Generic Node Removal for Factor-Graph SLAM - Robotics Institute Carnegie Mellon University

Generic Node Removal for Factor-Graph SLAM

Nicholas Carlevaris-Bianco, Michael Kaess, and Ryan M. Eustice
Journal Article, IEEE Transactions on Robotics, Vol. 30, No. 6, pp. 1371 - 1385, December, 2014

Abstract

This paper reports on a generic factor-based method for node removal in factor-graph simultaneous localization and mapping (SLAM), which we call generic linear constraints (GLCs). The need for a generic node removal tool is motivated by long-term SLAM applications whereby nodes are removed in order to control the computational cost of graph optimization. GLC is able to produce a new set of linearized factors over the elimination clique that can represent either the true marginalization (i.e., dense GLC), or a sparse approximation of the true marginalization using a Chow-Liu tree (i.e., sparse GLC). The proposed algorithm improves upon commonly used methods in two key ways: First, it is not limited to graphs with strictly full-state relative-pose factors and works equally well with other low-rank factors such as those produced by monocular vision. Second, the new factors are produced in a way that accounts for measurement correlation, a problem encountered in other methods that rely strictly upon pairwise measurement composition. We evaluate the proposed method over multiple real-world SLAM graphs and show that it outperforms other recently-proposed methods in terms of Kullback-Leibler divergence. Additionally, we experimentally demonstrate that the proposed GLC method provides a principled and flexible tool to control the computational complexity of long-term graph SLAM, with results shown for 34.9 h of real-world indoor-outdoor data covering 147.4 km collected over 27 mapping sessions spanning a period of 15 months.

BibTeX

@article{Carlevaris-Bianco-2014-7939,
author = {Nicholas Carlevaris-Bianco and Michael Kaess and Ryan M. Eustice},
title = {Generic Node Removal for Factor-Graph SLAM},
journal = {IEEE Transactions on Robotics},
year = {2014},
month = {December},
volume = {30},
number = {6},
pages = {1371 - 1385},
keywords = {Simultaneous localization and mapping (SLAM), long-term autonomy, mobile robotics, factor graphs, marginalization},
}