  This paper presents a novel method to attenuate large horizontal wind
disturbance for a small-scale unmanned autonomous helicopter combining wind
tunnel-based experimental data and a backstepping algorithm. Large horizontal
wind disturbance is harmful to autonomous helicopters, especially to small ones
because of their low inertia and the high cross-coupling effects among the
multiple inputs. In order to achieve more accurate and faster attenuation of
large wind disturbance, a new hybrid control architecture is proposed to take
advantage of the direct force/moment compensation based on the wind tunnel
experimental data. In this architecture, large horizontal wind disturbance is
treated as an additional input to the control system instead of a small
perturbation around the equilibrium state. A backstepping algorithm is then
designed to guarantee the stable convergence of the hilicopter to the desired
position. The proposed technique is finally evaluated in simulation on the
platform, HIROBO Eagle, compared with a traditional wind velocity compensation
method.
