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2015 | Buch

15. Internationales Stuttgarter Symposium

Automobil- und Motorentechnik

herausgegeben von: Michael Bargende, Hans-Christian Reuss, Jochen Wiedemann

Verlag: Springer Fachmedien Wiesbaden

Buchreihe: Proceedings

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Über dieses Buch

Das Mobilitätsverhalten in unserer Gesellschaft wandelt sich und mit ihm die Anforderungen an das Kraftfahrzeug. In Zeiten von Klimawandel durch steigende Luftverschmutzung, Verknappung und Verteuerung fossiler Energien aber auch zunehmender Digitalisierung verändern sich die aktuellen Fahrzeugkonzepte und entwickeln sich weiter. Das Auto der Zukunft muss sparsam, umweltfreundlich, sicher, komfortabel, digital vernetzt und automatisiert sein. Gleichzeitig soll es das Bedürfnis nach Individualität erfüllen, den Fahrer emotional ansprechen und so den Reiz erzeugen, das Fahrzeug sein Eigen nennen zu wollen. Dies ist ein Balanceakt, der die Automobilindustrie vor sehr große Herausforderungen stellt.

Inhaltsverzeichnis

Frontmatter
Formula 1: The show must go on?

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Friedrich Indra
The Audi V6 TDI for Le Mans

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Ulrich Baretzky, H. Diehl, W. Kotauschek, S. Dreyer, A. Schneider, P. Kuntz, M. Mühlmeier
Anti-combustion deposit fuel development for 2009 Toyota Formula One racing engine

There are many advantages of the development for the motorsports engines. One example, thanks to high performance, even very small phenomenon such as deterioration of engine performance can be caught. This is a little bit old story, however very interesting how the combustion chamber deposit affects the engine performance deterioration. Toyota participated in Formula One Racing (F1) from 2002 to 2009. As a result of the downturn in the world economy, various engine developments within F1 were restricted in order to reduce the cost of competing in F1. The limit on the maximum number of engines allowed has decreased year by year. Toyota focused on the engine performance deterioration due to the combustion chamber deposits. In 2009, Toyota was successful in reducing around 40% of the deterioration by making combustion chamber cleaner in cooperation with ExxonMobil.

Kazuo Takeuchi, Peer Pfeilmaier
PERSIST – A scalable software architecture for the control of diverse automotive hybrid topologies

Software development for modern powertrains requires the handling of increasing functional complexity at shorter development cycles and a high quality level. Hybrid vehicles are especially affected since multiple components and functions need to interact. Appropriate software architectures is the core lever to ease software reuse and ensure quality already during the specification phase. This article presents an approach where hybrid control software functions are developed inside an architecture framework with consistent design guidelines based on a quality model, a methodology how to derive the architecture from required control features and finally a verification and validation strategy to ensure quality already on architecture level. Also, concrete figures will be shown for a series development project.

Johannes Richenhagen, Hariharan Venkitachalam, Stefan Pischinger, Axel Schloßer
Predictive operation strategy for hybrid vehicles

The hybrid electric vehicle (HEV) is considered to be one of the best solutions for the automobile industry, to cope with the diminishing oil resources and environmental problems, by achieving low emissions and fuel consumption. The HEV is powered by two sources, composed of an internal combustion engine (ICE) and its transmission as well as one or two electric machines (EM), battery pack and converters. The additional electric power system brings further degrees of freedom for powertrain arrangement and operation, which lead to a challenge the research and development. A number of publications [Radke13] [Schroeter13] [Albers13] [Ambühl09] [Stiegeler08] discussed predictive operation strategies with global optimization methods, e.g. dynamic programming. However, the computing and memory requirements of the global optimization method are significantly higher than those from a heuristic optimization method, thus rendering its complete application in onboard electronic control units (ECU) almost impossible. Some predictive operation strategies are combinations of global optimization and heuristic optimization method [Katsargyri09] [LaSch13]. In order to develop an online operation strategy for HEV by using the traffic context for semi-automated driving, a heuristic method is applied in this work and with consideration of longitudinal dynamics. Beside the fuel consumption the driving comfort and operation complexity are considered in this method to be optimized, which is lacked in many publications. This work presents the method and simulation results of this strategy. The details about real time capability will be done in the future work.

