Auswahl der wissenschaftlichen Literatur zum Thema „Automotive Embedded Systems“

The exponential growth of computer power is no longer limited to stand alone computing systems but applies to all areas of commercial embedded computing systems. The ongoing rapid growth in intelligent embedded systems is visible in the commercial automotive area, where a modern car today implements up to 80 different electronic control units (ECUs) and their total memory size has been increased to several hundreds of megabyte. This growth in the commercial mass production world has led to new challenges, even within the automotive industry but also in other business areas where cost pressure is high. The need to drive cost down means that every cent spent on recurring engineering costs needs to be justified. A conflict between functional requirements (functionality, system reliability, production and manufacturing aspects etc.), testing and maintainability aspects is given. Software reprogramming, as a key issue within the automotive industry, solve that given conflict partly in the past. Software Reprogramming for in-field service and maintenance in the after sales markets provides a strong method to fix previously not identified software errors. But the increasing software sizes and therefore the increasing software reprogramming times will reduce the benefits. Especially if ECU’s software size growth faster than vehicle’s onboard infrastructure can be adjusted. The thesis result enables cost prediction of embedded systems’ software reprogramming by generating an effective and reliable model for reprogramming time for different existing and new technologies. This model and additional research results contribute to a timeline for short term, mid term and long term solutions which will solve the currently given problems as well as future challenges, especially for the automotive industry but also for all other business areas where cost pressure is high and software reprogramming is a key issue during products life cycle.

