Application of “Planar Muscle” with Soft Skin-Like Outer Function Suitable for Musculoskeletal Humanoid

In recent years, human-like robots have received a lot of attentions. A musculoskeletal humanoid is an effective approach for making a human-like robot, and many musculoskeletal humanoids have been developed. However, none have been equipped with really human-like bones and muscles, especially shapes and alignments. Formaking really human-like musculoskeletal humanoids, we thought of the “planar muscle” as the key. A planar muscle is an enhanced wiredriven system in which a motor winds a wire. In a prior system, one motor controlled one wire and the linear muscle needed one motor per wire and complex control systems. We therefore developed the planar muscle that controlled several wires simultaneously by using two moving pulley bars and one motor. The planar muscle is suited to musculoskeletal humanoids because they need a lot of motors and complex control systems in the case of using linear muscles. Furthermore, planar muscles are useful for soft skin-like outers that protect external shocks and sense touch. Using the planar muscles, we are developing a new musculoskeletal humanoid that has human-like bones and muscles. In this paper, we show the planarmuscle concept, especially its soft skin-like outer functions, and evaluate its motion with a body trunk model having multiple vertebrae that we developed.