Jue Wang, Hermann Koch-Groeber
Concept analysis & system design of a hybrid electric vehicle with virtual test driving

The electrification of automotive powertrains is one of the key factors of meeting the development targets for fuel consumption and emissions. Both with and without the use of plug-in technology, powertrain hybridization assists the internal combustion engine in operating in optimal conditions and enables the recuperation of kinetic energy during braking. The technology thus helps to increase fuel efficiency and reduce exhaust gas emissions, and – depending on the concept – offers the possibility of running in full electric mode to avoid local exhaust emissions without the range limitations of full electric vehicles. Besides these aspects, powertrain electrification offers many possibilities for increasing longitudinal and lateral vehicle dynamics [1]. However, in view of the wide range of variants and concepts of hybrid electric vehicles, finding optimized setups often poses a challenge due to the varying boundary conditions, different cases of application, as well as interdependent vehicle subsystems. In this case, optimization processes and tools assist in finding the best compromise, taking into account all the various constraints.

Christian Donn, Michael Folie, Valerie Bensch, Johannes Friebe, Jonathan Spike, Paul Goossens, Christine Schwarz
Operating strategy for optimized CO2 and NOx emissions of diesel-engine mild-hybrid vehicles

Over the last decades the pollutant emissions of passenger-car diesel engines have been reduced significantly. Particulate emissions were cut back to a minimum with the introduction of diesel particulate filters. The upcoming EU6 exhaust regulation will further reduce the nitrogen-oxide emissions. In many cases an efficient nitrogenoxide exhaust-gas aftertreatment system will be installed. In the years to come, however, the requirements for passenger-car diesel engines will become even more demanding in various regards. On the one hand, current discussions are focusing on the registration of pollutant emissions produced during real driving (RDE, real driving emissions). Compared to the currently applicable European driving cycle for passenger cars future test cycles will include stricter requirements regarding output and transient operations. On the other hand, significant further reductions of CO

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emissions must be achieved for all passenger cars. For this purpose, improvements on the diesel engine (e.g. reduced friction, further development of more efficient combustion methods, etc.) will be complemented by various approaches of hybridization. Robert Bosch GmbH is running comprehensive studies on the optimization of the operating behaviour of hybridized diesel-engine powertrains. The aim of these studies is to develop scalable engine-control functions resulting in the efficient and optimum matching of the diesel engine and the hybridization concept. The functions presented in this paper support the significant further reduction of the NO

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emissions of diesel passenger cars especially under real driving conditions while leading only to minor fuel consumption penalties.

Marcel Wüst, Michael Krüger, Dirk Naber, Lisa Cross, Andreas Greis, Sebastian Lachenmaier, Ingo Stotz
Einführung in das Geschäftsfeld Automotive am Fraunhofer IPA

Durch den systematisch-interdisziplinären Ansatz gilt das Fraunhofer IPA in ausgewählten Kompetenzfeldern als renommierter Partner für die Automobilindustrie. Die übergreifende Funktion des Geschäftsfeldes ermöglicht es, Kompetenzen verschiedener Abteilungen zu kombinieren. So werden verschiedene Dienstleistungen über den gesamten Projektzyklus entlang der Wertschöpfungskette angeboten. An den Schnittstellen zwischen den Anforderungen der Branche und den Kompetenzen der Abteilung wird die Chance, neue Projektideen und Projekte zu initiieren, genutzt.

