Les travaux présentés dans cette thèse ont pour but la maîtrise des méthodes d'étalonnage par multilatération. Ils s'inscrivent dans une collaboration entre le Laboratoire national de métrologie et d'essais (LNE) et le Laboratoire Universitaire de Recherche en Production Automatisée (LURPA). Dans ces travaux, la multilatération est dite séquentielle car réalisée avec un unique Laser Tracer positionné successivement plusieurs points de l'espace. La détermination de ces positions ainsi que des bras-morts de l'interféromètre est le point clef de la méthode. Pour l'évaluation des incertitudes, le raccordement aux étalons est fait via les longueurs interférométriques délivrées par le Laser Tracer. Elles sont associées à des défauts caractéristiques d'une cinématique particulière ou aux coordonnées des points mesurés. Elles sont évaluées au travers de la stratégie de mesure et des performances de chaque composant intervenant lors de la procédure d'étalonnage. Mesurer les coordonnées d'un point cible de l'espace par multilatération implique de connaître les positions des points de vue depuis lesquels le point est visé, ainsi que les longueurs qui le séparent des points de vue qui en pratique sont les centres des Laser Tracer. La méthode que nous proposons permet d'identifier les positions et bras-morts des Laser Tracer qui constituent un repère de mesure qualifié de Système Mesurant de Référence (SMR), puis de réaliser la multilatération. Ensuite, l'extraction de défauts volumiques permet éventuellement d'identifier les défauts cinématiques d'une chaîne de solides particulière associée au volume de mesure. Dans cette optique, nous proposons une procédure type inspirée des travaux du LNE axés sur l'utilisation d'une barre à trous pour identifier les défauts cinématiques d'une MMT à trois axes cartésiens. Cette méthode se démarque des approches actuellement proposées car le SMR est construit indépendamment de l'identification des défauts de l'appareil de mesure. De plus, la procédure d'étalonnage que nous proposons repose sur une investigation axe par axe plutôt que par une optimisation globale du problème d'étalonnage. En nous focalisant sur les machines à mesurer tridimensionnelles (MMT), nous proposons un bilan d'incertitudes qui a inclus des facteurs dont le rôle n'était auparavant pas pris en compte dans la littérature. Ces facteurs sont liés au fait de n'utiliser qu'un seul Laser Tracer pour étalonner la MMT. Nous proposons un module d'évaluation des incertitudes qui permet, grâce à des simulations de Monte Carlo, d'identifier l'influence de chacun de facteurs d'incertitude. La pertinence d'une stratégie d'étalonnage peut donc être évaluée à priori de la mise en œuvre de la procédure. L'outil de simulation proposé s'appuie sur la simulation du comportement de la MMT et de celui du Laser Tracer lors de la mesure. Deux indicateurs d'incertitude sont proposés pour l'étude des incertitudes. L'un est lié à l'exactitude de calcul du SMR construit sur les positions successives du Laser Tracer, l'autre est une image de l'incertitude obtenu sur les profils des défauts cinématiques calculés. Cet outil de simulation a permis de valider l'importance des sources d'incertitudes établies initialement pour l'étalonnage d'une MMT à trois axes cartésiens. L’ensemble de la démarche a été appliqué et validé pour une MMT à 3 axes cartésiens en conditions de laboratoire chez un industriel. Cependant, l’approche proposée découple la construction du SMR de l’identification des défauts cinématiques. Elle peut donc être facilement étendue à des systèmes de mesure 3D variés. Nous montrons donc que la démarche globale peut s’appliquer à des espaces de mesure sans cinématique machine. Il s’agit alors d’identifier les défauts volumiques associés à l’espace de mesure, ainsi que les incertitudes associées à la méthode d’étalonnage mise en œuvre. Afin d’illustrer notre propos, nous traitons le cas d’espaces de travail associés à un système de mesure optique. / This thesis aims at developing calibration procedures and methods for measuring tools such as coordinate measuring machines (CMMs) and stereovision devices. This work is incorporated within the framework of a collaboration between the Laboratoire national de métrologie et d’essais (LNE) and the Automated Production Research Laboratory (LURPA). In the scope of this thesis, multilateration is qualified as sequential because it is carried out by a single tracking interferometer (Laser Tracer) that is placed in different positions during the calibration procedure. In order to assess the calibration uncertainties, the link to the length standards is obtained through the measured lengths provided by the interferometer. Each one of these measured lengths is linked to the kinematic chain parametric errors that cause the volumetric errors of the CMM or directly to the measured points coordinates. They are assessed thanks to the study of both the calibration procedure