High accuracy localization of objects is a crucial function for many modern applications, such as virtual and augmented reality, robotics, and self-driving cars, among others. This requires determining precise location of objects indoors, which is a challenging task. In recent years, Ultra-Wideband technology has seen increasing interest as a potential solution to this problem by the research community. This is mainly due to its innate capabilities of high update frequency and low power consumption which makes it a suitable technology for precise distance measurement and location determination. This study has aimed to answer what the state-of-the-art in the field of trilateration in Ultra-Wideband based indoor positioning systems utilizing other complementary technologies is. This was done by conducting a document survey using a Grounded theory approach for the analysis. To ensure validity and reliability of the study, the sample was collected through searching IEEE Xplore using different sets of keywords, and the potential samples was then checked using a data quality form. The analysis consisted of identifying categories and concepts in the sample. The analysis found that the Ultra-wideband based systems can achieve high positioning accuracy, but limitations such as non-line-of-sight disturbance must still be overcome for the technology to consistently achieve centimetre accuracy. These limitations are being mitigated using filtering, machine learning, and multi-sensory fusion. With these complementary technologies researchers can eliminate some of the limitations. The field does however seem to be in an exploratory stage where best practices for overcoming the current limitations are yet established.

The navigation tasks in advanced home robotic applications incorporating reliable revisiting strategies are dependent on very low cost but nevertheless rather accurate localization systems. In this paper a localization system based on the principle of trilateration is described. The proposed system uses only a single small base station, but achieves accuracies comparable to systems using spread beacons and it performs sufficiently for map building. Thus it is a standalone system and needs no odometry or other auxiliary sensors. Furthermore a new approach for the problem of the reliably detection of areas without direct line of sight is presented. The described system is very low cost and it is designed for use in indoor service robotics. The paper gives an overview on the system concept and special design solutions and proves the possible performances with experimental results.

Inom fallskärmshoppning behövs förutom ett välfungerande fallskärmssystem även en precis höjdmätare. Båda är avgörande komponenter när det gäller utrustning för att kunna genomföra ett säkert hopp. Genom digitalisering och den tekniska utvecklingen finns det idag intressen för att ta fram en digital höjdmätare med bättre precision, flera funktioner och bättre samt tydligare användargränssnitt. Det existerar ett flertal tekniker för mätning av höjd. De tekniker som tas upp i examensarbetet är global positioning system (GPS), radar och barometer. Målet med examensarbetet var att ta fram en robust algoritm för mätning av höjd, med möjlighet till utveckling. Examensarbetet skulle även innehålla riskanalys av vald(a) teknik(er) , samt förslag på lämpliga presentationstekniker och systemlösningar satt i ett större perspektiv. Systemlösningarna skulle vara anpassade för enkel integration av nya funktioner. I mån av tid skulle även en prototyp utvecklas samt testas. Metoden som valdes var en digital höjdmätare på grund av att den passade bäst för det mål som upprättats för projektet. Fr att beräkna höjden med den digitala höjdmätaren användes sambandet mellan lufttryck och höjd. Resultatet av dessa beräkningar visade på ett tillräckligt precist mätvärde för att vara godtagbart. Eftersom mätvärdets precision var godtagbar beslutades det att inga ytterligare rättningar skulle göras. Arbetet fortsattes med att utveckla en prototyp och testning av denna utfördes. Resultatet blev att en fungerande prototyp togs fram. Framtida utvecklingsmöjligheter finns inom presentationsteknik, chassi, ytterligare rättningar av formeln för höjdmätning och fler iterationer av hårdvaran. / In skydiving, in addition to a well-functioning parachute system, a good and precise altimeter is needed. Both which are crucial parts of equipment in order to be able to perform a safe jump. Through digitalization and the technological development, there are today interests of developing a digital altimeter with better precision and several functions There are a number of techniques for measuring altitude. Those that are included in this bachelor thesis are GPS, radar and barometers. The aim of the thesis was to develop a robust algorithm for measuring height, with the possibility of development. The thesis work would also include risk analysis of selected technology or techniques, as well as suggestions for suitable presentation techniques and system solutions in a larger perspective. The system solutions would be adapted for easy integration of new features. If time allowed it, a prototype would also be developed and tested. The method chosen was a digital altimeter because it was best suited for the goals set for the project. To calculate the height with the digital altimeter, the relationship between air pressure and height was used. The result of these calculations showed a sufficiently precise measurement value to be acceptable. Since the accuracy of the measurement value was acceptable, it was decided that no further corrections would be made. The work continued with developing a prototype and testing it. The result was a functioning prototype. Future development opportunities are available within presentation technology, chassis, further corrections of the formula for height measurement and more iterations of hardware.

