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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.
21

Dvoukomorový tester pro akumulátorové vrtačky / Two-chamber Tester for Cordless Drills

Kabátník, Václav January 2018 (has links)
This thesis deals with the design and subsequent realization of a bicameral tester for cordless drills. The tester will contain with two chambers in which the device will be tested. Part of the solution is the description of the parameters of the tested devices and the design of the tester concept. In addition, the thesis deals with the design of a mechanical structure that will test the equipment in both chambers and then design and realization of the relevant electrical equipment including the electrical switchboard. The thesis describes the Mosaic development environment for development of the PLC program according to IEC 61131-3. In this environment, control software has been created, which is described in its chapter. At the end of this work are enclosed images confirming the implementation to the real system and its functionality
22

Maîtrise de la couche hyperviseur sur les architectures multi-coeurs COTS dans un contexte avionique / Hypervisor control of COTS multi-cores processors in order to enforce determinism for future avionics equipment

Jean, Xavier 18 June 2015 (has links)
Nous nous intéressons dans cette thèse à la maîtrise de processeurs multi-cœurs COTS dans le but de les rendre utilisables dans des équipements avioniques, qui ont des exigences temps réelles dures. L’objectif est de permettre l'application de méthodes connues d’évaluation de pire temps d’exécution (WCET) sur un ensemble de tâches représentatif d’applications avioniques. Au cours de leur exécution, les tâches exécutées sur différents cœurs vont accéder simultanément à des ressources matérielles qui sont partagées entre les cœurs, en particulier la mémoire principale. Cela pourra entraîner des mises en attente de certains accès que l'on qualifie d'interférences. Ces interférences peuvent avoir un impact élevé sur le temps d'exécution du logiciel embarqué. Sur un processeur COTS, qui est acheté dans le commerce et vise un marché plus large que l'avionque, cet impact n'est pas borné. Nous cherchons à garantir l'absence d'interférences grâce à des moyens logiciels, dans la mesure où les processeurs COTS ne proposent pas de mécanismes adéquats au niveau matériel. Nous cherchons à étendre des concepts de logiciel déterministe de telle sorte à les rendre compatibles avec un objectif de réutilisation de logiciel existant. A cet effet, nous introduisons la notion de logiciel de contrôle, qui est un élément fonctionnellement neutre, répliqué sur tous les cœurs, et qui contrôle les dates des accès des cœurs aux ressources communes de telle sorte à offrir une isolation temporelle entre ces accès. Nous étudions dans cette thèse le problème de faisabilité d'un logiciel de contrôle sur un processeur COTS, et de son efficacité vis à vis d'applications avioniques. / We focus in this thesis on issues related to COTS multi-core processors mastering, especially regarding hard real-time constraints, in order to enable their usage in future avionics equipment. We aim at applying existing Worst Case Execution Time (WCET) evaluation methods on a set of tasks similar to those we can find in avionics software. At runtime, tasks executed among different cores are likely to access hardware resources at the same time, e.g. the main memory. It may lead to additional delays due to hardware contention, called “interferences”. Interferences slow down embedded software within ranges that may be important. Additionnally, no bound has been established for their impact on WCET when using COTS processors, that target larger markets than avionics. We try to provide guarantees that all interferences are eliminated through software, as COTS processors do not provide adequate mechanisms at hardware level. We extend deterministic software concepts that have been developed in the state of the art, in order to make them compliant with the use of legacy software. We introduce the concept of "control software", which is functionnaly neutral, is replicated among all cores, and performs active control of core's accesses to shared resources, so that concurrent accesses are temporally isolated. We formalize and study in this thesis the problem of control software feasibility on COTS processors, and questions of efficiency with regard to legacy avionics software.
23

Maintaining data consistency in embedded databases for vehicular systems

Gustafsson, Thomas January 2004 (has links)
The amount of data handled by real-time and embedded applications is increasing. This calls for data-centric approaches when designing embedded systems, where data and its metainformation (e.g., temporal correctness requirements) are stored centrally. The focus of this thesis is on efficient data management, especially maintaining data freshness and guaranteeing correct age on data. The contributions of our research are updating algorithms and concurrency control algorithms using data similarity. The updating algorithms keep data items up-to-date and can adapt the number of updates of data items to state changes in the external environment. Further, the updating algorithms can be extended with a relevance check allowing for skipping of unnecessary calculations. The adaptability and skipping of updates have positive effects on the CPU utilization, and freed CPU resources can be reallocated to, e.g., more extensive diagnosis of the system. The proposed multiversion concurrency control algorithms guarantee calculations reading data that is correlated in time. Performance evaluations show that updating algorithms with a relevance check give significantly better performance compared to well-established updating approaches, i.e., the applications use more fresh data and are able to complete more tasks in time. The proposed multiversion concurrency control algorithms perform better than HP2PL and OCC and can at the same time guarantee correct age on data items, which HP2PL and OCC cannot guarantee. Thus, from the perspective of the application, more precise data is used to achieve a higher data quality overall, while the number of updates is reduced. / <p>Report code: LiU-Tek-Lic-2004:67.</p>
24