Les véhicules modernes sont de plus en plus informatisés pour satisfaire les exigences de sureté les plus strictes et pour fournir de meilleures expériences de conduite. Par conséquent, le nombre d'unités de contrôle électronique (ECU) dans les véhicules modernes a augmenté de façon continue au cours des dernières années. En outre, les applications à calcul complexe offrent une demande de calcul plus élevée sur les ECU et ont des contraintes de temps-réel dures et souples, d'où le besoin d’une approche unifiée traitant les deux types de contraintes. Les architectures multi-cœur permettent d'intégrer plusieurs niveaux de criticité de sureté sur la même plate-forme. De telles applications ont été conçues à l'aide d'approches statiques; cependant, les approches dites statiques ne sont plus réalisables dans des environnements très dynamiques en raison de la complexité croissante et les contraintes de coûts strictes, d’où la nécessite des solutions plus souples. Cela signifie que, pour faire face aux environnements dynamiques, un système automobile doit être adaptatif; c'est-à-dire qu'il doit pouvoir adapter sa structure et / ou son comportement à l'exécution en réponse à des changements fréquents dans son environnement. Ces nouvelles exigences ne peuvent être confrontées aux approches actuelles des systèmes et logiciels automobiles. Ainsi, une nouvelle conception de l'architecture électrique / électronique (E / E) d'un véhicule doit être développé. Récemment, l'industrie automobile a convenu de changer la plate-forme AUTOSAR actuelle en "AUTOSAR Adaptive Platform". Cette plate-forme est développée par le consortium AUTOSAR en tant que couche supplémentaire de la plate-forme classique. Il s'agit d'une étude de faisabilité continue basée sur le système d'exploitation POSIX qui utilise une communication orientée service pour intégrer les applications dans le système à tout moment. L'idée principale de cette thèse est de développer de nouveaux concepts d'architecture basés sur l'adaptation pour répondre aux besoins d'une nouvelle architecture E / E pour les véhicules entièrement électriques (VEF) concernant la sureté, la fiabilité et la rentabilité, et les intégrer à AUTOSAR. Nous définissons l'architecture ASLA (Adaptive System Level in AUTOSAR), qui est un cadre qui fournit une solution adaptative pour AUTOSAR. ASLA intègre des fonctions de reconfiguration au niveau des tâches telles que l'addition, la suppression et la migration des tâches dans AUTOSAR. La principale différence entre ASLA et la plate-forme Adaptive AUTOSAR est que ASLA permet d'attribuer des fonctions à criticité mixtes sur le même ECU ainsi que des adaptations bornées temps-réel, tant dis que Adaptive AUTOSAR sépare les fonctions temps réel critiques (fonctionnant sur la plate-forme classique) des fonctions temps réel non critiques (fonctionnant sur la plate-forme adaptative). Pour évaluer la validité de notre architecture proposée, nous fournissons une implémentation prototype de notre architecture ASLA et nous évaluons sa performance à travers des expériences<br>Modern vehicles have become increasingly computerized to satisfy the more strict safety requirements and to provide better driving experiences. Therefore, the number of electronic control units (ECUs) in modern vehicles has continuously increased in the last few decades. In addition, advanced applications put higher computational demand on ECUs and have both hard and soft timing constraints, hence a unified approach handling both constraints is required. Moreover, economic pressures and multi-core architectures are driving the integration of several levels of safety-criticality onto the same platform. Such applications have been traditionally designed using static approaches; however, static approaches are no longer feasible in highly dynamic environments due to increasing complexity and tight cost constraints, and more flexible solutions are required. This means that, to cope with dynamic environments, an automotive system must be adaptive; that is, it must be able to adapt its structure and/or behaviour at runtime in response to frequent changes in its environment. These new requirements cannot be faced by the current state-of-the-art approaches of automotive software systems. Instead, a new design of the overall Electric/Electronic (E/E) architecture of a vehicle needs to be developed. Recently, the automotive industry agreed upon changing the current AUTOSAR platform to the “AUTOSAR Adaptive Platform”. This platform is being developed by the AUTOSAR consortium as an additional product to the current AUTOSAR classic platform. This is an ongoing feasibility study based on the POSIX operating system and uses service-oriented communication to integrate applications into the system at any desired time. The main idea of this thesis is to develop novel architecture concepts based on adaptation to address the needs of a new E/E architecture for Fully Electric Vehicles (FEVs) regarding safety, reliability and cost-efficiency, and integrate these in AUTOSAR. We define the ASLA (Adaptive System Level in AUTOSAR) architecture, which is a framework that provides an adaptive solution for AUTOSAR. ASLA incorporates tasks-level reconfiguration features such as addition, deletion and migration of tasks in AUTOSAR. The main difference between ASLA and the Adaptive AUTOSAR platform is that ASLA enables the allocation of mixed critical functions on the same ECU as well as time-bound adaptations while adaptive AUTOSAR separates critical, hard real-time functions (running on the classic platform) from non-critical/soft-real-time functions (running on the adaptive platform). To assess the validity of our proposed architecture, we provide an early prototype implementation of ASLA and evaluate its performance through experiments

Embedded systems are a crucial part of modern vehicles today and are used widely by the automotive industry to control safety-critical functions. To verify that the software will work correctly, formal verification can be used to prove that the code will always behave correctly according to some specification. This report will look into how to formulate the specification in such a way that it is easy to use, consistent and can be used efficiently for code verification. Two different models are looked into in the report, and applied to real automotive embedded code. From this, conclusions are made about the different models.<br>Inbäddade system är en viktig del av moderna motorfordon idag,  och används av stora delar av fordonsindustrin för att kontrollera säkerhetskritiska funktioner. För att verifiera att mjukvaran fungerar korrent, kan man använda formell verifiering för att bevisa att koden alltid fungerar korrekt enligt en specifikation. Den här rapporten kommer att studera hur man bäst formulerar en sådan specifikation så att den är lätt att använda, konsekvent och kan användas effektivt för kodverifiering. Två olika modeller används i rapporten, och appliceras till en riktig kodmodul från fordonsindustrin. Från detta görs sedan slutsatser om de olika modellerna.

