134 research outputs found
Ethernet Over Plastic Optical Fiber for Use in the Control System Network for Automotive Applications
Plastic optical fiber (POF) for use in automotive applications is not a new concept and has been used in some vehicles for infotainment media distribution within the Media Oriented Systems Transport protocol. However, the use of POF for the control network’s physical layer is a concept that has not been implemented in automotive applications. Many aspects of a vehicle can be improved by implementing POF as the physical backbone for the control network. Currently, the Controller Area Network (CAN) is used as the primary backbone control network protocol for most automobiles as it is inexpensive and reliable. However, CAN is limited to 500 kbps in most vehicles and is easily accessible. Ethernet may provide the improvements of speed and security needed in today’s feature rich and connected vehicles. The feasibility of implementing Ethernet over POF as the control network for automotive applications is the topic of this research investigation
Performance improvements of automobile communication protocols in electromagnetic interference environments
Electromagnetic Interference (EMI) is frequently encountered in automobile communication systems due to a large number of inductive nodes used in these systems. This thesis investigates the effects of EMI on two types of automobile communication systems, the Controller Area Network (CAN) and the FlexRay. It also proposes a modified Automatic Repeat reQuest (ARQ) scheme to improve the communication performances in EMI environments --Abstract, page iii
Arquitecturas de hardware para um veĂculo elĂ©ctrico
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 201
Estudo do impacto de transientes elétricos em protocolos de comunicação em sistemas embarcados
O aumento da complexidade e responsabilidade dos dispositivos embarcados nos veĂculos hoje, tem orientado os esforços no desenvolvimento de sistemas de controle para que estes sejam mais rápidos, precisos, robustos e principamente seguros. Com isso, estes dispositivos estĂŁo levando os protocolos de comunicação a um patamar inĂ©dito de exigĂŞncia, tanto no quesito de capacidade como confiabilidade. Protocolos como CAN, CAN-FD e FlexRay entre outros, tem sido utilizados devido Ă s suas caracterĂsticas de segurança e a capacidade de atender aos requisitos temporais dos diversos circuitos embarcados. O desenvolvimento e utilização cada vez mais frequente de dispositivos focados em segurança, fazem com que a comunicação entre os diversos componentes destes dispositivos seja exigida ao máximo, levando Ă necessidade de respostas confiáveis ao extremo. Sistemas como freios ABS, suspensĂŁo ativa, frenagem autonoma de emergĂŞncia, controle de velocidade e distância adaptativo, entre outros, que envolvem várias ECUs distribuĂdas ao longo do veĂculo, dispões de frações de segundo para a reação do sistema, entre o sinal de entrada e a atuação correspondente, demandando uma comunicação segura e tolerante Ă falhas. Os veĂculos hoje estĂŁo passando por grandes mudanças conceituais, trazendo cada vez mais elementos onde o funcionamento demanda mais energia das fontes de alimentação. Diversos sistemas existentes nos veĂculos geram ruĂdos como os Transientes ElĂ©tricos Rápidos, ou "Electric Fast Transient" (EFT), que estĂŁo presentes nas mais simples operações cotidianas do veĂculo, como ligar e desligar o farol, o ar condicionado, o limpador de para brisas, ou mesmo o acionamento de iluminação diurna (DRL), etc. Neste trabalho foram realizados diversos ensaios, utilizando ECUs com diferentes funções e protocolos, para identificar a susceptibilidade dos referidos sistemas e os protocolos Ă presença destes ruĂdos. Visando atender Ă s normas IEC 62228 e a ISO26262, este trabalho demandou o projeto e construção de dois circuitos eletrĂ´nicos diferentes, um circuito observando os dados de tempos de subida e de descida (rise and fall time) dos pulsos de EFT, e outro observando a arquitetura do layout da placa de circuito impresso (PCB), as suas entradas, saĂdas, componentes, etc. Estes ensaios visaram identificar o quanto estes protocolos sĂŁo suscetĂveis Ă estes tipos de ruĂdos, utilizando mĂ©tricas de análise baseadas nos tempos de latĂŞncia e variação de jitter dos pacotes de comunicação.The increasing complexity and accountability of embedded devices in vehicles today has driven efforts to develop control systems to make them faster, accuratest, safest, robustest. Thus, these devices are taking communication protocols to an unprecedented level of demand, both in terms of capacity and reliability. Protocols such as CAN, CANFD and FlexRay among others have been used due to their safety characteristics and the ability to meet the time requirements of various embedded circuits. The increasing development and use of safety-focused