Evaluation of GUI technologies for CERN's Beam Interlock System

Skarhed, Tobias January 2023 (has links)
This thesis presents an evaluation of various graphical user interface (GUI) technologies for use in the supervision software of CERN’s Beam Interlock System (BIS). The evaluation is necessary because the current GUItechnology used by the supervision software, JavaFX, is no longer supported by Oracle. It also relies on aninternal library that is no longer maintained. Furthermore, a second version of the BIS is being developed, anda GUI is needed that works with BIS and BIS2 in parallel.Which technology is most suitable for the next version of the BIS supervision GUI?This question was answered by gathering user stories from users and experts. Simple proof of concepts weredeveloped for each technology, in order to identify technical limitations and register the development time. Theuser stories relevant to the choice of technology were listed, and each technology received points depending onwhether they were able to fulfill the requirement or not.Furthermore, in order to evaluate the ease of use, wireframes were created based on some of the user stories.These were qualitatively evaluated with stakeholders, which produced feedback that may be used for furtherdevelopment.Out of the four technologies evaluated, PyQt scored 6, ACW scored 4, WRAP scored 6 and Grafana scored3. WRAP and Grafana were discarded as viable options, since they were not able to fulfill hard requirements.ACW scored lower because it is web based and comes with a bigger maintenance overhead. / <p>This thesis was done as a part of a technical studentship at CERN.</p>
25

Exploration robotique de l’environnement aquatique : les modèles au coeur du contrôle / Robotic exploration of the aquatic environment : Models at the core of the control

Lasbouygues, Adrien 10 December 2015 (has links)
Les robots sous-marins peuvent aujourd'hui évoluer dans des environnements complexes difficilement accessibles à l'Homme pour des raisons de coût ou de sécurité. Ils peuvent donc intervenir dans une grande variété de missions en environnement aquatique. Or, la complexité de ces milieux impose de doter le vecteur robotique d'une autonomie opérationnelle suffisante afin qu'il puisse mener sa mission à bien tout en préservant son intégrité. Cela nécessite de développer des lois de commande répondant aux spécificités de l'application. Ces lois de commande se basent sur des connaissances provenant de différentes disciplines scientifiques ce qui souligne l'interdisciplinarité inhérente à la robotique. Une fois la loi de commande développée, il faut implémenter le contrôleur sur le robot sous forme de logiciel de contrôle basé sur une architecture logicielle temps-réel.Or la conception actuelle des lois de commande, sous forme de blocs "monolithiques", rend difficile l'évolution d'une loi de commande d'une application à l'autre, l'intégration de connaissances provenant d'autres disciplines scientifiques que ne maitrisent pas forcément les automaticiens et pénalisent son implémentation sur des architectures logicielles qui nécessitent la modularité. Pour résoudre ces problèmes nous cherchons à proprement séparer les différentes connaissances afin que chacune soit aisément manipulable, son rôle clair et que les relations établies entre les différentes connaissances soient explicites. Cela permettra en outre une projection plus efficace sur l'architecture logicielle. Nous proposons donc un nouveau formalisme de description des lois de commande selon une composition modulaire d'entités de base appelées Atomes et qui encapsulent les différents éléments de connaissance. Nous nous intéressons également à l'établissement d'une meilleure synergie entre les aspects automatique et génie logiciel qui se construit autour de préoccupations communes telles que les contraintes temporelles et la stabilité. Pour cela, nous enrichissons nos Atomes de contraintes chargées de véhiculer les informations relatives à ces aspects temporels. Nous proposons également une méthodologie basée sur notre formalisme afin de guider l'implémentation de nos stratégies de commande sur un Middleware temps-réel, dans notre cas le Middleware ContrACT développé au LIRMM.Nous illustrons notre approche par diverses fonctionnalités devant être mises en oeuvre lors de missions d'exploration de l'environnement aquatique et notamment pour l'évitement de parois lors de l'exploration d'un aquifère karstique. / Underwater robots can nowadays operate in complex environments in a broad scope of missions where the use of human divers is difficult for cost or safety reasons. However the complexity of aquatic environments requires to give the robotic vector an autonomy sufficient to perform its mission while preserving its integrity. This requires to design control laws according to application requirements. They are built on knowledge from several scientific fields, underlining the interdisciplinarity inherent to robotics. Once the control law designed, it must be implemented as a control Software working on a real-time Software architecture.Nonetheless the current conception of control laws, as "monolithic" blocks, makes difficult the adaptation of a control from an application to another and the integration of knowledge from various scientific fields which are often not fully understood by control engineers. It also penalizes the implementation of control on Software architectures, at least its modularity and evolution. To solve those problems we seek a proper separation of knowledge so that each knowledge item can be easily used, its role precisely defined and we want to reify the interactions between them. Moreover this will allow us a more efficient projection on the Software architecture. We thus propose a new formalism for control laws description as a modular composition of basic entities named Atoms used to encapsulate the knowledge items.We also aim at building a better synergy between control and software engineering based on shared concerns such as temporal constraints and stability. Hence we extend the definition of our Atoms with constraints carrying information related to their temporal behaviour. We propose as well a methodology relying on our formalism to guide the implementation of control on a real-time Middleware. We will focus on the ContrACT Middleware developed at LIRMM.Finally we illustrate our approach on several robotic functionalities that can be used during aquatic environments exploration and especially for wall avoidance during the exploration of a karst aquifer.
26

