3D Dynamic Walking with Underactuated Humanoid Robots: A Direct Collocation Framework for Optimizing Hybrid Zero Dynamics
Loading...
Author(s)
Hereid, Ayonga
Cousineau, Eric A.
Hubick, Christian M.
Ames, Aaron D.
Advisor(s)
Editor(s)
Collections
Supplementary to:
Permanent Link
Abstract
Hybrid zero dynamics (HZD) has emerged as a
popular framework for dynamic and underactuated bipedal
walking, but has significant implementation difficulties when
applied to the high degrees of freedom present in humanoid
robots. The primary impediment is the process of gait design–
it is difficult for optimizers to converge on a viable set of virtual
constraints defining a gait. This paper presents a methodology
that allows for the fast and reliable generation of efficient
multi-contact robotic walking gaits through the framework of
HZD, even in the presence of underactuation. To achieve this
goal, we unify methods from trajectory optimization with the
control framework of multi-domain hybrid zero dynamics. By
formulating a novel optimization problem in the context of
direct collocation and generating analytic Jacobians for the
constraints, solving the resulting nonlinear program becomes
tractable for large-scale nonlinear programming solvers, even
for systems as high-dimensional as humanoid robots. We
experimentally validated our methodology on the spring-legged
prototype humanoid, DURUS, showing that the optimization
approach yields dynamic and stable 3D walking gaits.
Sponsor
Date
2016-05
Extent
Resource Type
Text
Resource Subtype
Proceedings