Adaptive backstepping sliding mode trajectory tracking control for a quad-rotor

A quad-rotor aircraft is an under-actuated, strongly coupled nonlinear system with parameter uncertainty and un-modeled disturbance. In order to make the aircraft track the desired trajectory, a nested double-loops control system is adopted in this paper. A position error proportional-derivative (PD) controller is designed as the outer-loop controller based on the coupling action between rotational and translational movement, and an adaptive backstepping sliding mode control algorithm is used to stabilize the attitude. Finally, both the numerical simulation and prototype experiment are utilized to demonstrate the effectiveness of the proposed control system.