Abstract
In this paper, we investigate holding by free links connected to the other active links through joints that lack not only acutuators but also sensors. In the previous reseach, we propose an open-loop control method for the two-link underactuated manipulator in order to swing up and stabilize at the upright position of its unactuated link, that is to say free link. We suggest a mechanism of gripper by using this method.
