This thesis deals with the possibility of connecting inertial navigation sensors (accelerometer, magnetometer and gyroscope) to determine with the highest precision the position of the user without the help of GPS or other networks. This is inherently connected with the need to deal with many sources of errors, which are connected with this positioning method. The research section describes the principle and history of selected navigation methods and current trends in the use of inertial positioning or navigation methods. The methodical part deals with the design of a system able to determine with the highest accuracy the current position of the user from different input conditions. It is designed to obtain the necessary data from both the sensors and the user and their subsequent processing and use to render the user's position. The application section then describes the practical procedure for creating an Android mobile OS application output and in the discussion part is presented and evaluated the knowledge of testing both during the creation and in the final survey among the test users. The conclusion evaluates the goals and summarizes the practical possibilities and limits of the usability of these positioning methods in mobile phones. It also provides suggestions for further development and...

Standard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicles (USVs). To overcome this, the thesis presents a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes. The work integrates an Inertial Measurement Unit (IMU), a GPS receiver, a flux-gate compass, a tilt sensor and develops a software package, using real time data fusion methods, for an USV to aid in the navigation and control as well as controlling an onboard Acoustic Doppler Current Profiler (ADCP).While ADCPs non-intrusively measure water flow, they suffer from the inability to discriminate between motions in the water column and self-motion. Thus, the vessel motion contamination needs to be removed to analyze the data and the system developed in this thesis provides the motion measurements and processing to accomplish this task. / by Chrystel Gelin. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

A presente pesquisa engloba a análise de diversos aspectos a respeito da avaliação de irregularidade longitudinal de pavimentos, tratando mais detidamente das situações em que tal avaliação é executada a partir de perfis longitudinais medidos com perfilômetros inerciais, tipo de equipamento que também é objeto de exame. A análise é iniciada com o entendimento da evolução histórica deste tipo de avaliação funcional que abrange não só os equipamentos, como também os métodos de avaliação e os índices de irregularidade utilizados no Brasil. O trabalho relata as principais etapas do desenvolvimento do perfilômetro inercial que foi usado nesta pesquisa, seus aspectos técnicos e operacionais, além dos resultados dos testes que evidenciaram seu funcionamento e também uma comparação com os resultados obtidos por um medidor de irregularidade do tipo resposta. A pesquisa é completada com uma série de análises a respeito do método mais adequado para a verificação do funcionamento de perfilômetros inerciais, abarcando importantes recomendações para a escolha e medição de perfis de referência indispensáveis em tais verificações. São discutidos importantes aspectos do processamento de perfis para a determinação do QI que concluíram pela indicação da redução do espaçamento entre pontos do perfil para 25 cm. As incertezas dos índices QI e IRI obtidos a partir de perfilômetros inerciais são também abordadas, sendo que se constatou que o índice QI é afetado por grandes comprimentos de onda que normalmente não são considerados como irregularidade. A correlação entre os índices QI e IRI é amplamente avaliada através de dados reais de perfis de centenas de quilômetros de rodovias, que evidenciaram a existência de grande dispersão em tal correlação indicando que o melhor é não correlacioná-los. Por fim, a pesquisa deixa como legado a proposta de um anteprojeto de norma brasileira para este tipo de avaliação que abarca os julgamentos de todo o trabalho. / This research includes de analysis of several aspects regarding longitudinal pavement roughness evaluation, more specifically when these evaluations are done using an inertial profiler - kind o equipment that is also an object of this study. The analysis is initiated with the comprehension of the historical evolution of this type of functional evaluation that not only encloses equipment, but also the methods and the roughness indexes more common in Brazil. The main stages throughout of the development of the inertial profiler used on this research, its technical and operational features, the results of the tests that proved its good functionality and also the comparison of the results obtained with a response type roughness meter were incorporated. The research is completed with a series of analysis regarding the methods more appropriate for the verification of inertial profilers functioning, including important recommendations for the choice and measurement of reference profiles, indispensable in such verifications. Important aspects concerning profiles processing for the QI determination were verified and concluded for reduction of the displacement between the profile elevations for 25 cm. The uncertainties of QI and IRI indexes obtained from inertial profiles measurements were also researched and at this opportunity it was verified that value of QI is affected by long wavelengths that usually are not considered roughness. The correlation between QI and IRI indexes were widely evaluated using real data of hundreds of kilometers of highways profiles, and evidenced the existence of a great dispersion in such correlation what indicates that the best recommendation is not to correlate them. Finally, this research leaves as a legacy the proposal of a first draft for a Brazilian standard for this type of roughness evaluation that accumulates most of the judgments presented here.

