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Configuration design and assisting effect evaluation of a novel double-support closed-chain unpowered load-carrying exoskeleton based on variable pivot gait

Published online by Cambridge University Press:  07 October 2025

Cunjin Ai Open the ORCID record for Cunjin Ai [Opens in a new window] ,
Jianjun Zhang ,
Jun Wei Open the ORCID record for Jun Wei [Opens in a new window] ,
Jingke Song Open the ORCID record for Jingke Song [Opens in a new window] ,
Chenglei Liu  and
Anyu Shi
Cunjin Ai
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China School of Intelligent Manufacturing Engineering/Automotive Engineering, Chongqing University of Arts and Sciences, Chongqing, 402160, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China
Jianjun Zhang*
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China Hebei Provincial Key Laboratory of Robot Perception and Human–Machine Fusion, Tianjin, 300401, China
Jun Wei*
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China Hebei Provincial Key Laboratory of Robot Perception and Human–Machine Fusion, Tianjin, 300401, China
Jingke Song
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China Hebei Provincial Key Laboratory of Robot Perception and Human–Machine Fusion, Tianjin, 300401, China
Chenglei Liu
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China Hebei Provincial Key Laboratory of Robot Perception and Human–Machine Fusion, Tianjin, 300401, China
Anyu Shi
Affiliation:
School of Mechanical Engineering, Hebei University of Technology , Tianjin, 300401, China Intelligent Rehabilitation Device and Detection Technology Engineering Research Center of the Ministry of Education, Tianjin, 300401, China Hebei Provincial Key Laboratory of Robot Perception and Human–Machine Fusion, Tianjin, 300401, China
*
Corresponding authors: Jianjun Zhang; Email: zhjjun@hebut.edu.cn, Jun Wei; Email: jun.wei@hebut.edu.cn
Corresponding authors: Jianjun Zhang; Email: zhjjun@hebut.edu.cn, Jun Wei; Email: jun.wei@hebut.edu.cn
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Abstract

Based on the characteristics of the variable pivot gait during the human load-carrying, this paper proposes a double-leg coordination assistance principle for load-carrying: assisting support of the guiding leg at the heel-pivot stage by the spring to reduce the collision, which can reduce the ankle moment of the following leg that is performing the push-off at the toe-pivot stage. A novel unpowered load-carrying exoskeleton (ULE) with a double-support closed-chain configuration is designed, and the theoretical verification is carried out. Five subjects participate in the load-carrying and metabolic cost experiments for assisting and energy-saving effect evaluation, and the angle and moment of human joints, plantar pressure, spring compression and human net metabolic rate are analyzed. Compared with carrying load by the human alone, wearing the novel ULE with spring reduces the human peak ankle moment performing the push-off by up to 11.9 ± 1.6% (Mean±SE, 10 kg), average ankle moment over the support phase by up to 36.8 ± 9.1% (Mean±SE, 5 kg) and the average vertical plantar pressure by up to 8.1 ± 1%% (Mean±SE, 15 kg). Meanwhile, wearing the novel ULE reduces the human net metabolic rate by 5.6 ± 0.5% (Mean±SE, 10 kg), 4.1 ± 0.7% (Mean±SE, 15 kg) and 5.9 ± 1.6% (Mean±SE, 20 kg). The results show that the novel ULE can provide support and joint moment assistance over the whole support phase while reducing human net metabolic rate. This study can also be applied to the powered load-carrying exoskeleton, providing a new avenue.

Keywords

variable pivot gaitunpowered exoskeletondouble-support closed-chainload-carrying

Information

Type
Research Article
Information
Robotica , First View , pp. 1 - 25
Copyright
© The Author(s), 2025. Published by Cambridge University Press

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