Double-Acting Sleeve Muscle Actuator for Bio-Robotic Systems.

Xiangrong Shen,Hao Zheng

doi:10.3390/act2040129

Abstract

This paper presents a new type of muscle-like actuator, namely double-acting (DA) sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc.). Developed based on the traditional pneumatic muscle actuator, the new DA sleeve muscle incorporates a unique insert at the center. With the insert occupying the central portion of the internal volume, this new actuator enjoys multiple advantages relative to the traditional pneumatic muscle, including a consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation. Furthermore, the insert encompasses an additional chamber, which generates an extension force when pressurized. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. To demonstrate this new actuator concept, a prototype has been designed and fabricated, and experiments conducted on this prototype demonstrated the enhanced force capacity and the unique bi-directional actuation capability.

Highlights

Taking inspiration from biological organisms has been one of the major methods of innovation in modern robotics research
Note that this work is built upon the original sleeve muscle concept, which has been demonstrated to provide multiple advantages over traditional pneumatic muscle, such as consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation [16]
A new DA sleeve muscle is presented as a significant advance over the traditional pneumatic muscle actuator

Summary

Introduction

Taking inspiration from biological organisms has been one of the major methods of innovation in modern robotics research. With the interior volume pressurized, the tube expands in the radial direction and shortens in the axial direction, generating a contraction force to the external load With this structure, the pneumatic muscle possesses multiple unique advantages, including simple structure, high power density, and similar elastic characteristics to biological skeletal muscles. Note that this work is built upon the original sleeve muscle concept, which has been demonstrated to provide multiple advantages over traditional pneumatic muscle, such as consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation [16] Sharing these outstanding properties, the DA sleeve muscle actuator represents a significant step forward over the traditional pneumatic muscle and can potentially become a highly competitive actuator choice for the future high-performance robotic systems. DA sleeve muscle and the application of DA sleeve muscle in bio-robotic systems; Section 5 presents the conclusions of this paper

Rationale and Basic Structure of the DA Sleeve Muscle

Sleeve Muscle

F F1 F2

DA Sleeve Muscle

DA Sleeve Muscle Prototype and Experimental Results

Future work

Conclusions