Functional design and testing of an upper-limb exoskeleton for wheelchair-mounted assistance

Abstract

Upper-limb exoskeletons mounted on wheelchairs represent a promising solution for paraplegic patients, as they can reduce shoulder overload while enabling the performance of daily activities. This paper presents the modeling, functional design, and prototyping of a novel five-degree-of-freedom (5-DoF) upper-limb exoskeleton, developed with a strong emphasis on lightness and biomechanical compatibility to ensure low-effort use by patients. The proposed mechanical architecture is specifically designed to facilitate seamless integration with a wheelchair. Kinematic modeling is performed using Denavit-Hartenberg (DH) parameters and is experimentally validated through motion capture data obtained with an OptiTrack system. The results demonstrate that the joint ranges closely match physiological human motion and confirm the validity of the proposed kinematic model. This work establishes a solid baseline for the development of intelligent control strategies in future research, in which motorization will be introduced to actuate at least one degree of freedom of the system, specifically shoulder abduction.