Reduced-Observer Design And Research For Nonlinear System

The state feedback has shown its advantages in many synthetical problems. Because of the complexity of nonlinear systems, observer design method for non-linear system has not yet formed a complete system. Therefore, the problem of observer design of nonlinear system is one of the hot issues.The present thesis focuses on the investigation of the reduced-order observer design for several different classes of nonlinear systems. The main research results are given as follows:Firstly, the problem of reduced-order observer design for a class of differential Lipschitz nonlinear system is investigated. The proposed approach avoids high gain by comparison. Furthermore, to ensure asymptotic convergence, in both continu-ous and discrete time system, sufficient conditions for existence of reduced-order observer are presented.In addition, by using the differential mean value theorem and a group of Linear matrix inequalities, we propose sufficient conditions for the existence of reduced-order observer of the class of nonlinear system. The present method is applicable not only to the differential Lipschitz nonlinear system, but also to a class of nonlinear systems which are not usual Lipschitz nonlinear systems.