Spring uses in exoskeleton actuation design

Shiqian Wang, Wietse van Dijk, Herman van der Kooij

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

44 Citations (Scopus)

Abstract

An exoskeleton has to be lightweight, compliant, yet powerful to fulfill the demanding task of walking. This imposes a great challenge for the actuator design. Electric motors, by far the most common actuator in robotic, orthotic, and prosthetic devices, cannot provide sufficiently high peak and average power and force/torque output, and they normally require high-ratio, heavy reducer to produce the speeds and high torques needed for human locomotion. Studies on the human muscle-tendon system have shown that muscles (including tendons and ligaments) function as a spring, and by storing energy and releasing it at a proper moment, locomotion becomes more energy efficient. Inspired by the muscle behavior, we propose a novel actuation strategy for exoskeleton design. In this paper, the collected gait data are analyzed to identify the spring property of the human muscle-tendon system. Theoretical optimization results show that adding parallel springs can reduce the peak torque by 66%, 53%, and 48% for hip flexion/extension (F/E), hip abduction/adduction (A/A), and ankle dorsi/plantar flexion (D/PF), respectively, and the rms power by 50%, 45%, and 61%, respectively. Adding a series spring (forming a Series Elastic Actuator, SEA) reduces the peak power by 79% for ankle D/PF, and by 60% for hip A/A. A SEA does not reduce the peak power demand at other joints. The optimization approach can be used for designing other wearable robots as well.
Original languageEnglish
Title of host publication2011 IEEE International Conference on Rehabilitation Robotics
Place of PublicationPiscataway, NJ
PublisherIEEE
Number of pages6
ISBN (Electronic)978-1-4244-9862-8
ISBN (Print)978-1-4244-9863-5
DOIs
Publication statusPublished - 29 Jun 2011
EventIEEE 12th International Conference on Rehabilitation Robotics, ICORR 2011 - ETH Zurich , Zürich, Switzerland
Duration: 29 Jun 20111 Jul 2011
Conference number: 12
http://www.icorr2011.org/

Publication series

NameIEEE International Conference on Rehabilitation Robotics
PublisherIEEE
Volume2011
ISSN (Print)1945-7898
ISSN (Electronic)1945-7901

Conference

ConferenceIEEE 12th International Conference on Rehabilitation Robotics, ICORR 2011
Abbreviated titleICORR
CountrySwitzerland
CityZürich
Period29/06/111/07/11
Internet address

Fingerprint

Muscle
Tendons
Actuators
Torque
Orthotics
Ligaments
Electric motors
Prosthetics
Robotics
Robots

Keywords

  • Exoskeleton
  • Wearable robots
  • PEA
  • SEA
  • Spring
  • Actuation

Cite this

Wang, S., van Dijk, W., & van der Kooij, H. (2011). Spring uses in exoskeleton actuation design. In 2011 IEEE International Conference on Rehabilitation Robotics (IEEE International Conference on Rehabilitation Robotics; Vol. 2011). Piscataway, NJ: IEEE. https://doi.org/10.1109/ICORR.2011.5975471
Wang, Shiqian ; van Dijk, Wietse ; van der Kooij, Herman. / Spring uses in exoskeleton actuation design. 2011 IEEE International Conference on Rehabilitation Robotics. Piscataway, NJ : IEEE, 2011. (IEEE International Conference on Rehabilitation Robotics).
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title = "Spring uses in exoskeleton actuation design",
abstract = "An exoskeleton has to be lightweight, compliant, yet powerful to fulfill the demanding task of walking. This imposes a great challenge for the actuator design. Electric motors, by far the most common actuator in robotic, orthotic, and prosthetic devices, cannot provide sufficiently high peak and average power and force/torque output, and they normally require high-ratio, heavy reducer to produce the speeds and high torques needed for human locomotion. Studies on the human muscle-tendon system have shown that muscles (including tendons and ligaments) function as a spring, and by storing energy and releasing it at a proper moment, locomotion becomes more energy efficient. Inspired by the muscle behavior, we propose a novel actuation strategy for exoskeleton design. In this paper, the collected gait data are analyzed to identify the spring property of the human muscle-tendon system. Theoretical optimization results show that adding parallel springs can reduce the peak torque by 66{\%}, 53{\%}, and 48{\%} for hip flexion/extension (F/E), hip abduction/adduction (A/A), and ankle dorsi/plantar flexion (D/PF), respectively, and the rms power by 50{\%}, 45{\%}, and 61{\%}, respectively. Adding a series spring (forming a Series Elastic Actuator, SEA) reduces the peak power by 79{\%} for ankle D/PF, and by 60{\%} for hip A/A. A SEA does not reduce the peak power demand at other joints. The optimization approach can be used for designing other wearable robots as well.",
keywords = "Exoskeleton, Wearable robots, PEA, SEA, Spring, Actuation",
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Wang, S, van Dijk, W & van der Kooij, H 2011, Spring uses in exoskeleton actuation design. in 2011 IEEE International Conference on Rehabilitation Robotics. IEEE International Conference on Rehabilitation Robotics, vol. 2011, IEEE, Piscataway, NJ, IEEE 12th International Conference on Rehabilitation Robotics, ICORR 2011, Zürich, Switzerland, 29/06/11. https://doi.org/10.1109/ICORR.2011.5975471

