3,030 research outputs found
3DFeat-Net: Weakly Supervised Local 3D Features for Point Cloud Registration
In this paper, we propose the 3DFeat-Net which learns both 3D feature
detector and descriptor for point cloud matching using weak supervision. Unlike
many existing works, we do not require manual annotation of matching point
clusters. Instead, we leverage on alignment and attention mechanisms to learn
feature correspondences from GPS/INS tagged 3D point clouds without explicitly
specifying them. We create training and benchmark outdoor Lidar datasets, and
experiments show that 3DFeat-Net obtains state-of-the-art performance on these
gravity-aligned datasets.Comment: 17 pages, 6 figures. Accepted in ECCV 201
Navigace mobilních robotů v neznámém prostředí s využitím měření vzdáleností
The ability of a robot to navigate itself in the environment is a crucial step towards its autonomy. Navigation as a subtask of the development of autonomous robots is the subject of this thesis, focusing on the development of a method for simultaneous localization an mapping (SLAM) of mobile robots in six degrees of freedom (DOF). As a part of this research, a platform for 3D range data acquisition based on a continuously inclined laser rangefinder was developed. This platform is presented, evaluating the measurements and also presenting the robotic equipment on which the platform can be fitted. The localization and mapping task is equal to the registration of multiple 3D images into a common frame of reference. For this purpose, a method based on the Iterative Closest Point (ICP) algorithm was developed. First, the originally implemented SLAM method is presented, focusing on the time-wise performance and the registration quality issues introduced by the implemented algorithms. In order to accelerate and improve the quality of the time-demanding 6DOF image registration, an extended method was developed. The major extension is the introduction of a factorized registration, extracting 2D representations of vertical objects called leveled maps from the 3D point sets, ensuring these representations are 3DOF invariant. The extracted representations are registered in 3DOF using ICP algorithm, allowing pre-alignment of the 3D data for the subsequent robust 6DOF ICP based registration. The extended method is presented, showing all important modifications to the original method. The developed registration method was evaluated using real 3D data acquired in different indoor environments, examining the benefits of the factorization and other extensions as well as the performance of the original ICP based method. The factorization gives promising results compared to a single phase 6DOF registration in vertically structured environments. Also, the disadvantages of the method are discussed, proposing possible solutions. Finally, the future prospects of the research are presented.Schopnost lokalizace a navigace je podmínkou autonomního provozu mobilních robotů. Předmětem této disertační práce jsou navigační metody se zaměřením na metodu pro simultánní lokalizaci a mapování (SLAM) mobilních robotů v šesti stupních volnosti (6DOF). Nedílnou součástí tohoto výzkumu byl vývoj platformy pro sběr 3D vzdálenostních dat s využitím kontinuálně naklápěného laserového řádkového scanneru. Tato platforma byla vyvinuta jako samostatný modul, aby mohla být umístěna na různé šasi mobilních robotů. Úkol lokalizace a mapování je ekvivalentní registraci více 3D obrazů do společného souřadného systému. Pro tyto účely byla vyvinuta metoda založená na algoritmu Iterative Closest Point Algorithm (ICP). Původně implementovaná verze navigační metody využívá ICP s akcelerací pomocí kd-stromů přičemž jsou zhodnoceny její kvalitativní a výkonnostní aspekty. Na základě této analýzy byly vyvinuty rozšíření původní metody založené na ICP. Jednou z hlavních modifikací je faktorizace registračního procesu, kdy tato faktorizace je založena na redukci dat: vytvoření 2D „leveled“ map (ve smyslu jednoúrovňových map) ze 3D vzdálenostních obrazů. Pro tuto redukci je technologicky i algoritmicky zajištěna invariantnost těchto map vůči třem stupňům volnosti. Tyto redukované mapy jsou registrovány pomocí ICP ve zbylých třech stupních volnosti, přičemž získaná transformace je aplikována na 3D data za účelem před-registrace 3D obrazů. Následně je provedena robustní 6DOF registrace. Rozšířená metoda je v disertační práci v popsána spolu se všemi podstatnými modifikacemi. Vyvinutá metoda byla otestována a zhodnocena s využitím skutečných 3D vzdálenostních dat naměřených v různých vnitřních prostředích. Jsou zhodnoceny přínosy faktorizace a jiných modifikací ve srovnání s původní jednofázovou 6DOF registrací, také jsou zmíněny nevýhody implementované metody a navrženy způsoby jejich řešení. Nakonec následuje návrh budoucího výzkumu a diskuse o možnostech dalšího rozvoje.
