Design and analysis of a passive upper limb exoskeleton for augmented construction worker strength

Construction workers often operate at great heights, relying heavily on their muscles to support work-related weight. Over time, this leads to fatigue, and in worst-case scenarios, accidents occur when workers drop heavy objects due to exhaustion. This study then focuses on designing and implementing a passive upper limb exoskeleton to enhance worker performance and reduce fatigue in industrial environments. The exoskeleton utilizes a rack-and-pinion mechanism synchronized with natural arm movements to provide gravitational support. Key features include an adjustable range screw for easy disengagement and a ball-and-socket joint for arm dexterity. The exoskeleton is customizable through torque adjustment, ensuring user-specific support. Three different designs were created in SolidWorks and evaluated in Ansys simulation to select the best one. These designs incorporated materials such as carbon fiber and nylon. Loading tests were conducted on the designs, and for the best design, the maximum deformation for carbon fiber was 0.8mm, while for nylon, it was 1.17mm. The maximum stress for carbon fiber was 11.9 MPa, while for nylon, it was 18.16 MPa. The factor of safety for the carbon fiber material was 2.1, while for nylon, it was 1.38.