La caractérisation et l’étude de l’homogénéisation temps réel d’un mélange de produits liquides ou solides présente une opération clé pour de nombreux domaines industriels.Dans le présent travail, nous proposons un modèle de capteur acoustique sphérique miniaturisé et autonome, adapté à des fonctions de caractérisations en ligne des milieux hétérogènes de différentes natures. Ce capteur a la possibilité d’être dispersé dans un système dynamique en constituant un réseau de capteurs géo-localisables permettant une cartographie des propriétés recherchées du milieu. Sa forme sphérique creuse nous offre la possibilité de loger une électronique programmable pour gérer son fonctionnement par unité ou dans un réseau de capteurs identifiés par codage.D’un point de vu mécanique, le résonateur proposé est assemblé à partir de deux demi-sphères faites d'un matériau approprié (Plexiglas dans le cadre de notre étude), le capteur est mis en résonance à l’aide d’un élément piézo-électrique déposé entre les deux demi-sphères ayant la forme d'un anneau.Après une validation expérimentale du système en adoptant le principe de la trilatération, une étude sur l’atténuation et la vitesse de propagation de l’onde acoustique a été effectuée dans différentes solutions à 35 °C; eau, glucose, huile de colza, lait, gel laitier et grain de caillé en suspension (différente taille). / The characterization and the study of real-time homogenization of a mixture of liquid and solid products present a key operation for many industrial sectors.In this work, we propose a model of spherical acoustic sensor miniaturized and autonomous adapted to different functions of characterization online of heterogeneous media of various kinds. This sensor has the ability to be dispersed in a dynamic system by creating a network of geo-localization for mapping desired properties of the medium. Its spherical hollow shape gives us the opportunity to accommodate a programmable electronic for managing its function as a unit or in a sensor network identified by coding.From a mechanical point of view, the proposed resonator is assembled from two hemi-spheres made of a suitable material (Plexiglas in our study), the sensor is brought into resonance by using an element piezoelectric introduced between the two hemi-spheres having the shape of a ring.After an experimental validation of the system by adopting the principle of trilateration, a mitigation study and propagation velocity of the acoustic wave was performed in different solutions at 35 ° C; water, glucose, rapeseed oil, milk, dairy and grain curd gel suspension (different sizes).

The traditional way of increasing capacity in a wirelesscommunication system has been cell splitting and fixedchannel-allocation based on prediction tools. However, theplanning complexity increases rapidly with the number of cellsand the method is not suitable for the large temporal andspatial traffic variations expected in the future. A lot ofresearch has therefore been performed regarding adaptivechannel allocation, where a channel can be used anywhere aslong as the signal-to-interference ratio (SIR) is acceptable. Acommon opinion is that these solutions must be decentralizedsince a centralized one would be overly complex. In this thesis, we study the locally centralizedbunch conceptfor radio resource management (RRM) in aManhattan environment and show that it can give a very highcapacity both for outdoor users and for indoor users covered byoutdoor base stations. We show how measurement limitations anderrors affect the performance and wepropose methods to handlethese problems, e.g. averaging of measured values, robustchannel selection algorithms, and increased SIR margins. Wealso study the computational and signaling complexities andshow that they can be reduced by splitting large bunches, usingsparse matrix calculations, and by using a simplified admissionalgorithm. However, a reduction of the complexity often means areduction of the system capacity. The measurements needed for RRM can also be used to find amobile terminal's geographical position. We propose and studysome simple yet accurate methods for this purpose. We alsostudy if position information can enhance RRM as is oftensuggested in the literature. In the studied scenario, thisinformation seems to be of limited use. One possible use is toestimate the mobile user's speed, to assist handover decisions.Another use is to find the location of user hotspots in anarea, which is beneficial for system planning. Our results show that the bunch concept is a promisingcandidate for radio resource management in future wirelesssystems. We believe that the complexity is manageable and themain price we have to pay for high capacity is frequentreallocation of connections. <b>Keywords:</b>bunch concept, radio resource management,network-assisted resource management, base station selection,dynamic channel allocation, DCA, channel selection,least-interfered, interference avoidance, interferenceaveraging, handover, power control, path-loss measurements,signal strength, link-gain matrix, TD-CDMA, UTRA TDD, Manhattanscenario, microcells, mobile positioning, position accuracy,trilateration, triangulation, speed estimation

