This dissertation was conducted as part of the efforts related to WPI's Precision Personnel Location (PPL) project, the purpose of which is to locate emergency personnel in hazardous indoor environments using radio location techniques. The current PPL system prototype uses a radio transmitter worn by the personnel, indoors, and receivers on reference units, outdoors. This dissertation proposes a new system architecture with bidirectional radio transmissions to replace the current unidirectional system architecture. This allows the development of a synchronization scheme that can extract additional Time of Arrival (TOA) information for estimating the location of personnel. This dissertation also describes an extension of the multi-signal fusion technique previously used that incorporates this TOA information. At the cost of a more complicated mobile unit design, resultant benefits of this approach include rejection of signal reflectors as solutions, improved accuracy with limited reference unit geometries, improved noise rejection and significant computation reduction. In this dissertation the mathematical underpinnings of this approach are presented, a performance analysis is developed and the results are evaluated in the context of experimental data.

This thesis was conducted as part of the efforts related to WPI's Precision Personnel Location (PPL) project, the purpose of which is to locate emergency personnel in hazardous indoor environments using radio location techniques. A unique signal processing algorithm, sART, developed within the PPL project provides means to determine precise position estimates of a wideband transmitter from multipath corrupted signals captured by distributed receivers. This algorithm has synchronization requirements that can not be met without extraordinary expense and complexity by direct means. This thesis develops digital signal processing that achieves the necessary synchronization to satisfy the sART algorithm requirements without additional implementation complexity. The mathematical underpinnings of this solution are introduced and the results are evaluated in the context of experimental data.

Our increased reliance on localization devices such as GPS navigation has led to an increased demand for localization solutions in all environments, including indoors. Indoor localization has received considerable attention in the last several years for a number of application areas including first responder localization to targeted advertising and social networking. The difficult multipath encountered indoors degrades the performance of RF based localization solutions and so far no optimal solution has been published. This dissertation presents an algorithm called Coherent Array Reconciliation Tomography (CART), which is a Direct Positioning Algorithm (DPA) that incorporates signal fusion to perform a simultaneous leading edge and position estimate for a superior localization solution in a high multipath environment. The CART algorithm produces position estimates that are near optimal in the sense that they achieve nearly the best theoretical accuracy possible using an Impulse Radio (IR) Ultra-Wideband (UWB) waveform. Several existing algorithms are compared to CART including a traditional two step Leading Edge Detection (LED) algorithm, Singular value Array Reconciliation Tomography (SART), and Transactional Array Reconciliation Tomography (TART) by simulation and experimentation. As shown under heavy simulated multipath conditions, where traditional LED produces a limited solution and the SART and TART algorithms fail, the CART algorithm produces a near statistically optimal solution. Finally, the CART algorithm was also successfully demonstrated experimentally in a laboratory environment by application to the fire fighter homing device that has been a part of the ongoing research at Worcester Polytechnic Institute (WPI).

Along with the huge growth of mobile devices in recent years we have seen a matching growth in interest for mobile applications, with location-aware applications experiencing rapid growth for mobile devices. Radiolocation from measurements of radio received signal strength has demonstrated excellent precision, although despite a decade of research there have been no wide-spread deployments of indoor location systems. The majority of the existing research has been focused towards producing improved precision at the cost of increased time requirements for system configuration and maintenance. This thesis proposes taking a step back from increasing complexity by giving up precision in exchange for simplicity and speed of deployment, while still providing sufficient accuracy for many indoor location tasks. This is accomplished by putting aside the standard x, y, z coordinate systems and by using a method based on defined areas. Carefully choosing the defined areas to include Wi-Fi access points and to have signal attenuating walls separating the area from the next, this work demonstrates locational accuracy of over 90% in most cases. While this method is not applicable to wide open areas that lack signal attenuating features, it is highly applicable to many indoor environments. / Graduate

