  This paper presents nonlinear tracking control systems for a quadrotor
unmanned aerial vehicle under the influence of uncertainties. Assuming that
there exist unstructured disturbances in the translational dynamics and the
attitude dynamics, a geometric nonlinear adaptive controller is developed
directly on the special Euclidean group. In particular, a new form of an
adaptive control term is proposed to guarantee stability while compensating the
effects of uncertainties in quadrotor dynamics. A rigorous mathematical
stability proof is given. The desirable features are illustrated by numerical
example and experimental results of aggressive maneuvers.
