Adaptive Support and Integrated Force Measurement for Passive Exoskeletons

In logistics and industrial assembly, repetitive tasks such as lifting heavy loads and overhead work cause significant physical strain, leading to musculoskeletal disorders and reduced job satisfaction. Both passive and active exoskeletons can help to reduce strain by supporting key body parts; however, passive systems provide constant, non-adjustable support with limited user feedback, which can reduce their acceptance and effectiveness. This study extends a passive exoskeleton by integrating a load cell for real-time force measurement and a servo-driven switching mechanism. Custom activity recognition, implemented through motion sensors, dynamically toggles the support: activating it during high-force tasks (e.g., lifting) to reduce strain, and deactivating it during movement (e.g., walking) to ensure mobility. The force measurement system is used to visualize the real-time support profile, providing the users with insights into the support delivered. A laboratory study with five participants validated the system in a simulated workflow, that include loading, transporting, and unloading boxes. Results show the exoskeleton adapts effectively to user activity, providing targeted support during demanding tasks while maintaining flexibility, which may enhance user acceptance and trust.