| Because of the advantages of the interval type-2 fuzzy sets in proces,sing parameter uncertainty and reducing computational complexity,it has been to the hot spot for a long time.Besides,with the complexity of the actual control systems increase in daily life,the influence of factors such as high nonlinearity and time delay in the systems is in also.Therefore,the study of uncertain time delay fuzzy systems has important significance and value in the case of interval type-2 T-S model.Based on the interval type-2 T-S model,this paper studies the robust H? control problems for three different nonlinear systems.The research content consists of the following three parts:In the first part,we deal with robust H? control problem for interval type-2 neu-tral fuzzy systems with discrete and distributed time delays.First,suitable Lyapunov-Krasovskii functional with augmented matrices and triple integrals is constructed,and a delay-dependent sufficient condition for the systems is obtained by using free weight matrices and inequality scaling techniques.Then,a state feedback controller is derived to make the closed-loop neutral fuzzy systems asymptotically stable under the given H?performance index based on this condition.The effectiveness of the method is verified by examples at last.The second part is concerned with the problem of H? control for interval type-2 fuzzy systems with parameter uncertainties and time-varying delays.An augmented Lyapunov-Krasovskii functional is presented by introducing delay-product-type terms.Based on the estimation of the derivative of the constructed Lyapunov-Krasovskii by us-ing an improved reciprocally convex inequality and Wirtinger-based inequality,a H? state feedback controller is developed for uncertain interval type-2 delayed fuzzy systems.To demonstrate the effectiveness of the provided approach,their applications are proposed with three numerical examples at last.The third part is considered with the robust H? control for uncertain stochastic de-layed fuzzy systems with linear fractional uncertainties.In the process of the construction of Lyapunov-Krasovskii functional,the geometric partition of time-delay interval division method is used and the triple integral term is introduced.Combined with the existing inte-gral inequality and slack matrix technique,a robust H? controller is designed.Within the allowable range of parameter uncertainties,the designed controller guarantees the result-ing closed-loop system is robustly mean-square asymptotically stable with a prescribed H? disturbance attenuation level.Numerical examples are provided to show the advan-tage of the proposed method. |
PDF Full Text Request