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Requirements and metrics for location and tracking for ambient assisted living

Eisa, Samih; Moreira, Adriano
Fonte: IEEE Xplore Publicador: IEEE Xplore
Tipo: Conferência ou Objeto de Conferência
Publicado em 13/11/2012 Português
Relevância na Pesquisa
476.27918%
Location and tracking services and technologies are becoming fundamental components for supporting healthcare solutions. They facilitate patients’ tracking and monitoring processes and also allow for better and long-term daily activity recognition. Various location and tracking services have been developed, over the last years, to provide real time localization for different applications. However, most of these services are not designed particularly to comply with all the requirements of Ambient Assisted Living (AAL) and, as a result, they reduce the viability of adopting AAL services as an alternative for continuous healthcare services. In this paper we set out the general requirements for location and tracking services for AAL. The requirements are extracted from a typical scenario of AAL. From the scenario, we define the requirements and also we identify a set of metrics to be used as evaluation criteria. If the identified requirements and metrics are adopted widely, potential location and tracking services will fit the real needs of AAL, and thus will increase the accessibility to AAL services by a larger sector of people. Moreover, in the paper, we evaluate two of the existing location techniques through the use of the proposed metrics. The aim is to asses to which level these solutions fulfill the identified requirements.; This work was supported by the FEDER program through the COMPETE and the Portuguese Science and Technology Foundation (FCT)...

Removing useless APs and fingerprints from WiFi indoor positioning radio maps

Eisa, Samih; Peixoto, João; Meneses, Filipe; Moreira, Adriano
Fonte: IEEE Publicador: IEEE
Tipo: Conferência ou Objeto de Conferência
Publicado em 28/10/2013 Português
Relevância na Pesquisa
475.98625%
Maintaining consistent radio maps for WiFi fingerprinting-based indoor positioning systems is an essential step to improve the performance of the positioning engines. The radio maps consist of WiFi fingerprints collected at a predefined set of positions/places within a positioning area. Each fingerprint consists of the identification and radio signal level of the surrounding Access Points (APs). Due to the wide proliferation of WiFi networks, it is very common to observe 10 to 20 APs at a single position and more than 50 APs across a single building. However, in practical, not all of the detected APs are useful for the position estimation process. Some of them might have weak signals at certain positions or might have less significance for a position’s fingerprint. Thus, those useless APs will add additional computational overheads during the position estimation, and consequently they will reduce the overall performance of the positioning engines. A similar phenomenon also occurs with some of the collected fingerprints. While it is widely accepted that the larger and more detailed the radio map is, the better is the accuracy of the positioning system, we found that some of the fingerprint samples on the radio maps do not contribute significantly to the estimation process. In this paper...

Fine-Grained localization system for indoor environments; Sistema de localização fina para ambientes interiores

Gomes, Rui Pedro Lebreiro
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
491.3225%
The increasing demand for tracking solutions in indoor environments has led to the development of many indoor location systems based in the most diverse technologies. They are trying to fill a market niche left by the current available location systems such as the well-known Global Positioning System (GPS). These systems are limited to an outdoor usage due to the drastic attenuation of the GPS signals in closed areas and they cannot provide enough resolution to meet the requirements of certain applications. Therefore, it’s here proposed the conception of a system capable of locating a mobile module in indoor environments with an accuracy of a few centimeters. The system’s concept is based in measuring the time difference of arrival (TDOA) between a radio frequency signal and an ultrasonic burst in order to measure distances. The huge difference between the propagation velocities of RF waves comparatively to sound waves allows the system to accurately measure the time difference between the two arrivals and use that value to estimate the distance that separates the source from the destination. This document describes the development of all the necessary hardware for the conception of a final prototype and all the aspects regarding the software implementation. This system is composed by two types of devices that can be divided in Ultrasonic (US) transmitters and receivers. Each device is equipped with a RF module that allows them to communicate through a wireless network based in the IEEE802.15.4 protocol. In the end...

