Robust Control Of Hypersonic Vehicles And Visualization

Compared with common airplane or flight vehicles, there is a larger flight envelope and more complex flight condition for hypersonic vehicles. Therefore, it is more essential for hypersonic vehicles to keep stable and highly maneuverable in flight. Robust control is usually applied to stabilize the system and make the closed loop system process the required dynamic performances when the system exist some uncertainties. Visual simulation for the flight control system is to apply the CAD, Virtual Reality technology and system simulation synthetically to analyzing the stability and the performance for airplanes and hypersonic vehicles. All uncertainties considered in this paper include the uncertainty in state matrix, the uncertainty in control input matrix and the uncertainty in controller implementation. Robust control for uncertain systems, applications of the design of robust controller in flight control systems and the visual simulation for flight control system is studied in this paper. Explicit research work include:1) Analyzing and formulating existing conditions and designing methods for three kind of robust controllers, including non-fragile robust tracking control for uncertain systems, non-fragile guaranteed cost control for uncertain systems, non-fragile reliable control for uncertain systems; The method of solving Riccati equation and LMI approach are discussed and compared through a computation example.2) Analyzing the nonlinear model for a certain hypersonic test vehicle and determining the model for control through multipoint linearization; Realizing height and speed control for this vehicle; Analyzing the lateral model for a certain re-entry test vehicle and building the flow procedures for digital simulation, then finishing tracking control of angle of bank for this vehicle; Gust disturbance is considered for a certain airplane, the mentioned controllers are applied to restrain the disturbance of angle of attack for the airplane.3) Determining contents and the flow chart for the visual simulation, the deep research works include: building the virtual scene and the configuration of three-dimensional model for a certain hypersonic vehicle; implementing the mutual UI (user interface), the realization of simulation algorithms; controlling the movement of the three-dimensional model simultaneously by data simultaneously calculated; implementing the function of digital simulations.In recent years, LMI technique is a kind of effective tool, which is used to study all kinds of problems in the field of control theory and application. The problems of robust control analysis and synthesis can be converted to solving LMI problems. LMI technique is used to design the robust controllers in this thesis. The software platform is realized through programming in VC integration environment and specific realization is in virtue of MFC combined with OpenGL programming techniques.