Sensors (Dec 2022)

Real-Time Human Activity Recognition with IMU and Encoder Sensors in Wearable Exoskeleton Robot via Deep Learning Networks

  • Ismael Espinoza Jaramillo,
  • Jin Gyun Jeong,
  • Patricio Rivera Lopez,
  • Choong-Ho Lee,
  • Do-Yeon Kang,
  • Tae-Jun Ha,
  • Ji-Heon Oh,
  • Hwanseok Jung,
  • Jin Hyuk Lee,
  • Won Hee Lee,
  • Tae-Seong Kim

DOI
https://doi.org/10.3390/s22249690
Journal volume & issue
Vol. 22, no. 24
p. 9690

Abstract

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Wearable exoskeleton robots have become a promising technology for supporting human motions in multiple tasks. Activity recognition in real-time provides useful information to enhance the robot’s control assistance for daily tasks. This work implements a real-time activity recognition system based on the activity signals of an inertial measurement unit (IMU) and a pair of rotary encoders integrated into the exoskeleton robot. Five deep learning models have been trained and evaluated for activity recognition. As a result, a subset of optimized deep learning models was transferred to an edge device for real-time evaluation in a continuous action environment using eight common human tasks: stand, bend, crouch, walk, sit-down, sit-up, and ascend and descend stairs. These eight robot wearer’s activities are recognized with an average accuracy of 97.35% in real-time tests, with an inference time under 10 ms and an overall latency of 0.506 s per recognition using the selected edge device.

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