14,765 research outputs found
From Safety Analysis to Experimental Validation by Fault InjectionâCase of Automotive Embedded Systems
En raison de la complexitĂ© croissante des systĂšmes automobiles embarquĂ©s, la sĂ»retĂ© de fonctionnement est devenue un enjeu majeur de lâindustrie automobile. Cet intĂ©rĂȘt croissant sâest traduit par la sortie en 2011 de la norme ISO 26262 sur la sĂ©curitĂ© fonctionnelle. Les dĂ©fis auxquelles sont confrontĂ©s les acteurs du domaine sont donc les suivants : dâune part, la conception de systĂšmes sĂ»rs, et dâautre part, la conformitĂ© aux exigences de la norme ISO 26262. Notre approche se base sur lâapplication systĂ©matique de lâinjection de fautes pour la vĂ©rification et la validation des exigences de sĂ©curitĂ©, tout au long du cycle de dĂ©veloppement, des phases de conception jusquâĂ lâimplĂ©mentation. Lâinjection de fautes nous permet en particulier de vĂ©rifier que les mĂ©canismes de tolĂ©rance aux fautes sont efficaces et que les exigences non-fonctionnelles sont respectĂ©es. Lâinjection de faute est une technique de vĂ©rification trĂšs ancienne. Cependant, son rĂŽle lors de la phase de conception et ses complĂ©mentaritĂ©s avec la validation expĂ©rimentale, mĂ©ritent dâĂȘtre Ă©tudiĂ©s. Notre approche sâappuie sur lâapplication du modĂšle FARM (Fautes, Activations, RelevĂ©s et Mesures) tout au long du processus de dĂ©veloppement. Les analyses de sĂ»retĂ© sont le point de dĂ©part de notre approche, avec l'identification des mĂ©canismes de tolĂ©rance aux fautes et des exigences non-fonctionnelles, et se terminent par la validation de ces mĂ©canismes par les expĂ©riences classiques d'injection de fautes. Enfin, nous montrons que notre approche peut ĂȘtre intĂ©grĂ©e dans le processus de dĂ©veloppement des systĂšmes embarquĂ©s automobiles dĂ©crits dans la norme ISO 26262. Les contributions de la thĂšse sont illustrĂ©es sur lâĂ©tude de cas dâun systĂšme dâĂ©clairage avant dâune automobile. ABSTRACT :
Due to the rising complexity of automotive Electric/Electronic embedded systems, Functional Safety becomes a main issue in the automotive industry. This issue has been formalized by the introduction of the ISO 26262 standard for functional safety in 2011. The challenges are, on the one hand to design safe systems based on a systematic verification and validation approach, and on the other hand, the fulfilment of the requirements of the ISO 26262 standard. Following ISO 26262 recommendations, our approach, based on fault injection, aims at verifying fault tolerance mechanisms and non-functional requirements at all steps of the development cycle, from early design phases down to implementation.
Fault injection is a verification technique that has been investigated for a long time. However, the role of fault injection during design phase and its complementarities with the experimental validation of the target have not been explored. In this work, we investigate a fault injection continuum, from system design validation to experiments on implemented targets. The proposed approach considers the safety analyses as a starting point, with the identification of safety mechanisms and safety requirements, and goes down to the validation of the implementation of safety mechanisms through fault injection experiments. The whole approach is based on a key fault injection framework, called FARM (Fault, Activation, Readouts and Measures). We show that this approach can be integrated in the development process of the automotive embedded systems described in the ISO 26262 standard. Our approach is illustrated on an automotive case study: a Front-Light system
A synthesis of logic and bio-inspired techniques in the design of dependable systems
Much of the development of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, can be attributed to the application of advances in formal logic and its application to fault forecasting and verification of systems. In parallel, work on bio-inspired technologies has shown potential for the evolutionary design of engineering systems via automated exploration of potentially large design spaces. We have not yet seen the emergence of a design paradigm that effectively combines these two techniques, schematically founded on the two pillars of formal logic and biology, from the early stages of, and throughout, the design lifecycle. Such a design paradigm would apply these techniques synergistically and systematically to enable optimal refinement of new designs which can be driven effectively by dependability requirements. The paper sketches such a model-centric paradigm for the design of dependable systems, presented in the scope of the HiP-HOPS tool and technique, that brings these technologies together to realise their combined potential benefits. The paper begins by identifying current challenges in model-based safety assessment and then overviews the use of meta-heuristics at various stages of the design lifecycle covering topics that span from allocation of dependability requirements, through dependability analysis, to multi-objective optimisation of system architectures and maintenance schedules
A synthesis of logic and biology in the design of dependable systems
