wirtinger inequality,convex combination lemma and other methods are used to deal with the integral term from the functional derivative.Combined with the generalized Finsler lemma,the stability criterion with less conservatism is given in the form of linear matrix inequalities.Finally,the validity of the results is verified by numerical examples and Simulink simulations.(2)The stability of NCSs with stochastic delay is studied.Firstly,a random variable is defined to obey a Bernoulli distribution,and construct NCSs model with stochastic delay.In order to improve the utilization rate of the delay information,the augmented matrix and triple integral term are introduced into the constructed Lyapunov functional.Secondly,Jensen inequality and other techniques are used to limit the integral term from the weak infinite operation,generalized Finsler lemma is used to establish more internal relations among the states of the system,and the stability criterion with less conservatism is given.Finally,some examples are given to verify the validity of the results.(3)The robust H_?stability problem for NCSs with stochastic delay and uncertain parameters is studied.Firstly,a Lyapunov functional is constructed by introducing a triple integral term.Secondly,the robust H_?stability theorem satisfying the performance index of the system is derived by means of inequality scaling and Schur complementary lemma.Finally,LMI toolbox is used to obtain the upper bound of time delay and other parameters.Combined with the simulation diagrams,the validity of the obtained results is verified.(4)The robust H_?controller design for NCSs with stochastic delay and uncertain parameters is studied.The formulas from the previous chapter are rewritten and equivalent transformed,the nonlinear term is linearized,the controller design scheme is derived,and the controller gain is obtained.Finally,the validity of the controller design scheme is verified by the analysis of numerical examples and simulations.