Whole-body pushing manipulation with contact posture planning of large and heavy object for humanoid robot

Humanoid robot is able to execute various behavior to manipulate objects because of high degree-of-freedom around the whole-body. Although hands contact with objects and exert force in ordinary pushing motion by robot, pushing motion contacting with the object at various regions of whole-body has potential for extending the scope of feasible manipulation. We derive the fundamental formulas of humanoid robot in the situation that the external force is applied to the arbitrary region of whole-body, and then propose the method to generate and execute the pushing motion based on the formulas. The proposed method is generalized for enabling to select a contact point with an object from whole-body regions and control the pushing force applied to the sensorless region. In order to verify the effectiveness, we show the experimental result that a lifesized humanoid carries large and heavy objects by pushing with various regions of whole-body.

I. Introduction

Carrying large and heavy objects is one of the important tasks which are expected to be achieved by a robot. Humanoid robot is distributing much flexibility around whole-body, so humanoid can make the best use of self body structure. As shown in Fig. 1, humanoid can exert large pushing force by tilting whole-body and using self-weight, that is an advantage compared with manipulation robot with wheel. Human manipulates objects by switching various strategies depending on object and environment unconsciously. Humanoid, which has the same body structure with human, should be able to achieve various carrying strategies. Pushing behavior which was achieved by humanoid so far is limited to pushing with hands. However, there is no doubt that humanoid structure has a potential for achieving more various pushing behavior.