Interal Sliding Mode And Robust Control For Singular System Based On LMI Approach

Study on the uncertain system is more practical because of considering the some factors such as modeling error,external disturbance,and the uncertainty inevitably exists in the actual system.The sliding mode control is completely robust to the matching uncertainty,and the sliding mode motion is independent of the matching uncertainty,which is a major advantage of the sliding mode control.Robust H? control is also a good control means for the uncertain system.How to combine these two control strategies effectively is the main research content of this thesis.In this paper,we combine two control strategies and study on the corresponding algorithm to solve the problem of a series of uncertain systems.The main work of this paper is as follows:1.For uncertain normal systems,we design a robust controller based on LMI.firstly,we prove the invariance theorem of the sliding mode motion relating to matched uncertainties;Secondly,I design integral sliding surface and discontinuous sliding mode controller to offset the unmatched uncertainties and to get sliding mode with unmatched uncertainties.Using LMI inequality to design the corresponding H? controller to reduce the influence of unmatched uncertainties,we verify the stability of closed loop system.2.For uncertain normal systems with sate,we design a robust controller based on LMI.Considering state simultaneously exist the matched and unmatched uncertainties,we improve the sliding surface and the design of sliding controller to get the sliding mode whose state exists the unmatched uncertainties.Also getting stability of the closed-loop system,we improve the H? robust controller to meet the corresponding performance index.3.In this paper,we study the algorithm of implicit systems based on the normal uncertainty system.Firstly,we proves the invariance theorem of the sliding mode motion which is same as the normal system;Secondly,we design the sliding surface and controller,which is divided into two parts:discontinuous sliding mode controller solves the matched uncertainties and state feedback H? robust controller solves the unmatched uncertainties to ensures the system without pulse and the closed-loop system is regular?stable without pulse.