  The paper takes the first step towards the de- velopment of a control
framework for underactuated flying humanoid robots. These robots may thus have
the capacities of flight, contact locomotion, and manipulation, and benefit
from technologies and methods developed for Whole-Body Control and Aerial
Manipulation. As in the case of quadrotors, we as- sume that the humanoid robot
is powered by four thrust forces. For convenience, these forces are placed at
the robot hands and feet. The control objective is defined as the asymptotic
stabilization of the robot centroidal momentum. This objective allows us to
track a desired trajectory for the robot center of mass and keep small errors
between a reference orientation and the robot base frame. Stability and
convergence of the robot momentum are shown to be in the sense of Lyapunov.
Simulations carried out on a model of the humanoid robot iCub verify the
soundness of the proposed approach.
