2,129 research outputs found

    System design and development of Front-X: an X-band dual-polarization phased array weather radar

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    2019 Spring.Includes bibliographical references.The electronic beam steering capability of phased array weather radars has the potential to improve the temporal resolution of meteorological data and enable the development of multifunction radars, yet questions about their dual-polarimetric performance remain an ongoing topic of research. This thesis presents the system design and development of Front-X, an X-band dual-polarization phased array weather radar capable of both electronic and mechanical beam steering, whose purpose is to serve as a test-bed for implementing adaptive scan strategies, developing phased array radar calibration techniques, and exploring the efficacy of electronic scanning for weather applications. The design, development, calibration, and configuration of a system controller, antenna positioner, and signal processor are discussed. Furthermore, the system is demonstrated through a comparison of polarimetric electronic and mechanical scan weather data, including various electronic scan correction methods, and visually verified through a comparison to data collected with the proven CHILL X-band radar

    A new architecture for single-event upset detection & reconfiguration of SRAM-based FPGAs

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    Field Programmable Gate Arrays (FPGA) are used in a variety of applications, ranging from consumer electronics to devices in spacecrafts because of their flexibility in achieving requirements such as low cost, high performance, and fast turnaround. SRAM-based FPGAs can experience single bit flips in the configuration memory due to high-energy neutrons or alpha particles hitting critical nodes in the SRAM cells, by transferring enough energy to effect the change. High energy particles can be emitted by cosmic radiation or traces of radioactive elements in device packaging. The result of this could range from unwanted functional or data modification, data loss in the system, to damage to the cell where the charged particle makes impact. This phenomenon is known as a Single Event Upset (SEU) and makes fault tolerance a critical requirement in FPGA design. This research proposes a shift in architecture from current SRAM-based FPGAs such as Xilinx Virtex. The proposed architecture includes an inherent SEU detection through parity checking of the configuration memory. The inherent SEU detection sets a syndrome flag when an odd number of bit flips occur within a data frame of the configuration memory. To correct a fault, the FPGA the affected data frame is partially reconfigured. Existing and proposed solutions include: Triple Modular Redundancy (TMR) systems; readback and compare the configuration memory; and periodically reprogramming the entire configuration memory, also known as scrubbing. The advantages afforded by the proposed architecture over existing solutions include: faster error detection and correction latency over the readback method and better area and power overhead over TMR

    Using Relocatable Bitstreams for Fault Tolerance

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    This research develops a method for relocating reconfigurable modules on the Virtex-II (Pro) family of Field Programmable Gate Arrays (FPGAs). A bitstream translation program is developed which correctly changes the location of a partial bitstream that implements a module on the FPGA. To take advantage of relocatable modules, three fault-tolerance circuit designs are developed and tested. This circuit can operate through a fault by efficiently removing the faulty module and replacing it with a relocated module without faults. The FPGA can recover from faults at a known location, without the need for external intervention using an embedded fault recovery system. The recovery system uses an internal PowerPC to relocate the modules and reprogram the FPGA. Due to the limited architecture of the target FPGA and Xilinx tool errors, an FPGA with automatic fault recovery could not be demonstrated. However, the various components needed to do this type of recovery have been implemented and demonstrated individually

    An Adaptable Optimal Network Topology Model for Efficient Data Centre Design in Storage Area Networks

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    In this research, we look at how different network topologies affect the energy consumption of modular data centre (DC) setups. We use a combined-input directed approach to assess the benefits of rack-scale and pod-scale fragmentation across a variety of electrical, optoelectronic, and composite network architectures in comparison to a conventional DC. When the optical transport architecture is implemented and the appropriate resource components are distributed, the findings reveal fragmentation at the layer level is adequate, even compared to a pod-scale DC. Composable DCs can operate at peak efficiency because of the optical network topology. Logical separation of conventional DC servers across an optical network architecture is also investigated in this article. When compared to physical decentralisation at the rack size, logical decomposition of data centers inside each rack offers a small decrease in the overall DC energy usage thanks to better resource needs allocation. This allows for a flexible, composable architecture that can accommodate performance based in-memory applications. Moreover, we look at the state of fundamentalmodel and its use in both static and dynamic data centres. According to our findings, typical DCs become more energy efficient when workload modularity increases, although excessive resource use still exists. By enabling optimal resource use and energy savings, disaggregation and micro-services were able to reduce the typical DC's up to 30%. Furthermore, we offer a heuristic to duplicate the Mixed integer model's output trends for energy-efficient allocation of caseloads in modularized DCs

