The Analysis And Synthesis Of Input-Constrained System Based On Optimal Control

The constrained systems problem is one of the fields that have atracted much attention in the control theory fields and in the practice application, and so it has led to a considerable amount of results in both the fields.Based on Lyapunov stability, this paper discusses the design approach of inuput feedback controllers of lconstrained systems, according to the systematic desires, in which algebraic Riccatiequalities(ARE) and passivity system theory are the important tools.The whole paper includes the following five parts: In Part I, the practice background and the purpose of the research on constrained systems are introduced. And the research present status, results and methods are also summarized respectively. In addition, the following knowledge points are represented in brief:, the definition and the approaches of solution of linear matrix inequalities(LMI) and module predictive control (MPC). and the system robust control is summarized respectively. At last, summarizing the whole research in this paper, the present problems are indicated.In Part II, the preparative knowledge in this paper is given, such as basic definitions and theorems of Lyapunov stability, the definition and means of robust control, and so on. The related knowledge of passivity theory and the ARE are stressed ad hoc which are the main tools in this paper.In Part III, Based on the feedback control of inuput-contrained system production before which used ARE as the research method, the nonlinear parameters is added and the new research conclude is used in the robust ststus-feedback control and output-feedback control. Then this part presents use this ststus-feedback control design method for rotational maneuvers of a flexible spacecraft. The difficulty and the approach of choosing the parameters is discussed and illustrated. Furthermore, This method can implement more optimal system performance compared to other method, for example, enhancing the disturbance rejection, robustness, and discrese overshoot and so on.In Part IV, the design of the optimal control law for a class of nonlinear system with saturated inputs is presented. First, the feasible of HJB optimal method for input-constrained nonlinear system is discussed. But some problems are existence. Then, the new optimal control method based on passivity theory is discussed, and the corresponding conclusions are given with the terms of lemmas. At last, the conclusions are synthesized to get the conclude, and instances are to illustrate the method and result.In Part V, after summarizing the whole paper, the present problems are indicated, and then the research trend is prospected.