Adaptive Attitude Control for a Coaxial Tilt-Rotor UAV via Immersion and Invariance Methodology

Dear Editor, This letter is concerned with the attitude control for a novel tilt-rotor unmanned aerial vehicle with two pairs of tiltable coaxial rotors and one rear rotor. An immersion and invariance-based adaptive attitude controller for the tilt-rotor unmanned aerial vehicle is proposed. In the proposed control strategy, an adaptive update law is specially designed to compensate for the uncertainties of damping coefficients. The stability of the resulting closed-loop coaxial tilt-rotor unmanned aerial vehicle (CTRUAV) system is proved by the Lyapunov methodology and LaSalle's invariance theory. Finally, to validate the effectiveness of the designed control strategy, simulations and experiments are performed.