Implementation of Human Mimetic Knee Joint with Screw-Home Mechanism and Achievement of Motion under Environment Contact by Musculoskeletal Humanoid

Abstract

Human knee joint has a yaw-axis rotational DOF and a locking mechanism called screw-home mechanism(SHM). We focus on this mechanism and implement it to a musculoskeletal humanoid through hardware design. In this paper, we first explained human knee characteristic of SHM and joint range of motion. Next, we explained hardware design and implementation method of the mechanism. As an evaluation of our developed knee joint, we checked the function of SHM from viewpoint of moment arm of the yaw rotational axis and the yaw angle displacement during squat motion. Lastly, as unique and integrated motions that involve the use of yaw DOF derived from SHM, we made several motion achievement including humanlike twisting squat, heel move motion and switch pedals, under a condition of contacting environment. This result demonstrates human mimetic rotational DOF of knee contributes motion achievement.