An observer-based robust tracking control for uncertain linear systems

In this paper, we treat the robust tracking problem for uncertain systems with value bounded uncertainties in the state matrix. The Linear Quadratic control is used and the state variables are provided by an observer which is based on the nominal system. The condition of feedback quadratic stability is implicitly guaranteed when the condition. under which the tracking error is bounded, is verified. The robust tracking controller is obtained by solving two Linear Matrix Inqualities. one to minimize the tracking error bound and the other to maximize its decaying rate.