Eulerian ZMP resolution based bipedal walking: Discussions on the intrinsic angular momentum rate change about center of mass

This paper is aimed at implementing Eulerian ZMP Resolution method to bipedal walking pattern generation. The main strategy in this method is to ensure the dynamic balance by generating feasible ZMP-based CoM trajectories. For this purpose, we employ ZMP equations in spherical coordinates, so that the intrinsic angular momentum rate change about center of mass is included explicitly in a natural way. This fact results in two merits: 1) Undesired torso angle fluctuation and body twists are expected to be more restrainable comparing to other methods in which intrinsic angular momentum information is ignored or zero-referenced. 2) The interference between motions in sagittal and lateral planes can be extracted. In this article, we mainly investigate the first merit and briefly discuss about the second merit. Applying the aforementioned technique, Eulerian ZMP Resolution, we simulated bipedal walking on a 3-D dynamic simulator. Secondarily, we conducted bipedal walking experiments on the actual bipedal robot. In conclusion, we obtained dynamically equilibrated bipedal walking cycles, which satisfactorily verify the efficiency of Eulerian ZMP Resolution technique over conventional methods.