Interoperability of Digital Rights Management Systems via the Exchange of XML-based Rights Expressions

Guth, Susanne 02 1900 (has links) (PDF)
The dissertation deals with the cutting-edge subject of electronic contracts, which have the potential to automatically process and control the access rights for (electronic) goods. The dissertation shows the design and the implementation of a rights expression exchange framework. The framework enables digital rights management systems to exchange electronic contracts with each other and thus, provides DRM system compatibility. The electronic contracts, which are formulated in a standardized rights expression language, serve as exchange format between different DRM systems. The dissertation introduces a methodology for the standardized composition, exchange and processing of electronic contracts respectively rights expressions. (author´s abstract)
27

Development Of A Miniaturized Automated Production Control System

Korkmaz, Ozgur 01 January 2012 (has links) (PDF)
In this thesis a custom embedded system and control software developed for an Automated Storage and Retrieval System (AS/RS) which is based on the Computer Integrated Manufacturing Laboratory (CIMLAB) located in the Department of Mechanical Engineering, Middle East Technical University. Primary objective of this study is AS/RSs related control rules can be applicable to the current physical system. The secondary objective is determined as developing the control system in a flexible way that allows adding new equipments to the system and configuring parts of the system. Two types of control board are manufactured and also boards&rsquo / firmware and computer software are developed. These two boards communicate with computer one at a time. Some AS/RS related control rules are implemented at the control software. According to these rules the control software assigns tasks to the related board. Also the control software records necessary information in order to measure the performance of the AS/RS. Several control rules as storage assignment, dwell point and sequencing of storage and retrieval order rules are applicable to the AS/RS without need for low level programming. Because of the physical limitation, batching rules cannot be applied to the current system. Also a graphical user interface is developed for using the system easily and observing the real time status of the system equipments. Two experiments are designed and run in order to show flexibility of the control system. Different control rules applied to each of the experiment. Experiment results put forth the control system was quite successful in meeting the objectives.
28

Processus et outils qualifiables pour le développement de systèmes critiques certifiés en avionique basés sur la génération automatique de code / Processes and qualifiable tools for the development of safety-critical certified systems in avionics based on automated code generation