and the performance of each component that takes part in the calibration procedure.Performing multilateration to obtain the spatial coordinates of a point requires to know both the stand points from which the point is measured and the distances between the stand points and the measured point. Practically, the stand points are the Laser Tracer positions. The proposed method aims at identifying the Laser Tracer’s positions and dead-paths lengths first in order to build a reference measuring frame, then performing multilateration. Then, if the measuring device is a CMM, its kinematic chain parametric errors are identified. For this matter, we propose a specific procedure based on the LNE knowledge on CMM calibration carried out using hole-bars. The originality of the proposed method lies in the fact that the reference measuring frame and the measuring device errors are calculated independently from each other. Plus, when addressing the case of a CMM calibration, the kinematic chain parametric errors are extracted one by one when a global optimization algorithm is usually performed nowadays.We focus on the case of CMMs calibration and we propose a precise analysis of all the sources of errors. It includes factors which influence was not studied before. They appear to result from the fact that a single tracking interferometer is used to calibrate the CMM. A simulation module based on a Monte Carlo approach has been developed. It enables the study of the influence of each source of errors independently from the other ones. Hence, the relevance of a measuring strategy can be assessed beforehand. This module simulates the behaviour of both the CMM and the Laser Tracer to evaluate uncertainties. We propose two indicators to observe the relative influence of each uncertainty factor. The first one is linked to the reference frame that is built on the successive positions of the Laser Tracer. The second one represents the global uncertainty one the kinematic chain parametric errors. This uncertainty assessment module has been successfully used to highlight the importance of sources of errors which role used to not be studied.The calibration procedure and uncertainty assessment module we propose have been successfully applied to a 3-axis cartesian CMM in laboratory conditions. Plus, since the reference measuring frame and the kinematic chain parametric errors identification are performed separately, the method we propose can be applied to other measuring devices. We especially explain how to apply it in the case of a measuring device based on stereovision.

This thesis explores the possibility of using ultra wideband technology to localize anoutdoor mobile robot. More explicitly, this project focuses on the multilaterationproblem where the topology of the static reference anchors are changed. Insteadof having stationary anchors they are placed on a mobile robot and by pinpointingone single static tag node the position of the robot is established. The research usesa robotic lawn mover from Husqvarna, the Automover 430X. The robot is used asa base platform for this thesis to evaluate if this approach is applicable for othergeneric robots in the same size. The feasibility of this solution is demonstratedthrough simulation using Matlab and the robot simulation environment Gazebo.Results show that this specific topology is feasible for tracking a specific point butis also suitable for positioning a mobile robot if coupled with an accurate headingsensor. The system was evaluated for several scenarios of which all indicated anadequate accuracy, provided that data from an encoder was used. The upper limitfor the position error in a one sided 95% confidence interval was 0.469m at a rangeof 40m. / Detta examensarbete tar sig an problemet att lokalisera en långsamtgående mobilrobot i en utomhusmiljö genom att använda sig av ultra wideband radioteknik. Vanligtvisplaceras stationära noder i miljön som används för att positionera en ensamnod i dess närhet. Detta projekt tar sig an frågeställningen om det är möjligt attvända på problemet och placera dessa stationära noder på den mobila roboten föratt sedan fixera robotens position genom att bestämma vart den ensamma nodenär placerad. Husqvarnas robotgräsklippare Automover 430X har används som plattformför att evaluera och testa om denna tes är applicerbar för andra generiska robotari samma storlek. Positionsuppskattningen utförs genom simulationer i Matlabsamt simulationsmiljön Gazebo som tar hänsyn till diverse fysiska fenomen. Resultatenpekar på att denna topologi är möjlig för att lösa multilatereringsproblemetom en riktningssensor med hög precision används. För alla scenarion som simuleradesindikerades att en någorlunda god precision kan uppnås och det krävdes attsystemet kombinerades med annan indata, som en enkoder i detta fall för att förbättraestimeringen. Den övre gränsen för felet i ett 95% konfidensintervall var 0.469mpå ett avstånd upp till 40m.

