A preliminary experiment for transferring human motion to a musculoskeletal robot - Decomposition of human running based on muscular coordination

The study of decomposition of body movement into motor primitives is evolving in neuroscience. Meanwhile, in robotics, the motor control of human-like musculoskeletal robots is difficult due to redundant degrees of freedom (DOF) of the robot body. The application of the concept of decomposing into units of motor function to robotics is anticipated to render the control of the robot low-dimensional. We try to achieve fewer-DOF control of a human-like musculoskeletal robot by using our knowledge of the units of motor function based on muscular coordination. In this paper, we introduce ??the agonist-antagonist muscle pairs (A-A) ratio?? and ??A-A activity.?? These parameters are defined by using electromyographic (EMG) data for describing the coordination between the agonist and antagonist muscles. Human running is decomposed into two units of motor function using Principal Component Analysis (PCA) for these parameters. We propose a new method of modular control of a musculoskeletal leg robot using the extracted patterns of muscle coordination, and we thus find kinematic meanings of the patterns of muscle coordination.