  Jumping can be an effective way of locomotion to overcome small terrain gaps
or obstacles. In this paper we propose two different approaches to perform
jumps with a humanoid robot. Specifically, starting from a pre-defined CoM
trajectory we develop the theory for a velocity controller and for a torque
controller based on an optimization technique for the evaluation of the joints
input. The controllers have been tested both in simulation and on the humanoid
robot iCub. In simulation the robot was able to jump using both controllers,
while the real system jumped with the velocity controller only. The results
highlight the importance of controlling the centroidal angular momentum and
they suggest that the joint performances, namely maximum power, of the legs and
torso joints, and the low level control performances are fundamental to achieve
acceptable results.
