Lower thigh design of detailed musculoskeletal humanoid “Kenshiro”

In order to know human dynamics, humanoid as a human body simulator is increasing its importance. Such humanoid is expected to have human musculoskeletal structure as close as possible. From this viewpoint, we are trying to create new musculoskeletal humanoid which has detailed human imitating structure, such as bi-articular muscle, muscle arrangement, joint structure and so on. In this paper, we address the design of lower thigh. The concepts of the thigh include leg configuration, new knee joint and link, and artificial muscle arrangements, especially knee joint structure imitating human flexible motion. The knee joint has yaw axis DOF and its locking mechanism which is usually simplified in robotics. Finally, we conduct extension, flexion and rotation as basic experiment to confirm the joint characteristics. Also, we conduct rotation experiment in the ground state to confirm the contribution of yaw axis DOF for human-like motion.