A passive upper-limb exoskeleton for industrial application based on pneumatic artificial muscles

In recent years, exoskeletons are increasingly spreading into the industrial manufacturing sector to improve productivity and to reduce the incidence of work-related musculoskeletal diseases. The aim of this paper is to present a 2 degrees of freedom (DoF) passive upper-limb exoskeleton, consisting of two McKibben pneumatic artificial muscles (PAMs), and used for assisting workers during activities that require them to keep their hands in a sustained position over the head for a long time. Simulations are performed to test two different commercial PAMs and two different designs of the transmission system used to convey the traction force exerted by the pneumatic muscles to the limb; then the results are discussed. A preliminary assembly of the exoskeleton is also presented. The study confirms that PAMs can be used to realize a passive upper-limb exoskeleton for industrial application and that appropriate working space can be obtained with an accurate design of the transmission system.