The use of ubiquitous network has made real time tracking of objects, animals and human beings easy through the use of radio frequency identification system (RFID). Localization techniques in RFID rely on accurate estimation of the read range between the reader and the tags. The tags consist of a small chip and a printed antenna which receives from and transmits information to the reader. The range information about the distance between the tag and the reader is obtained from the received signal strength indication (RSSI). Accuracy of the read range using RSSI can be very complicated especially in complicated propagation environment due to the nature and features of the environment. There are different kinds of localisation systems and they are Global Positioning System (GPS) which can be used for accurate outdoor localization; while technologies like artificial vision, ultrasonic signals, infrared and radio frequency signals can be employed for indoor localization. This project focuses on the location estimation in RFID Non Line-of-Sight (NLOS) environment using Real Time Localization System (RTLS) with passive tags, in carrying out passengers and baggage tracking at the airport. Indoor location radio sensing suffers from reflection, refraction and diffractions due to the nature of the environment. This unfavourable phenomenon called multipath leads to delay in the arrival of signal and the strength of signal received by receiving antenna within the propagation channel which in turns affects the RSSI, yielding inaccurate location estimation. RTLS based on time difference of arrival and error compensation technique and extended Kalman filter technique were employed in a NLOS environment to determine the location of tag. The better method for location estimation in a NLOS between the Kalman filtering and extended Kalman filtering is investigated. According to simulation results, the extended Kalman filtering technique is more suitable to be applied to RTLS.

Traditional satellite positioning systems have limited resolution and have proved inaccuratein areas such as urban canyons where signals are subject to bounce phenomena or indeed may be entirely unavailable. An alternative method of positioning is that of tri/multilateration, which uses known positions and distances from beacon points to locate a receiver. In this project, a software was developed which used DSRC Basic Safety Messages (containing locational information) in combination with Received Signal Strength metrics (translated to distance information) to carry out such positioning in static environments. Initial studies confirmed that a signal received on the Craton 2 hardware was subject to considerable signal strength spread approximating a Gaussian distribution. A software was developed to simulate BSMs, including a measure of perturbation, over TCP. Three different traffic scenarios were constructed. Furthermore, multilaterationsoftware was developed to receive the BSMs and calculate position using three separate algorithms. The performance of these algorithms in the three different traffic scenarios was then evaluated. Lastly, the multilateration software was further developed to allow for the capture and processing of real BSMs sent on the 5.9 GHzband. The multilateration software was capable of determining the location of the receiver to varying degrees of accuracy, depending on the geometrical distribution of surrounding vehicles and the algorithm used to multilaterate. The 3D Linear Least Squares method performed well in situations where beacons were well spaced in three dimensions. Other implemented multilateration algorithms, i.e., a 2D Linear Least Squares method and a 3D Gauss Newton method, performed better in typical traffic scenarios where vehicles tend to be coplanar.The software developed provides a useful starting point for further developmentof static, but also dynamic, multilateration algorithms.