devices, means that communication between the various components of these devices is required to the utmost, leading to the need for extremely reliable responses. Systems such as ABS brakes, active suspension, autonomous emergency braking, adaptative cruise control, among others, which involve various ECUs distributed throughout the vehicle, have milliseconds for system reaction, between input signal and concrete actuation, requiring safe and failure tolerant communication. Vehicles today are undergoing major conceptual changes, bringing more and more elements whose operation require more energy from power supplies. These systems generate noise such as "Electric Fast Transient" (EFT), which are present in the simplest daily operations of the vehicle, such as turning the headlight on, the air conditioner, the windscreen wiper, or even the daytime running light (DRL), etc. In this work several tests were carried out, using different ECUs with different functions and different protocols to identify the susceptibility of these systems and the protocols to these noises. In order to comply with IEC 62228 and ISO 26262 standards, this work required the design and construction of two different electronic circuits, one circuit observing the rise and fall time data of the EFT pulses, and the other observing the architecture of the printed circuit board (PCB) layout, its inputs and outputs, components, etc. These tests aimed to identify how susceptible these protocols are to these types of noise, using analysis metrics based on latency time and jitter variation of communication packets
Services for safety-critical applications on dual-scheduled TDMA networks
Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200
A framework and methods for on-board network level fault diagnostics in automobiles
A significant number of electronic control units (ECUs) are nowadays networked
in automotive vehicles to help achieve advanced vehicle control and eliminate
bulky electrical wiring. This, however, inevitably leads to increased complexity in
vehicle fault diagnostics. Traditional off-board fault diagnostics and repair at
service centres, by using only diagnostic trouble codes logged by conventional onboard
diagnostics, can become unwieldy especially when dealing with intermittent
faults in complex networked electronic systems. This can result in inaccurate and
time consuming diagnostics due to lack of real-time fault information of the
interaction among ECUs in the network-wide perspective.
This thesis proposes a new framework for on-board knowledge-based
diagnostics focusing on network level faults, and presents an implementation of a
real-time in-vehicle network diagnostic system, using case-based reasoning. A
newly developed fault detection technique and the results from several practical
experiments with the diagnostic system using a network simulation tool, a
hardware- in-the- loop simulator, a disturbance simulator, simulated ECUs and real
ECUs networked on a test rig are also presented. The results show that the new
vehicle diagnostics scheme, based on the proposed new framework, can provide
more real-time network level diagnostic data, and more detailed and self-explanatory
diagnostic outcomes. This new system can provide increased diagnostic capability when compared with conventional diagnostic methods in
terms of detecting message communication faults. In particular, the underlying
incipient network problems that are ignored by the conventional on-board
diagnostics are picked up for thorough fault diagnostics and prognostics which can
be carried out by a whole-vehicle fault management system, contributing to the
further development of intelligent and fault-tolerant vehicles
Design of in-vehicle networked control system architectures through the use of new design to cost and weight processes : innovation report
Over the last forty years, the use of electronic controls within the automotive industry
has grown considerably. In-vehicle network technologies such as the Controller Area
Network (CAN) and Local Interconnect Network (LIN) are used to connect
Electronic Control Units (ECU) together, mainly to reduce the amount of wiring that
would be required if hardwired integration were used.
Modern passenger cars contain many networks, which means that for the
architecture designer, there is an almost overwhelming number of choices on how to
design/partition the system depending on factors such as cost, weight, availability of
ECUs, safety, Electro-Magnetic Compatibility (EMC) etc. Despite the increasing role
played by in-vehicle networks in automotive electrical architectures, its design could
currently be described as a “black art”. Not only is there an almost overwhelming
number of choices facing the designer, but there is currently a lack of a quantifiable
process to aid decision making and there is a dearth of published literature available.
