Unimanual and bimanual weight discrimination in lifting objects with a power assist system

In this paper, we designed a 1 DOF power assist system for lifting objects based on human operator's perception of object weight. We established psychophysical relationships between the actual weights and the power assisted weights of objects lifted with the power assist system. We also determined the excess of the load forces that humans applied while lifting objects with the system. The psychophysical relationships were established and the excessive load forces were determined for two protocols independently: 1) unimanual lifting, and 2) bimanual lifting. Then, we suggested using the findings to design power assist systems for carrying heavy objects in various industries that would enhance maneuverability, naturalness, ease of use, stability, safety etc. while carrying heavy objects with the power assist systems.