La conception des systèmes embarqués est une tâche complexe. Les ingénieurs sont confrontés à divers contraintes liées à la technologie, au coût,à la complexité et aux contraintes de sécurité. Toutes ces contraintes ont un grand impact sur l’architecture du système et par conséquence sur le coût final. Nous proposons dans cette thèse une approche pour la conception des système et l’optimisation de l’architecture guidée par les contraintes de sécurité et de coût. Elle s’agit d’une approche de synthèse de l’architecture qui prend en compte les contraintes de sécurité dans le contexte du standard ISO 26262. Elle permet, d’une part, d’atteindre une architecture préliminaire du système en choisissant les éléments de l’architecture permettant de réduire le coût global. D’autre part, elle conduit à une allocation des fonctions aux éléments de l’architecture qui respecte les contraintes liées aux niveaux de sécurité et les défaillances de ces éléments. Nous utilisons des algorithmes exhaustive et génétique pour l’exploration de l’espace de conception. En l’appliquant sur un cas d’étude industriel, nous démontrons sa contribution pour parvenir à la conception conforme et sa capacité à réduire les coûts entraîne par les contraintes de sécurité<br>The embedded system design is a challenging task. The engineers are faced with technological, cost, complexity and safety constraints. These constraints have a big impact on the system architecture and consequently on the final cost. we propose in this thesis an approach for system design and architecture optimization driven by safety and cost constraints. It consists of an architecture synthesis approach that takes into account the safety constraints in the ISO 26262 context. It allows, at one hand, to reach a system preliminary architecture by choosing the architecture elements that reduce the overall cost. On the other hand, it leads to a functions mapping that respects the safety constraints related to the integrity levels and to the dependent failures. We use exhaustive and genetic algorithm for the design space exploration. By applying it on an industrial study-case we demonstrate its contribution in reaching compliant design and its capability in reducing the safety constraints costs

Modern vehicles are equipped with electrical and electronic systems that implement highly complex functions, such as anti-lock braking, cruise control, etc. To realize and integrate such complex embedded systems, the automotive development process requires an updated methodology that takes into consideration the system’s intricate features and examines both their functional and extra-functional requirements. Early design artifacts like architectural models represent convenient abstractions for reasoning about the system’s structure and functionality. In this context, the EAST-ADL language has been developed as a domain-specific architectural language that targets the automotive industry and is aligned with the AUTOSAR automotive standard. To fully enjoy the benefits of these abstract system descriptions, architectural models need to be integrated into a model-driven development framework that enables also verification by, e.g., model checking and model-based testing. One major drawback in developing such a framework lies in the fact that architectural models, while capturing the system’s structure and inter-component communication, often lack direct means to represent the desired internal behavior of the system in a semantically well-defined way. To overcome this, one needs to provide means of integrating both structural as well as behavioral information, desirably within the same framework backed by formal semantics, in order to enable the model’s formal verification. In this thesis, we propose a tool-supported integrated formal modeling and verification framework tailored for automotive embedded systems that are originally described in the EAST-ADL architectural language. To achieve this, we first provide formal semantics to the architectural model and its behavior by proposing an equivalent formal description as a network of timed automata. This enables us to analyze the resulting network of timed automata formally by model checking, using both the UPPAAL PORT and UPPAAL SMC model checkers. UPPAAL PORT is providing efficient component-aware verification via the partial order reduction technique, while UPPAAL SMC is extending UPPAAL with statistical model-checking capabilities via probabilistic algorithms. We focus the analysis on functional and timing requirements, but also on the system’s resource usage with respect to different resources specified in the model, such as memory and energy. In an attempt to narrow the gap between the original architectural model and the eventual system implementation, we define an executable semantics of the UPPAAL PORT components that guarantees that the implementation preserves the invariant properties of the model. Assuming a system implementation that conforms to the formal model, we investigate how to provide test cases suitable for the eventual verification of such implementation, by exploiting the model checker’s ability to generate witness traces for reachability verification. Such a witness trace represents a execution of the system from its initial state to the goal state encoded by the reachability property, and becomes our abstract test case. By pairing the automated model-based test case generator with an automatic transformation from the abstract test cases to Python scripts, we enable the execution of the generated Python scripts on the system under test, which ends up in pass/fail testing verdicts. Dependency analysis is a method that is able to identify crucial intra- and inter-component dependencies early in the system’s development life cycle, if applied on architectural models. In this thesis, we also investigate how such dependencies, resulting from applying dependency analysis on EAST-ADL models, can be exploited during formal verification in order to reduce the verified state-spaces during model checking. The framework is supported by the ViTAL tool and its applicability is shown on an automotive industrial prototype, namely a Brake-by-Wire system.