This dissertation introduces Inverse Synthetic Array Reconciliation Tomography (ISART), an algorithm that exploits the short-time accuracy of inertial navigation systems (INS) and the time-stability of radio frequency (RF) positioning algorithms to achieve a high level of positioning accuracy. Novel array processing and data fusion techniques are employed to acheive performance far greater than RF and INS algorithms previously developed. This research is directed toward addressing the need for a viable tracking solution for firefighters and other first responders in urban and indoor environments. The approaches in this work are fundamentally different from other RF-INS fusion approaches, in the way we combine INS data with RF data. Rather than simply fusing the measurements from two systems that are estimating position (or states directly related to position) we use the inertial navigation data to improve the accuracy of our RF estimates at the signal level, before integrating them into an overall fusion system through the use of an extended Kalman filter (EKF). This work outlines the theoretical basis for ISART, and shows the results of simulations that support the claimed accuracy improvement of the ISART algorithm over existing methods. The viability of ISART in real world settings is then examined through the results of three field tests what were conducted in support of this research.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Currently, one of the main problems is that “time” is becoming more important, which will cause people to perform multiple tasks every day because of a hectic lifestyle, and with it the issue of lost articles. and poorly placed also increases significantly. Although there have been initiatives by some small companies to offer solutions characterized by the use of positioning technologies, these have not achieved the desired success. That is why, in this research, a scheme for the design, evaluation and implementation and marketing of a product with RFID technology with location and alert functions in the absence of proximity to solve the aforementioned problem has been proposed. The scheme and the product were validated through focus tools, surveys and scenario analysis. Likewise, the components of the business model of the scheme allow to reach the demand.

Problem solving for location is one of the most critical cognitive skills that can be utilized in deriving a naive location and/or finding a primed location in large open spaces of the built environment. Wayfinding or locating objects in large open spaces is not often easy for individuals due their limitations in building effective mental models of the open space or their lack of a correct procedure for determining the grid coordinates of an object within that space. With the success of the global positioning system (GPS) in providing location information, it is expected that this technology could be utilized to control and improve building construction and facility management productivity within building interior spaces as well. However, GPS cannot perform robustly inside buildings due to the exterior walls or roofs, which weaken the signal. The Cricket indoor location support technology has been developed to respond to this limitation. Cricket uses a combination of radio frequency (RF), ultrasonic sound signals, and the triangular rule to calculate a user's current location. This research investigated performances within the context of a work order system between a human-based system and a computer-based system. Thirty subjects participated in this study. The subjects were asked to derive, find and verify a target box's location. Locating time-on-task, accuracy, and attitudes were measured. The overwhelming results demonstrated the speed and accuracy of the computer-based system over the human-based system. In addition to longer procedural processing times, subject errors included: 1) an incorrect estimation of distance, 2) an inability to correctly locate and/or project the X-axis and Y-axis grid lines, and 3) an incorrect treatment of the positive and negative characteristics of these coordinates. Even though half of the subjects liked the human-based system more, they significantly believe the computer-based system to be more accurate. All but one subject preferred that the computer-based system be used in his or her own future business. Finally, results indicate that the computer-based system does relieve humans of cognitive dependency, which may be further evidence that the computer-based system developed and tested in this study achieved its purpose.

Submitted by marco aurélio santos (marrco.santos@gmail.com) on 2018-07-30T01:42:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Approved for entry into archive by Secretaria PPGI (secretariappgi@icomp.ufam.edu.br) on 2018-07-30T18:34:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-07-31T18:29:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) / Made available in DSpace on 2018-07-31T18:29:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) msc_dissertacao_marcoSantos.pdf: 6142716 bytes, checksum: 17219663e0f7676d5c438178de493d89 (MD5) Previous issue date: 2018-04-16 / Internal positioning systems allow the localization of people or certain objects indoors, as well as assist in navigation and orientation. Proposals for indoor location systems based on only one technology have achieved unsatisfactory performance in localization, mainly due to the limitations in relation to the conflicting characteristics present in these environments. This work aims at the development of a hybrid location system, integrating the PDR and Wi-Fi technologies, which aims to provide the location of a user in an internal environment, allowing the user to move around and visualize their current location through a representation on a map. The results were satisfactory, including the direct influence of factors such as: physical characteristics (height, body mass, size of the past), smartphone location, speed of the adopted march and adoption of constant movements. / Os sistemas de posicionamento internos permitem a localização de pessoas ou certos objetos em ambientes internos, assim como ajudam na navegação e orientação. As propostas de sistemas de localização para ambientes internos baseados em somente uma tecnologia tem alcançado desempenho insatisfatório na localização, principalmente, devido às limitações em relação às características conflitantes presentes nesses ambientes. Este trabalho tem como objetivo o desenvolvimento de um sistema híbrido de localização, integrando as tecnologias PDR e Wi-Fi, que visa fornecer a localização de um usuário em um ambiente interno, permitindo ao usuário locomover-se e visualizar a sua localização corrente através de uma representação em um mapa. Os resultados obtidos foram satisfatórios, constando-se a direta influência de fatores como: características físicas (altura, massa corporal, tamanho da passada) do usuário, localização do smartphone, velocidade da marcha adotada e adoção de movimentos constantes.

