Assistive Control of Knee Exoskeletons for Human Walking on Sandy Terrain.

Journal: IEEE transactions on bio-medical engineering
Published Date:

Abstract

Human walkers encounter diverse terrains such as sand and solid ground, which result in distinct gait locomotion and energy costs. This study aims to design and validate a knee stiffness-based model predictive control approach for knee exoskeletons to assist walking on sand. A comparative analysis of human gait, kinematics, and kinetics on sand versus solid ground is conducted. A machine learning-based estimation scheme is developed to predict ground reaction forces in real time. These predictions, combined with human joint torque estimates, are used to design a knee exoskeleton controller that employs a model predictive stiffness control strategy. The experiments demonstrate significant differences in lower limb kinematics and kinetics, as well as a 15% reduction in major muscle activation and a 3.7% (albeit insignificant) reduction in metabolic cost during exoskeleton-assisted walking on sand. These results confirm that the proposed control framework effectively improves walking efficiency on sandy terrain by reducing both muscular effort and metabolic demand.

Authors

  • Chunchu Zhu
  • Xunjie Chen
  • Jingang Yi

Keywords

No keywords available for this article.