<p>The traditional way of increasing capacity in a wirelesscommunication system has been cell splitting and fixedchannel-allocation based on prediction tools. However, theplanning complexity increases rapidly with the number of cellsand the method is not suitable for the large temporal andspatial traffic variations expected in the future. A lot ofresearch has therefore been performed regarding adaptivechannel allocation, where a channel can be used anywhere aslong as the signal-to-interference ratio (SIR) is acceptable. Acommon opinion is that these solutions must be decentralizedsince a centralized one would be overly complex.</p><p>In this thesis, we study the locally centralized<i>bunch concept</i>for radio resource management (RRM) in aManhattan environment and show that it can give a very highcapacity both for outdoor users and for indoor users covered byoutdoor base stations. We show how measurement limitations anderrors affect the performance and wepropose methods to handlethese problems, e.g. averaging of measured values, robustchannel selection algorithms, and increased SIR margins. Wealso study the computational and signaling complexities andshow that they can be reduced by splitting large bunches, usingsparse matrix calculations, and by using a simplified admissionalgorithm. However, a reduction of the complexity often means areduction of the system capacity.</p><p>The measurements needed for RRM can also be used to find amobile terminal's geographical position. We propose and studysome simple yet accurate methods for this purpose. We alsostudy if position information can enhance RRM as is oftensuggested in the literature. In the studied scenario, thisinformation seems to be of limited use. One possible use is toestimate the mobile user's speed, to assist handover decisions.Another use is to find the location of user hotspots in anarea, which is beneficial for system planning.</p><p>Our results show that the bunch concept is a promisingcandidate for radio resource management in future wirelesssystems. We believe that the complexity is manageable and themain price we have to pay for high capacity is frequentreallocation of connections.</p><p><b>Keywords:</b>bunch concept, radio resource management,network-assisted resource management, base station selection,dynamic channel allocation, DCA, channel selection,least-interfered, interference avoidance, interferenceaveraging, handover, power control, path-loss measurements,signal strength, link-gain matrix, TD-CDMA, UTRA TDD, Manhattanscenario, microcells, mobile positioning, position accuracy,trilateration, triangulation, speed estimation</p>

[pt] Neste trabalho, foca-se em uma solução alternativa para se expressar a incerteza de medição que é aplicada na localização por identificação por rádio-frequência (RFID). Elabora-se um modelo para a expressão da incerteza de medição, incerteza máxima possível diferencial (IMPD), que aplica-se aos métodos de identificação de células (Cell-Id ou Cid), vizinho mais próximo (VMP) e trilateração (3L) e que possa servir de auxílio à escolha dos parâmetros relevantes para localização, antes da implementação. Propõe-se uma modificação da Cell-ID, denominada Cell-ID média (MCid), e constrói-se o modelo de incertezas tanto para a Cid quanto para a MCid, levando em conta os parâmetros não considerados no modelo da literatura. Os modelos propostos neste trabalho levam, naturalmente, à definição de um alcance ótimo para as tags. Consequentemente, derivam-se fórmulas fechadas para a sua determinação direta e rápida. Com todo o ferramental construído, desenvolveu-se um experimento numérico aplicado à localização de chamadas de emergência segundo critérios do E911, cujos resultados indicaram a possibilidade de localização com a metodologia proposta, ainda que o alcance varie de 40 m em magnitude, em relação ao alcance esférico geralmente adotado na literatura. Mostrou-se como modelar a incerteza dos métodos VMP e 3L e também se comparou a incerteza de medição determinada pelo método proposto neste trabalho com a determinada tanto por simulação de Monte Carlo quanto pela lei de propagação de incertezas. Os resultados indicaram que o método proposto pode estimar a incerteza para altas probabilidades de abrangência, sendo especialmente útil quando nem todas as grandezas de entrada podem ser medidas. / [en] In this work, the focus is on an alternative solution for expressing the uncertainty of a measurement, which is applied in location by the identification through radio-frequency (RFID). A proposal of a model for the expression of measurement uncertainty is presented, named as the maximum possible differential uncertainty (IMPD, in Portuguese), and its application to the Cell-Id (Cid), nearest neighbor (VMP, in Portuguese) and trilateration (3L) methods that may be of use for choosing the relevant parameters for location before implementation. A modification of Cell-ID is proposed, named mean Cell-ID (MCid), and built the error model for both Cid and MCid, taking into account the parameters not considered in the literature. The models proposed in this work conducted, naturally, to the definition of an optimal range for the tags. Consequently, it is derived closed formulae for its direct and fast determination. Finally, with all the tools built, a numerical experiment applied to the location of emergency calls is developed, according to criteria for the E911 (Enhanced 911). The results indicated the possibility of positioning, even if the range shows variations of 40 m, in magnitude, in relation to the spherical range generally adopted in the literature. It was shown how to model the uncertainty of VMP and 3L, and performed a comparison between the measurement uncertainty as given by the method proposed in this work with the one determined by a Monte Carlo simulation. The results indicate that the proposed approach can estimate the measurement uncertainty for high coverage probabilities, and that it is especially useful when one or more input quantities cannot be measured.

