The design of longitudinal control augmentation system for aircraft based on L1 adaptive control

In order to improve robust and tracking performance of aircraft controller, this paper presents a design method of nonlinear controller for the longitudinal system of aircraft based on L1 adaptive control. Firstly, considered the characteristic of aircraft, the nonlinear part is regarded as uncertainties. Then, the control augmentation controller configuration of angle of attack is established. And then the adaptive law and control law of control augmentation systems are designed so that tracking error rapidly converges and keeping robust. Lastly, stability is analyzed and proved by using Lyapunov function. The simulation result show that it still can make aircraft achieve satisfactory control requirements by using L1 adaptive control method, even control surface efficiency reduced. That L1 adaptive control method has passive fault-tolerant effect is verified.