Development of an Indoor Location Based Service Test Bed and Geographic Information System with a Wireless Sensor Network

Jan, Shau-Shiun; Hsu, Li-Ta; Tsai, Wen-Ming
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 30/03/2010 Português
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503.42727%
In order to provide the seamless navigation and positioning services for indoor environments, an indoor location based service (LBS) test bed is developed to integrate the indoor positioning system and the indoor three-dimensional (3D) geographic information system (GIS). A wireless sensor network (WSN) is used in the developed indoor positioning system. Considering the power consumption, in this paper the ZigBee radio is used as the wireless protocol, and the received signal strength (RSS) fingerprinting positioning method is applied as the primary indoor positioning algorithm. The matching processes of the user location include the nearest neighbor (NN) algorithm, the K-weighted nearest neighbors (KWNN) algorithm, and the probabilistic approach. To enhance the positioning accuracy for the dynamic user, the particle filter is used to improve the positioning performance. As part of this research, a 3D indoor GIS is developed to be used with the indoor positioning system. This involved using the computer-aided design (CAD) software and the virtual reality markup language (VRML) to implement a prototype indoor LBS test bed. Thus, a rapid and practical procedure for constructing a 3D indoor GIS is proposed, and this GIS is easy to update and maintenance for users. The building of the Department of Aeronautics and Astronautics at National Cheng Kung University in Taiwan is used as an example to assess the performance of various algorithms for the indoor positioning system.

A Hybrid Stochastic Approach for Self-Location of Wireless Sensors in Indoor Environments

Lloret, Jaime; Tomas, Jesus; Garcia, Miguel; Canovas, Alejandro
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 15/05/2009 Português
Relevância na Pesquisa
397.51227%
Indoor location systems, especially those using wireless sensor networks, are used in many application areas. While the need for these systems is widely proven, there is a clear lack of accuracy. Many of the implemented applications have high errors in their location estimation because of the issues arising in the indoor environment. Two different approaches had been proposed using WLAN location systems: on the one hand, the so-called deductive methods take into account the physical properties of signal propagation. These systems require a propagation model, an environment map, and the position of the radio-stations. On the other hand, the so-called inductive methods require a previous training phase where the system learns the received signal strength (RSS) in each location. This phase can be very time consuming. This paper proposes a new stochastic approach which is based on a combination of deductive and inductive methods whereby wireless sensors could determine their positions using WLAN technology inside a floor of a building. Our goal is to reduce the training phase in an indoor environment, but, without an loss of precision. Finally, we compare the measurements taken using our proposed method in a real environment with the measurements taken by other developed systems. Comparisons between the proposed system and other hybrid methods are also provided.

The Cricket indoor location system

Priyantha, Nissanka Bodhi, 1968-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 199 p.; 12205565 bytes; 12213940 bytes; application/pdf; application/pdf
Português
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508.54508%
Indoor environments present opportunities for a rich set of location-aware applications such as navigation tools for humans and robots, interactive virtual games, resource discovery, asset tracking, location-aware sensor networking etc. Typical indoor applications require better accuracy than what current outdoor location systems provide. Outdoor location technologies such as GPS have poor indoor performance because of the harsh nature of indoor environments. Further, typical indoor applications require different types of location information such as physical space, position and orientation. This dissertation describes the design and implementation of the Cricket indoor location system that provides accurate location in the form of user space, position and orientation to mobile and sensor network applications. Cricket consists of location beacons that are attached to the ceiling of a building, and receivers, called listeners, attached to devices that need location. Each beacon periodically transmits its location information in an RF message. At the same time, the beacon also transmits an ultrasonic pulse. The listeners listen to beacon transmissions and measure distances to nearby beacons, and use these distances to compute their own locations.; (cont.) This active-beacon passive-listener architecture is scalable with respect to the number of users...

Exploration and analysis of sensor technologies for efficient indoor location-based services; Erfoschung und Analyse von Senortechnologien fuer die Implementierung effizienter Dienste zur Positionsbestimmung innerhalb Gebaeuden

