Description and execution of humanoid´s object manipulation based on object-environment-robot contact states

In the case of object manipulation by a humanoid robot, it is important to deal with contact states between objects, a robot, and an environment both to avoid falling down and to achieve objective manipulations. We propose a method to describe and uniformly execute various object manipulations by a humanoid robot. In description, we focus on the contact states and define manipulation phases according to the contact states. In execution, the humanoid´s controller autonomously switches manipulation phases and substantiates the contact-force controller. According to switching of the manipulation phases, the humanoid´s manipulation system switches the inputs for the contact-force controller, which includes the estimation of object´s information and motion generation. We evaluated our proposed system through experiments in which the HRP-2 robot manipulates four objects without information about the objects´ masses and necessary operational forces.