Ivica Kolaric
Electrochemical capacitors for electromobility: A review

Scarcity of resources and emissions increasingly demand sustainable mobility concepts. To compete with conventional vehicles on the market, electromobility requires high-performance rechargeable energy storage systems ideally equipped with high energy and power density, cost-efficiency [1], long lifetimes, extraordinary reliability [2] and safety as well as minimal environmental impact [3]. The last decades have triggered an increasing interest in capacitive energy storage, an electrical storage mechanism found in electrochemical capacitors (ECs), widely called supercapacitors. There are an increasing number of concepts for automobile energy storage systems which make use of this technology [4]. Electrochemical capacitors are already used in markets around the world and have experienced a rapid growth over the past years. This paper provides a general overview of electrochemical capacitors for electromobile applications. It covers their distinctive features, their components, structures and compositions, current and future applications as well as the latest challenges and achievements in research and development.

Sabrina Hellstern, Peter Kitzler, Raphael Neuhaus, Ivica Kolaric
Nanocarbons in aluminium alloys for automotive applications – Advantages, challenges and outlook

The use of reinforced metallic materials in automotive sector is gaining momentum and more and more automobile manufacturing companies are introducing advanced smart materials within their production lines. The reasons is, that the car manufacturers have to reduce the weight of the automobiles to fulfil strict fuel economy requirement in order to reduce the emission of greenhouse gases, while the demands of the consumers for improved safety, advanced electronic systems for interior comforts, navigation and entertainment would lead to a raised weight. To meet these challenges, car manufacturers are turning to light weight metals as a solution. Besides reducing mass, using advanced metal-matrix composites can also provide improved reliability and efficiency. The concept of MMCs is not new, though the processing challenges -compared to their polymer matrix analogues - have impeded their advancement somewhat so far. Since the discovery of CNTs in the early 90s there has been a raising interest in using nanocarbons in MMCs. Recent advances in carbon nanotubes synthesis and their relative comparable costs have opened the opportunity for the inclusion of CNTs to improve current technologies by increasing their mechanical performance.

Raphael Addinall, C. Hubrich, Ivica Kolaric
MBS-integrated control of longitudinal and lateral dynamics for riding comfort simulation

In modern vehicle development processes simulations of virtual roads are an essential part for the analysis of riding comfort. Especially the combination of multi-body simulations (MBS) and 3D-simulators for the true experience of vibrations creates a big opportunity of improving design results and reducing costs at the same time in an early development stage. However, the requirements and restrictions of MBS and the input of its results into 3D-simulators strongly complicate the development of a virtual, MBS-integrated driving dynamics controller. Since standard approaches can’t be used here, a new control solution including a parameterized anti-windup law for the longitudinal dynamics as well as a special gain-scheduled law for the lateral dynamics is presented. At the end, the control algorithms are applied to realistic car models and different simulation load cases like driving on virtual bumpy roads or braking maneuvers – always with the main goals of good vibrational comfort and a true experience in the 3D-simulator in mind.

Michael Herrnberger, Victor Fäßler
Advanced model-based control functions to design the longitudinal vehicle dynamics in passenger cars

This paper presents a novel approach to design the longitudinal vehicle dynamics with model-based control functions implementable in an ECU. It is shown that an observer, based on a physically motivated model, is capable to capture the longitudinal vehicle behavior reflected by the half shaft torque very well. Thus no additional hardwaresensor is required. Different approaches of observers were evaluated on a real vehicle and obtained good results. Comfort reducing drive train reactions (e.g. drive train oscillations, effect of backlash, etc.) can be minimized by providing an estimated half shaft torque to the control functions. Furthermore this approach allows to implement objective criteria of drivability within online algorithms, to cope with the tradeoff between comfort and agility. Thereupon the acceleration of a passenger car can be directly designed in conformity with human perception within closed-loop control.