Subramanian, Ponmalar Suguna
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
Relevância na Pesquisa
713.5449%
In recent years, there is a mounting obligation for indoor location based services Comparable to outdoor location based services . Indoor guidance systems provide ample utilities to a user explicitly huge complex at shopping malls , hospitals and at vast libraries for any directed assistance. Pedestrian navigation is one such promising indoor location based service. Localization remains a basis for all location based services . Although, few pedestrian -based indoor localization are systems available in market , they lack either one of the attributes as such accuracy, reliability, scalability and / or expensive. GPS is not meant for indoors and even if so used at indoors , its relatively weak signal still stay a hurdle for any indoor location based services . In this dissertation , the aim is to build an efficient and precise indoor localization approach that can be implemented for most of the large indoor environments. The projected approach in this study incomparable to GPS that works outdoors will, remain eminently than other available indoor localization based approaches. All prerequisite for efficient localization such as accuracy, reliability, scalability, flexibility, availability, cost efficiency , minimum latency and robustness were evaluated reconstructed for this approach that is herewith demonstrated in my dissertation. The dissertation is structured as various chapters . Each of the chapter in this dissertation portrays novel methods utilizing major sensor technologies such as Bluetooth...

Infraestructura móvil para el despliegue de servicios basados en la localización en la Universidad Carlos III de Madrid : (Plataforma iOS)

Casado Rivas, Adrián
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: info:eu-repo/semantics/bachelorThesis; info:eu-repo/semantics/masterThesis Formato: application/pdf
Português
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El problema que pretende resolver el presente proyecto fin de carrera es la localización en interiores, también denominada localización indoor, de lugares y personas en la Universidad Carlos III de Madrid. Se ha detectado que los miembros de la comunidad universitaria de la Universidad Carlos III de Madrid tienen dificultades a la hora de encontrar la ubicación de un lugar, como aulas, laboratorios o despachos, y recordar dónde desempeña su trabajo el personal perteneciente a los colectivos PDI y PAS. Estas dificultades se presentan en diferentes etapas de una persona en su relación con la Universidad ya que el perfil de los potenciales usuarios varía entre personas recién llegadas a la institución y personas que ya la conocen y que necesitan en un momento puntual saber la ubicación de un lugar o de una persona. La motivación principal para la realización del presente proyecto es proveer de un servicio de localización indoor a las personas que en algún momento de su relación con la Universidad Carlos III de Madrid, necesiten conocer la ubicación de un lugar o de una persona y no sepan cómo encontrarlo. Para que la aplicación resultante del proyecto pueda ser utilizada en cualquier contexto, se ha optado por su desarrollo para las plataformas móviles...

A Dynamic Service Lookup and Discovery Scheme using a Self-Organizing Overlay Network for Indoor Location-Based Service

Jeong, Seol Young; Jo, Hyeong Gon; Kang, Soon Ju
Fonte: Universidad Carlos III de Madrid Publicador: Universidad Carlos III de Madrid
Tipo: info:eu-repo/semantics/publishedVersion; info:eu-repo/semantics/conferenceObject
Publicado em 04/12/2012 Português
Relevância na Pesquisa
591.3225%
Indoor location-based service (LBS) has various challenges, including that of numerous service lookups being requested concurrently and frequently from several locations, and that the network infrastructure needs to support high scalability, such as inserting or deleting network nodes anytime and anywhere. In general, indoor LBS resources are generally located in close proximity to the requested point. However, a traditional centralized LBS system needs to maintain a geographical map of the entire building or complex in its central server, which can cause low scalability and traffic congestion. This paper presents a self-organizing and fully distributed indoor LBS platform through regional cooperation among devices, and a service lookup algorithm that searches for the shortest physical path to the service resource. An evaluation of the performance of the proposed platform has been compared to the traditional centralized method regarding the service turnaround time according to the number of concurrent lookup increases.; This work was supported by the IT R&D program of MKE/KEIT. [10041145, Self-Organized Softwareplatform(SOS) for welfare devices]; REACTION 2012. 1st International workshop on Real-time and distributed computing in emerging applications. December 4th...

Multi-Sensor and Multi Agents Architecture for Indoor Location

Blázquez Gil, Gonzalo; Berlanga, Antonio; Molina, José M.
Fonte: Springer Publicador: Springer
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/conferenceObject; info:eu-repo/semantics/bookPart
Publicado em //2010 Português
Relevância na Pesquisa
482.14996%
This paper aims to present a new architecture to provide location services using multiple communication technologies such as Wi , UWB,RFID and so on. Firstly, it will explain the advantages of multi sensor archi- tecture against to use unique indoor location system and the reasons which led us to take this solution. Besides, this paper discusses the suitability of using ontologies for modeling message structure to locate in context-aware services platforms. This message will be described based on the concept of Asterix format used in aerospace multi-sensor communications; This work was supported in part by Projects CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, CAM CONTEXTS (S2009/TIC-1485) and DPS2008-07029-C02-02; Proceedings of: Forth International Workshop on User-Centric Technologies and applications (CONTEXTS 2010). Valencia, 7-10 September , 2010.

