Leg motion primitives for a dancing humanoid robot

The goal of the study described in this paper is to develop a total technology for archiving human dance motions. A key feature of this technology is a dance replay by a humanoid robot. Although human dance motions can be acquired by a motion capture system, a robot cannot exactly follow the captured data because of different body structure and physical properties between the human and the robot. In particular, leg motions are too constrained to be converted from the captured data because the legs must interact with the floor and keep dynamic balance within the mechanical constraints of current robots. To solve this problem, we have designed a symbolic description of leg motion primitives in a dance performance. Human dance actions are recognized as a sequence of primitives and the same actions of the robot can be regenerated from them. This framework is more reasonable than modifying the original motion to adapt the robot constraints. We have developed a system to generate feasible robot motions from a human performance, and realized a dance performance by the robot HRP-1S.