Characterization of handover orientations used by humans for efficient robot to human handovers

To enable robots to learn handover orientations from observing natural handovers, we conduct a user study to measure and compare natural handover orientations with giver-centered and receiver-centered handover orientations for twenty common objects. We use a distance minimization approach to compute mean handover orientations. We posit that, computed means of receiver-centered orientations could be used by robot givers to achieve more efficient and socially acceptable handovers. Furthermore, we introduce the notion of affordance axes for comparing handover orientations, and offer a definition for computing them. Observable patterns were found in receiver-centered handover orientations. Comparisons show that depending on the object, natural handover orientations may not be receiver-centered; thus, robots may need to distinguish between good and bad handover orientations when learning from natural handovers.