Displacement-load force-perceived weight relationships in lifting objects with power-assist

This paper deals with the design of a 1-DOF power assist system (PAS) for lifting objects in vertical direction based on a hypothesis that pertains to operator's weight perception. We particularly studied the relationships among object's displacement, load force (vertical lifting force) and perceived weight for the objects lifted with the PAS. We also compared the load force features for power-assist-lifted objects to that for manually lifted objects for equal heaviness. Finally, we proposed using the findings to develop human-friendly PASs for lifting heavy objects in industries such as construction, military operations, manufacturing and assembly, logistics and transport, mining etc.