Evaluation of a machine-learning-driven active-passive upper-limb exoskeleton robot: Experimental human-in-the-loop study.

Journal: Wearable technologies
Published Date:

Abstract

Evaluating exoskeleton actuation methods and designing an effective controller for these exoskeletons are both challenging and time-consuming tasks. This is largely due to the complicated human-robot interactions, the selection of sensors and actuators, electrical/command connection issues, and communication delays. In this research, a test framework for evaluating a new active-passive shoulder exoskeleton was developed, and a surface electromyography (sEMG)-based human-robot cooperative control method was created to execute the wearer's movement intentions. The hierarchical control used sEMG-based intention estimation, mid-level strength regulation, and low-level actuator control. It was then applied to shoulder joint elevation experiments to verify the exoskeleton controller's effectiveness. The active-passive assistance was compared with fully passive and fully active exoskeleton control using the following criteria: (1) post-test survey, (2) load tolerance duration, and (3) computed human torque, power, and metabolic energy expenditure using sEMG signals and inverse dynamic simulation. The experimental outcomes showed that active-passive exoskeletons required less muscular activation torque (50%) from the user and reduced fatigue duration indicators by a factor of 3, compared to fully passive ones.

Authors

  • Ali Nasr
    Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
  • Jason Hunter
    Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
  • Clark R Dickerson
    Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
  • John McPhee
    Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.

Keywords

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