Research On Modeling And Adaptive Trajectory Linearization Control Of An Aerospace Vehicle

This task is just about one of the research"some important and basic problems of the aerospace vehicle"which is carried out by National Natural Science Foundation of China.Firstly, geometrical model, manipulative characteristic and six-freedom nonlinear model of the aerospace vehicle are introduced. Then, the relative aspects of the nonlinear model are given. At last, the nonlinear model is transformed to be affine based on the multi time-scale fundamental and the open-loop characteristic of the model is analyzed.Secondly, the interrelated theories of nonlinear systems and linear time-varying systems are introduced at first. In the base of the above theories, the basic theory and thinking in design of nonlinear trajectory linearization control is presented. After that, nonlinear pseudo dynamic inverse and linear time-varying system which are the two most important aspects of trajectory linearization control are put forward. Later, trajectory linearization control method is used to design the flight control system for the aerospace vehicle. The designed controller not only possesses good dynamic performance, but also some robust characteristics.Thirdly, four adaptive trajectory linearization control methods are presented emphasized for a class of multi-input multi-output uncertain nonlinear systems. The four control methods are: (1) adaptive trajectory linearization control method based on fuzzy theory, (2) robust adaptive fuzzy control method based on trajectory linearization method, (3) adaptive trajectory linearization tracking control method based on fuzzy disturbance observer, (4) robust adaptive trajectory linearization control method based on T-S fuzzy theory, (5) robust adaptive trajectory linearization control method based on small gain theory. All the signals of the whole closed–loop system are guaranteed to be uniformly ultimately bounded by the proposed five control methods. At the same time, the whole system has a good tracking performance and robust property. At last, the proposed five methods are used to design the flight control system of the aerospace vehicle and the simulation result shows the effectiveness.