A proposta deste trabalho é contribuir com a construção de uma plataforma de veículo autônomo para viabilizar as pesquisas na área pelo Departamento de Engenharia de Transportes da USP. Até o momento o departamento dispõe de uma plataforma que, a partir de sua posição conhecida, consegue navegar autonomamente até um ponto de destino utilizando apenas uma solução GNSS, no caso, GPS. Para ampliar a mobilidade da plataforma, está sendo sugerida aqui, a adição de sensores inerciais ao veículo, para que ele consiga obter uma solução de posição mesmo em áreas sem cobertura GNSS. Um Sistema de Navegação Inercial não depende de infraestrutura externa, exceto para inicializar suas variáveis, o que neste caso pode ser feito com auxílio de um receptor GPS. Sensores inerciais de alto desempenho são caros, tem alta complexidade mecânica e em geral são de grande porte. A alternativa é o uso de sensores do tipo MEMS que são pequenos, fáceis de serem manipulados e apresentam baixo consumo de energia. A contrapartida é que a solução é mais susceptível a ruído do que seus pares que custam na faixa de centena de milhões de dólares. / The proposal of this paper is to build an autonomous vehicle platform to enable the researches in this area by the Transport Engineering Department of the USP. Until now the Department has a platform that, once its initial position is known, it can navigate autonomously to a destination point using only the GNSS, in this case, GPS. To expand the mobility resources of the platform, it is being suggested here the addition of inertial sensors to the vehicle, enabling it to acquire a position solution even in areas where there is no coverage of the GNSS. An Inertial Navigation System does not depend on an external infra-structure, with the exception on the initial setup, where the GPS can be used to provide this kind of initialization. High performance inertial sensors are expensive, have high mechanical complexity and in general are big. The alternative is the usage of MEMS sensors, which are small, easy to handle and has low power consumption. In the opposite side this solution is more susceptible to noises in comparison to those High performance sensors that cost hundreds of thousands of dollars.

The design, implementation, and testing of an experimental setup intended to evaluate the dynamic maneuvering performance of the Wave Adaptive Modular Vessel (WAM-V) class USV12, a 3.7 meter unmanned surface vehicle (USV) is described. A comprehensive sensor package was designed, fabricated and assembled to record the vehicle's dynamic response to various control inputs. All subsystems were fabricated and installed on a test vehicle, GUSS, and full system, open-loop maneuvering tests were conducted to show validity of data collection technique. Simulations were performed using model parameters found in the literature to create a "simulated experimental" data set, upon which system identification techniques were used to rediscover a suitable model with similar parameterization. Combined, the sensor package and the method for creating this model support future work in the design of automatic control, navigation, and guidance systems for the WAM-V USV12. / by Janine L. Mask. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

The design and integration of an unmanned surface vehicle (USV) control system is described. A survey of related work in both USV control, and unmanned vehicle operating software is presented. The hardware subsystem comprising a modular Guidance, Navigation, and Control (GNC) package is explained. A multi-threaded software architecture is presented, utilizing a decentralized, mutex-protected shared memory inter-process communication subsystem to provide interoperability with additional software modules. A generic GNC approach is presented, with particular elaboration on a virtual rudder abstraction of differential thrust platforms. A MATLAB Simulink simulation is presented as a tool for developing an appropriate controller structure, the result of which was implemented on the target platform. Software validation is presented via a series of sea trials. The USV was tested both in open- and closed-loop control configurations, the results of which are presented here. Lastly recommendations for future development of the GNC system are enumerated. / by Thomas C. Furfaro. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Le développement des instabilités hydrodynamiques lors d'une expérience de fusion par confinement inertiel représente un sévère obstacle à l'obtention des conditions nécessaires à l'allumage et l'auto-entretien des réactions thermonucléaires. Il est ainsi crucial de comprendre, modéliser et éventuellement contrôler ces instabilités. L'instabilité se développant au front d'ablation est particulièrement étudiée dans le cadre du schéma d'attaque directe, à cause notamment du phénomène d'empreinte laser. Cependant le stade fortement non-linéaire de l'instabilité de Rayleigh-Taylor au front d'ablation reste peu explore. Cette étude vise donc à analyser ce régime.Dans un premier temps, une nouvelle plateforme expérimentale est développée sur le laser National Ignition Facility (NIF) permettant l'étude de phénomènes hydrodynamiques avec plusieurs dizaines de nanosecondes d'impulsion laser. Cette plateforme est ensuite calibrée avec l'étude de la croissance d'une perturbation 2D sous l'effet de l'instabilité de Rayleigh-Taylor. Une plateforme de simulations numériques 2D est également développée sur le code hydrodynamique CHIC capable de modéliser les expériences réalisées.L'étude du régime fortement non-linéaire de l'instabilité de Rayleigh-Taylor est réalisée a partir d'une perturbation multimode 3D imprimée par laser.L'impact de la condition initiale est étudiée en utilisant un faisceau d'empreinte lisse d'une part et non lisse d'autre part. L'analyse des données de radiographie dans l'espace de Fourier et dans l'espace réel permet d'évaluer tous les différents paramètres de l'instabilité (taux de croissance linéaire, vitesses de saturation, taux de coalescence de bulles et paramètre de croissance auto-semblable ) et de comparer les mesures aux modèles existants.L'importance de la condition initiale au stade fortement non-linéaire de la perturbation est ainsi démontrée dans les résultats obtenus. / Experimental and numerical study of the non-linear stage of the ablative Rayleigh-Taylor instability in direct drive

