Fundamental Three-Dimensional Configuration of Wire-Wound Muscle-Tendon Complex Drive

TL;DR

This paper introduces a three-dimensional wire-wound muscle-tendon complex drive system for robots, enabling more natural movement and environmental interaction by addressing limitations of previous two-dimensional designs.

Contribution

The study develops a fundamental method for constructing 3D muscle exterior structures and demonstrates their application in a robot that maintains movement during environmental contact.

Findings

3D ww-MTC allows continuous robot movement during environmental contact.

The design reduces wire wear and interference compared to previous systems.

The robot with 3D ww-MTC can adapt to environmental changes while moving.

Abstract

For robots to become more versatile and expand their areas of application, their bodies need to be suitable for contact with the environment. When the human body comes into contact with the environment, it is possible for it to continue to move even if the positional relationship between muscles or the shape of the muscles changes. We have already focused on the effect of geometric deformation of muscles and proposed a drive system called wire-wound Muscle-Tendon Complex (ww-MTC), an extension of the wire drive system. Our previous study using a robot with a two-dimensional configuration demonstrated several advantages: reduced wire loosening, interference, and wear; improved robustness during environmental contact; and a muscular appearance. However, this design had some problems, such as excessive muscle expansion that hindered inter-muscle movement, and confinement to planar motion. In this study, we develop the ww-MTC into a three-dimensional shape. We present a fundamental construction method for a muscle exterior that expands gently and can be contacted over its entire surface. We also apply the three-dimensional ww-MTC to a 2-axis 3-muscle robot, and confirm that the robot can continue to move while adapting to its environment.