7 research outputs found
Fault-tolerant satellite computing with modern semiconductors
Miniaturized satellites enable a variety space missions which were in the past infeasible, impractical or uneconomical with traditionally-designed heavier spacecraft. Especially CubeSats can be launched and manufactured rapidly at low cost from commercial components, even in academic environments. However, due to their low reliability and brief lifetime, they are usually not considered suitable for life- and safety-critical services, complex multi-phased solar-system-exploration missions, and missions with a longer duration. Commercial electronics are key to satellite miniaturization, but also responsible for their low reliability: Until 2019, there existed no reliable or fault-tolerant computer architectures suitable for very small satellites. To overcome this deficit, a novel on-board-computer architecture is described in this thesis.Robustness is assured without resorting to radiation hardening, but through software measures implemented within a robust-by-design multiprocessor-system-on-chip. This fault-tolerant architecture is component-wise simple and can dynamically adapt to changing performance requirements throughout a mission. It can support graceful aging by exploiting FPGA-reconfiguration and mixed-criticality. Experimentally, we achieve 1.94W power consumption at 300Mhz with a Xilinx Kintex Ultrascale+ proof-of-concept, which is well within the powerbudget range of current 2U CubeSats. To our knowledge, this is the first COTS-based, reproducible on-board-computer architecture that can offer strong fault coverage even for small CubeSats.European Space AgencyComputer Systems, Imagery and Medi
Nova combinação de hardware e de software para veículos de desporto automóvel baseada no processamento directo de funções gráficas
Doutoramento em Engenharia EletrónicaThe main motivation for the work presented here began with previously
conducted experiments with a programming concept at the time named
"Macro". These experiments led to the conviction that it would be possible to
build a system of engine control from scratch, which could eliminate many of
the current problems of engine management systems in a direct and intrinsic
way. It was also hoped that it would minimize the full range of software and
hardware needed to make a final and fully functional system.
Initially, this paper proposes to make a comprehensive survey of the state of
the art in the specific area of software and corresponding hardware of
automotive tools and automotive ECUs. Problems arising from such software
will be identified, and it will be clear that practically all of these problems stem
directly or indirectly from the fact that we continue to make comprehensive use
of extremely long and complex "tool chains". Similarly, in the hardware, it will
be argued that the problems stem from the extreme complexity and
inter-dependency inside processor architectures. The conclusions are
presented through an extensive list of "pitfalls" which will be thoroughly
enumerated, identified and characterized.
Solutions will also be proposed for the various current issues and for the
implementation of these same solutions. All this final work will be part of a
"proof-of-concept" system called "ECU2010". The central element of this
system is the before mentioned "Macro" concept, which is an graphical block
representing one of many operations required in a automotive system having
arithmetic, logic, filtering, integration, multiplexing functions among others. The
end result of the proposed work is a single tool, fully integrated, enabling the
development and management of the entire system in one simple visual
interface. Part of the presented result relies on a hardware platform fully
adapted to the software, as well as enabling high flexibility and scalability in
addition to using exactly the same technology for ECU, data logger and
peripherals alike.
Current systems rely on a mostly evolutionary path, only allowing online
calibration of parameters, but never the online alteration of their own
automotive functionality algorithms. By contrast, the system developed and
described in this thesis had the advantage of following a "clean-slate"
approach, whereby everything could be rethought globally. In the end, out of all
the system characteristics, "LIVE-Prototyping" is the most relevant feature,
allowing the adjustment of automotive algorithms (eg. Injection, ignition,
lambda control, etc.) 100% online, keeping the engine constantly working,
without ever having to stop or reboot to make such changes. This consequently
eliminates any "turnaround delay" typically present in current automotive
systems, thereby enhancing the efficiency and handling of such systems.A principal motivação para o trabalho que conduziu a esta tese residiu na
constatação de que os actuais métodos de modelação de centralinas
automóveis conduzem a significativos problemas de desenvolvimento e
manutenção. Como resultado dessa constatação, o objectivo deste trabalho
centrou-se no desenvolvimento de um conceito de arquitectura que rompe
radicalmente com os modelos state-of-the-art e que assenta num conjunto de
conceitos que vieram a ser designados de "Macro" e "Celular ECU". Com este
modelo pretendeu-se simultaneamente minimizar a panóplia de software e de
hardware necessários à obtenção de uma sistema funcional final.
Inicialmente, esta tese propõem-se fazer um levantamento exaustivo do
estado da arte na área específica do software e correspondente hardware das
ferramentas e centralinas automóveis. Os problemas decorrentes de tal
software serão identificados e, dessa identificação deverá ficar claro, que
praticamente todos esses problemas têm origem directa ou indirecta no facto
de se continuar a fazer um uso exaustivo de "tool chains" extremamente
compridas e complexas. De forma semelhante, no hardware, os problemas
têm origem na extrema complexidade e inter-dependência das arquitecturas
dos processadores. As consequências distribuem-se por uma extensa lista de
"pitfalls" que também serão exaustivamente enumeradas, identificadas e
caracterizadas.
