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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Inflight detection of errors for enhanced aircraft flight safety and vertical accuracy improvement using digital terrain elevation data with an inertial navigation system, global positioning system and radar altimeter

Gray, Robert A. January 1999 (has links)
No description available.
42

Implementation of the numerical electromagnetic code (NEC-2) for modeling the VOR navigation system in the presence of parasitic scatterers

Barre, Paul R. January 1986 (has links)
No description available.
43

Design of a Generic Runtime Monitor Approach using Formal Specifications to Enhance UAV Situational Awareness

Patil, Girish 01 November 2016 (has links) (PDF)
Software is the crux of many commercial, industrial and military systems. The software systems need to be very reliable especially in case of safety critical systems. Unmanned Aerial Vehicle (UAV) and manned aircraft are safety critical systems and hence failures related to software or software-hardware interaction leads to huge problems. The software systems need to be certified before they are deployed. Even after being certified several accidents and incidents have occurred and are occurring. The software errors can occur during any phase of software development. The reliability of the software is enhanced using the verification process. Runtime monitoring has various advantages over testing and model checking. Hence this thesis work explores runtime monitoring of UAV. The runtime monitoring shall verify the run of the current system state. The runtime monitoring shall monitor the health of the UAV and shall report to the operator about its status. The software faults and errors if not prevented shall lead to software failure. UAV lacks the situational awareness due to absence of pilot onboard. This motivated to use runtime monitor to enhance the situation awareness. The runtime monitor shall detect the software errors and avoid failures. This monitor shall also enhance the situational awareness of the remote operator. The runtime monitor that enhance situation awareness shall not only be applicable to specific UAV but this shall be applicable to all the UAV’s. Hence this work provides an independent Generic Runtime Monitor (GRM) to enhance the situation awareness. The runtime monitor has various methods but using formal specifications in specific using Linear Temporal Logic(LTL) to generate monitor is considered in this work. Runtime monitoring makes UAV more safe and at the same time reduces the costs as it verifies only the current run of the system state by providing a detection of critical errors. The situation awareness includes functional and environmental states that remote pilot shall not be aware of. The architecture plays vital role for the system design. GRM architecture is one such architecture which chalks out the overall independent system design for the runtime monitoring of the UAV system. This architecture is an extensible one. The generic requirements were elicited from different sources such as Aircraft Incidents and Accidents, Boeing Aero Magazine, Autonomous Rotorcraft Testbed for Intelligent Systems (ARTIS) requirements, generic Autonomy Levels for Unmanned Rotorcraft Systems (ALFURS) framework etc. The situation awareness can be categorized into three levels namely perception, comprehension and projection. The requirements were elicited for all the three levels of situation awareness. These requirements further formalized using temporal logics. The formalized requirements further translated into state automaton automatically.
44

Advanced Nonlinear Techniques for Low Cost Land Vehicle Navigation

Georgy, Jacques 27 July 2010 (has links)
Present land vehicle positioning and navigation relies mostly on the Global Positioning System (GPS). However, in urban canyons, tunnels, and other GPS-denied environments, the GPS positioning solution may be interrupted or suffer from deterioration in accuracy due to satellite signal blockage, poor satellite geometry or multipath effects. In order to achieve continuous positioning services, GPS is augmented with complementary systems capable of providing additional sources of positioning information, like inertial navigation systems (INS). Kalman filtering (KF) is traditionally used to provide integration of both INS and GPS utilizing linearized dynamic system and measurement models. Targeting low cost solution for land vehicles, Micro-Electro-Mechanical Systems (MEMS) based inertial sensors are used. Due to the inherent errors of MEMS inertial sensors and their stochastic nature, which is difficult to model, KF has limited capabilities in providing accurate positioning in challenging GPS environments. This research aims at developing reliable integrated navigation system capable of demonstrating accurate positioning during long periods of challenging GPS environments. Towards achieving this goal, Mixture Particle filtering (MPF) is suggested in this research as a nonlinear filtering technique for INS/GPS integration to accommodate arbitrary inertial sensor characteristics, motion dynamics and noise distributions. Since PF can accommodate nonlinear models, this research develops total-state nonlinear system and measurement models without any linearization, thus enabling reliable integrated navigation and mitigating one of the major drawbacks of KF. Exploiting the capabilities of PF, Parallel Cascade Identification (PCI), which is a nonlinear system identification technique, is used to obtain efficient stochastic models for inertial sensors instead of the currently utilized linear models, which are not adequate for MEMS-based sensors. Moreover, this research proposes a method to update the stochastic bias drift of inertial sensors from GPS data when the GPS signal is adequately received. Furthermore, a technique for automatic detection of GPS degraded performance is developed and led to improving the performance in urban canyons. The performance is examined using several road test experiments conducted in downtown cores to verify the adequacy and the benefits of the methods suggested. The results obtained demonstrate the superior performance of the proposed methods over conventional techniques. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2010-07-23 20:27:02.12
45

