Aircraft control for spin-recovery with rate saturation in actuators

In recovering an aircraft from spinning by a closed-loop control system,the saturations in actuator rate due to insufficient power may cause adverse oscillations of the aircraft motion.To deal with this problem,we propose a control scheme based on the backstepping method.The aircraft model is developed in three cascading layers:the angle lawyer, the angular-rate layer and the actuator layer.The control laws for the angle layer and the angular-rate layer are designed by using the backstepping method.The control law for the actuator layer is designed by constraining the control input corresponding to the actuator rate limits,and ensuring the stability of the closed-loop system according to a Lyapunov function.The analysis is given on the control effect of the developed method with actuator rate saturation.Simulation of the control for a modern fighter aircraft shows superior performances to those obtained by conventional control with dynamic inversion or backstepping methods.