Design of a perfect balance system for active upper-extremity exoskeletons

Richard L. Smith, Joan Lobo Prat, Herman van der Kooij, Arno H.A. Stienen

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

    9 Citations (Scopus)


    Passive gravity compensation in exoskeletons significantly reduces the amount of torque and energy needed from the actuators. So far, no design has been able to achieve perfect balance without compromising the exoskeleton characteristics. Here we propose a novel design that integrates an existing statically-balanced mechanism with two springs and four degrees of freedom into a general-purpose exoskeleton design, that can support any percentage of the combined weight of exoskeleton and arm. As it allows for three rotational degrees of freedom at the shoulder and one at the elbow, it does not compromise exoskeleton characteristics and can be powered with any choice of passive or active actuation method. For instance, with this design a perfectly balanced exoskeleton design with inherently safe, passive actuators on each joint axis becomes possible. The potential reduction in required actuator torque, power and weight, simplification of control, improved dynamic performance, and increased safety margin, all while maintaining perfect balance, are the major advantages of the design, but the integrated systems does add a significant amount of complexity. Future integration in an actual exoskeleton should prove if this tradeoff is beneficial.
    Original languageEnglish
    Title of host publication2013 IEEE 13th International Conference on Rehabilitation Robotics (ICORR)
    Subtitle of host publicationSeattle, WA, USA, 24-26 June 2013
    Place of PublicationPiscataway, NJ
    ISBN (Print)978-146736024-1
    Publication statusPublished - 24 Jun 2013
    EventIEEE 13th International Conference on Rehabilitation Robotics, ICORR 2013: Design and Control of Robotic Exoskeletons with Compliant Joints and Actuation Systems - University of Washington , Seattle, United States
    Duration: 24 Jun 201326 Jun 2013
    Conference number: 13

    Publication series

    NameIEEE International Conference on Rehabilitation Robotics (ICORR)
    ISSN (Print)1945-7898


    ConferenceIEEE 13th International Conference on Rehabilitation Robotics, ICORR 2013
    Abbreviated titleICORR
    Country/TerritoryUnited States
    Internet address


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