46 research outputs found

    Trajectory planning based on adaptive model predictive control: Study of the performance of an autonomous vehicle in critical highway scenarios

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    Increasing automation in automotive industry is an important contribution to overcome many of the major societal challenges. However, testing and validating a highly autonomous vehicle is one of the biggest obstacles to the deployment of such vehicles, since they rely on data-driven and real-time sensors, actuators, complex algorithms, machine learning systems, and powerful processors to execute software, and they must be proven to be reliable and safe. For this reason, the verification, validation and testing (VVT) of autonomous vehicles is gaining interest and attention among the scientific community and there has been a number of significant efforts in this field. VVT helps developers and testers to determine any hidden faults, increasing systems confidence in safety, security, functional analysis, and in the ability to integrate autonomous prototypes into existing road networks. Other stakeholders like higher-management, public authorities and the public are also crucial to complete the VTT process. As autonomous vehicles require hundreds of millions of kilometers of testing driven on public roads before vehicle certification, simulations are playing a key role as they allow the simulation tools to virtually test millions of real-life scenarios, increasing safety and reducing costs, time and the need for physical road tests. In this study, a literature review is conducted to classify approaches for the VVT and an existing simulation tool is used to implement an autonomous driving system. The system will be characterized from the point of view of its performance in some critical highway scenarios.O aumento da automação na indústria automotiva é uma importante contribuição para superar muitos dos principais desafios da sociedade. No entanto, testar e validar um veículo altamente autónomo é um dos maiores obstáculos para a implantação de tais veículos, uma vez que eles contam com sensores, atuadores, algoritmos complexos, sistemas de aprendizagem de máquina e processadores potentes para executar softwares em tempo real, e devem ser comprovadamente confiáveis e seguros. Por esta razão, a verificação, validação e teste (VVT) de veículos autónomos está a ganhar interesse e atenção entre a comunidade científica e tem havido uma série de esforços significativos neste campo. A VVT ajuda os desenvolvedores e testadores a determinar quaisquer falhas ocultas, aumentando a confiança dos sistemas na segurança, proteção, análise funcional e na capacidade de integrar protótipos autónomos em redes rodoviárias existentes. Outras partes interessadas, como a alta administração, autoridades públicas e o público também são cruciais para concluir o processo de VTT. Como os veículos autónomos exigem centenas de milhões de quilómetros de testes conduzidos em vias públicas antes da certificação do veículo, as simulações estão a desempenhar cada vez mais um papel fundamental, pois permitem que as ferramentas de simulação testem virtualmente milhões de cenários da vida real, aumentando a segurança e reduzindo custos, tempo e necessidade de testes físicos em estrada. Neste estudo, é realizada uma revisão da literatura para classificar abordagens para a VVT e uma ferramenta de simulação existente é usada para implementar um sistema de direção autónoma. O sistema é caracterizado do ponto de vista do seu desempenho em alguns cenários críticos de autoestrad

    Estudo do impacto de transientes elétricos em protocolos de comunicação em sistemas embarcados

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    O aumento da complexidade e responsabilidade dos dispositivos embarcados nos veículos 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 estão levando os protocolos de comunicação a um patamar inédito de exigência, tanto no quesito de capacidade como confiabilidade. Protocolos como CAN, CAN-FD e FlexRay entre outros, tem sido utilizados devido às suas características 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 à necessidade de respostas confiáveis ao extremo. Sistemas como freios ABS, suspensão ativa, frenagem autonoma de emergência, controle de velocidade e distância adaptativo, entre outros, que envolvem várias ECUs distribuídas ao longo do veículo, 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 à falhas. Os veículos hoje estão passando por grandes mudanças conceituais, trazendo cada vez mais elementos onde o funcionamento demanda mais energia das fontes de alimentação. Diversos sistemas existentes nos veículos geram ruídos como os Transientes Elétricos Rápidos, ou "Electric Fast Transient" (EFT), que estão presentes nas mais simples operações cotidianas do veículo, 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 à presença destes ruídos. Visando atender às normas IEC 62228 e a ISO26262, este trabalho demandou o projeto e construção de dois circuitos eletrônicos 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, saídas, componentes, etc. Estes ensaios visaram identificar o quanto estes protocolos são suscetíveis à estes tipos de ruídos, utilizando métricas de análise baseadas nos tempos de latência 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