Spring uses in exoskeleton actuation design. / Wang, Shiqian; van Dijk, Wietse; van der Kooij, Herman.

2011 IEEE International Conference on Rehabilitation Robotics. Piscataway, NJ : IEEE, 2011. (IEEE International Conference on Rehabilitation Robotics; Vol. 2011).

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

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N2 - An exoskeleton has to be lightweight, compliant, yet powerful to fulfill the demanding task of walking. This imposes a great challenge for the actuator design. Electric motors, by far the most common actuator in robotic, orthotic, and prosthetic devices, cannot provide sufficiently high peak and average power and force/torque output, and they normally require high-ratio, heavy reducer to produce the speeds and high torques needed for human locomotion. Studies on the human muscle-tendon system have shown that muscles (including tendons and ligaments) function as a spring, and by storing energy and releasing it at a proper moment, locomotion becomes more energy efficient. Inspired by the muscle behavior, we propose a novel actuation strategy for exoskeleton design. In this paper, the collected gait data are analyzed to identify the spring property of the human muscle-tendon system. Theoretical optimization results show that adding parallel springs can reduce the peak torque by 66%, 53%, and 48% for hip flexion/extension (F/E), hip abduction/adduction (A/A), and ankle dorsi/plantar flexion (D/PF), respectively, and the rms power by 50%, 45%, and 61%, respectively. Adding a series spring (forming a Series Elastic Actuator, SEA) reduces the peak power by 79% for ankle D/PF, and by 60% for hip A/A. A SEA does not reduce the peak power demand at other joints. The optimization approach can be used for designing other wearable robots as well.

AB - An exoskeleton has to be lightweight, compliant, yet powerful to fulfill the demanding task of walking. This imposes a great challenge for the actuator design. Electric motors, by far the most common actuator in robotic, orthotic, and prosthetic devices, cannot provide sufficiently high peak and average power and force/torque output, and they normally require high-ratio, heavy reducer to produce the speeds and high torques needed for human locomotion. Studies on the human muscle-tendon system have shown that muscles (including tendons and ligaments) function as a spring, and by storing energy and releasing it at a proper moment, locomotion becomes more energy efficient. Inspired by the muscle behavior, we propose a novel actuation strategy for exoskeleton design. In this paper, the collected gait data are analyzed to identify the spring property of the human muscle-tendon system. Theoretical optimization results show that adding parallel springs can reduce the peak torque by 66%, 53%, and 48% for hip flexion/extension (F/E), hip abduction/adduction (A/A), and ankle dorsi/plantar flexion (D/PF), respectively, and the rms power by 50%, 45%, and 61%, respectively. Adding a series spring (forming a Series Elastic Actuator, SEA) reduces the peak power by 79% for ankle D/PF, and by 60% for hip A/A. A SEA does not reduce the peak power demand at other joints. The optimization approach can be used for designing other wearable robots as well.

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DO - 10.1109/ICORR.2011.5975471

M3 - Conference contribution

SN - 978-1-4244-9863-5

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BT - 2011 IEEE International Conference on Rehabilitation Robotics

PB - IEEE

CY - Piscataway, NJ

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Wang S, van Dijk W, van der Kooij H. Spring uses in exoskeleton actuation design. In 2011 IEEE International Conference on Rehabilitation Robotics. Piscataway, NJ: IEEE. 2011. (IEEE International Conference on Rehabilitation Robotics). https://doi.org/10.1109/ICORR.2011.5975471