5 research outputs found
DS-SLAM: A Semantic Visual SLAM towards Dynamic Environments
Simultaneous Localization and Mapping (SLAM) is considered to be a
fundamental capability for intelligent mobile robots. Over the past decades,
many impressed SLAM systems have been developed and achieved good performance
under certain circumstances. However, some problems are still not well solved,
for example, how to tackle the moving objects in the dynamic environments, how
to make the robots truly understand the surroundings and accomplish advanced
tasks. In this paper, a robust semantic visual SLAM towards dynamic
environments named DS-SLAM is proposed. Five threads run in parallel in
DS-SLAM: tracking, semantic segmentation, local mapping, loop closing, and
dense semantic map creation. DS-SLAM combines semantic segmentation network
with moving consistency check method to reduce the impact of dynamic objects,
and thus the localization accuracy is highly improved in dynamic environments.
Meanwhile, a dense semantic octo-tree map is produced, which could be employed
for high-level tasks. We conduct experiments both on TUM RGB-D dataset and in
the real-world environment. The results demonstrate the absolute trajectory
accuracy in DS-SLAM can be improved by one order of magnitude compared with
ORB-SLAM2. It is one of the state-of-the-art SLAM systems in high-dynamic
environments. Now the code is available at our github:
https://github.com/ivipsourcecode/DS-SLAMComment: 7 pages, accepted at the 2018 IEEE/RSJ International Conference on
Intelligent Robots and Systems (IROS 2018). Now the code is available at our
github: https://github.com/ivipsourcecode/DS-SLA
LoST? Appearance-Invariant Place Recognition for Opposite Viewpoints using Visual Semantics
Human visual scene understanding is so remarkable that we are able to
recognize a revisited place when entering it from the opposite direction it was
first visited, even in the presence of extreme variations in appearance. This
capability is especially apparent during driving: a human driver can recognize
where they are when travelling in the reverse direction along a route for the
first time, without having to turn back and look. The difficulty of this
problem exceeds any addressed in past appearance- and viewpoint-invariant
visual place recognition (VPR) research, in part because large parts of the
scene are not commonly observable from opposite directions. Consequently, as
shown in this paper, the precision-recall performance of current
state-of-the-art viewpoint- and appearance-invariant VPR techniques is orders
of magnitude below what would be usable in a closed-loop system. Current
engineered solutions predominantly rely on panoramic camera or LIDAR sensing
setups; an eminently suitable engineering solution but one that is clearly very
different to how humans navigate, which also has implications for how naturally
humans could interact and communicate with the navigation system. In this paper
we develop a suite of novel semantic- and appearance-based techniques to enable
for the first time high performance place recognition in this challenging
scenario. We first propose a novel Local Semantic Tensor (LoST) descriptor of
images using the convolutional feature maps from a state-of-the-art dense
semantic segmentation network. Then, to verify the spatial semantic arrangement
of the top matching candidates, we develop a novel approach for mining
semantically-salient keypoint correspondences.Comment: Accepted for Robotics: Science and Systems (RSS) 2018. Source code
now available at https://github.com/oravus/lost
Real-Time Accurate Visual SLAM with Place Recognition
El problema de localización y construcción simultánea de mapas (del inglés Simultaneous Localization and Mapping, abreviado SLAM) consiste en localizar un sensor en un mapa que se construye en línea. La tecnología de SLAM hace posible la localización de un robot en un entorno desconocido para él, procesando la información de sus sensores de a bordo y por tanto sin depender de infraestructuras externas. Un mapa permite localizarse en todo momento sin acumular deriva, a diferencia de una odometría donde se integran movimientos incrementales. Este tipo de tecnología es crítica para la navegación de robots de servicio y vehículos autónomos, o para la localización del usuario en aplicaciones de realidad aumentada o virtual. La principal contribución de esta tesis es ORB-SLAM, un sistema de SLAM monocular basado en características que trabaja en tiempo real en ambientes pequeños y grandes, de interior y exterior. El sistema es robusto a elementos dinámicos en la escena, permite cerrar bucles y relocalizar la cámara incluso si el punto de vista ha cambiado significativamente, e incluye un método de inicialización completamente automático. ORB-SLAM es actualmente la solución más completa, precisa y fiable de SLAM monocular empleando una cámara como único sensor. El sistema, estando basado en características y ajuste de haces, ha demostrado una precisión y robustez sin precedentes en secuencias públicas estándar.Adicionalmente se ha extendido ORB-SLAM para reconstruir el entorno de forma semi-densa. Nuestra solución desacopla la reconstrucción semi-densa de la estimación de la trayectoria de la cámara, lo que resulta en un sistema que combina la precisión y robustez del SLAM basado en características con las reconstrucciones más completas de los métodos directos. Además se ha extendido la solución monocular para aprovechar la información de cámaras estéreo, RGB-D y sensores inerciales, obteniendo precisiones superiores a otras soluciones del estado del arte. Con el fin de contribuir a la comunidad científica, hemos hecho libre el código de una implementación de nuestra solución de SLAM para cámaras monoculares, estéreo y RGB-D, siendo la primera solución de código libre capaz de funcionar con estos tres tipos de cámara. Bibliografía:R. Mur-Artal and J. D. Tardós.Fast Relocalisation and Loop Closing in Keyframe-Based SLAM.IEEE International Conference on Robotics and Automation (ICRA). Hong Kong, China, June 2014.R. Mur-Artal and J. D. Tardós.ORB-SLAM: Tracking and Mapping Recognizable Features.RSS Workshop on Multi VIew Geometry in RObotics (MVIGRO). Berkeley, USA, July 2014. R. Mur-Artal and J. D. Tardós.Probabilistic Semi-Dense Mapping from Highly Accurate Feature-Based Monocular SLAM.Robotics: Science and Systems (RSS). Rome, Italy, July 2015.R. Mur-Artal, J. M. M. Montiel and J. D. Tardós.ORB-SLAM: A Versatile and Accurate Monocular SLAM System.IEEE Transactions on Robotics, vol. 31, no. 5, pp. 1147-1163, October 2015.(2015 IEEE Transactions on Robotics Best Paper Award).R. Mur-Artal, and J. D. Tardós.Visual-Inertial Monocular SLAM with Map Reuse.IEEE Robotics and Automation Letters, vol. 2, no. 2, pp. 796-803, April 2017. (to be presented at ICRA 17).R.Mur-Artal, and J. D. Tardós. ORB-SLAM2: an Open-Source SLAM System for Monocular, Stereo and RGB-D Cameras.ArXiv preprint arXiv:1610.06475, 2016. (under Review).<br /
Meaningful maps – Object-oriented semantic mapping
For intelligent robots to interact in deeply meaningful ways with their environment, they must understand both the geometric and semantic properties of the scene surrounding them. The majority of research to date has addressed these mapping challenges separately, focusing on either geometric or semantic mapping. In this paper we address the problem of building environmental maps that include both semantically meaningful, object-level entities and point-or mesh-based geometrical representations. We simultaneously build geometric point cloud models of previously unseen instances of known object classes and create a map that contains these object models as central entities. Our system leverages sparse, feature-based RGB-D SLAM, image-based deep-learning object detection and 3D unsupervised segmentation. We demonstrate the efficacy of our approach through quantitative evaluation in an automated inventory management task using a new real-world dataset recorded over a building office floor