Tracking objects or people in an indoor environment has a wide variety of uses in many different areas, similarly to positioning systems outdoors. Indoor positioning systems operate in a very different environment however, having to deal with obstructions while also having high accuracy. A common solution for indoor positioning systems is to have three or more stationary anchor antennas spread out around the perimeter of the area that is to be monitored. The position of a tag antenna moving in range of the anchors can then be found using trilateration. One downside of such a setup is that the anchors must be setup in advance, meaning that rapid deployment to new areas of such a system may be impractical. This thesis aims to investigate the possibility of using a different setup, where three anchors are placed close together, so as to fit in a small hand-held device. This would allow the system to be used without any prior setup of anchors, making rapid deployment into new areas more feasible. The measurements done by the antennas for use in trilateration will always contain noise, and as such algorithms have had to be developed in order to obtain an approximation of the position of a tag in the presence of noise. These algorithms have been developed with the setup of three spaced out anchors in mind, and may not be sufficiently accurate when the anchors are spaced very closely together. To investigate the feasibility of such a setup, this thesis tested four different algorithms with the proposed setup, to see its impact on the performance of the algorithms. The algorithms tested are the Weighted Block Newton, Weighted Clipped Block Newton, Linear Least Squares and Non-Linear Least Squares algorithms. The Linear Least Squares algorithm was also run with measurements that were first run through a simple Kalman filter. Previous studies have used the algorithms to find an estimated position of the tag and compared their efficiency using the positional error of the estimate. This thesis will also use the positional estimates to determine the angular position of the estimate in relation to the anchors, and use that to compare the algorithms. Measurements were done using DWM1001 Ultra Wideband (UWB) antennas, and four different cases were tested. In case 1 the anchors and tag were 10 meters apart in line-of-sight, case two were the same as case 1 but with a person standing between the tag and the anchors. In case 3 the tag was moved behind a wall with an adjacent open door, and in case 4 the tag was in the same place as in case 3 but the door was closed. The Linear Least Squares algorithm using the filtered measurements was found to be the most effective in all cases, with a maximum angular error of less than 5$^\circ$ in the worst case. The worst case here was case 2, showing that the influence of a human body has a strong effect on the UWB signal, causing large errors in the estimates of the other algorithms. The presence of a wall in between the anchors and tag was found to have a minimal impact on the angular error, while having a larger effect on the spatial error. Further studies regarding the effects of the human body on UWB signals may be necessary to determine the feasibility of handheld applications, as well as the effect of the tag and/or the anchors moving on the efficiency of the algorithms.

The diploma thesis describes localization of communications nodes in the Wireless Sensor Networks. This thesis contains basic algorithms for localization sensor's nodes as are Map-Growing and ABC (Assumption Based Coordinates). Then is chosen acceptable algorithm for simulation on random sensor networks. For research these problems is used software MATLAB. For a given the university's environment are researched appropriate algorithms with possible optimalization algorithms. The result of diploma thesis is a localization algorithm with initial multilateration system and this system is located in the center sensor's network. As algorithm IMap4-Growing (Improved Map4-Growing) with optimization, which uses optimization distance between sensors and radio range. In the diploma thesis is simulated optimalization algorithm Mass-Spring.

