Design and Experimental Evaluation of a Lower-Limb Exoskeleton for Assisting Workers With Motorized Tuning of Squat Heights

Abstract

This paper presents the E-LEG, a novel semi-passive lower-limb exoskeleton for worker squatting assistance, with motorized tuning of the assistive squatting height. Compared with other passive industrial exoskeletons for the lower-limbs, the E-LEG presents novel design features namely inertial sensor for measuring the tilt angle of thigh and the novel electromagnetic switch for adjusting squat height. These features could enhance the effectiveness of the system. In addition to the introduction to exoskeleton design, this paper also reports the systematic experimental evaluation of human subjects. With the assistance of different conditions, the variability of muscular activity was evaluated in long-term static squatting task. The set of metrics to evaluate the effect of the device included leg muscle activity, plantar pressure fluctuation, plantar pressure center fluctuation and gait angles. Results show that the exoskeleton can reduce the muscular activity of the user during squatting, and it will have little affect the normal gait of the user during walking. In this study, we found that the E-LEG exoskeleton has potential effectiveness in reducing the muscular strain on long-term continuous squatting activities.

Gait Recognition and Assistance Parameter Prediction Determination Based on Kinematic Information Measured by Inertial Measurement Units

“…By adjusting the timing and magnitude of the assistance force, the exoskeleton can match the gait characteristics of the wearer well, thereby improving adaptability and efficiency. However, the adjustment is usually based on experience, resulting in poor adaptability of the exoskeleton and poor auxiliary effects [ 16 , 17 , 18 ]. To solve this problem, human-in-the-loop (HIL) optimization [ 19 , 20 ], which is the method of optimizing control parameters for individualized assistance within soft exosuits, has attracted increasing attention.…”

Design and analysis of a lower limb assistive exoskeleton robot

“…As a human body auxiliary system, assistive exoskeleton robots are widely used in military, industry, aviation, medical treatment and so on [ 7 ]. Exoskeleton robots have been developed by a number of researchers for various applications [ 8 , 9 , 10 , 11 ]. In terms of military, the “BLEEX” assistive exoskeleton robot was designed by University of California, Berkeley [ 12 , 13 , 14 , 15 , 16 , 17 ].…”

Design and Gait Control of an Active Lower Limb Exoskeleton for Walking Assistance

“…In recent years, significant advancements have been made in exoskeleton technology, catering to a wide range of applications in industries, healthcare, and military usages [1][2][3][4][5][6][7][8]. For example, assistive exoskeletons can help patients with stroke and spinal cord injuries to restore their movement abilities as effectively as the rehabilitation robots [8][9][10][11][12][13].…”