%0 Journal Article
%T Kinematic primitives for walking and trotting gaits of a quadruped robot with compliant legs
%A Alexander T. Spr£¿witz
%A Mostafa Ajallooeian
%A Alexandre Tuleu
%A Auke Jan Ijspeert
%J Frontiers in Computational Neuroscience
%D 2014
%I Frontiers Media
%R 10.3389/fncom.2014.00027
%X In this work we research the role of body dynamics in the complexity of kinematic patterns in a quadruped robot with compliant legs. Two gait patterns, lateral sequence walk and trot, along with leg length control patterns of different complexity were implemented in a modular, feed-forward locomotion controller. The controller was tested on a small, quadruped robot with compliant, segmented leg design, and led to self-stable and self-stabilizing robot locomotion. In-air stepping and on-ground locomotion leg kinematics were recorded, and the number and shapes of motion primitives accounting for 95% of the variance of kinematic leg data were extracted. This revealed that kinematic patterns resulting from feed-forward control had a lower complexity (in-air stepping, 2¨C3 primitives) than kinematic patterns from on-ground locomotion (¦Ím4 primitives), although both experiments applied identical motor patterns. The complexity of on-ground kinematic patterns had increased, through ground contact and mechanical entrainment. The complexity of observed kinematic on-ground data matches those reported from level-ground locomotion data of legged animals. Results indicate that a very low complexity of modular, rhythmic, feed-forward motor control is sufficient for level-ground locomotion in combination with passive compliant legged hardware.
%K motion primitives
%K locomotion patterns
%K central pattern generator
%K quadruped robot
%K passive leg compliance
%K entrainment
%K principal component analysis
%K walk and trot
%U http://www.frontiersin.org/Journal/10.3389/fncom.2014.00027/abstract