Walking with springs

Thomas Sugar, Kevin W. Hollander, Joseph K. Hitt

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

Developing bionic ankles poses great challenges due to the large moment, power, and energy that are required at the ankle. Researchers have added springs in series with a motor to reduce the peak power and energy requirements of a robotic ankle. We developed a "robotic tendon" that reduces the peak power by altering the required motor speed. By changing the required speed, the spring acts as a "load variable transmission." If a simple motor/gearbox solution is used, one walking step would require 38.8J and a peak motor power of 257 W. Using an optimized robotic tendon, the energy required is 21.2 J and the peak motor power is reduced to 96.6 W. We show that adding a passive spring in parallel with the robotic tendon reduces peak loads but the power and energy increase. Adding a passive spring in series with the robotic tendon reduces the energy requirements. We have built a prosthetic ankle SPARKy, Spring Ankle with Regenerative Kinetics, that allows a user to walk forwards, backwards, ascend and descend stairs, walk up and down slopes as well as jog.

Original languageEnglish (US)
Title of host publicationElectroactive Polymer Actuators and Devices (EAPAD) 2011
DOIs
StatePublished - May 17 2011
EventElectroactive Polymer Actuators and Devices (EAPAD) 2011 - San Diego, CA, United States
Duration: Mar 7 2011Mar 10 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7976
ISSN (Print)0277-786X

Other

OtherElectroactive Polymer Actuators and Devices (EAPAD) 2011
CountryUnited States
CitySan Diego, CA
Period3/7/113/10/11

Keywords

  • Energy
  • Power
  • Prosthetic ankle
  • Spring

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Walking with springs'. Together they form a unique fingerprint.

  • Cite this

    Sugar, T., Hollander, K. W., & Hitt, J. K. (2011). Walking with springs. In Electroactive Polymer Actuators and Devices (EAPAD) 2011 [797602] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7976). https://doi.org/10.1117/12.882214