Evaluation of action-similarity awareness effect in rhythm ensemble co-creation

There are many robots which have communication skills with human but most of their actions and responses are preprogrammed and few researches inspect psychological aspects of behavior in human-robot co-creation. In this paper, we focus on action-similarity awareness as a key for building up co-creative relationship with humans. Here, action-similarity awareness means that one recognizes affinity to one´s own actions derived from other´s actions. As a simple task involving action-similarity awareness, we focused on rhythm ensemble. The ensemble is a type of drumming session in which even people who have little musical experience easily take part. In this research we expect to realize the awareness in the rhythm ensemble session by employing the other´s past action and mixing it to metrical structure, a basic beat structure in music. To make sure of this idea in real session, we developed a robot system which can actually play a drumming session with humans and control action-similarity awareness. We conducted a subjective experiment and analyzed questionnaire and interaction record. From the questionnaire results, it was confirmed that the sense of prediction increases with action contributing rate and that it is effective to imitate humans actions and add 10% to 30% originality. From the interaction record it was confirmed that phrase structure was shared by making consent on which part to be varied or fixed.