This thesis deals with the issue of locating devices in wireless networks. It takes existing solutions as example and extends them using additional approaches. This thesis designs and describes the implementation of a prototype of a new proprietary indoor localization system used for locating devices within a WiFi network. In the final part of the thesis the testing of this system is described and its results are analysed and compared with another localization systems based on similar technologies.

Les systèmes de positionnement ont connu un progrès indéniable. Actuellement, la précision atteint quelques centimètres sous certaines conditions : espace ouvert, ciel dégagé, technique très spécifique, etc. Néanmoins, le problème du positionnement dans un environnement intérieur demeure persistant : les trajets multiples qui compliquent les modèles de propagation, l'atténuation, etc. Différents systèmes ont vu le jour, utilisant des technologies telles que l'UWB, le WiFi ou l'Infrarouge. Ces systèmes apportent des résultats de positionnement intéressants, atteignant l'ordre du mètre. Cette précision reste liée à certaines contraintes : une infrastructure, une technologie utilisée, une calibration, une technique de calcul, etc. Afin de réduire toutes ces contraintes, nous proposons une nouvelle approche de positionnement. Notre approche utilise tous les équipements réseaux présents dans un environnement. Elle se base sur deux étapes fondamentales : l'étude de visibilité et l'élaboration de liens géographiques. L'étude de visibilité permet d'obtenir les équipements visibles par un équipement. Nous avons exposé plusieurs modèles de visibilité et nous avons effectué une comparaison des résultats. L'élaboration de liens géographiques permet de construire un graphe géographique tridimensionnel reliant tous les équipements de l'environnement. Ce graphe nous permet de visualiser la répartition des équipements et d'estimer les positions géographiques de chaque équipement. Pour la mise en œuvre de notre approche, nous avons développé un simulateur sous Matlab. Le simulateur élaboré évalue d'abord le nombre d'équipements visibles. Il estime les distances séparant cet équipement de chaque équipement visible. Enfin, il construit un graphe géographique et calcul les positions géographiques. Des résultats de simulations sont présentés pour valider notre approche qui permet d'aboutir à un système capable d'opérer, sans aucune infrastructure additionnelle, un positionnement dans un environnement intérieur et extérieur / Positioning systems have undeniably progressed. Currently, in an outdoor environment, the accuracy reaches a few centimetres under certain conditions: open space, clear sky, specific measurement techniques, etc. Nevertheless, the problem of positioning in an indoor environment remains persistent: multipath, attenuation, etc. Different systems for indoor positioning have been developed, using technologies such as UWB, WiFi or Infrared. These systems provide interesting results that could allow to reach one meter accuracy. But, this accuracy is related to many criteria: infrastructure, technology, calibration, technical computing, etc. To reduce these constraints, we propose a new approach for positioning. Our approach utilizes all the network equipments present in an environment. The approach is based on two fundamental steps: the study of visibility and the development of geographical links. The study of visibility estimates the visible equipments in the environment. We have studied several models of visibility and we carried out a comparison of the results. A three-dimensional graph is build using the study of geographical links between equipments. This graph allows us to visualize the distribution of equipments and to estimate the geographic positions of each device. To implement our approach, we developed a simulator in Matlab. The simulator first studies the visible equipments for the unknown device. Then, it estimates the distances between the device and the visible equipments. Finally, it constructs a graph and calculates the geographical positions. Simulation results are presented to validate our approach. Our approach is a positioning system capable of operating without additional infrastructure in an indoor environment