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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.
1

Motion Planning and Control of Robot Manipulators

Pluzhnikov, Sergey January 2012 (has links)
When a robot performs a task in an unstructured dynamic environment, it has to account for many factors. It should not only keep the track of where it is and how it should move, but also ensure that the kinematic, dynamic and task specific limitations are observed. It is also important that the robot can effectively avoid collisions with static and moving obstacles. In the current thesis we present design and implementation of an algorithm capable to face all these challenges. The system combines principles of dynamic roadmaps and elastic roadmaps frameworks, both of which are the state-of-art approaches to motion planning problem. The suggested solution is presented in the context of a broad overview of the literature in motion planning domain focusing on methodology of sample-based and feedback planning in dynamic environments. The implemented algorithm is applied to a 7-degree-of-freedom manipulator and is demonstrated and analyzed through a variety of simulated test scenarios. The result is an extensible and future-oriented planning system that can plan and execute movement between a starting and target position while preserving task constraints and reacting to environment changes in real time.
2

Low-Cost MemBIST for Micro-Controllers

Atashi, Hossein January 2012 (has links)
The challenge of testing SRAM memories consists in providing realistic fault models and test solutions with minimal application time. While classical memory tests cover the static faults, they are not sufficient to cover dynamic faults which have emerged in VDSM technologies. The purpose of this thesis is implementation of a memory BIST that targets static faults as well as dynamic faults while maintaining an acceptable test time and area overhead.At first, and as a semester project, the functional fault models (FFMs) associated with state-of-the-art SRAM technologies have been studied and state-of-the-art memory testing algorithms, targeting these FFMs have been presented.Next, and as part of this master's thesis, a combination of March LR and March AB memory testing algorithms is selected and modified to support testing word-oriented memories. Furthermore, this algorithm is extended to provide support for detecting Data-Retention Faults. This algorithm is then implemented using Verilog HDL in Register-Transfer Level of abstraction.The implemented MemBIST is then evaluated with respect to area, performance and fault coverage. A bit-oriented March LR-based MemBIST, currently in use on Atmel® AVR® micro-controllers, is used as a reference for benchmarking purposes. All target fault primitives (FPs) have been implemented using behavioral Verilog HDL and simulated with both MemBISTs.Our evaluations show that our word-oriented MemBIST can provide a 500% performance advantage (due to the word-oriented execution) for 32-bit memories and at the same time has a better fault coverage compared to the reference MemBIST. The implemented algorithm can detect all static and realistic dynamic inter-word memory faults as well as most static and realistic dynamic intra-word faults. The implemented MemBIST also maintains a very small area overhead due to sharing the required registers with existing system components.Keywords: MemBIST, Built-In Self Test, Memory Testing, March Test, Fault Model, Fault Coverage, Fault Detection
3

From dataflow-based video coding tools to dedicated embedded multi-core platforms

Yviquel, Hervé 25 October 2013 (has links) (PDF)
The development of multimedia technology, along with the emergence of parallel architectures, has revived the interest on dataflow programming for designing embedded systems. Indeed, dataflow programming offers a flexible development approach in order to build complex applications while expressing concurrency and parallelism explicitly. Paradoxically, most of the studies focus on static dataflow models of computation, even if a pragmatic development process requires the expressiveness and the practicality of a programming language based on dynamic dataflow models, such as the language included in the Reconfigurable Video Coding framework. In this thesis, we describe a complete development environment for dataflow programming that eases multimedia development for embedded multi-core platforms. This development environment is built upon a modular software architecture that benefits from modern software engineering techniques such as meta modeling and aspect-oriented programming. Then, we develop an optimized software implementation of dataflow programs targeting desktop and embedded multi-core platforms. Our implementation aims to bridge the gap between the practicality of the programming language and the efficiency of the execution. Finally, we present a set of runtime actors mapping/scheduling algorithms that enable the execution of dynamic dataflow programs over multi-core platforms with scalable performance.
4

