Author
Uğurlu, Regaip Barkan, Havoutis, I., Semini, C., Kayamori, K., Caldwell, D. G., Narikiyo, T.
Publication Date
2015-04
Publication Place
-
Springer Science+Business Media
Subject
Quadrupedal locomotion, Dynamic trot-walking, Active compliance, Pattern generation
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
1573-7527
Record ID
ddf9eee3-3ffa-4444-8491-67b43af41918
Library Location
Mechanical Engineering
Date
2015-04
Notes
Due to copyright restrictions, the access to the full text of this article is only available via subscription.
Sample Text
In this paper, we introduce a method that synergistically combines an analytical pattern generator and a feedback controller frame, which are developed for the purpose of synthesizing dynamic quadrupedal trot-walking locomotion on flat and uneven surfaces. To begin with, the pattern generator analytically produces feasible and dynamically balanced joint motions in accordance with the desired trot-walking characteristics, with no empirical parameter tuning requirements. In concurrence with the pattern generation, a two-phased controller frame is constructed for closed-loop sensory feedback: (i) virtual admittance controller via force sensing, (ii) upper torso angular momentum regulation via gyro sensing. The former controller evaluates joint force errors and generates the corresponding joint displacement for a given set of virtual spring-damper couples. Together with the position constraints, these displacements are additionally fed-back to local servos for achieving compliant quadrupedal locomotion with which the position/force trade-off is addressed. The second controller, that is simultaneously used, evaluates the upper torso angular momentum rate change error using measured and reference orientation information. It then regulates the torso orientation in a dynamically consistent way as the rotational inertia is characterized. In order to validate the proposed methodology several experiments are conducted on both flat and uneven surfaces, using two robots with distinct properties; a ∼7 kg cat-sized electrically actuated quadruped (RoboCat-1), and a ∼80 kg Alpine Ibex-sized hydraulically actuated quadruped (HyQ). As a result we demonstrate continuous, repetitive, compliant and dynamically balanced trot-walking cycles in real-robot experiments, adequately confirming the effectiveness of the proposed approach.
DOI
10.1007/s10514-015-9422-7
