Research On High-Bandwidth/High-Precision Longitudinal Control For A Hypersonic Vehicle

The characteristics of hypersonic vehicle are analyzed. Furthermore through a generic hypersonic longitudinal aerodynamic mathematical model, the equilibrium point and the eigenvalues are analyzed, and the flight specialty of the hypersonic vehicle can be understood.The theory of feedback linearization introduced can convert accurately nonlinear mathematical model into equivalent linear model for control design. By the proper transformation, dynamic inversion flight control systems for the hypersonic vehicle designed can stabilize the system and relieve the coupling effects.Aiming to the high-precision and high-bandwidth research for a hypersonic aircraft, dynamic inversion control system with the optimal controller as a complementary controller system is designed. The dynamic control law functions as an inner loop, the optimal control as the outer loop. Dynamic inverse controller relieves the nonlinear coupling of input and output, and the optimal controller is to improve the system for the bandwidth and precision. In order to select the appropriate parameters for the optimal control, genetic algorithm is used to search a design parameter space of the nonlinear-dynamic-inversion structure, identify the parameters to improve the bandwidth and accuracy of system.For hypersonic vehicle uncertainties and the impact of the imprecise mathematical model, an adaptive neural network to compensate inverse error is synthesized and the adaptive control architecture of study online of neural network is designed. When the aerodynamic parameters have stirred or the system has been disturbed, the feedback error is able to adjust network weights online to impend over inverse errors, so that the affection on the whole control system is killed dynamically.