From dataflow-based video coding tools to dedicated embedded multi-core platforms / Depuis des outils de codage vidéo basés sur la programmation flux de données vers des plates-formes multi-coeur embarquées et dédiées

Yviquel, Hervé 25 October 2013 (has links)
Le développement du multimédia, avec l'émergence des architectures parallèles, a ravivé l'intérêt de la programmation flux de données pour la conception de systèmes embarqués. En effet, la programmation flux de données offre une approche de développement suffisamment flexible pour créer des applications complexes tout en exprimant la concurrence et le parallélisme explicitement. Paradoxalement, la plupart des études portent sur des modèles flux de données statiques, même si un processus de développement pragmatique nécessite l'expressivité et la practicité d'un langage de programmation basé sur un modèle flux de données dynamiques, comme le langage de programmation utilisé dans le cadre de Reconfigurable Video Coding. Dans cette thèse, nous décrivons un environnement de développement pour la programmation flux de données qui facilite le développement multimédia pour des plates-formes multi-coeur embarquées. Cet environnement de développement repose sur une architecture logicielle modulaire qui bénéficie de techniques modernes de génie logiciel telles que la méta modélisation et la programmation orientée aspect. Ensuite, nous développons une implémentation logicielle optimisée des programmes flux de données ciblant aussi bien les ordinateurs de bureau que les plates-formes embarquées. Notre implémentation vise à combler le fossé entre la practicité du langage de programmation et l'efficacité de son exécution. Enfin, nous présentons un ensemble d'algorithmes de projection et d'ordonnancement d'acteurs qui permettent l'exécution de programmes flux de données dynamiques sur des plates-formes multi-coeur avec des performances extensibles. / The development of multimedia technology, along with the emergence of parallel architectures, has revived the interest on dataflow programming for designing embedded systems. Indeed, dataflow programming offers a flexible development approach in order to build complex applications while expressing concurrency and parallelism explicitly. Paradoxically, most of the studies focus on static dataflow models of computation, even if a pragmatic development process requires the expressiveness and the practicality of a programming language based on dynamic dataflow models, such as the language included in the Reconfigurable Video Coding framework. In this thesis, we describe a complete development environment for dataflow programming that eases multimedia development for embedded multi-core platforms. This development environment is built upon a modular software architecture that benefits from modern software engineering techniques such as meta modeling and aspect-oriented programming. Then, we develop an optimized software implementation of dataflow programs targeting desktop and embedded multi-core platforms. Our implementation aims to bridge the gap between the practicality of the programming language and the efficiency of the execution. Finally, we present a set of runtime actors mapping/scheduling algorithms that enable the execution of dynamic dataflow programs over multi-core platforms with scalable performance.
5

Une architecture évolutive flexible et reconfigurable dynamiquement pour les systèmes embarqués haute performance / A scalable flexible and dynamic reconfigurable architecture for high performance embedded computing