This work addresses the problem of localizing an impact in a dispersive medium (waveguide) using a network of vibration sensors (accelerometers), distributed at various locations in the waveguide, measuring (and detecting the arrival of) the impact-generated seismic wave. In particular, the last part of this document focuses on the problem of localizing footsteps using underfloor accelerometers. The author believes the outcomes of this work pave the way for realizing real-time indoor occupant tracking using underfloor accelerometers; a system that is tamper-proof and non-intrusive compared to occupant tracking systems that rely on video image processing. A dispersive waveguide (e.g., a floor) causes the impact-generated wave to distort with the traveled distance and renders conventional time of flight localization methods inaccurate. Therefore, this work focuses on laying the foundation of a new alternative approach to impact localization in dispersive waveguides. In this document, localization algorithms, including wave-signal detection and signal processing, are developed utilizing the fact that the generated wave's energy is attenuated with the traveled distance. The proposed localization algorithms were evaluated using simulations and experiments of hammer impacts, in addition to occupant tracking experiments. The experiments were carried out on an instrumented floor section inside a smart building. As will be explained in this document, energy-based localization will turn out to be computationally cheap and more accurate than conventional time of flight techniques. / PHD

Passive localization of aircraft in flight using signal time of arrival (TOA) poses some unique challenges. The sensors must be deployed in an approximately coplanar configuration, which produces significant vertical uncertainty in the estimated position. This dissertation examines the traditional algorithms used in passive localization. It presents general forms of linear TOA, time difference of arrival (TDOA), angle of arrival (AOA), and frequency difference of arrival (FDOA) equations from the literature and explains how to apply an intuitive geometric interpretation of these equations. It presents two novel algorithms for passive localization. One uses a one dimensional AOA (1AOA) to improve the vertical estimate. The other employs an a priori estimate to approximate the non-linear localization problem as a linear problem and produce a high quality position estimate. A comprehensive survey of the literature is presented. This dissertation provides a summary and classification of passive localization algorithms from the literature with simple descriptions of how the form of the equations relate to their numerical stability. It presents two novel algorithms for passive localization. The hybrid multilateration and triangulation algorithm improves wide area multilateration by using vertical 1AOA to constrain the vertical position. The multilateration with a priori estimates algorithm provides a linear localization method that utilizes previous location estimates.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Gulf Range Drone Control Upgrade System (GRDCUS) Mobile Control System (GMCS) is an integral part of the test ranges located on the Gulf of Mexico. This paper begins with a brief overview of the current Gulf Range systems. These systems consist of five major components: ground stations, ground computer systems, data link/transponders, consoles, and software. The GMCS van contains many of these components to provide a stand-alone range capability for remote operations. This paper describes the development and assembly of the GMCS van and focuses on the on-board computer systems, consoles, and data link technology. An overall system engineering approach was used during GMCS development and is highlighted through the use of rapid prototyping. This methodology and the lessons learned are presented in the paper. Suggestions for future applications are considered.

The indoor positioning system is a series of networking systems used to monitor/locate objects at indoor area as opposed that of GPS which does the same at outdoor. The increase in the popularity of the Internet of Things made the demand for Bluetooth Low Energy technology more and more essential due to their compatibility in the smartphones which makes it to access easier. The BLE’s reliable signal and accuracy in calculating the distance has a cutting edge on others in IPS. In this thesis, the Bluetooth Low Energy indoor positioning system was designed and implemented in the office area, and the positionofIoTdevicesweremonitored. OntheIoTdevices,thebeaconswereplaced. And thesebeaconswerecoveringtheofficearea. Thereceiver,smartphoneinourcase,recorded theReceivedSignalStrengthIndicationofthetransmittedsignalsfromthebeaconswithin the range of the signal and stored the collected data in a database. Two experiments have beenconducted. Oneisforbeaconsthatarestationaryandonethatismoving. Toevaluate these experiments, a few tests were performed to predict the position of beacons based on therecordedreceivedsignalstrength’s. Inthecaseofstationarybeacons, itoffersaccuracy range from 1 m to 5 m, and 3 m to 9.5 m in anticipating the position of each beacon in the case of moving beacon. This methodology was a mixture of fingerprinting and an algorithm of multilateration. Finally, the experiments show that the algorithm used provides the most accurate indoor position using BLE beacons that can be monitored through an Android-based application in real-time.