Improving Indoor Air Quality for Poor Families : A Controlled Experiment in Bangladesh; Indoor Air

Dasgupta, S.; Wheeler, D.; Huq, M.; Khaliquzzaman, M.
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Journal Article; Journal Article
Português
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396.04945%
The World Health Organization's 2004 Global and Regional Burden of Disease Report estimates that acute respiratory infections from indoor air pollution (pollution from burning wood, animal dung, and other bio-fuels) kill a million children annually in developing countries, inflicting a particularly heavy toll on poor families in South Asia and Africa. This paper reports on an experiment that studied the use of different fuels in conjunction with different combinations of construction materials, space configurations, cooking locations, and household ventilation practices (use of doors and windows) as potentially-important determinants of indoor air pollution. Results from controlled experiments in Bangladesh were analyzed to test whether changes in these determinants can have significant effects on indoor air pollution. Analysis of the data shows, for example, that pollution from the cooking area is transported into living spaces rapidly and completely. Furthermore, it is important to factor in the interaction between outdoor and indoor air pollution. Hence, the optimal cooking location should take 'seasonality' in account. Among fuels, seasonal conditions seem to affect the relative severity of pollution from wood, dung, and other biomass fuels. However...

Enabling Indoor Location-based Services Using Ultrasound

Javed, Tayyab
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
496.5197%
In the context of location, large amounts of information are available on the Internet to be accessed by people via different devices. However, at times people have to manually search and access it. If the space where location-based services are available can be identified by hand-held devices, people can be prompted with services available around them. This thesis explores the use of ultrasound as a communication medium to tag such spaces and access location-based services with the related information; and demonstrates the indoor implementation of the prototype of a location-based services enabling system for hand-held devices. This system allows users to search and access the available services in their surroundings through their hand-held devices. A beacon generator placed in the service location broadcasts a service code mappable to the services particular to that location encoded in an ultrasound signal. The hand-held device can identify this signal and prompt the user with available services. System design and architecture is demonstrated and the viability of the system is tested through a variety of environments and scenarios showing that potentially this has both a wide range of applications and can enhance the way people access location-based services.; Thesis (Master...

Spatial models for context-aware indoor navigation systems: A survey

AFYOUNI, Imad; RAY, Cyril; CLARAMUNT, Christophe
Fonte: Arts et Métiers ParisTech Publicador: Arts et Métiers ParisTech
Português
Relevância na Pesquisa
486.42473%
This paper surveys indoor spatial models developed for research fields ranging from mobile robot mapping, to indoor location-based services (LBS), and most recently to context-aware navigation services applied to indoor environments. Over the past few years, several studies have evaluated the potential of spatial models for robot navigation and ubiquitous computing. In this paper we take a slightly different perspective, considering not only the underlying properties of those spatial models, but also to which degree the notion of context can be taken into account when delivering services in indoor environments. Some preliminary recommendations for the development of indoor spatial models are introduced from a context-aware perspective. A taxonomy of models is then presented and assessed with the aim of providing a flexible spatial data model for navigation purposes, and by taking into account the context dimensions.

Redes neurais artificiais aplicadas ao problema da localização em ambientes fechados; Artificial neural networks applied to the problem of location in indoor environments

Loiola, Roberto Rodrigues
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
Relevância na Pesquisa
403.8356%
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2009.; Essa dissertação aborda o problema da localização em ambientes fechados baseada em técnicas de redes neurais artificiais. Nesse sistema, a informação da intensidade do sinal recebido (RSSI) disponibilizada por interfaces de rede sem fio padrão é a base para a previsão de localização de dispositivos móveis. Métodos tradicionais de localização indoor possuem diversas características indesejáveis, tais como dificuldade de implementação, pouca flexibilidade (não permitem a utilização da infra-estrutura presente no local sem grandes alterações na disposição de APs), número elevado de parâmetros e alto custo computacional. Foram realizadas implementações de algoritmos tradicionais de localização (Algoritmo do Vizinho mais Próximo), métodos baseados em Redes Neurais Multicamadas (Perceptron MLP) e mapas auto-organizáveis de Kohonen. Conclui-se que esta última implementação (Kohonen) é capaz de prover resultados significativamente superiores àqueles obtidos em estudos recentes de localização indoor. _______________________________________________________________________________ ABSTRACT; This thesis addresses the indoor location problem using on artificial neural networks-based techniques. In this system...

