Achilles: An autonomous lightweight ankle exoskeleton to provide push-off power

Cor Meijneke, Wietse van Dijk, Herman van der Kooij

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

35 Citations (Scopus)
67 Downloads (Pure)

Abstract

This paper presents the Achilles exoskeleton, an autonomous ankle exoskeleton that can generate 52% of the positive plantarflexion power around the ankle of a 80 kg individual with only 1.5 kg of mass added around the ankle joint. The mass of the exoskeleton is lower and the power density is higher than that of existing autonomous exoskeletons. This high power density was achieved by designing a series elastic actuator that consists of an electric motor and ball-screw gear with a carbon fiber reinforced leaf-spring as lever-arm. A dynamic model that includes the motor and gear properties, spring stiffness, and exoskeleton geometry was used to optimize the design parameters for positive power injection. Doing this for multiple combinations of preselected motors and gears and comparing their support to weight ratio, revealed the best drive combination. The performance of the realized exoskeleton was assessed in several tests. The actuator can track the optimized actuator stroke trajectory with a following error that has a RMS of 2.3 mm, it can track force reference signals with amplitudes of 1 N to 100 N with a bandwidth between 8.1 Hz and 20.6 Hz, and it outputs a maximum mechanical power of 80.2 W. These results show that the device is suitable for fulfilling its purpose: reducing the metabolic cost of walking with an autonomous device.
Original languageEnglish
Title of host publication5th IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics, BioRob 2014; Sao Paulo; Brazil; 12-15 August 2014; Category numberCFP14BRB-PRT; Code 109564
Place of PublicationPiscataway, NJ
PublisherIEEE
Pages918-923
ISBN (Electronic)978-1-4799-3128-6
ISBN (Print)978-147993126-2
DOIs
Publication statusPublished - 12 Aug 2014
Event5th IEEE RAS & EMBS Interantional Conference on Biomedical Robotics and Biomechatronics, BioRob 2014 - Palacio das Convenções Anhembi, Sao Paulo, Brazil
Duration: 12 Aug 201415 Aug 2014
Conference number: 5

Publication series

NameIEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics
PublisherIEEE
Number5
Volume2014
ISSN (Print)2155-1774
ISSN (Electronic)2155-1782

Conference

Conference5th IEEE RAS & EMBS Interantional Conference on Biomedical Robotics and Biomechatronics, BioRob 2014
Abbreviated titleBioRob
Country/TerritoryBrazil
CitySao Paulo
Period12/08/1415/08/14

Keywords

  • 2023 OA procedure

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