Dynamic modeling of a new over-actuated compliant joint mechanism for human limb rehabilitation

  • Narek Zakaryan
  • Sarik Ghazaryan
  • Mikayel HarutyunyanEmail author
  • Yuri Sargsyan
Conference paper
Part of the Mechanisms and Machine Science book series (Mechan. Machine Science, volume 73)


The paper focuses on the design and simulation of the 4-bar linkage mechanism (including human limb as a link) with a compliant joint over-actuated by multiple electroactive polymers (EAPs). Multiple EAPs with elastic elements compose the compliant joint, provide safety of the mechanism and 3 rotational degrees of freedom of the human joint depending on their connecting and acting modes․ The linkage mechanism introduced in this paper has the ad-vantage of mechanical and kinematic simplicity compared to the existing devices while at the same time it is fully capable of carrying out all the exercises required by a rehabilitation treatment. The analysis undergoing the optimal synthesis of the linkage mechanism leads towards the maximization of human joint rotation range, dexterity, torque output, ensures lightness and compactness of the device. The proposed device makes use of actuation redundancy to eliminate singularity, allows to operate with increased number of less powerful EAPs (compared to some types of permissible actuators, such as electromechanical, pneumatic artificial muscles) and greatly improves the workspace dexterity. Finally, the performance of the mechanism as a rehabilitation device of a hip joint is studied by using MSC ADAMS.


Rehabilitation device 4-bar linkage EAPs redundant actuation compliant joint dynamic modeling 


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This work is supported by the grant 18T-2D236 of SSC, Armenia.


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Narek Zakaryan
    • 1
  • Sarik Ghazaryan
    • 1
  • Mikayel Harutyunyan
    • 1
    Email author
  • Yuri Sargsyan
    • 1
  1. 1.National Polytechnic University of ArmeniaYerevanArmenia

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