Nonlinear Adaptive Flight Control Using Backstepping and Neural Networks Controller

Anonlinearadaptive  ight control system is proposed using a backstepping and neural networks controller. The backstepping controller is used to stabilize all state variables simultaneouslywithout the two-timescale assumption that separates the fast dynamics, involvingthe angularrates of the aircraft, from the slow dynamics,which includes angle of attack, sideslip angle, and bank angle. It is assumed that the aerodynamic coefŽ cients include uncertainty, and an adaptive controller based on neural networks is used to compensate for the effect of the aerodynamic modeling error. Under mild assumptions on the aerodynamic uncertainties and nonlinearities, it is shown by the Lyapunov stability theorem that the tracking errors and the weights of neural networks exponentially converge to a compact set. Finally, nonlinear six-degree-of-freedom simulationresults for an F-16 aircraft model are presented to demonstrate the effectiveness of the proposed control law.