844 research outputs found
Target Tracking in Confined Environments with Uncertain Sensor Positions
To ensure safety in confined environments such as mines or subway tunnels, a
(wireless) sensor network can be deployed to monitor various environmental
conditions. One of its most important applications is to track personnel,
mobile equipment and vehicles. However, the state-of-the-art algorithms assume
that the positions of the sensors are perfectly known, which is not necessarily
true due to imprecise placement and/or dropping of sensors. Therefore, we
propose an automatic approach for simultaneous refinement of sensors' positions
and target tracking. We divide the considered area in a finite number of cells,
define dynamic and measurement models, and apply a discrete variant of belief
propagation which can efficiently solve this high-dimensional problem, and
handle all non-Gaussian uncertainties expected in this kind of environments.
Finally, we use ray-tracing simulation to generate an artificial mine-like
environment and generate synthetic measurement data. According to our extensive
simulation study, the proposed approach performs significantly better than
standard Bayesian target tracking and localization algorithms, and provides
robustness against outliers.Comment: IEEE Transactions on Vehicular Technology, 201
Victim Detection and Localization in Emergencies
Detecting and locating victims in emergency scenarios comprise one of the most powerful tools to save lives. Fast actions are crucial for victims because time is running against them. Radio devices are currently omnipresent within the physical proximity of most people and allow locating buried victims in catastrophic scenarios. In this work, we present the benefits of using WiFi Fine Time Measurement (FTM), Ultra-Wide Band (UWB), and fusion technologies to locate victims under rubble. Integrating WiFi FTM and UWB in a drone may cover vast areas in a short time. Moreover, the detection capacity of WiFi and UWB for finding individuals is also compared. These findings are then used to propose a method for detecting and locating victims in disaster scenarios.This work was performed in the framework of the Horizon 2020 project LOCUS (Grant Agreement Number 871249), receiving funds from the European Union. This work was also partially funded by Junta de Andalucia (Project PY18-4647:PENTA)
A Survey of Positioning Systems Using Visible LED Lights
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.As Global Positioning System (GPS) cannot provide satisfying performance in indoor environments, indoor positioning technology, which utilizes indoor wireless signals instead of GPS signals, has grown rapidly in recent years. Meanwhile, visible light communication (VLC) using light devices such as light emitting diodes (LEDs) has been deemed to be a promising candidate in the heterogeneous wireless networks that may collaborate with radio frequencies (RF) wireless networks. In particular, light-fidelity has a great potential for deployment in future indoor environments because of its high throughput and security advantages. This paper provides a comprehensive study of a novel positioning technology based on visible white LED lights, which has attracted much attention from both academia and industry. The essential characteristics and principles of this system are deeply discussed, and relevant positioning algorithms and designs are classified and elaborated. This paper undertakes a thorough investigation into current LED-based indoor positioning systems and compares their performance through many aspects, such as test environment, accuracy, and cost. It presents indoor hybrid positioning systems among VLC and other systems (e.g., inertial sensors and RF systems). We also review and classify outdoor VLC positioning applications for the first time. Finally, this paper surveys major advances as well as open issues, challenges, and future research directions in VLC positioning systems.Peer reviewe
Bidirectional UWB Localization: A Review on an Elastic Positioning Scheme for GNSS-deprived Zones
A bidirectional Ultra-Wideband (UWB) localization scheme is one of the three
widely deployed design integration processes ordinarily destined for time-based
UWB positioning systems. The key property of the bidirectional UWB localization
is its ability to serve both the navigation and tracking assignments on-demand
within a single localization scheme. Conventionally, the perspective of
navigation and tracking in wireless localization systems is viewed distinctly
as an individual system because different methodologies were required for the
implementation process. The ability to flexibly or elastically combine two
unique positioning perspectives (i.e., navigation and tracking) within a single
scheme is a paradigm shift in the way location-based services are observed.
Thus, this article addresses and pinpoints the potential of a bidirectional UWB
localization scheme. Regarding this, the complete system model of the
bidirectional UWB localization scheme was comprehensively described based on
modular processes in this article. The demonstrative evaluation results based
on two system integration processes as well as a SWOT (strengths, weaknesses,
opportunities, and threats) analysis of the scheme were also discussed.
Moreover, we argued that the presented bidirectional scheme can also be used as
a prospective topology for the realization of precise location estimation
processes in 5G/6G wireless mobile networks, as well as Wi-Fi fine-time
measurement-based positioning systems in this article.Comment: 30 pages, 12 figure
A survey on Human Mobility and its applications
Human Mobility has attracted attentions from different fields of studies such
as epidemic modeling, traffic engineering, traffic prediction and urban
planning. In this survey we review major characteristics of human mobility
studies including from trajectory-based studies to studies using graph and
network theory. In trajectory-based studies statistical measures such as jump
length distribution and radius of gyration are analyzed in order to investigate
how people move in their daily life, and if it is possible to model this
individual movements and make prediction based on them. Using graph in mobility
studies, helps to investigate the dynamic behavior of the system, such as
diffusion and flow in the network and makes it easier to estimate how much one
part of the network influences another by using metrics like centrality
measures. We aim to study population flow in transportation networks using
mobility data to derive models and patterns, and to develop new applications in
predicting phenomena such as congestion. Human Mobility studies with the new
generation of mobility data provided by cellular phone networks, arise new
challenges such as data storing, data representation, data analysis and
computation complexity. A comparative review of different data types used in
current tools and applications of Human Mobility studies leads us to new
approaches for dealing with mentioned challenges
Integrated Management System for Coal Mine Locomotive Transportation
Combined with the reconstruction project of underground locomotive transportation system in Guqiao Coal Mine of Huainan Mining Group, the dissertation studies the comprehensive management system of coal mine locomotive transportation. The accuracy of ZigBee wireless positioning technology is improved through Gaussian filtering to make it applicable to more complex underground coal mine environment. Frequency conversion control is used in the motor control circuit to realize real-time calculation of the running speed of the locomotive. By analyzing the control scheme of the turnout and traffic lights, the explosion isolation and essential safety control sub-station suitable for gas mine are designed. Communication platform construction of the system is realized through wireless base station of Benan mine and industrial network of coal mine. System relevant data can be uploaded to the ground dispatching center in real time, so that the scheduling staff can reasonably arrange the scheduling tasks in a timely manner. The optimized logistics management and storage management system makes the material dispatching and transportation more reasonable and scientific. Through the analysis of the running data, the construction and personnel management of the locomotives are realized
Height Information Aided 3D Real-Time Large-Scale Underground User Positioning
Due to the cost of inertial navigation and visual navigation equipment and lake of satellite navigation signals, they cannot be used in large‐scale underground mining environment. To solve this problem, this study proposes large‐scale underground 3D real‐time positioning method with seam height assistance. This method uses the ultrawide band positioning base station as the core and is combined with seam height information to build a factor graph confidence transfer model to realise3D positioning. The simulation results show that the proposed real‐time method is superior to the existing algorithms in positioning accuracy and can meet the needs of large‐scale underground users
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