Title :
Control and Planning of 3-D Dynamic Walking With Asymptotically Stable Gait Primitives
Author :
Gregg, Robert D. ; Tilton, Adam K. ; Candido, Sal ; Bretl, Timothy ; Spong, M.W.
Author_Institution :
Dept. of Mech. Eng., Northwestern Univ., Chicago, IL, USA
Abstract :
In this paper, we present a hierarchical framework that enables motion planning for asymptotically stable 3-D bipedal walking in the same way that planning is already possible for zero moment point walking. This framework is based on the construction of asymptotically stable gait primitives for a class of hybrid dynamical systems with impacts. Each primitive corresponds to an asymptotically stable hybrid limit cycle that admits rules a priori for sequential composition with other primitives, reducing a high-dimensional feedback motion planning problem into a low-dimensional discrete tree search. As a constructive example, we develop this planning framework for the 3-D compass-gait biped, where each primitive corresponds to walking along an arc of constant curvature for a fixed number of steps. We apply a discrete search algorithm to plan a sequence of these primitives, taking the 3-D biped stably from start to goal in workspaces with obstacles. We finally show how this framework generalizes to more complex models by planning walking paths for an underactuated five-link biped.
Keywords :
asymptotic stability; feedback; legged locomotion; path planning; tree searching; 3D compass-gait biped; 3D dynamic walking; asymptotically stable 3D bipedal walking; asymptotically stable gait primitives; constant curvature; high-dimensional feedback motion planning problem; hybrid dynamical system; legged locomotion; low-dimensional discrete tree search; underactuated five-link biped; walking path planning; zero moment point walking; Legged locomotion; Limit-cycles; Path planning; Stability analysis; Switched systems; Asymptotic stability; legged locomotion; path planning; robot control; switched systems;
Journal_Title :
Robotics, IEEE Transactions on
DOI :
10.1109/TRO.2012.2210484