7 research outputs found

    Development Board for 32-bit Microcontroller Atmel AT91SAM9261

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    Vestavený hardware je velice populární v této době. Proto jsme se rozhodli vytvořit desku s mikrokontrolérem AT91SAM9261 spolu so standartným a nestandartným hardwarem. Standartným, běžným by se dal nazvat port LAN alebo audio vstup-výstup. Nestandartným, špecialním by mohl být obvod FPGA firmy Xilinx o velikosti 200k. Toto dovoluje využít zažízení v oblastech, kde výpočetní síla obyčejnýho CPU již není dostačující.Embedded hardware is very popular nowadays; we chose to design a board with AT91SAM9261 microcontroller with some standard and non-standard peripherals attached. As for the standard, common we have included audio port or a LAN controller. The non-standard, special is a 200k Xilinx FPGA. Using the FPGA, we may be able to achive higher throughput in some applications that are not very suitable for plain CPUs.

    An electrical power system for CubeSats

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    The advent of CubeSats has provided a platform for relatively low-budget programmes to realise space missions. In South Africa, Stellenbosch University and the Cape Peninsula University of Technology have impressive space programmes and have been involved in numerous successful satellite launches. A number of CubeSat projects are currently in progress and commercial-grade Attitude Determination and Control Systems (ADCS), and communications modules, are being developed by the respective universities. The development of a CubeSat-compatible Electrical Power System remains absent, and would be beneficial to future satellite activity here in South Africa. In this thesis, some fundamental aspects of electronic design for space applications is looked at, including but not limited to radiation effects on MOSFET devices; this poses one of the greatest challenges to space-based power systems. To this extent, the different radiation-induced effects and their implications are looked at, and mitigation strategies are discussed. A review of current commercial modules is performed and their design and performance evaluated. A few shortcomings of current systems are noted and corresponding design changes are suggested; in some instances these changes add complexity, but they are shown to introduce appreciable system reliability. A single Li-Ion cell configuration is proposed that uses a 3.7 V nominal bus voltage. Individual battery charge regulation introduces minor inefficiencies, but allows isolation of cells from the pack in the case of cell failure or degradation. A further advantage is the possibility for multiple energy storage media on the same power bus, allowing for EPS-related technology demonstrations, with an assurance of minimum system capabilities. The design of each subsystem is discussed and its respective failure modes identified. A limited number of single points of failure are noted and the mitigation strategies taken are discussed. An initial hardware prototype is developed that is used to test and characterise system performance. Although a few minor modifications are needed, the overall system is shown to function as designed and the concepts used are proven

    UAV Formation Flight Utilizing a Low Cost, Open Source Configuration

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    The control of multiple unmanned aerial vehicles (UAVs) in a swarm or cooperative team scenario has been a topic of great interest for well over a decade, growing steadily with the advancements in UAV technologies. In the academic community, a majority of the studies conducted rely on simulation to test developed control strategies, with only a few institutions known to have nurtured the infrastructure required to propel multiple UAV control studies beyond simulation and into experimental testing. With the Cal Poly UAV FLOC Project, such an infrastructure was created, paving the way for future experimentation with multiple UAV control systems. The control system architecture presented was built on concepts developed in previous work by Cal Poly faculty and graduate students. An outer-loop formation flight controller based on a virtual waypoint implementation of potential function guidance was developed for use on an embedded microcontroller. A commercially-available autopilot system, designed for fully autonomous waypoint navigation utilizing low cost hardware and open source software, was modified to include the formation flight controller and an inter-UAV communication network. A hardware-in-the-loop (HIL) simulation was set up for multiple UAV testing and was utilized to verify the functionality of the modified autopilot system. HIL simulation results demonstrated leader-follower formation convergence to 15 meters as well as formation flight with three UAVs. Several sets of flight tests were conducted, demonstrating a successful leader-follower formation, but with relative distance convergence only reaching a steady state value of approximately 35 +/- 5 meters away from the leader

    Architectures of the third cloud : distributed, mobile, and pervasive systems design

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    Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 117-125).In recent years, we have seen the proliferation of ubiquitous computers invading our public and private spaces. While personal computing is unfolding to become mobile activity, it rarely crosses the boundary of our personal devices, using the public interactive infrastructure as a substrate. This thesis develops an approach to interoperability and modular composition in the design of ubiquitous devices and systems. The focus is placed on the relationship between mobile devices and public infrastructure, in particular how a device with access to information about its physical and social context can dynamically configure and extend functionality of its cooperative environment to augment its interactive user experience. Based on Internet concepts of connectivity utility and resource utility, we derive the concept of interaction utility which we call the Third Cloud. Two complementary systems designs and implementations are presented to support this vision of computing. Substrate is an authoring framework and an execution environment intended to provide the necessary language and tools to easily compose self-operable applications capable of dynamically instantiate desired functionality in their proximate environment. The Amulet is a discrete portable device able to act on behalf of its user in a multitude of contexts. We evaluate the power and flexibility of these systems by using them in the construction of two applications. In the final chapter, we compare our approach with alternative ways of building such applications and suggest how our work can be extended.by David Gauthier.S.M

    Design of a remote monitoring and diagnostics platform for air conditioning installations

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    Includes abstract.Includes bibliographical references (p. 127-129).Faults and inefficiencies in air conditioning installations account for between 2% and 11% of allenergy consumed by commercial buildings in the United States each year. Diagnostics systems havebeen proven to improve the performance of air conditioning plants but the high costs of purchasing,retrofitting and maintaining such a system results in limited market adoption of such systems.This thesis discusses the design, implementation and results of low-cost remote monitoring anddiagnostic platform for use in air conditioning installations. The design of the various hardwarecomponents is presented along with the structure of the framework developed for each device. The thesis also contains information regarding the selection, integration and installation of the various types of sensors required on the various installations. A specially-designed protocol was also developed to handle communication between the hardware devices. Both the physical configuration and details of the protocol structure are presented in detail in this thesis. The mechanism through which the device uploads data to a server is also described in this thesis and includes details on both the hardware and the server technologies used in the upload process. The system has been installed on two different sites in Cape Town, South Africa and has produced meaningful diagnostic information since November 2007

    Developing neurostimulation techniques to investigate antidepressant and mood modulating behaviors / by Rajas Prakash Kale

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     My PhD consisted of a multidisciplinary approach towards primary research in the field of translational neuroscience. Incorporation of preclinical research, behavioral neuroscience, translational psychiatry, neural engineering, and biomedical device development techniques drives my continuing passion towards helping patients through innovation
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