    Modellbasierte Entwicklung funktional sicherer Hardware nach ISO 26262

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    The compliance with functional safety according to the standard ISO 26262 in context of the increasing electrification of road vehicles is a significant challenge. This work provides a concept and methodology for the model-based development of functional safe hardware. This is characterized by the description of hardware designs, annotation of failure data and performing the demanded safety evaluations

    Modellbasierte Entwicklung funktional sicherer Hardware nach ISO 26262

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    Die Absicherung von funktionaler Sicherheit nach dem Standard ISO 26262 ist im Kontext der zunehmenden Elektrifizierung von Fahrzeugen ein herausforderndes Unterfangen. Diese Arbeit liefert ein Konzept und eine Vorgehensweise zur modellbasierten Entwicklung funktional sicherer Hardware. Diese zeichnet sich durch die Beschreibung von Hardwaredesigns, Anreicherung um Fehlerinformationen sowie Ausführung der geforderten Sicherheitsevaluationen aus

    Software Technologies - 8th International Joint Conference, ICSOFT 2013 : Revised Selected Papers

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    Proceedings of the International Workshop "Innovation Information Technologies: Theory and Practice": Dresden, Germany, September 06-10.2010

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    This International Workshop is a high quality seminar providing a forum for the exchange of scientific achievements between research communities of different universities and research institutes in the area of innovation information technologies. It is a continuation of the Russian-German Workshops that have been organized by the universities in Dresden, Karlsruhe and Ufa before. The workshop was arranged in 9 sessions covering the major topics: Modern Trends in Information Technology, Knowledge Based Systems and Semantic Modelling, Software Technology and High Performance Computing, Geo-Information Systems and Virtual Reality, System and Process Engineering, Process Control and Management and Corporate Information Systems

    Funktionale Sicherheit nach ISO 26262 in der Konzeptphase der Entwicklung von Elektrik/Elektronik Architekturen von Fahrzeugen

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    Die Entwicklung von softwarebasierten Fahrzeugsystemen unter Befolgung des neuen Standards IO 26262 erfordert ein gemeinsames Verständnis sowie die Verzahnung des Vorgehens in beiden Domänen. Ziel dieser Arbeit ist die Berücksichtigung von Anforderungen der funktionalen Sicherheit während der Modellierung von Elektrik/Elektronik Architekturen, ihre formale Zuteilung zu Modellinhalten sowie die Unterstützung nebenläufiger und nachfolgender Aktivitäten der Fahrzeugentwicklung

    Quantification of plausibility cross-checks in safety related control system architecture design for automotive applications

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    When designing safety critical systems for automotive applications it is imperative that the chosen architecture can fulfil the designated safety goals. One significant aspect of this is proving architectural metrics are satisfied. The method developed in this thesis demonstrates, very early in the design process, that a system architecture can be systematically described and analysed to show that the final architectural metric targets for functional safety will be met. The system architecture model proposed can be used to explain a very complex system to other engineers / managers in an easily understood concept diagram, specifically tailored to examine the achievable diagnostic coverage of potential failures in the electrical /electronic system. Once the first architectural model is established, the method analyses architectural metrics in a quantified way, identifies potential weak areas and guides the designer towards additional Plausibility Cross-checks, or, in some cases, completely different architectures to improve the architectural metrics. The metrics can be calculated very quickly in comparison to the level of detail required for the final design. This permits quantified analysis of each candidate architecture allowing an informed decision to be made on which architecture to take through to the final design process. Often, multiple solutions will meet functional requirements, however, only a subset will meet functional safety requirements. The necessity to build safety into products has always been an important aspect of overall system design. This method allows decisions based on justifiable data, early in a project timeline to influence design decisions and ensure that concepts are correct. As demonstrated through examples this is achieved with a high level of confidence
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