How dynamic is dynamic walking? Human vs. robotic gait

For design and control of biped walking robots, it is important to quantify the different level of dynamicity. We propose the Dynamic Gait Measure (DGM) that quantifies the dynamicity of a given biped walking motion. The DGM is associated with the gait stability, and quantifies the effects of inertia in terms of the Zero-Moment Point (ZMP) and the ground projection of center of mass (GCOM). Also, DGM takes into account the stance foot dimension and the relative threshold between static and dynamic walking. Human-like and robotic walking motions are generated for a planar biped system from an optimization problem. The resulting DGMs demonstrate their dependence on the stance foot dimension as well as the walking motion. The DGM results verify the dynamic nature of normal human walking. For a given gait motion, smaller foot dimension results in increased dynamicity. Moreover, the DGMs for normal human walking are greater than those for robotic walking. The proposed results will benefit the development of walking robots. Copyright © 2011 by ASME.