The car is the most common vehicle in the world. Millions of cars are produced annually. In order for each car to find its buyer, car companies are forced to constantly improve the design of the car. Modern models are emerging, new car systems are being developed and implemented. All this is accompanied by a huge flow of information, in which it is easy to get lost. This master’s work is devoted to the trace analysis and connection of two different files. The paper proposes a developed algorithm of trace analysis for some functions of the vehicle in the C++ programming language. The files that we use to trace analysis relate to the model and the final result of its simulation.EATOP is a tool with which a model based on the EAST-ADL language was developed. Adapt is an event simulator with which our model of automotive functionality was simulated. The purpose of the study is to identify possible ways to meet timing requirements. The work is carried out in collaboration with Volvo Group Truck Technology. This company provided the LogFile, which presents results of the simulation, and model. We get an analysis of performance, one of the ways to trace data and timing. The results of our implementation are presented and discussed.

The number of electronic control units in heavy-duty vehicles has grown dramatically overthe last few decades. This has led to the use of communication buses to reduce the complexityand weight of the networks. There are reasons to believe that the de facto standardcommunication interface in the automotive industry, the Controller Area Network, is obsoletein some areas. Hence an evaluation of available communication interfaces is needed.This study focuses on lower levels of the Open Systems Interconnect (osi) model. Initially atheoretical study is presented in order to give an overview of automotive embedded systemsin general and different communication interfaces in particular. Ethernet and FlexRay areidentified as two interfaces of interest for future use in Scanias vehicles. The former is new inautomotive applications but is believed to become popular over the years to come. A possibleuse of this interface could be as a backbone to take the load off other interfaces. The use ofFlexRay in Scanias vehicles is limited because of the modular system used and the staticscheduling needed. It could however be used between mandatory ecus where the nodes andthe messages are all known beforehand.The report also contains the result from emission measurements on a number of interfacesperformed using a stripline antenna in a shielded enclosure. Strong conclusions can not bedrawn since it’s hard to tell what the transceivers, circuit boards and interfaces contributedto in the spectra with the method used. The FlexRay hardware is worse than for the otherinterfaces. Similarities can be seen between low-speed and high-speed can but it could becharacteristics of the transceivers used rather than the interface itself.

With ever increasing contents (safety, driver assistance, infotainment, etc.) in today's automotive systems that rely on electronics and software, the supporting architecture is integrated by a complex set of heterogeneous data networks. A modern automobile contains up to 100 ECUs and several heterogeneous communication buses (such as CAN, FlexRay, etc.), exchanging thousands of signals. The automotive Original Equipment Manufacturers (OEMs) and suppliers face a number of challenges such as reliability, safety and cost to incorporate the growing functionalities in vehicles. Additionally, reliability, safety and cost are major concerns for the industry. One of the important challenges in automotive design is the efficient and reliable transmission of signals over communication networks such as CAN and CAN-FD. With the growing features in automotives, the OEMs already face the challenge of saturation of bus bandwidth hindering the reliability of communication and the inclusion of additional features. In this dissertation, we study the problem of optimization of bandwidth utilization (BU) over CAN-FD networks. Signals are transmitted over the CAN/CAN-FD bus in entities called frames. The signal-to-frame-packing has been studied in the literature and it is compared to the bin packing problem which is known to be NP-hard. By carefully optimizing signal-to-frame packing, the CAN-FD BU can be reduced. In Chapter 3, we propose a method for offset assignment to signals and show its importance in improving BU. One of our contributions for an industrial setting is a modest improvement in BU of about 2.3%. Even with this modest improvement, the architecture's lifetime could potentially be extended by several product cycles, which may translate to saving millions of dollars for the OEM. Therefore, the optimization of signal-to-frame packing in CAN-FD is the major focus of this dissertation. Another challenge addressed in this dissertation is the reliable mapping of a task model onto a given architecture, such that the end-to-end latency requirements are satisfied. This avoids costly redesign and redevelopment due to system design errors.<br>Ph. D.