Understanding the motion of a camera from only the image(s) it captures is a di cult problem. At best we might hope to estimate the relative motion between camera and scene if we assume a static subject, but once we start considering scenes with dynamic content it becomes di cult to di↵erentiate between motion due to the observer or motion due to scene movement. In this thesis we show how the invaluable cues provided by inertial sensor data can be used to simplify motion analysis and relax requirements for several computer vision problems. This work was funded by the University of Bath.

In this dissertation, we have focused on conflicts that occur due to disagreeing motions in multi-modal localization algorithms. In spite of the recent achievements in robust localization by means of multi-sensor fusion, these algorithms are not applicable to all environments. This is primarily attributed to the following fundamental assumptions: (i) the environment is predominantly stationary, (ii) only ego-motion of the sensor platform exists, and (iii) multiple sensors are always in agreement with each other regarding the observed motion. Recently, studies have shown how to relax the static environment assumption using outlier rejection techniques and dynamic object segmentation. Additionally, to handle non ego-motion, approaches that extend the localization algorithm to multi-body tracking have been studied. However, there has been no attention given to the conditions where multiple sensors contradict each other with regard to the motions observed. Vision based localization has become an attractive approach for both indoor and outdoor applications due to the large information bandwidth provided by images and reduced cost of the cameras used. In order to improve the robustness and overcome the limitations of vision, an Inertial Measurement Unit (IMU) may be used. Even though visual-inertial localization has better accuracy and improved robustness due to the complementary nature of camera and IMU sensor, they are affected by disagreements in motion observations. We term such dynamic situations as environments with motion conflictbecause these are caused when multiple different but self- consistent motions are observed by different sensors. Tightly coupled visual inertial fusion approaches that disregard such challenging situations exhibit drift that can lead to catastrophic errors. We have provided a probabilistic model for motion conflict. Additionally, a novel algorithm to detect and resolve motion conflicts is also presented. Our method to detect motion conflicts is based on per-frame positional estimate discrepancy and per- landmark reprojection errors. Motion conflicts were resolved by eliminating inconsistent IMU and landmark measurements. Finally, a Motion Conflict aware Visual Inertial Odometry (MC- VIO) algorithm that combined both detection and resolution of motion conflict was implemented. Both quantitative and qualitative evaluation of MC-VIO on visually and inertially challenging datasets were obtained. Experimental results indicated that MC-VIO algorithm reduced the absolute trajectory error by 70% and the relative pose error by 34% in scenes with motion conflict, in comparison to the reference VIO algorithm. Motion conflict detection and resolution enables the application of visual inertial localization algorithms to real dynamic environments. This paves the way for articulate object tracking in robotics. It may also find numerous applications in active long term augmented reality.

Rigid body targets in exo-atmospheric free fall undergo motions defined by classical dynamics. Radar signatures provide a platform for estimation of various parameters relating to the motion and scattering characteristics of the target. This thesis provides a Radar based, physics constrained, estimator of the motion which generates these signatures. As part of this analysis, it defines a motion model for a ``nearly' axially symmetric target in terms of its inertial parameters. We show that the time-varying range to a point on the rigid body can be expressed in the form of an amplitude and frequency modulated signal. The frequency decomposition of this range function is used to estimate the target's elliptic modulus, an inertial parameter directly related to the asymmetry. This result has immediate application as a tool to assist the radar analyst in further target characterization and constitutes and essential step to the full reconstruction of a target's geometry from its signature.