Advanced Methods Research On Attitude Control For Hypersonic Vehicle

Hypersonic vehicle model is indeed complicated which has features like high nonlinearity,strong coupling,elastic vibration and others.The wide aircraft flight envelope,uncertainties of the aerodynamic parameters,as well as higher demands of vehicles’ stability and maneuverability make the task of designing a strong robust controller adapt to high maneuverability the keystone and difficult point of hypersonic aircraft’s development.Based on deep study of the US hypersonic vehicle model,this paper made design of nonlinear controller and side/aerodynamic force controller for attitude control,which enhanced the robustness and maneuverability of flight vehicles,and the interaction of uncertain factors was also restrain at the same time.A comprehnsive Winged-Cone hypersonic vehicle model was established on Matlab/Simulink simulation platform on the basis of relevant domestic and international researches,including six-degree-freedom nonlinear model,aerodynamic dynamic model,scramjet engine model and elastic model,etc.Meanwhile,a dynamic inverse PID controller appropriate for complex nonlinear system of hypersonic vehicle system was designed according to its strong non-linearity and coupling.The inverse controller systems of attitude angle rate loop and attitude angle control loop were designed based on time-scale separation theory,which enhanced the robustness by PID controller,and then the control commands would be transfer to rudder surface deflection according to the control allocation algorithm.With the growing demand of the hypersonic vehicle maneuverability,the rudder surface deflection was saturated when the dynamic pressure was insufficient,which led to the vehicle unstability,so the side force,output of the reaction control system,was added to blended controller design.Based on hypersonic vehicle model,stability criterion was deduced,which was used as the control strategy to open the side jets.With the analysis above,this paper makes simulation experiments of dynamic inverse PID controller and blended controller for attitude control,and the results indicate that the dynamic inverse PID controller can adapt to high maneuvering flight and the robustness on disturbance rejection is ensured.Further more,the blended controller on the basis of stability criterion is more stable and adaptive than traditional blended controller.