36,789 research outputs found
Pose Graph Optimization for Unsupervised Monocular Visual Odometry
Unsupervised Learning based monocular visual odometry (VO) has lately drawn
significant attention for its potential in label-free leaning ability and
robustness to camera parameters and environmental variations. However,
partially due to the lack of drift correction technique, these methods are
still by far less accurate than geometric approaches for large-scale odometry
estimation. In this paper, we propose to leverage graph optimization and loop
closure detection to overcome limitations of unsupervised learning based
monocular visual odometry. To this end, we propose a hybrid VO system which
combines an unsupervised monocular VO called NeuralBundler with a pose graph
optimization back-end. NeuralBundler is a neural network architecture that uses
temporal and spatial photometric loss as main supervision and generates a
windowed pose graph consists of multi-view 6DoF constraints. We propose a novel
pose cycle consistency loss to relieve the tensions in the windowed pose graph,
leading to improved performance and robustness. In the back-end, a global pose
graph is built from local and loop 6DoF constraints estimated by NeuralBundler
and is optimized over SE(3). Empirical evaluation on the KITTI odometry dataset
demonstrates that 1) NeuralBundler achieves state-of-the-art performance on
unsupervised monocular VO estimation, and 2) our whole approach can achieve
efficient loop closing and show favorable overall translational accuracy
compared to established monocular SLAM systems.Comment: Accepted to ICRA'201
Graph Element Networks: adaptive, structured computation and memory
We explore the use of graph neural networks (GNNs) to model spatial processes
in which there is no a priori graphical structure. Similar to finite element
analysis, we assign nodes of a GNN to spatial locations and use a computational
process defined on the graph to model the relationship between an initial
function defined over a space and a resulting function in the same space. We
use GNNs as a computational substrate, and show that the locations of the nodes
in space as well as their connectivity can be optimized to focus on the most
complex parts of the space. Moreover, this representational strategy allows the
learned input-output relationship to generalize over the size of the underlying
space and run the same model at different levels of precision, trading
computation for accuracy. We demonstrate this method on a traditional PDE
problem, a physical prediction problem from robotics, and learning to predict
scene images from novel viewpoints.Comment: Accepted to ICML 201
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