A Compliant Robotic Leg Based on Fibre Jamming

TL;DR

This paper introduces a robotic leg with fibre jammed structures that act as passive, tunable compliant mechanisms, inspired by human muscle responses, to improve stability and shock absorption in legged robots.

Contribution

The paper presents a novel multi-material fibre jammed tendon design that can be 3D printed in one step, enabling variable stiffness and damping for robotic legs.

Findings

Fibre jammed tendons effectively absorb shocks and enhance joint stability.

Numerical simulations show tendons' contribution to overall leg stiffness.

Potential for improved stability in legged locomotion using morphological tuning.

Abstract

Humans possess a remarkable ability to react to unpredictable perturbations through immediate mechanical responses, which harness the visco-elastic properties of muscles to maintain balance. Inspired by this behaviour, we propose a novel design of a robotic leg utilising fibre jammed structures as passive compliant mechanisms to achieve variable joint stiffness and damping. We developed multi-material fibre jammed tendons with tunable mechanical properties, which can be 3D printed in one-go without need for assembly. Through extensive numerical simulations and experimentation, we demonstrate the usefulness of these tendons for shock absorbance and maintaining joint stability. We investigate how they could be used effectively in a multi-joint robotic leg by evaluating the relative contribution of each tendon to the overall stiffness of the leg. Further, we showcase the potential of these jammed structures for legged locomotion, highlighting how morphological properties of the tendons can be used to enhance stability in robotic legs.