Whole-Body Humanoid Balance Control with Dynamically Loading/Unloading Objects

Abstract

When a humanoid lifts a heavy object, or carries an object in a bag or a carriage, it needs to change the reference CoM(center of mass) and ZMP(Zero Moment Position) in order not to fall down. However, it is not natural to design a reference CoM and ZMP to lift or to carry an object every time. In this paper, objects held by a hand are considered as an augmented virtual link connected at the end of the hand, and it is included in calculating the humanoid CoM. The mass augmentation is done in real time and thus objects can be loaded and unloaded dynamically without any change of reference CoM and ZMP. The balanced pose of the humanoid is obtained by using MECoM(Motion-Embedded CoM) Jacobian resolution method. The proposed method is verified by an experiment.