Physical and Virtual Assessment of a Passive Exoskeleton

The paper describes the testing activity carried out on a commercial passive lower limb exoskeleton: the Chairless Chair, a wearable sitting support that allows workers to switch between a standing and a sitting posture. Tests were carried out with FCA workers who volunteered for the study. Laboratory trials served to familiarize the users and to obtain an initial feedback on the usability of the device in the assembly line. At a second step, virtual modelling of a few static postures was carried out, reproducing the anthropometry and the postural angles of the worker while using the exoskeleton. A main output of the model is the estimate of what forces are exchanged between the subject and the exoskeleton. In the case of the lower limb exoskeleton, an important parameter to consider is the percentage of the subject's weight that is sustained by the exoskeleton frame. The higher is this percentage, the lower will be the strain on the subject's lower limbs. First comparison between experimental and simulated results showed good agreement and auspicious advantages of exoskeletons in relieving the strain on workers.