Title
Centroidal dynamics of a humanoid robot
Abstract
The center of mass (CoM) of a humanoid robot occupies a special place in its dynamics. As the location of its effective total mass, and consequently, the point of resultant action of gravity, the CoM is also the point where the robot's aggregate linear momentum and angular momentum are naturally defined. The overarching purpose of this paper is to refocus our attention to centroidal dynamics: the dynamics of a humanoid robot projected at its CoM. In this paper we specifically study the properties, structure and computation schemes for the centroidal momentum matrix (CMM), which projects the generalized velocities of a humanoid robot to its spatial centroidal momentum. Through a transformation diagram we graphically show the relationship between this matrix and the well-known joint-space inertia matrix. We also introduce the new concept of "average spatial velocity" of the humanoid that encompasses both linear and angular components and results in a novel decomposition of the kinetic energy. Further, we develop a very efficient $$O(N)$$ O ( N ) algorithm, expressed in a compact form using spatial notation, for computing the CMM, centroidal momentum, centroidal inertia, and average spatial velocity. Finally, as a practical use of centroidal dynamics we show that a momentum-based balance controller that directly employs the CMM can significantly reduce unnecessary trunk bending during balance maintenance against external disturbance.
Year
DOI
Venue
2013
10.1007/s10514-013-9341-4
Auton. Robots
Keywords
Field
DocType
Centroidal momentum matrix,Angular momentum,Robot dynamics algorithms,Average spatial velocity,Humanoid balance controller,Momentum based balance control
Angular momentum,Computer science,Matrix (mathematics),Simulation,Momentum,Inertia,Sylvester's law of inertia,Robot,Center of mass,Humanoid robot
Journal
Volume
Issue
ISSN
35
2-3
0929-5593
Citations 
PageRank 
References 
66
2.51
27
Authors
3
Name
Order
Citations
PageRank
David E. Orin145452.19
Ambarish Goswami21345119.12
Sung-Hee Lee333424.19