A study of terrain following controller based on backstepping and variable structure control

A new algorithm is proposed for adaptive angle terrain following (TF) approach by using angle of attack. The block control model, which is suitable for backstepping design, is given for nonlinear model of aircraft. Making full use of the characteristics of the system and combining block control principle, backstepping technique, and variable structure control method, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors converge to the neighborhoods of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the aircraft model are presented to demonstrate the effectiveness of the proposed control law.