Hierarchical estimation of multiple objects from proximity relationships arising from tool manipulation

In this paper, we propose a novel method to estimate a tool's function for a humanoid robot observing a person using a tool. In this method, two types of evaluations are integrated: the relational hierarchy between a tool and objects, and their accompanying movements. This enables to estimate not only moving or conveying function but also cutting or stinging function. To estimate the relational hierarchy, overlapping regions of multiple objects are explicitly tracked based on their viewable regions. We tested this system by basic experiments in which a robot tracked a tool and an object, and estimated functions of the tool in a kitchen environment.