MScEng / Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Accurate dimensional measurement devices are critical for international industrial competitiveness for South Africa. An overview of all the necessary components of a laser tracking system using a multilateration technique for very accurate dimensional metrology is presented. A prototype laser tracker station was built to further investigate this type of system. The prototype successfully tracks a target within a volume of at least 200 200 200 mm3, approximately 300 mm away from the tracker. This system includes the mechanical design of a prototype tracker station, electronic implementation of ampli cation and motor control circuits, a tracking control algorithm, microcontroller programming and interfacing, as well as a user interface. Kinematic modelling along with Monte Carlo analyses nd the main error source of such a tracker as the beam steering mechanism gimbal axes misalignment. Multilateration is also motivated by the results found by the analysis. Furthermore, an initial sequential multilateration algorithm is developed and tested. The results of these tests are promising and motivate the use of multilateration over a single beam laser tracking system. / AFRIKAANSE OPSOMMING: Dit is van kritieke belang dat Suid-Afrika akkurate dimensionele metingstoestelle ontwikkel vir internasionale industriële medinging. 'n Oorsig van al die nodige komponente vir 'n Laser-Volgsisteem, wat slegs van multilaterasie gebruik maak om baie akkurate drie dimensionele metings te kan neem, word in hierdie projek voorgestel. 'n Prototipe Laser-Volgsisteem-stasie word gebou om so 'n sisteem verder te ondersoek. Die prototipe slaag wel daarin om 'n teiken, binne 'n volume van 200 200 200 mm3 op 'n afstand van omtrent 300 mm te volg. Die sisteem sluit die meganiese ontwerp van die sodanige stasie, elektroniese seinversterking, motorbeheer, 'n volgingsbeheer algoritme, mikroverwerker programeering en intergrasie, asook 'n gebruikerskoppelvlak program in. Kinematiese modelering, tesame met Monte Carlo simulasies, toon aan dat die hoof oorsaak van metingsfoute by so 'n stasie by die rotasie-asse van die laserstraal-stuurmeganisme, wat nie haaks is nie, lê. Die multilaterasie metode word ook verder ondersteun deur dié modelering. 'n Algoritme wat sekwensiële multilateratsie toepas word boonop ontwikkel en getoets. Die resultate van die toetse dui daarop dat die algoritme funksioneer en dat daar voordele daarin kan wees om so 'n metode in plaas van 'n Enkelstraal-Volgsisteem te gebruik.

Range-based localization is a widely used technique for position estimation where distances are measured to anchors, nodes with known positions, and the position is analytically estimated. It offers the benefits of providing high localization accuracy and involving simple operation over multiple deployments. Examples are the Global Positioning System (GPS) and network-based cellular handset localization. Range-based localization is promising for a range of applications, such as robot deployment in emergency scenarios or monitoring industrial processes. However, the presence of clutter in some of these environments leads to a severe degradation of the localization accuracy due to non-line-of-sight (NLOS) signal propagation. Moreover, current literature in NLOS-mitigation techniques requires that the NLOS distances constitute only a minority of the total number of distances to anchors. The key ideas proposed in the dissertation are: 1) multi-hop localization offers significant advantages over single-hop localization in NLOS-prone environments; and 2) it is possible to further reduce position errors by carefully placing intermediate nodes among the clutter to minimize multi-hop distances between the anchors and the unlocalized node. We demonstrate that shortest path distance (SPD) based multi-hop localization algorithms, namely DV-Distance and MDS-MAP, perform the best among other competing techniques in NLOS-prone settings. However, with random node placement, these algorithms require large node densities to produce high localization accuracy. To tackle this, we show that the strategic placement of a relatively small number of nodes in the clutter can offer significant benefits. We propose two algorithms for node placement: first, the Optimal Placement for DV-Distance (OPDV) focuses on obtaining the optimal positions of the nodes for a known clutter topology; and second, the Adaptive Placement for DV-Distance (APDV) offers a distributed control technique that carefully moves nodes in the monitored area to achieve localization accuracies close to those achieved by OPDV. We evaluate both algorithms via extensive simulations, as well as demonstrate the APDV algorithm on a real robotic hardware platform. We finally demonstrate how the characteristics of the clutter topology influence single-hop and multi-hop distance errors, which in turn, impact the performance of the proposed algorithms.