724 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
3D Visual Perception for Self-Driving Cars using a Multi-Camera System: Calibration, Mapping, Localization, and Obstacle Detection
Cameras are a crucial exteroceptive sensor for self-driving cars as they are
low-cost and small, provide appearance information about the environment, and
work in various weather conditions. They can be used for multiple purposes such
as visual navigation and obstacle detection. We can use a surround multi-camera
system to cover the full 360-degree field-of-view around the car. In this way,
we avoid blind spots which can otherwise lead to accidents. To minimize the
number of cameras needed for surround perception, we utilize fisheye cameras.
Consequently, standard vision pipelines for 3D mapping, visual localization,
obstacle detection, etc. need to be adapted to take full advantage of the
availability of multiple cameras rather than treat each camera individually. In
addition, processing of fisheye images has to be supported. In this paper, we
describe the camera calibration and subsequent processing pipeline for
multi-fisheye-camera systems developed as part of the V-Charge project. This
project seeks to enable automated valet parking for self-driving cars. Our
pipeline is able to precisely calibrate multi-camera systems, build sparse 3D
maps for visual navigation, visually localize the car with respect to these
maps, generate accurate dense maps, as well as detect obstacles based on
real-time depth map extraction
Self-Supervised Deep Visual Odometry with Online Adaptation
Self-supervised VO methods have shown great success in jointly estimating
camera pose and depth from videos. However, like most data-driven methods,
existing VO networks suffer from a notable decrease in performance when
confronted with scenes different from the training data, which makes them
unsuitable for practical applications. In this paper, we propose an online
meta-learning algorithm to enable VO networks to continuously adapt to new
environments in a self-supervised manner. The proposed method utilizes
convolutional long short-term memory (convLSTM) to aggregate rich
spatial-temporal information in the past. The network is able to memorize and
learn from its past experience for better estimation and fast adaptation to the
current frame. When running VO in the open world, in order to deal with the
changing environment, we propose an online feature alignment method by aligning
feature distributions at different time. Our VO network is able to seamlessly
adapt to different environments. Extensive experiments on unseen outdoor
scenes, virtual to real world and outdoor to indoor environments demonstrate
that our method consistently outperforms state-of-the-art self-supervised VO
baselines considerably.Comment: Accepted by CVPR 2020 ora
- …