OpenLS for indoor positioning : strategies for standardizing location based services for indoor use; Open location-based services for indoor positioning

Kolodziej, Krzysztof W., 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 212 p.; 19345519 bytes; 19371426 bytes; application/pdf; application/pdf
Português
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410.5267%
The combination of location positioning technologies such as GPS and initiatives like the US Federal Communications Commission's E911 telecommunication initiatives has generated a lot of interest in applications and services that are a function of a user's location, referred to as location-based services (LBS). However, despite GPS technology and the positioning capabilities of cellular network such as GSM, millions of square meters of indoor space are out of reach of these systems. A multitude of applications and services would also benefit from indoor (in-building) positioning and navigation. Fortunately, over the past decade, advances in location positioning technology have made it possible to locate objects indoors (in-building). These alternative technologies are now being introduced to the market enabling many kinds of indoor LBS applications. While a start, these standalone applications are unlikely to make a large impact on the marketplace, for a number of reasons discussed in this thesis. The argument of this thesis is that in order for indoor LBS to become widely used, there is a need for both the infrastructure investment and the "killer" application (or at least a collection of sufficiently valuable applications). Without the LBS application the market will not invest in infrastructure...

MagicFinger: 3D Magnetic Fingerprints for Indoor Location

Carrillo, Daniel; Moreno, Victoria; Úbeda, Benito; Skarmeta, Antonio F.
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 15/07/2015 Português
Relevância na Pesquisa
493.3971%
Given the indispensable role of mobile phones in everyday life, phone-centric sensing systems are ideal candidates for ubiquitous observation purposes. This paper presents a novel approach for mobile phone-centric observation applied to indoor location. The approach involves a location fingerprinting methodology that takes advantage of the presence of magnetic field anomalies inside buildings. Unlike existing work on the subject, which uses the intensity of magnetic field for fingerprinting, our approach uses all three components of the measured magnetic field vectors to improve accuracy. By using adequate soft computing techniques, it is possible to adequately balance the constraints of common solutions. The resulting system does not rely on any infrastructure devices and therefore is easy to manage and deploy. The proposed system consists of two phases: the offline phase and the online phase. In the offline phase, magnetic field measurements are taken throughout the building, and 3D maps are generated. Then, during the online phase, the user's location is estimated through the best estimator for each zone of the building. Experimental evaluations carried out in two different buildings confirm the satisfactory performance of indoor location based on magnetic field vectors. These evaluations provided an error of (11.34 m...

EDIPS: an Easy to Deploy Indoor Positioning System to support loosely coupled mobile work

Aldunate, Roberto; Ochoa Delorenzi, Sergio; Vera, Rodrigo
Fonte: Springer Publicador: Springer
Tipo: Artículo de revista
Português
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399.2756%
Artículo de publicación ISI; Loosely coupled mobile work is characterized by nomadic workers collaborating in sporadically and ondemand ways. Supporting nomadic workers’ interactions requires knowing the location of the potential collaborator; therefore, indoor/outdoor positioning systems play a key role. Locating persons in outdoor environments is well addressed by Global Positioning Systems (GPS); however, for the indoor scenario, the solution is not so clear. Although several proposals for indoor positioning have been reported in the literature, most of them demand important setup efforts. This article presents the Easy to Deploy Indoor Positioning System (EDIPS), a WiFi-based system able to support the typical location requirements involved in loosely coupled mobile work. EDIPS is aimed for fast deployment and real-time operations rather than for location accuracy. The system was preliminary evaluated as a support for locating medical interns’ in a simulated hospital. The results obtained indicate the solution is able to locate nomadic workers in an indoor scenario, with enough accuracy to support loosely coupled mobile work, while requiring minimal setup effort.; This work was partially supported by Fondecyt (Chile)...