    VERILOG DESIGN AND FPGA PROTOTYPE OF A NANOCONTROLLER SYSTEM

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    Many new fabrication technologies, from nanotechnology and MEMS to printed organic semiconductors, center on constructing arrays of large numbers of sensors, actuators, or other devices on a single substrate. The utility of such an array could be greatly enhanced if each device could be managed by a programmable controller and all of these controllers could coordinate their actions as a massively-parallel computer. Kentucky Architecture nanocontroller array with very low per controller circuit complexity can provide efficient control of nanotechnology devices. This thesis provides a detailed description of the control hierarchy of a digital system needed to build nanocontrollers suitable for controlling millions of devices on a single chip. A Verilog design and FPGA prototype of a nanocontroller system is provided to meet the constraints associated with a massively-parallel programmable controller system

    Adapting the SpaceCube v2.0 Data Processing System for Mission-Unique Application Requirements

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    The SpaceCube (sup TM) v2.0 system is a superior high performance, reconfigurable, hybrid data processing system that can be used in a multitude of applications including those that require a radiation hardened and reliable solution. This paper provides an overview of the design architecture, flexibility, and the advantages of the modular SpaceCube v2.0 high performance data processing system for space applications. The current state of the proven SpaceCube technology is based on nine years of engineering and operations. Five systems have been successfully operated in space starting in 2008 with four more to be delivered for launch vehicle integration in 2015. The SpaceCube v2.0 system is also baselined as the avionics solution for five additional flight projects and is always a top consideration as the core avionics for new instruments or spacecraft control. This paper will highlight how this multipurpose system is currently being used to solve design challenges of three independent applications. The SpaceCube hardware adapts to new system requirements by allowing for application-unique interface cards that are utilized by reconfiguring the underlying programmable elements on the core processor card. We will show how this system is being used to improve on a heritage NASA GPS technology, enable a cutting-edge LiDAR instrument, and serve as a typical command and data handling (C&DH) computer for a space robotics technology demonstration

    Ein flexibles, heterogenes Bildverarbeitungs-Framework für weltraumbasierte, rekonfigurierbare Datenverarbeitungsmodule

