Adaptive backstepping control for electrically driven unmanned helicopter

This paper addresses the attitude control problem for a twin rotor unmanned helicopter driven by DC motors. The control objective is to have the helicopter attitude, i.e., pitch and yaw angles, track specified angles. From the considered dynamics of the plant, it is observed that the main difficulty of the control problem is due to the existing nonlinear coupling effects between the two perpendicular rotors. Hence, a novel adaptive control approach based on the backstepping concept is developed to solve the problem. In the controller design, the system parameters are assumed to be unavailable and are estimated on-line. The stability of the overall closed-loop system is proven to be asymptotically stable based on the Lyapunov theorem. In order to demonstrate the applicability of the proposed control scheme, computer simulations and experiments are shown.