Viswanathan, Venkatasubramanian 12 October 2015 (has links)
Dans cette thèse, nous proposons une architecture reconfigurable scalable et flexible, avec un réseau de communication parallèle « full-duplex switched » ainsi que le modèle d’exécution approprié ce qui nous a permis de redéfinir les paradigmes de calcul, de communication et de reconfiguration dans les systèmes embarqués à haute performance (HPEC). Ces systèmes sont devenus très sophistiqués et consommant des ressources pour trois raisons. Premièrement, ils doivent capturer et traiter des données en temps réel à partir de plusieurs sources d’E/S parallèles. Deuxièmement, ils devraient adapter leurs fonctionnalités selon l’application ou l’environnement. Troisièmement, à cause du parallélisme potentiel des applications, multiples instances de calcul réparties sur plusieurs nœuds sont nécessaires, ce qui rend ces systèmes massivement parallèles. Grace au parallélisme matériel offert par les FPGAs, la logique d’une fonction peut être reproduite plusieurs fois pour traiter des E/S parallèles, faisant du modèle d’exécution « Single Program Multiple Data » (SPMD) un modèle préféré pour les concepteurs d’architectures parallèles sur FPGA. En plus, la fonctionnalité de reconfiguration dynamique est un autre attrait des composants FPGA permettant la réutilisation efficace des ressources matérielles limitées. Le défi avec les systèmes HPEC actuels est qu’ils sont généralement conçus pour répondre à des besoins spécifiques d’une application engendrant l’obsolescence rapide du matériel. Dans cette thèse, nous proposons une architecture qui permet la personnalisation des nœuds de calcul (FPGA), la diffusion des données (E/S, bitstreams) et la reconfiguration de plusieurs nœuds de calcul en parallèle. L’environnement logiciel exploite les attraits du réseau de communication pour implémenter le modèle d’exécution SPMD.Enfin, afin de démontrer les avantages de notre architecture, nous avons mis en place une application d’encodage H.264 sécurisé distribué évolutif avec plusieurs protocoles de communication avioniques pour les données et le contrôle. Nous avons utilisé le protocole « serial Front Panel Data Port (sFPDP) » d’acquisition de données à haute vitesse basé sur le standard FMC pour capturer, encoder et de crypter le flux vidéo. Le système mis en œuvre s’appuie sur 3 FPGA différents, en respectant le modèle d’exécution SPMD. En outre, nous avons également mis en place un système d’E/S modulaire en échangeant des protocoles dynamiquement selon les besoins du système. Nous avons ainsi conçu une architecture évolutive et flexible et un modèle d’exécution parallèle afin de gérer plusieurs sources vidéo d’entrée parallèles. / In this thesis, we propose a scalable and customizable reconfigurable computing platform, with a parallel full-duplex switched communication network, and a software execution model to redefine the computation, communication and reconfiguration paradigms in High Performance Embedded Systems. High Performance Embedded Computing (HPEC) applications are becoming highly sophisticated and resource consuming for three reasons. First, they should capture and process real-time data from several I/O sources in parallel. Second, they should adapt their functionalities according to the application or environment variations within given Size Weight and Power (SWaP) constraints. Third, since they process several parallel I/O sources, applications are often distributed on multiple computing nodes making them highly parallel. Due to the hardware parallelism and I/O bandwidth offered by Field Programmable Gate Arrays (FPGAs), application can be duplicated several times to process parallel I/Os, making Single Program Multiple Data (SPMD) the favorite execution model for designers implementing parallel architectures on FPGAs. Furthermore Dynamic Partial Reconfiguration (DPR) feature allows efficient reuse of limited hardware resources, making FPGA a highly attractive solution for such applications. The problem with current HPEC systems is that, they are usually built to meet the needs of a specific application, i.e., lacks flexibility to upgrade the system or reuse existing hardware resources. On the other hand, applications that run on such hardware architectures are constantly being upgraded. Thus there is a real need for flexible and scalable hardware architectures and parallel execution models in order to easily upgrade the system and reuse hardware resources within acceptable time bounds. Thus these applications face challenges such as obsolescence, hardware redesign cost, sequential and slow reconfiguration, and wastage of computing power.Addressing the challenges described above, we propose an architecture that allows the customization of computing nodes (FPGAs), broadcast of data (I/O, bitstreams) and reconfiguration several or a subset of computing nodes in parallel. The software environment leverages the potential of the hardware switch, to provide support for the SPMD execution model. Finally, in order to demonstrate the benefits of our architecture, we have implemented a scalable distributed secure H.264 encoding application along with several avionic communication protocols for data and control transfers between the nodes. We have used a FMC based high-speed serial Front Panel Data Port (sFPDP) data acquisition protocol to capture, encode and encrypt RAW video streams. The system has been implemented on 3 different FPGAs, respecting the SPMD execution model. In addition, we have also implemented modular I/Os by swapping I/O protocols dynamically when required by the system. We have thus demonstrated a scalable and flexible architecture and a parallel runtime reconfiguration model in order to manage several parallel input video sources. These results represent a conceptual proof of a massively parallel dynamically reconfigurable next generation embedded computers.

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