In this paper, we propose a hand-over motion model based on analyses of hand motions and voice utterances of humans. This model generates a motion in which a robot hands over an object to a human accompanied by a voice greeting. In this model, a hand-over motion is generated based on the analyses of human hand-over motions; in particular, the timing between the voice utterances and the release motions of humans is analyzed. Then, the model generates the release motion of a robot in response to a voice utterance from a human. Furthermore, using the proposed hand-over motion model, two types of hand-over robot systems are developed. The first type is a human-arm handing-over robot system which is fabricated according to the average size of a human arm. The other type is a Cartesian-coordinate handing-over robot system. The effectiveness of the proposed model is demonstrated by sensory evaluation using these hand-over robot systems. Furthermore, using the Cartesian-coordinate handing-over robot system, the number of degrees of freedom is analyzed in order to generate a handing-over motion which is preferred by humans.
