Modeling and Simulation of an Upper Limb Exoskeleton

Abstract Exoskeletons are wearable devices that use mechanical structures to provide additional strength, activate and/or reinforce movements, and better distribute mechanical loads across the human musculoskeletal structure when people handle mechanical loads, treating motor disabilities or mitigating physical health issues due to fatigue or musculoskeletal injuries. This work presents the modeling and simulation of a human operator utilizing a passive upper limb exoskeleton. By simulating routine tasks, such as object lifting and overhead movements, this model facilitates a detailed study of human-machine interaction. Various spring mechanisms were evaluated to determine their impact on mechanical assistance. Furthermore, since attachment pads are vital for operator comfort and device stability, the loads on these pads were analyzed across all configurations. The results demonstrate that understanding spring behavior, particularly identifying regions of constant torque, can optimize control during lifting tasks. The simulation also underscores the importance of waist and mid-back pads, which distribute the majority of the spring-generated loads across the operator's body.