Generalização cartográfica para um Sistema de Navegação e Guia de Rota em Automóvel áudio-dinâmico com múltiplas escalas /

Marques, Ana Paula da Silva January 2011 (has links)
Resumo: O objetivo desta pesquisa consiste na elaboração de mapas áudio-dinâmicos em múltiplas escalas automáticas, para um Sistema de Navegação e Guia de Rota em Automóvel (SINGRA). O projeto das representações cartográficas foi dividido em duas fases: projeto de composição geral e projeto áudio-gráfico. Os mapas visuais dinâmicos foram elaborados com base nos princípios da comunicação cartográfica e da percepção visual, com ênfase nas operações de generalização. A área de estudo apresenta uma malha urbana com diferentes tipos de vias, cruzamentos e limites de velocidade. Os mapas foram projetados para serem exibidos em um monitor de pequeno formato (sete polegadas), com alta resolução, e um total de quatro escalas de representação foi determinado: 1/10.000, 1/5.000, 1/2.500 e 1/1.000. Tais escalas foram definidas em função do tamanho da mídia de apresentação e do tipo de tarefa tática. Os mapas generalizados foram obtidos pela aplicação das operações de simplificação, exagero e deslocamento, sobre uma base cartográfica na escala 1/1.000. As representações áudio-dinâmicas foram produzidas a partir de variáveis áudio-dinâmicas. As mensagens de voz foram pré-gravadas na voz feminina, executadas em sincronia com as informações visuais. O projeto foi implementado em um SINGRA disponível na FCT-UNESP, a partir do compilador Visual Basic e da biblioteca MapObjects. Ao comparar o sistema de múltiplas escalas com o de escala única, observa-se que os novos mapas adaptados ao contexto de direção do motorista, podem permitir que o usuário receba a informação de acordo com a tarefa de navegação desenvolvida ao longo da rota ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this research is to design and implement an automatics multi-scale and audio-dynamic map for an In-Car Route Guidance and Navigation System (RGNS). The design was organized in two stages: general composition and auditory-graphic design. The visual-dynamic maps were designed based on cartographic communication principles and visual perception, especially on the generalization operators. The area of study presents an urban network with different types of roads, nodes, and speed limits. The maps were designed for a small-screen display, and a total of four different scales were employed: 1:10.000, 1:5.000, 1:2.500 and 1:1.000. These scales were chosen according to the media size and type of tactical task. The maps were derived from an accurate cartographic database at scale of 1:1000, by applying generalization techniques, such as simplification, displacement, and enhancement. The audio-dynamic representations were produced by taking account a set of audio-dynamic variables. The voice messages were recorded in a female voice, and they were presented with visual information, simultaneously. The design was implemented in a navigation system, which is available in the Faculty of Sciences and Technology, by using Visual Basic compiler and MapObjects library. The results of comparison between the automatic multiple-scale and single scale system show that the new system, enhanced driver's context, can allow the user receiving information according to the tasks performed along of the route. From the employment of generalization technique it was possible to present in a properly way the amount of information in the display, in which it can contribute for reducing navigational errors and visual demand, when compared with single-scale map ... (Complete abstract click electronic access below) / Orientador: Mônica Modesta Santos Decanini / Coorientador: Edmur Azevedo Pugliesi / Banca: Claudia Robbi Sluter / Banca: Milton Hirokazu Shimabukuro / Mestre
46

