ZMP Analysis of a Humanoid Robot under Coordination of Arms and Legs

Abstract

This paper discusses the analysis of the ZMP (Zero Moment Point) of a humanoid robot under coordination of two arms and two legs. We show that there are two kinds of ZMPs for such coordination tasks, i.e., the conventional ZMP considering all sources of the force/moment acting in the foot supporting area, and the“Generalized Zero Moment Point (GZMP) ”which is a generalization of the conventional ZMP. By projecting the edges of the convex hull of the supporting points onto the floor, we show that the position and the region of the GZMP for keeping the dynamical balance can be uniquely obtained. We also show that there are edges of the convex hull where the robot can roll around the edge. The effectiveness of the proposed method is shown by some simulation results.