Load Sharing in Human-Robot Cooperative Manipulation

Physical cooperation with humans greatly enhances the capabilities of robotic systems when leaving standardized industrial settings. In particular, manipulation of bulky objects in narrow environments requires cooperating partners. Actuation redundancies arising in joint manipulation impose the question of load sharing among the interacting partners. In this paper, effort sharing policies are systematically derived from the geometric and dynamic task properties. Three policies are intuitively identified, resulting in unilateral and balanced effort distributions. These policies are evaluated within a novel hierarchical motion generation and control framework. The synthesized system is successfully validated in a three-degrees-of-freedom planar tracking experiment. This evaluation shows an interdependency of the load sharing strategy and the resulting task performance.