Semantic-assisted 3D Normal Distributions Transform for scan registration in environments with limited structure
Point cloud registration is a core problem of many robotic applications, including simultaneous localization and mapping. The Normal Distributions Transform (NDT) is a method that fits a number of Gaussian distributions to the data points, and then uses this transform as an approximation of the real data, registering a relatively small number of distributions as opposed to the full point cloud. This approach contributes to NDT’s registration robustness and speed but leaves room for improvement in environments of limited structure.
To address this limitation we propose a method for the introduction of semantic information extracted from the point clouds into the registration process. The paper presents a large scale experimental evaluation of the algorithm against NDT on two publicly available benchmark data sets. For the purpose of this test a measure of smoothness is used for the semantic partitioning of the point clouds. The results indicate that the proposed method improves the accuracy, robustness and speed of NDT registration, especially in unstructured environments, making NDT suitable for a wider range of applications
Point Cloud Registration for LiDAR and Photogrammetric Data: a Critical Synthesis and Performance Analysis on Classic and Deep Learning Algorithms
Recent advances in computer vision and deep learning have shown promising
performance in estimating rigid/similarity transformation between unregistered
point clouds of complex objects and scenes. However, their performances are
mostly evaluated using a limited number of datasets from a single sensor (e.g.
Kinect or RealSense cameras), lacking a comprehensive overview of their
applicability in photogrammetric 3D mapping scenarios. In this work, we provide
a comprehensive review of the state-of-the-art (SOTA) point cloud registration
methods, where we analyze and evaluate these methods using a diverse set of
point cloud data from indoor to satellite sources. The quantitative analysis
allows for exploring the strengths, applicability, challenges, and future
trends of these methods. In contrast to existing analysis works that introduce
point cloud registration as a holistic process, our experimental analysis is
based on its inherent two-step process to better comprehend these approaches
including feature/keypoint-based initial coarse registration and dense fine
registration through cloud-to-cloud (C2C) optimization. More than ten methods,
including classic hand-crafted, deep-learning-based feature correspondence, and
robust C2C methods were tested. We observed that the success rate of most of
the algorithms are fewer than 40% over the datasets we tested and there are
still are large margin of improvement upon existing algorithms concerning 3D
sparse corresopondence search, and the ability to register point clouds with
complex geometry and occlusions. With the evaluated statistics on three
datasets, we conclude the best-performing methods for each step and provide our
recommendations, and outlook future efforts.Comment: 7 figure
Fast Gravitational Approach for Rigid Point Set Registration with Ordinary Differential Equations
This article introduces a new physics-based method for rigid point set
alignment called Fast Gravitational Approach (FGA). In FGA, the source and
target point sets are interpreted as rigid particle swarms with masses
interacting in a globally multiply-linked manner while moving in a simulated
gravitational force field. The optimal alignment is obtained by explicit
modeling of forces acting on the particles as well as their velocities and
displacements with second-order ordinary differential equations of motion.
Additional alignment cues (point-based or geometric features, and other
boundary conditions) can be integrated into FGA through particle masses. We
propose a smooth-particle mass function for point mass initialization, which
improves robustness to noise and structural discontinuities. To avoid
prohibitive quadratic complexity of all-to-all point interactions, we adapt a
Barnes-Hut tree for accelerated force computation and achieve quasilinear
computational complexity. We show that the new method class has characteristics
not found in previous alignment methods such as efficient handling of partial
overlaps, inhomogeneous point sampling densities, and coping with large point
clouds with reduced runtime compared to the state of the art. Experiments show
that our method performs on par with or outperforms all compared competing
non-deep-learning-based and general-purpose techniques (which do not assume the
availability of training data and a scene prior) in resolving transformations
for LiDAR data and gains state-of-the-art accuracy and speed when coping with
different types of data disturbances.Comment: 18 pages, 18 figures and two table
Quasi-Newton Solver for Robust Non-Rigid Registration
Imperfect data (noise, outliers and partial overlap) and high degrees of
freedom make non-rigid registration a classical challenging problem in computer
vision. Existing methods typically adopt the type robust estimator
to regularize the fitting and smoothness, and the proximal operator is used to
solve the resulting non-smooth problem. However, the slow convergence of these
algorithms limits its wide applications. In this paper, we propose a
formulation for robust non-rigid registration based on a globally smooth robust
estimator for data fitting and regularization, which can handle outliers and
partial overlaps. We apply the majorization-minimization algorithm to the
problem, which reduces each iteration to solving a simple least-squares problem
with L-BFGS. Extensive experiments demonstrate the effectiveness of our method
for non-rigid alignment between two shapes with outliers and partial overlap,
with quantitative evaluation showing that it outperforms state-of-the-art
methods in terms of registration accuracy and computational speed. The source
code is available at https://github.com/Juyong/Fast_RNRR.Comment: Accepted to CVPR2020. The source code is available at
https://github.com/Juyong/Fast_RNR
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