The virtual COM joints approach for whole-body rh-1 motion

The full-scale humanoid robot RH-1 has been totally developed in the University Carlos III of Madrid. In this paper we present a novel approach for controlling the motion of the whole body of RH-1 robot, so that it can perform tasks in collaboration with humans. Given the mechanical limitations of the robot platform, it is not possible to achieve completely tasks in collaboration with humans. The lack of degrees of freedom (DOF) in robot arms are compensated using the virtual prismatic joints of the center of mass of the robot. This way, the movements that cannot be accomplished by using only the arms are assisted by the movement of the legs. The whole stability of the robot is also guaranteed by the posture control. All the models and algorithms are verified by several simulations and experimental results.