The technologies of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, have advanced in recent years. Much of this development can be attributed to the application of advances in formal logic and its application to fault forecasting and verification of systems. In parallel, work on bio-inspired technologies has shown potential for the evolutionary design of engineering systems via automated exploration of potentially large design spaces. We have not yet seen the emergence of a design paradigm that combines effectively and throughout the design lifecycle these two techniques which are schematically founded on the two pillars of formal logic and biology. Such a design paradigm would apply these techniques synergistically and systematically from the early stages of design to enable optimal refinement of new designs which can be driven effectively by dependability requirements. The paper sketches such a model-centric paradigm for the design of dependable systems that brings these technologies together to realise their combined potential benefits
Recommended from our members
Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS - a collection of Technical Notes Part 2
This report provides an introduction and overview of the Technical Topic Notes (TTNs) produced in the Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS (Tigars) project. These notes aim to support the development and evaluation of autonomous vehicles. Part 1 addresses: Assurance-overview and issues, Resilience and Safety Requirements, Open Systems Perspective and Formal Verification and Static Analysis of ML Systems. This report is Part 2 and discusses: Simulation and Dynamic Testing, Defence in Depth and Diversity, Security-Informed Safety Analysis, Standards and Guidelines
Developing a distributed electronic health-record store for India
The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India
Sharing Human-Generated Observations by Integrating HMI and the Semantic Sensor Web
Current âInternet of Thingsâ concepts point to a future where connected objects gather meaningful information about their environment and share it with other objects and people. In particular, objects embedding Human Machine Interaction (HMI), such as mobile devices and, increasingly, connected vehicles, home appliances, urban interactive infrastructures, etc., may not only be conceived as sources of sensor information, but, through interaction with their users, they can also produce highly valuable context-aware human-generated observations. We believe that the great promise offered by combining and sharing all of the different sources of information available can be realized through the integration of HMI and Semantic Sensor Web technologies. This paper presents a technological framework that harmonizes two of the most influential HMI and Sensor Web initiatives: the W3Câs Multimodal Architecture and Interfaces (MMI) and the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) with its semantic extension, respectively. Although the proposed framework is general enough to be applied in a variety of connected objects integrating HMI, a particular development is presented for a connected car scenario where driversâ observations about the traffic or their environment are shared across the Semantic Sensor Web. For implementation and evaluation purposes an on-board OSGi (Open Services Gateway Initiative) architecture was built, integrating several available HMI, Sensor Web and Semantic Web technologies. A technical performance test and a conceptual validation of the scenario with potential users are reported, with results suggesting the approach is soun
Improved thermal performance of a large laminated lithium-ion power battery by reciprocating air flow
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Thermal safety issues are increasingly critical for large-size laminated Lithium-Ion Batteries (LIBs). Despite a number of investigations conducted on the Battery Thermal Management System (BTMS) with reciprocating air-flow cooling, large laminated power LIBs are still not sufficiently investigated, particularly in the view of battery thermal characteristics. The present study investigates the thermal behaviors of an air-cooled NCM-type LIB (LiNi1âxâyCoxMnyO2 as cathode) from an experimental and systematic approach. The temperature distribution was acquired from different Depth of Discharge (DOD) by the infrared imaging (IR) technology. A reciprocating air-flow cooling method was proposed to restrict the temperature fluctuation and homogenize temperature distribution. Results showed that there was a remarkable temperature distribution phenomenon during the discharge process, the temperature distribution was affected by direction of air-flow. Forward air-flow (from current collector side to lower part of battery) was always recommended at the beginning of the discharge due to the thermal characteristics of the battery. After comprehensive consideration on battery temperature limit and cooling effect, the desired initial reversing timing was about 50% DOD at 3 C discharge rate. Different reversing strategies were investigated including isochronous cycles and aperiodic cycles. It was found that the temperature non-uniformity caused by heat accumulation and concentration was mitigated by reciprocating air-flow with optimized reversing strategy
- âŠ