São ainda propostas soluções para os diversos problemas actuais e
correspondentes implementações dessas mesmas soluções. Todo este
trabalho final faz parte de um sistema "proof-of-concept" designado
"ECU2010". O elemento central deste sistema é o já referido conceito de
“Macro”, que consiste num bloco gráfico que representa uma de muitas
operações necessárias num sistema automóvel, como sejam funções
aritméticas, lógicas, de filtragem, de integração, de multiplexagem, entre
outras. O resultado final do trabalho proposto assenta numa única ferramenta,
totalmente integrada que permite o desenvolvimento e gestão de todo o
sistema de forma simples numa única interface visual. Parte do resultado
apresentado assenta numa plataforma hardware totalmente adaptada ao
software, bem como na elevada flexibilidade e escalabilidade, para além de
permitir a utilização de exactamente a mesma tecnologia quer para a
centralina, como para o datalogger e para os periféricos.
Os sistemas actuais assentam num percurso maioritariamente evolutivo,
apenas permitindo a calibração online de parâmetros, mas nunca a alteração
online dos próprios algoritmos das funcionalidades automóveis. Pelo contrário,
o sistema desenvolvido e descrito nesta tese apresenta a vantagem de seguir
um "clean-slate approach", pelo que tudo pode ser globalmente repensado. No
final e para além de todas as restantes características, o
“LIVE-PROTOTYPING” é a funcionalidade mais relevante, ao permitir alterar
algoritmos automóveis (ex: injecção, ignição, controlo lambda, etc.) de forma
100% online, mantendo o motor constantemente a trabalhar e sem nunca ter
de o parar ou re-arrancar para efectuar tais alterações. Isto elimina
consequentemente qualquer "turnaround delay" tipicamente presente em
qualquer sistema automóvel actual, aumentando de forma significativa a
eficiência global do sistema e da sua utilização
Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)
The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones
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Support of Gulf of Mexico Hydrate Research Consortium: Activities of Support Establishment of a Sea Floor Monitoring Station Project
The Gulf of Mexico Hydrates Research Consortium (GOM-HRC) was established in 1999 to assemble leaders in gas hydrates research that shared the need for a way to conduct investigations of gas hydrates and their stability zone in the Gulf of Mexico in situ on a more-or-less continuous basis. The primary objective of the group is to design and emplace a remote monitoring station or sea floor observatory (SFO) on the sea floor in the northern Gulf of Mexico, in an area where gas hydrates are known to be present at, or just below, the sea floor and to discover the configuration and composition of the subsurface pathways or 'plumbing' through which fluids migrate into and out of the hydrate stability zone (HSZ) to the sediment-water interface. Monitoring changes in this zone and linking them to coincident and perhaps consequent events at the seafloor and within the water column is the eventual goal of the Consortium. This mission includes investigations of the physical, chemical and biological components of the gas hydrate stability zone - the sea-floor/sediment-water interface, the near-sea-floor water column, and the shallow subsurface sediments. The eventual goal is to monitor changes in the hydrate stability zone over time. Establishment of the Consortium succeeded in fulfilling the critical need to coordinate activities, avoid redundancies and communicate effectively among those involved in gas hydrates research. Complementary expertise, both scientific and technical, has been assembled to promote innovative methods and construct necessary instrumentation. Following extensive investigation into candidate sites, Mississippi Canyon 118 (MC118) was chosen by consensus of the Consortium at their fall, 2004, meeting as the site most likely to satisfy all criteria established by the group. Much of the preliminary work preceding the establishment of the site - sensor development and testing, geophysical surveys, and laboratory studies - has been reported in agency documents including the Final Technical Report to DOE covering Cooperative Agreement DEFC26-00NT40920 and Semiannual Progress Reports for this award, DE-FC26-02NT41628. Initial components of the observatory, a probe that collects pore-fluid samples and another that records sea floor temperatures, were deployed in MC118 in May of 2005. Follow-up deployments, planned for fall 2005, had to be postponed due to the catastrophic effects of Hurricane Katrina (and later, Rita) on the Gulf Coast. SFO completion, now anticipated for 2009-10, has, therefore, been delayed. Although delays caused scheduling and deployment difficulties, many sensors and instruments were completed during this period. Software has been written that will accommodate the data that the station retrieves, when it begins to be delivered. In addition, new seismic data processing software has been written to treat the peculiar data to be received by the vertical line array (VLA) and additional software has been developed that will address the horizontal line array (HLA) data. These packages have been tested on data from the test deployments of the VLA and on data from other, similar, areas of the Gulf (in the case of the HLA software). During the life of this Cooperative Agreement (CA), the CMRET conducted many cruises. Early in the program these were executed primarily to survey potential sites and test sensors and equipment being developed for the SFO. When MC118 was established as the observatory site, subsequent cruises focused on this location. Beginning in 2005 and continuing to the present, 13 research cruises to MC118 have been conducted by the Consortium. During September, 2006, the Consortium was able to secure 8 days aboard the R/V Seward Johnson with submersible Johnson SeaLink, a critical chapter in the life of the Observatory project as important documentation, tests, recoveries and deployments were accomplished during this trip (log appended). Consortium members have participated materially in a number of additional cruises including several of the NIUST autonomous underwater vehicle (AUV), Eagle Ray. Activities reports summarize cruise activities, including objectives, how they were met or not met, and challenges. Deployment cruises are scheduled for 2009 that are designed to complete installation of the major observatory components
Proceedings of the 19th Sound and Music Computing Conference
Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France).
https://smc22.grame.f