Um modelo de unidade de medida inercial utilizando tr?s aceler?metros triaxiais

Silva, Anderson Braulio Nobrega da 07 October 2013 (has links)
Made available in DSpace on 2014-12-17T14:56:18Z (GMT). No. of bitstreams: 1 AndersonBNS_DISSERT.pdf: 1465627 bytes, checksum: c03d80fd5309916ed15fcc6c0a45c8a8 (MD5) Previous issue date: 2013-10-07 / No espa?o tridimensional, um corpo r?gido qualquer pode efetuar transla??es e ou rota??es em rela??o a cada um de seus eixos. Identificar com precis?o o deslocamento realizado por um corpo ? fundamental para alguns tipos de sistemas em engenharia. Em sistemas de navega??o inercial tradicionais, utilizam-se aceler?metros para reconhecer a acelera??o linear e girosc?pios para reconhecer a velocidade angular registrada durante o deslocamento. O girosc?pio, entretanto, ? um dispositivo de custo mais elevado e com alto consumo de energia quando comparado a um aceler?metro. Essa desvantagem deu origem a pesquisas a respeito de sistemas e unidades de medidas inerciais que n?o utilizam girosc?pios. A ideia de utilizar apenas aceler?metros para calcular o movimento linear e angular surgiu no in?cio da d?cada de 60 e vem se desenvolvendo atrav?s de modelos que variam no n?mero de sensores, na maneira como estes s?o organizados e no modelo matem?tico que ? utilizado para derivar o movimento do corpo. Esse trabalho prop?e um esquema de configura??o para constru??o de uma unidade de medida inercial que utiliza tr?s aceler?metros triaxiais. Para identificar o deslocamento de um corpo r?gido a partir deste esquema, foi utilizado um modelo matem?tico que utiliza apenas os nove sinais de acelera??o extra?dos dos tr?s sensores. A proposta sugere que os sensores sejam montados e distribu?dos em formato de L . Essa disposi??o permite a utiliza??o de um ?nico plano do sistema de coordenadas, facilitando assim a instala??o e configura??o destes dispositivos e possibilitando a implanta??o dos sensores em uma ?nica placa de circuito integrado. Os resultados encontrados a partir das simula??es iniciais demonstram a viabilidade da utiliza??o do esquema de configura??o proposto
47

Implementace Business Intelligence řešení nad daty z provozu parkoviště / Business Intelligence implementation on top of parking lot traffic data

Machat, Sebastian January 2017 (has links)
In the world of increasing car sales and limited count of available parking spaces it is hard to imagine the parking space management issues would fade away anytime near. In a simi-lar way the Business Intelligence holds its position as one of the continuous trends in company IT environment. After the parking space navigation systems started to make its first appearance into the public parking lots, it started to be clear that their outputs could be potentially used to gain new information about the way the drivers behave and how the parking space is being used. That is the reason this thesis covers the field of acquirement of data from the parking space navigation system and its initial analytical use using the BI tools. Following the theoretic introduction of both Business Intelligence and BI project management comes the detailed info about the parking space navigation systems & the parking lot covered in the practical part of this text. These are followed by details of how the data collection procedures and navigation system data processing should be handled to allow building and filling of the data warehouse. On top of this DWH the analytic layer is both designed & implemented, followed by reports providing the information parking space owner requested. As the data warehouse contains a lot of additional data with expected possible use in the analytic processing, ie. using data mining tools, the last part of the thesis covers specifying single research question about the data available, which is later confirmed/denied using statistical analysis.
48

Developement of a INS/GPS navigation loop for an UAV

Rönnbäck, Sven January 2000 (has links)
This master thesis report presents the developement of an INS/GPS navigation loop written in ANSI C++ using a standard matrix library. The filter have been tested on an Unmanned Aerial Vehicle (UAV) called Brumby. Here data have been logged from the Inertial Measurement Unit (IMU) and the Global Positioning System (GPS) receiver. This data have then been postprocessed and run through the navigation filter for estimation of position, attitude and velocity of the vehicle during the flights. The error feedback to the Inertial Navigation System (INS) is done with a complement filter implemented using a kalman filter written in information form.The resulting navigation filter estimates the attitude within two degrees with 95% confidence and the position within two meter using 95% confidence. / <p>Validerat; 20101217 (root)</p>
49

Lokalizátor s ovládáním přes GSM rozhraní / Position navigation system with GSM interface

Pristach, Marián January 2010 (has links)
The objective of the diploma thesis is to design a device for positioning of mobile devices using GPS satellites. When coordinates are acquired they can be sent via the GSM network to a user's cell phone or to an SQL server. A web interface has been designed to access the stored data and to show the current device position and the history. This position datalogging system can be used for monitoring vehicles as well as a security system for cars.
50

Využití senzorů MEMS pro lokální určení polohy / The MEMS sensors usability for position detection

Bobalík, Lukáš January 2014 (has links)
Within this Master’s thesis, design and construction of a strapdown inertial navigation system based on MEMS sensors is described. The thesis includes theoretic analysis of physics behind determining the position of an object based on the object’s aceleration and changes in the object’s orientation in space. Included is also an overview of mathematical methods related to the position calculation.

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