Robust Control For Uncertain Linear Systems Based On State Observer

Any mathematical model is only an approximation of the actual physical system.The existence of the error of the model will inevitably reduce the function of the control system.Robust control is to examine this which due to the system model’s error affect the performance of control system.In practical application,some of the state of the system are unmeasurable or not easily to be observed, and the result of the measurement may be affected by the noise, so that we must use the observer. Furthermore, sometimes, we require that not only the system is stable but also meet the certain indicators as well as a number of other constraints. At the same time delay phenomenon is also widespread in practice,and sometimes it will be the main cause of deterioration of performance of the system.Due to the delay-dependent stability and control of the results have less conservative than the delay-independent, so aroused widespread concern. In view of observer based robust system, this paper mainly discusses the following two issues:First:Research about a class of uncertain linear robust which guaranteed cost control and based on state observer.Focused on a class of linear systems with normbounded uncertainty and external disturbance,the paper put forward a method which based observe for robust guaranteed costcontrol of systems with uncertainties. Yielded a sufficient condition for the existen ce of the controller by using state transformation and Lyapunov stability theorems. The designed controller can not only guarantee the stability of the closed-loop system,but also can ensure the closed-loop system has a certain linear two type energy index and H∞performance index. The effectiveness of the method has been verified by using the simulation.Second:Research about a class of uncertain timedelay system which based on the state observer of the H∞robust control. The uncertainties are time-varying and with confirmed structure.Through the establishment of the state observer,and state observer is used to implement feedback,so that the system is not only robust stabilization,but also meet certain performance indicators.In addition to using the LMI method to solve two linear in equalities and can obtain robust controller.