Compliant actuators that mimic biological muscle performance with applications in a highly biomimetic robotic arm

TL;DR

This paper introduces two novel compliant actuators, ICA and ECA, that mimic biological muscles and demonstrate their effectiveness in a biomimetic robotic arm through computational and experimental validation.

Contribution

The paper presents two new compliant actuators, ICA and ECA, designed for ligament-skeletal-inspired robots, with comparative analysis and application in a biomimetic robotic arm.

Findings

ECA and ICA show high power-to-volume and power-to-mass ratios.

Robotic arm successfully performs tasks like lifting, playing table tennis, and door opening.

Actuators emulate biological muscle performance effectively.

Abstract

This paper endeavours to bridge the existing gap in muscular actuator design for ligament-skeletal-inspired robots, thereby fostering the evolution of these robotic systems. We introduce two novel compliant actuators, namely the Internal Torsion Spring Compliant Actuator (ICA) and the External Spring Compliant Actuator (ECA), and present a comparative analysis against the previously conceived Magnet Integrated Soft Actuator (MISA) through computational and experimental results. These actuators, employing a motor-tendon system, emulate biological muscle-like forms, enhancing artificial muscle technology. A robotic arm application inspired by the skeletal ligament system is presented. Experiments demonstrate satisfactory power in tasks like lifting dumbbells (peak power: 36W), playing table tennis (end-effector speed: 3.2 m/s), and door opening, without compromising biomimetic aesthetics. Compared to other linear stiffness serial elastic actuators (SEAs), ECA and ICA exhibit high power-to-volume (361 x 10^3 W/m) and power-to-mass (111.6 W/kg) ratios respectively, endorsing the biomimetic design's promise in robotic development.