Design of motion capture system-aided lower limb exoskeleton
Journal
Advances in Mechanical Engineering
Journal Volume
17
Journal Issue
6
Start Page
16878132251349638
ISSN
1687-8132
1687-8140
Date Issued
2025-06-24
Author(s)
Abstract
This paper develops a human lower limb exoskeleton device combining kinematics, vibration, biomechanics, and a machine vision motion capture system that can replicate the physiological structure of human lower limbs, accurately and automatically follow the user’s movements, and assist the human body in weight-bearing walking. First, the visual environment is constructed and calibrated with 36 reflective marking balls using the CAST marker set method. The maximum error is 0.893 mm, indicating that the accuracy of the system is submillimeter. The maximum difference between the kinematic simulation and the experiment is 34.8% on the Y axis and 13.9% on the Z axis, both of which indicate good agreement. Then, finite element modeling is used to analyze the human lower limb exoskeleton in its standing phase and the equivalent position of the legs. The results showed that the corresponding force value of both legs’ support is the largest, being 51.8% of the 6061-T6 yield strength and thus meeting the strength requirements. The first-order intrinsic frequencies are 18.239 and 23.086 Hz for the standing phase and the leg brace phase, respectively. This indicates that the human lower limb exoskeleton does not resonate with the motor during walking. Walking experiments are conducted on subjects wearing a 20 kg load. The maximum booster effect occurs in the right thigh of the subjects, and the variation range of EMG amplitude of subjects wearing the human lower limb exoskeleton is 15.5% of that when not wearing it. The above results show that the exoskeleton assists the human body and can automatically follow the human body when walking.
Subjects
finite element analysis
human lower extremity exoskeleton
kinematic and dynamic analysis
structural design
SDGs
Publisher
SAGE Publications
Type
journal article