Le cadre de cette thèse est centré sur l'étude d'un radar ultra large bande (ULB) en mode impulsionnel, pour la « vision » à travers les murs (VAM), qui présente de nombreuses applications tant dans le domaine militaire (lors des assauts, des prises d’otages, …) que dans le secteur de la sécurité civile (recherche de personnes dans des décombres, dans un incendie, ...). Pour ces utilisations, l’image réelle de la scène observée n’est pas nécessaire, seules certaines informations pertinentes suffisent : nombre de personnes, position, vitesse de déplacement, etc. C'est dans ce contexte que nous avons développé un dispositif expérimental de détection et des techniques de localisation de cibles derrière un mur. Le radar développé est constitué d’un émetteur impulsionnel couvrant la gamme de fréquence de 3 GHz à 6 GHz, et de trois récepteurs indépendants, associés à des algorithmes de localisation et de reconstruction d'image.Le premier algorithme repose sur une technique de trilatération. Une fois, le modèle théorique présenté, plusieurs méthodes de résolution sont étudiées pour l'estimation de la mesure de la distance de propagation du signal. La méthode de Brent-Dekker a été retenue pour sa rapidité de convergence et son faible nombre d’itérations. Bien que cette technique soit précise, elle ne permet pas d’obtenir une image de la scène, mais juste de localiser les cibles, sans apporter des informations sur ses dimensions. C’est pourquoi une seconde approche, basée sur une « formation de faisceau », a été étudiée, afin d'obtenir une représentation 2D de la scène. Nous avons choisi de développer une méthode de rétroprojection non cohérente, technique la plus simple qui ne nécessite pas de contrainte forte sur la phase du signal ni sur le positionnement des antennes. Différentes variantes de rétroprojection ont été proposées : la rétroprojection avec cross corrélation, la rétroprojection cross corrélation améliorée et la rétroprojection bicross corrélée. Ces trois méthodes reposent sur une fusion d'informations capturées par l'antenne réceptrice avec celles obtenues sur des antennes dites de référence. Cette fusion a permis d'améliorer progressivement le rendu des images.Pour conclure ses travaux, une perspective est ébauchée afin de minimiser le taux de fausse détection, elle s'appuie sur la collaboration de la technique de trilatération avec la technique de rétroprojection bicross corrélée. Cette collaboration permet de mettre en correspondance les détections estimées par la technique de trilatération et celles utilisant la rétroprojection bicross corrélée. Les cibles non appariées sont alors supprimées selon des critères spécifiques à chacune des deux approches. / The content of this thesis is focused on the study of an UWB pulse radar for through the wall vision which has many applications in the military domain (assaults, hostage rescue,…) and in the civil security domain (people search in the rubble, in a fire).For these uses, the real observed scene image is not necessary, only some relevant information is enough: number of persons, position, velocity of movement, etc. It’s in this context where we have developed an experimental detection device and some through the wall targets localization techniques. The developed radar consists of a pulse transmitter covering the frequency range from 3GHz to 6GHz, and three independent receivers, combined with some localization algorithms and image reconstruction.The first algorithm is based on a technique of trilateration. Once the theoretical model is presented, many resolutions methods are studied for estimation of the signal propagation distance measurement. The Brent-Dekker method has been chosen for its fast convergence and low number of iterations. Although the trilateration technique is accurate, it does not allow obtaining a scene image, but just locate the targets, without providing their dimensions. Therefore a second approach, based on a “beam forming”, has been studied, in order to obtain a 2D scene representation. We have chosen to develop a non-coherent backprojection method, it is the most simple technique which does not require a strong constraint on the signal phase nor on the antenna positions. Different backprojection methods have been proposed: the backprojection with cross correlation, the improved backprojection with cross correlation and bi-cross correlated backprojection. These three methods are based on a fusion of captured information by the receiving antennas and with the obtained information on the “referenced” antennas. This fusion allows improving the image quality progressively.To conclude this work, a perspective is initiated in order to minimize the false detection rate, it is based on the cooperation of the trilateration technique and bi-cross correlated backprojection. This cooperation allows matching the estimated detection by the trilateration technique and the bi-cross correlated backprojection technique. The mismatched targets are removed according to some specific criterias to each approach.