Toward a Dancing Robot With Listening Capability: Keypose-Based Integration of Lower-, Middle-, and Upper-Body Motions for Varying Music Tempos

This paper presents the development toward a dancing robot that can listen to and dance along with musical performances. One of the key components of this robot is the ability to modify its dance motions with varying tempos, without exceeding motor limitations, in the same way that human dancers modify their motions. In this paper, we first observe human performances with varying musical tempos of the same musical piece, and then analyze human modification strategies. The analysis is conducted in terms of three body components: lower, middle, and upper bodies. We assume that these body components have different purposes and different modification strategies, respectively, for the performance of a dance. For all of the motions of these three components, we have found that certain fixed postures, which we call keyposes, tend to be preserved. Thus, this paper presents a method to create motions for robots at a certain music tempo, from human motion at an original music tempo, by using these keyposes. We have implemented these algorithms as an automatic process and validated their effectiveness by using a physical humanoid robot HRP-2. This robot succeeded in performing the Aizu-bandaisan dance, one of the Japanese traditional folk dances, 1.2 and 1.5 times faster than the tempo originally learned, while maintaining its physical constraints. Although we are not achieving a dancing robot which autonomously interacts with varying music tempos, we think that our method has a vital role in the dancing-to-music capability.