Design guidelines for industrial power assist robots for lifting heavy objects based on human's weight perception for better HRI

We hypothesized that weight perception (WP) due to inertia might be different from WP due to gravity for lifting an object with a power assist robot (PAR). Objects were lifted with a PAR independently under three different lifting schemes-unimanual, bimanual, and cooperative lift. Then, psychophysical relationships between actual and powerassisted weights (PAWs) as well as excess in load forces (LFs) were determined for each scheme separately. A novel control strategy was introduced to reduce the excess in LFs for each scheme. Finally, we proposed to use the findings as design guidelines to design PARs for lifting heavy objects in industries that would improve HRI in terms of human, robot and system.