Novel biomimetic control of a power assist robot for horizontal transfer of objects

This paper presents a power assist robot system developed for manipulating objects in horizontal direction in cooperation with a human. Weight perception was included in robot dynamics and control. The robot was simulated and optimum maneuverability conditions for object manipulation in horizontal direction were determined. Psychophysical relationships between actual and perceived weights were determined, and load forces and motion features were analyzed for manipulating objects with the robot. Then, the human characteristics were used to design and implement a novel biomimetic control scheme to reduce the excessive load forces and accelerations, and thus to improve the system performances. The novel control reduced excessive load forces and accelerations, and thus improved the performances in terms of maneuverability, safety, operability etc. We compared the findings for horizontal manipulation of objects with power-assist to that for vertical lifting of objects. Finally, we proposed to use the findings to develop human-friendly power assist robots for manipulating heavy objects in industries.