Cooperative Object Transfer: Effect of Observing Different Part of the Object on the Cooperative Task Smoothness

Designing robots with human characteristics is a great challenge to researcher to fulfill the needs of robotic technology in human occupied environment. This research aims to enable a smooth and natural cooperative object transfer by a human hand and a robot manipulator mimicking the same task performed by two humans. Prior to the development of the human-robot system, investigation on characteristics which generate a smooth cooperative object transfer in a human-human system is crucial. Perceiving certain part of an object in transfer, acts as a medium for the exchange of object's motion information between subjects. We have investigated the effect of perceiving different parts of the object in transfer to the cooperative motion smoothness (smoothness is quantitatively evaluated using Minimum Jerk Model). The result suggests that observing the center part of the experimental object produced more frequent, a smooth and natural motion for task executed in leftward/rightward and upward/downward direction. Moreover, the center part was associated with less object rotation during smooth task in these directions. However, there is no significant difference between End and Center case for the same task executed in forward/backward direction. We also considered the importance of having information of cooperative task initiation signal and a target position to the cooperative task smoothness. Regardless of which part of the object being perceived, smoother task is frequently generated when both signals are available to both subjects. Although the effect of End and Center case may be significant in human-human system; in human-robot system, both cases should be further tested and evaluated.