Navegação indoor baseada na rede WIFI como suporte a serviços baseados na localização: estudo de caso no campus da UL

Simões, Diogo Mourão
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2015 Português
Relevância na Pesquisa
397.75332%
Tese de mestrado, Sistemas de Informação Geográfica, Tecnologias e Aplicações, Universidade de Lisboa, Faculdade de Ciências, 2015; Os serviços baseados na localização dos utilizadores têm tido uma grande evolução ao longo destes últimos anos. O novo desafio prende-se com a possibilidade desses serviços serem transportados de um ambiente outdoor para indoor. Variados algoritmos e técnicas de posicionamento foram desenvolvidos, através de diversas tecnologias para o cálculo de posição dos dispositivos. Alguns destes sistemas já se encontram instalados em centros de grande afluência, como os centros comerciais. Neste documento vamos apresentar uma solução de um serviço baseado na localização em ambientes fechados, baseado na rede WiFi, para o caso do campus da Universidade de Lisboa. O trabalho desenvolvido pretende demonstrar o potencial de várias tecnologias combinadas, tendo como resultado uma aplicação móvel, desenvolvida para a plataforma Android, desempenhando um serviço baseado na localização do utilizador num espaço indoor.; The location-based services users have had a great evolution over the last few years. The new challenge is related to the the possibility of such services being transported from one outdoor environment for indoor. Various algorithms and positioning techniques were developed...

Indoor Positioning with Radio Location Fingerprinting

Kjærgaard, Mikkel Baun
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/04/2010 Português
Relevância na Pesquisa
402.2218%
An increasingly important requirement for many novel applications is sensing the positions of people, equipment, etc. GPS technology has proven itself as a successfull technology for positioning in outdoor environments but indoor no technology has yet gained a similar wide-scale adoption. A promising indoor positioning technique is radio-based location fingerprinting, having the major advantage of exploiting already existing radio infrastructures, like IEEE 802.11, which avoids extra deployment costs and effort. The research goal of this thesis is to address the limitations of current indoor location fingerprinting systems. In particular the aim is to advance location fingerprinting techniques for the challenges of handling heterogeneous clients, scalability to many clients, and interference between communication and positioning. The wireless clients used for location fingerprinting are heterogeneous even when only considering clients for the same technology. Heterogeneity is a challenge for location fingerprinting because it severely decreases the precision of location fingerprinting. To support many clients location fingerprinting has to address how to scale estimate calculation, measurement distribution, and distribution of position estimates. This is a challenge because of the number of calculations involved and the frequency of measurements and position updates. Positioning using location fingerprinting requires the measurement of...

Pedestrian localisation for indoor environments

Woodman, Oliver
Fonte: University of Cambridge; Faculty of Computer Science and Technology Publicador: University of Cambridge; Faculty of Computer Science and Technology
Tipo: Thesis; doctoral; PhD
Português
Relevância na Pesquisa
400.4718%
Ubiquitous computing systems aim to assist us as we go about our daily lives, whilst at the same time fading into the background so that we do not notice their presence. To do this they need to be able to sense their surroundings and infer context about the state of the world. Location has proven to be an important source of contextual information for such systems. If a device can determine its own location then it can infer its surroundings and adapt accordingly. Of particular interest for many ubiquitous computing systems is the ability to track people in indoor environments. This interest has led to the development of many indoor location systems based on a range of technologies including infra-red light, ultrasound and radio. Unfortunately existing systems that achieve the kind of sub-metre accuracies desired by many location-aware applications require large amounts of infrastructure to be installed into the environment. This thesis investigates an alternative approach to indoor pedestrian tracking that uses on-body inertial sensors rather than relying on fixed infrastructure. It is demonstrated that general purpose inertial navigation algorithms are unsuitable for pedestrian tracking due to the rapid accumulation of errors in the tracked position. In practice it is necessary to frequently correct such algorithms using additional measurements or constraints. An extended Kalman filter is developed for this purpose and is applied to track pedestrians using foot-mounted inertial sensors. By detecting when the foot is stationary and applying zero velocity corrections a pedestrian?s relative movements can be tracked far more accurately than is possible using uncorrected inertial navigation. Having developed an effective means of calculating a pedestrian?s relative movements...