Robust Control Of Interval Type-2 Fuzzy Systems With Time Delay

With the continuous progress of science and technology,T-S fuzzy system has become an important tool to deal with nonlinear systems,which can be seen in many production and life.However,due to the complexity of the external environment,the modeling results of T-S fuzzy system for uncertain system are often unsatisfactory.However,interval type-2 fuzzy system not only has significant advantages in dealing with uncertain parameters,but also makes up for the shortcomings of T-S fuzzy system.Therefore,the research on interval type-2 fuzzy systems has been widely concerned.This thesis mainly studies interval type-2 fuzzy time-delay systems,and the specific contents are as follows.In the first part,the stability and controller of interval type-2 fuzzy time-delay systems are discussed,The premise mismatched state feedback controller is designed to make the system asymptotically stable.Finally,a numerical example is given to illustrate the feasibility and superiority of the proposed method.In the second part,the problem of robust H_? control for a class of nonlinear systems with parameter uncertainty and time-varying delay is studied.For stability analysis and control synthesis design,the interval type-2 fuzzy uncertain system is used to represent the nonlinear system.Firstly,an interval type-2 fuzzy controller is proposed to stabilize the nonlinear system.Secondly,based on the Lyapunov functional,the interval type-2 fuzzy controller is proposed to stabilize the nonlinear system,The matrix decomposition method and free weighted matrix technique are used to express the relations in Newton Leibniz formula,and a delay dependent stability condition with H_?performance is given in the form of linear matrix inequality.Finally,a numerical example is given to illustrate the feasibility of this method.In the third part,the problem of passive control for a class of nonlinear systems with time-varying delay is studied.Firstly,the interval type-2 fuzzy system is used to describe the nonlinear system,and a Lyapunov function is designed.The Schur complement lemma and linear matrix inequality are used to reduce the parameters,A delay dependent stability condition is given in the form of linear matrix inequality,which makes the system passivity.Finally,a numerical example is given to illustrate the feasibility of the proposed method.