Under det senaste årtiondet har mängden kod som används i fordon ökat exponentiellt. På grund av detta skiftar bilindustrin mot att vara software-intensive. Som i de flesta mjukvaruintensiva branscher, drivs systemets utveckling i snabbtakt av marknadens krav. Återanvändningen av värdefull legacy-code är en effektiv metod för att minska tiden till marknaden. Vid Scania är mjukvaruutveckling främst baserat på en omfattande legacy plattform. I detta sammanhang är det nödvändigt för systemförståelse, återanvändning, underhåll, systemverifiering och säkerhetsanalys att upprätthålla en omfattande beskrivning av mjukvaruarkitekturen. Men för att skapa en sådan beskrivning behövs ytterligare resurser, och det är svårt att upprätthålla följdriktighet med föränderliga implementationer. Ett sättet att lösa detta problem är Reverse Engineering. Mjukvaruarkitekturen kan hämtas automatiskt från inbäddad källkod och presenteras på ett sätt som ärspecifikt för domänen.Denna avhandling är en del av ESPRESSO-projektet. En del av ESPRESSOprojektetgår ut på att återvinna lastbilens mjukvaruarkitektur från källkoden.Syftet med detta arbete är att utöka täckningen av arkitektursåterhämtningengenom att lägga till kopplingar mellan hård- och mjukvara. För att uppnå detta haren hårdvarumodell, inspirerad av EAST-ADL hårdvaru-meta-modell, utvecklats och använts i den befintliga infrastrukturen. Hårdvarumodellen användes för att samla in och bearbeta information för att lagra den i Neo4J grafdatabas. Förslag på användargränssnitttillhandahölls för interaktion med databasen, men implementationen var inte en del av examensarbetet. Utmaningarna under arbetets gång uppstod främst på grund av det faktum attvarje Scania-avdelning använder sin egen partiella systemmodell av lastbilsarkitekturen.Flera vyer och begrepp från olika avdelningar skulle slås samman i en enda modell. För att uppnå validering till en viss grad, användes databasen i samband med användargränssnittet. Gränssnittet var medelvärdet med vilket några scenarier kontrollerades både mot intern teknisk dokumentation och ingenjörer som arbetar med dessa system.<br>From the past decade onward, a trend has been seen in which the amount of code used in a vehicle is increasing exponentially. Because of this growing factor, the automotive industry is gradually shifting towards software-intensive. As in most software-intensive industries, the system’s evolution is driven at a fast pace by the market’s requirements. The re-usability of valuable legacy code is an effective method of reducing the time to market. In Scania, software development is predominantly based on an extensive legacy platform. In this context, maintaining a comprehensive software architecture description is necessary for system understanding, re-usability, maintenance, system verification and safety analysis. However, to develop such a description involves additional resources, and it is difficult to maintain consistency with evolving implementations. One way to solve this problem is Reverse Engineering. The software architecture can be retrieved automatically from embedded source code and presented in a manner specific to the domain. This thesis is part of the ESPRESSO project. One part of ESPRESSO is to recover the truck’s software architecture from source code. The objective of this work is to extend the coverage of the architecture recovery by adding connections between hardware and software. To achieve this, a hardware model, inspired by the EAST-ADL hardware meta-model, has been developed and employed in the existing infrastructure. The hardware model was used to gather and process information in order to store it to the Neo4J graph database. User interface suggestions were provided for querying, but the implementation was not part of the thesis. The challenges facing this work arose mainly due to the fact that each Scania department uses its own partial system model of the truck’s architecture. Multipleviews and concepts from different departments had to be merged in a single model. To achieve validation to a certain degree, the populated database was used in connection with the user interface. The interface was the mean by which a few scenarios were checked both against internal technical documentation and the engineers that are working with those systems.