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    Scientific instruments as payload of current space missions are often equipped with high-resolution sensors. Thereby, especially camera-based instruments produce a vast amount of data. To obtain the desired scientific information, this data usually is processed on ground. Due to the high distance of missions within the solar system, the data rate for downlink to the ground station is strictly limited. The volume of scientific relevant data is usually less compared to the obtained raw data. Therefore, processing already has to be carried out on-board the spacecraft. An example of such an instrument is the Polarimetric and Helioseismic Imager (PHI) on-board Solar Orbiter. For acquisition, storage and processing of images, the instrument is equipped with a Data Processing Module (DPM). It makes use of heterogeneous computing based on a dedicated LEON3 processor in combination with two reconfigurable Xilinx Virtex-4 Field-Programmable Gate Arrays (FPGAs). The thesis will provide an overview of the available space-grade processing components (processors and FPGAs) which fulfill the requirements of deepspace missions. It also presents existing processing platforms which are based upon a heterogeneous system combining processors and FPGAs. This also includes the DPM of the PHI instrument, whose architecture will be introduced in detail. As core contribution of this thesis, a framework will be presented which enables high-performance image processing on such hardware-based systems while retaining software-like flexibility. This framework mainly consists of a variety of modules for hardware acceleration which are integrated seamlessly into the data flow of the on-board software. Supplementary, it makes extensive use of the dynamic in-flight reconfigurability of the used Virtex-4 FPGAs. The flexibility of the presented framework is proven by means of multiple examples from within the image processing of the PHI instrument. The framework is analyzed with respect to processing performance as well as power consumption.Wissenschaftliche Instrumente auf aktuellen Raumfahrtmissionen sind oft mit hochauflösenden Sensoren ausgestattet. Insbesondere kamerabasierte Instrumente produzieren dabei eine große Menge an Daten. Diese werden üblicherweise nach dem Empfang auf der Erde weiterverarbeitet, um daraus wissenschaftlich relevante Informationen zu gewinnen. Aufgrund der großen Entfernung von Missionen innerhalb unseres Sonnensystems ist die Datenrate zur Übertragung an die Bodenstation oft sehr begrenzt. Das Volumen der wissenschaftlich relevanten Daten ist meist deutlich kleiner als die aufgenommenen Rohdaten. Daher ist es vorteilhaft, diese bereits an Board der Sonde zu verarbeiten. Ein Beispiel für solch ein Instrument ist der Polarimetric and Helioseismic Imager (PHI) an Bord von Solar Orbiter. Um die Daten aufzunehmen, zu speichern und zu verarbeiten, ist das Instrument mit einem Data Processing Module (DPM) ausgestattet. Dieses nutzt ein heterogenes Rechnersystem aus einem dedizierten LEON3 Prozessor, zusammen mit zwei rekonfigurierbaren Xilinx Virtex-4 Field-Programmable Gate Arrays (FPGAs). Die folgende Arbeit gibt einen Überblick über verfügbare Komponenten zur Datenverarbeitung (Prozessoren und FPGAs), die den Anforderungen von Raumfahrtmissionen gerecht werden, und stellt einige existierende Plattformen vor, die auf einem heterogenen System aus Prozessor und FPGA basieren. Hierzu gehört auch das Data Processing Module des PHI Instrumentes, dessen Architektur im Verlauf dieser Arbeit beschrieben wird. Als Kernelement der Dissertation wird ein Framework vorgestellt, das sowohl eine performante, als auch eine flexible Bilddatenverarbeitung auf einem solchen System ermöglicht. Dieses Framework besteht aus verschiedenen Modulen zur Hardwarebeschleunigung und bindet diese nahtlos in den Datenfluss der On-Board Software ein. Dabei wird außerdem die Möglichkeit genutzt, die eingesetzten Virtex-4 FPGAs dynamisch zur Laufzeit zu rekonfigurieren. Die Flexibilität des vorgestellten Frameworks wird anhand mehrerer Fallbeispiele aus der Bildverarbeitung von PHI dargestellt. Das Framework wird bezüglich der Verarbeitungsgeschwindigkeit und Energieeffizienz analysiert

    Real-time human action recognition on an embedded, reconfigurable video processing architecture

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    Copyright @ 2008 Springer-Verlag.In recent years, automatic human motion recognition has been widely researched within the computer vision and image processing communities. Here we propose a real-time embedded vision solution for human motion recognition implemented on a ubiquitous device. There are three main contributions in this paper. Firstly, we have developed a fast human motion recognition system with simple motion features and a linear Support Vector Machine (SVM) classifier. The method has been tested on a large, public human action dataset and achieved competitive performance for the temporal template (eg. “motion history image”) class of approaches. Secondly, we have developed a reconfigurable, FPGA based video processing architecture. One advantage of this architecture is that the system processing performance can be reconfiured for a particular application, with the addition of new or replicated processing cores. Finally, we have successfully implemented a human motion recognition system on this reconfigurable architecture. With a small number of human actions (hand gestures), this stand-alone system is performing reliably, with an 80% average recognition rate using limited training data. This type of system has applications in security systems, man-machine communications and intelligent environments.DTI and Broadcom Ltd
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