Analysis And Design Of Interval Type-2 Time-delay T-S Model Based Fuzzy Systems

The interval type-2 fuzzy sets have more advantages in dealing with the uncertainties and making up for the lack of type-1 of fuzzy sets in this aspect,which can deal with the problem of uncertain parameters in the system very well,because of its mathematical operation more complicated,mostly used in the interval type-2 fuzzy sets.Since T-S model systems have unique advantages in describing and handling complex nonlinear systems,it has become a very popular tool in nonlinear control systems.In the actual industrial control problems,due to the selection of control objectives and large-scale internal disturbances,uncertainties and time lags,the performance of the system will be affected in varying degrees,which brings about great problems for the analysis and control of the system.This thesis mainly focuses on the analysis and H? control design of interval type-2 time-delay T-S model based fuzzy systems.The main research results of this thesis can be divided into the following three parts:The first part focuses on the problem of H? performance and stabilization problems for time-delay systems with parameter uncertainties be studied on.Firstly,we define the appropriate Lyapunov function and analyze the system's H? performance by using the characteristics of linear fractional structure.The parallel distributed compensation method is used to construct:a state feedback con-troller without memory,the stabilization problem is transformed into finding the feasible solutions to linear inequalities.Finally,the simulation results ensure the stability and the given H? performance-to-noise factor ? of the system.In the second part is considered with the type-2 nonlinear stochastic time-delay fuzzy sys-tems.In the case of a bounded norm of the system parameter matrix,a reasonable delay-dependent Lyapunov function is constructed,based on relaxation matrix method and delay-dependent boundary-exponential realism,A controller was designed to make the closed-loop system satisfies the given H? performance index ?.When the system parameter matrix is determined,the integral inequality is processed by the time-delay decomposition method and Jensen inequality,and a controller that satisfies the conditions is designed.The Monte Carlo simulation idea verifies that the effectiveness of the proposed method.The third part is based on the second part to improve the result.According to the uncertain stochastic time-varying system with interval type-2 T-S model,by constructing suitable Lyapunov-Krasovskii functional and using the delay partition method to deal with the integral inequality,combining with the Jensen's inequality and Schur's complement theorem,based on the structural features of the linear fractional structure and the matrix decomposition technique,the matrix inequality is scaled appropriately.The stability of the system model with time-varying delay is analyzed,A stability criterion is proposed to make the stochastic system less conservative in mean square sense and the feasibility of the proposed approach is depicted by a simulation example.