Design and Performance Evaluation of Unpowered Hip-Assisted Exoskeletons

Abstract

Human augmentation is an important branch of robotics research aimed at reducing metabolic energy consumption, delaying fatigue, and increasing body speed. However, existing evaluation protocols lack systematic frameworks for unpowered hip devices. This study aims to reduce the energy consumption of human movement without providing additional power and to develop a hip-assisted exoskeleton device. Through gait, plantar pressure, and electromyography tests, the system studied the assistance performance of exoskeletons in three wearing states: “No exo.”, “Exo. on”, and “Exo. off”. A comprehensive evaluation method of unpowered lower limb wearable exoskeleton (CE-ULLWE) is established, featuring the novel three-condition design that isolates the structural mass effect from true assistance via the “Exo. off” condition, and integrates multi-indicator metrics including kinematics, dynamics, plantar pressure, EMG, and metabolic simulations. Combining wearing and exercise testing to obtain the human–machine compatibility of exoskeletons and the subjective comfort of users when wearing exoskeletons. Experimental results demonstrate that wearing the exoskeleton increases peak hip and knee angular velocities by 18.5% and 9.0%, reduces joint power, decreases plantar pressure center excursion by 32.3%, and lowers total metabolic energy consumption by 16.0%, confirming its effectiveness in reducing metabolic cost and delaying fatigue. This achievement has important theoretical guidance and practical application value for the design, function, and performance evaluation of wearable assistive exoskeleton products. The proposed CE-ULLWE offers a replicable, multi-indicator framework that clarifies assistive efficacy and guides future exoskeleton optimization.