Trajectory tracking control for a quad-rotor UAV based on integrator backstepping

One nonlinear dynamic model for a quad-rotor has been constructed and methods of backstepping have been employed in deriving the controllers for trajectory problem of quad-rotors in this paper. Difficulties due to the under-actuated characters of the quad-rotor have been successfully resolved through decoupling the position control system and the attitude control system in the framework of Backstepping. All states of the quad-rotor have been controlled to converge to desired values in the end. Numerical simulations using Matlab have illustrated the effectiveness of the controllers proposed in this paper.