NetGen is a software tool used to design CAN/J1939, LIN and FlexRay
networks. For the product to remain competitive, it is desirable to have novel features
over the competition. This report describes a body of work, the aim of which was to
research in-vehicle network design processes, and to provide an improvement to such
processes. The opportunities of customer projects and availability of customer
information resulted in the scope of the research focusing on the adoption of LIN
technology and whether the adoption of it could reduce the cost and weight of the
target architecture. The research can therefore be seen to address two issues: firstly
the general problem of network designers needing to design in-vehicle network based
architectures balancing the needs of many design targets such as cost, weight etc, and
secondly the commercial motivation to find novel features for the design tool, NetGen. The outcome of the research described in this report was the development of
design processes that can be used for the selection of low cost and weight automotive
electrical architectures using coarse information, such as that which would be easily
available at the very beginning of a vehicle design programme. The key benefit of
this is that a number of candidate networked architectures can be easily assessed for
their ability to reduce cost and weight of the electrical architecture
X-By-Wire via ISOBUS Communication Network
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): X-By-Wire via ISOBUS Communication Network. Manuscript ATOE 07 002. Vol. IX. July, 2007
Framework for media oriented transport systems
Dissertação de mestrado integrado em Engenharia Electrónica Industrial e ComputadoresThe natural evolution of embedded systems resulted in a faster execution of tasks,
increased possibility for including additional features, allied to lower power consumption
and benefiting from ever-growing rates of integration as far as silicon is
concerned. The automotive industry is not an exception with regards to the integration
of technology for a vast arrays of applications in systems which vary from
entertainment of infotainment to systems related to vehicle safety and stability
such as driver assists. The existence of diverse independent systems in modern
cars, combined with the necessity of centralizing the user interface, simplifying the
operation of the system and minimizing the user’s intervention, help to promote
the comfort and reduce the likelihood of distractions taking place while driving.
Modern communication oriented network standards, e.g. MOST or FlexRay, enable
information compatibility when exchanged between systems communicating
over different protocols. Moreover, the coexistence of packet, control and timesensitive
information are ensured within timing requirements, providing a reliable
QoS (Quality of Service) and by making use of a single physical transmission mean.
Synchronized multimedia data (e.g. synchronized video and audio transmission)
are example of this kind of (time-sensitive) information.
This dissertation proposes a framework for design and development of network
distributed applications in the field of automotive infotainment, compliant with
the industry standards and using FPGA technology in order to ensure the system
requirements satisfaction and promote IP Core re-utilization.A evolução natural dos sistemas embebidos traduziu-se numa maior rapidez na execução
de tarefas, a possibilidade de incluir mais funcionalidades, aliado a menores
consumos energéticos e beneficiando de crescentes e elevadas taxas de integração
ao nĂvel de silĂcio. A indĂşstria automĂłvel nĂŁo Ă© excepção no que diz respeito Ă
integração de tecnologia para as mais variadas aplicações, com ou sem tolerância
Ă falha, em sistemas que vĂŁo desde entretenimento ou infotainment a sistemas
relacionados com a estabilidade e segurança do veĂculo, como Ă© exemplo
as driver assists. Existem de vários sistemas independentes nos modernos veĂculos
automĂłveis. Estes, combinados com a necessidade de centralização ao nĂvel de
interface com o utilizador, tornam imperativa a simplicidade da operação. Para
tal, requerem a minimizaccão da intervenção do utilizador, promovendo o conforto
e diminuindo a probabilidade de desconcentração durante o exercĂcio de condução.
Os mais modernos standards de redes de comunicação como é exemplo o MOST
ou o FlexRay, permitem a compatibilidade de informação trocada entre sistemas
que comunicam através de distintos protocolos de comunicação. Para além disso,
ainda garantem a coexistência de informação de controlo, informação do entretenimento
e informação do tipo time-sensitive, onde os requisitos de temporização
devem ser assegurados, mantendo uma qualidade de serviço fià vel e fazendo uso
de um Ăşnico meio fĂsico de transmissĂŁo. SĂŁo exemplos deste tipo de informação,
dados sĂncronos do tipo multimĂ©dia (e.g. streaming de Ă udio e vĂdeo de forma
sincronizada). Pretende-se desenvolver uma framework para desenvolvimento de
aplicações de rede distribuĂdas, do tipo infotainment e que beneficia a aplicação de
tecnologias como FPGA, no offloading de computação para este dispositivo, como
meio de garantir a satisfação dos requisitos, e promover a reutilização deste tipo
de sistemas, mantendo o elevado desempenho na troca de dados e promovendo a
portabilidade e a modularidade
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