Bedin França, Ricardo 10 April 2012 (has links)
Le développement des logiciels avioniques les plus critiques, comme les commandes de vol électriques, présentent plusieurs contraintes qui peuvent être quasiment contradictoires – par exemple, performance et sûreté – et toutes ces contraintes doivent être respectées simultanément. L'objective de cette thèse est d'étudier et de proposer des évolutions dans le cycle de développement des logiciels de commande de vol chez Airbus afin d'améliorer leur performance, tout en respectant les contraintes industrielles existantes et en conservant des processus de vérification au moins aussi sûrs que ceux utilisés actuellement. Le critère principal d'évaluation de performance est le temps d'exécution au pire cas (WCET), vu qu'il est utilisé lors des analyses temporelles des logiciels de vol réels. Dans un premier temps, le DO-178, qui contient des considérations pour l'approbation des logiciels avioniques, est présenté. Le DO-178B et le DO-178C sont étudiés. Le DO-178B est la référence pour plusieurs logiciels de commande de vol développés chez Airbus et le DO-178C est la référence pour le développement des nouveaux logiciels à partir de 2012. Ensuite, l'étude de cas est présentée. Afin d'améliorer sa compréhension, le contexte historique est fourni à travers l'étude des autres logiciels de commande de vol, car plusieurs activités de son cycle de vie réutilisent des techniques qui ont été utilisées avec succès dans des projets précédents. Quelques activités qui présentent des causes potentielles de pertes de performance logicielle sont exposées et l'axe principal d'étude choisi pour le reste de la thèse est la phase de compilation. Ce choix se justifie dans le contexte des logiciels de commande de vol car la compilation est réalisée avec peu ou pas d'optimisations, son impact sur la performance des logiciels est donc important et des travaux de recherche récents permettent d'envisager un changement dans les paradigmes actuels de compilation sûre. / The development of safety-critical avionics software, such as aircraft flight control programs, presents many different constraints that are nearly contradictory, such as performance and safety requirements, and all must be met simultaneously. The objective of this Thesis is to propose modifications in the development cycle of Airbus flight control programs in order to improve their performance without weakening their verification processes or violating other industrial constraints. The main criterion for performance evaluation is the Worst-Case Execution Time (WCET), as it is used in the timing analysis that is performed in actual avionics software verification processes. In a first moment, the DO-178, which contains guidance for avionics software development approval, is presented. Both the DO-178B and the DO-178C are discussed, since the former was the reference for the development of many Airbus flight control programs and the latter shall be the reference for the development of new programs, starting from 2012. Then, the case study is presented. In order to better understand it, some historical context is provided by the study of other flight control programs - many of its life cycle activities reuse techniques that were successful in previous software projects. Each activity is evaluated in order to underline what are the performance bottlenecks in the flight control software development. Some potential underperforming activities are depicted and the main axis of study developed subsequently is the compilation phase: not only it is a well-known unoptimized activity that has important impacts over software performance, but it is also an activity that might undergo a paradigm change due to innovating compilers that are being developed by researchers. The CompCert compiler is presented and its use in the scope of this Thesis is justified - at the time of this Thesis, it was the compiler that was best prepared to perform meaningful experiments, such as compiling a large subset of the chosen case study. Its architecture is studied, together with its semantic preservation theorem, which is the backbone of its formally-verified part. Additional features that were developed in CompCert during this Thesis in order to meet Airbus's requirements - such as its annotation mechanism and its reference interpreter - are discussed in order to underline their usefulness in the development of flight control software. The evaluation of CompCert consists in a performance comparison with the current compilation strategy and an assessment of the impacts that its utilization might have over the verification strategy commonly employed in flight control software. The results of the performance comparison are promising, since CompCert-generated code has a WCET more than 10% lower than if it were compiled with a good quality non-optimizing compiler. As expected, the use of CompCert has impacts over some important verification activities but its formal development and increased verifiability helps in the development of new compiler verification activities that can keep the whole development process at least as safe as the current one. Some development strategy propositions are then presented, according to the certification credit that might be required by using CompCert.
29

Integration of Mission Control System, On-board Computer Core and spacecraft Simulator for a Satellite Test Bench: Integration of Mission Control System,On-board Computer Core and spacecraft Simulator for a Satellite Test Bench

Chintalapati, Lakshmi Venkata Bharadwaj 04 November 2016 (has links)
The satellite avionics platform has been developed in cooperation with Airbus and is called „Future Low-cost Platform“ (FLP). It is based on an Onboard Computer (OBC) with redundant processor boards based on SPARC V8 microchips of type Cobham Aeroflex UT699. At the University of Stuttgart a test bench with a real hardware OBC and a fully simulated satellite is available for testing real flight scenarios with the Onboard Software (OBSW) running on representative hardware. The test bench as later the real flying satellite "Flying Laptop" – is commanded from a real Ground Control Centre (GCC). The main challenges in the FLP project were - Onboard computer design, - Software design and - Interfaces between platform and payloads In the course of industrialization of this FLP platform technology for later use in satellite constellations, Airbus has started to set up an in-house test bench where all the technologies shall be developed. The initial plan is to get first core elements of the FLP OBSW ported to the new dual-core processor and the new Space Wire(SpW) routing network. The plan also has an inclusion of new Mission Control Software with which one can command the OBC. The new OBC has a dual core processor Cobham Gaisler GR712 and hence, all the payload and related functionality are to be implemented only in a second core which involves a lot of low-level task distribution. The consequent SpW router network application and dual-core platform/payload OBSW sharing are entirely new in the field of satellite engineering.
30

Řešení protierozní ochrany na modelovém povodí matematickým modelováním. / Solution of erosion protection at the model basin using mathematical modeling

KŘÍHA, Jan January 2010 (has links)
The contents of this thesis is an examination and assessment of erosion processes in the catchment Budského stream. The area of interest falls into three cadastral territory, Malče, Besednice a Soběnov. Catchment area is 7.1 km2. Integral part of work is the pedological and hydrological research. It was evaluated the impact of waste in the surrounding villages. In the catchment basin, has a significant influence Besednice reservoir. It was assessing its impact on the environment and erosion control functions. Using the acquired information has been calculated N-year water and the amount of drifted soil by Wischmeier and Smith. Another goal is to process this data using software modeling and evaluate output. Against this background and the results are recommended measures to reduce soil loss from these plots.

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