Christoph André Malonga Makosi, Frank Uphaus, Frank Kirschbaum, Julien Pillas
Methodological approaches for the development of a test facility to represent system dynamic aspects in automotive engineering

In the future, the development of motor vehicles will be shaped more than in the past by new and more stringent requirements from legislators and customers. In the course of this eventuality, the main focus is quality and product safety. Furthermore, shorter development cycles, increasing modularization, increasing number of derivatives, and simultaneously increasing system complexity will additionally complicate the development process. From these findings stems the desire for cost-benefit optimized development processes that require less prototypes, have high-performance simulation methods, and thereby allow a clear risk management. This requires a careful selection of test methods and test facilities. In the present paper some first general requirements and constraints are determined for automotive engineering development areas influenced by system dynamics. This is specifically dis-cussed in the development areas of driving dynamics, ride comfort, and durability. Finally, specific requirements for simulative and experimental methods are derived and individual solutions developed. In the ensuing synthesis these requirements are compared with each other, evaluated, and set in relation with other constraints of building, location, and process specifications, so that new test facility and simulation concepts for components, assemblies, and a total vehicle testing can be derived. The resulting 12 test rig concepts are then aggregated in a further development stage through constructed space studies, connecting and operating concepts in a layout for a vehicle technical test center. A method of creating an interface between the building and test facility is presented. The paper provides further insight into the design and planning process of the Vehicle Test Center, discusses the vibration control separation at high spatial proximity of the test rigs, and pro-vides the thus created opportunities for research activities on system dynamic aspects in the motor vehicle. Finally, excerpts for results of the planning process will be presented.

Kay Büttner, André Stoller, Günther Prokop
A methodology for the optimized design of an E/E architecture component platform

In recent years, more and more cars are built upon mechanical platforms and, thus, enable to reduce development time and cost due to increased reuse of already developed mechanical components like combustion engines or suspensions. But, to support a seamless platform-based development of the whole car, also the Electric/Electronic (E/E) architecture and the included vehicle electronics have to be build based on E/E architecture component platforms. There, component manifestations like different hardware versions of an Electronic Control Unit (ECU) should be reused whenever possible and beneficial. To enable this, the work at hand proposes to use a multi-variant Design Space Exploration that enables an automatic multi-objective optimization of the E/E architecture component platform as well as the individual variants’ E/E architectures at once. This allows to enhance the E/E architecture design process by means of design automation approaches. Based on previous work proposing a symbolic encoding of the overall optimization problem, practically relevant design space restrictions are proposed and efficiently integrated in an existing multi-variant problem encoding. In combination with the multi-objective optimization, this enables the developer to ponder between several important design objectives while automatically ensuring the validity of the obtained solutions with respect to real-world design restrictions. Within the context of an INI.FAU project, the proposed methodology is used to model real-world use cases from the automotive safety domain and enables to automatically optimize upcoming vehicle safety-architecture component platforms for future cars.

Sebastian Graf, Michael Glaß, Jürgen Teich, Daniel Platte
EcoGuru – A system for the integrated management of electrified mobility systems

Ecological and social reasons, e. g. CO2 emission or living quality in cities, enforce new holistic solutions for mobility. The use of electricity in the drivetrain is seen as one of the key success factors for establishing such solutions. While operating costs of electrical vehicles are satisfying, total cost of ownership (TCO), due to high prices and limited lifetime of batteries, are still a formidable challenge. Company fleets of vehicles handled as a holistic mobility solution allow considerable improvement of the situation. This can be achieved by implementing suitable enterprise fleet processes in real time and creating integrated value added services (IVAS). EcoGuru is a real-time capable software for holistic enterprise mobility system management which was developed by the application center KEIM. It offers integrated value added services (IVAS) like vehicle booking together with charging scheduling. The application center KEIM, a division of Fraunhofer IAO, has a specialised focus on the development and research of information and communication technology (ICT) systems and interfaces to find out best practices for future mobility systems. EcoGuru successfully passed its proof of setup in the ″Living Lab eFleet″ (LLEF). The Living Lab eFleet contains one of the biggest electrical vehicle fleet and charging infrastructure in Germany, located at Fraunhofer Campus in Stuttgart. This mobility system contains electric vehicles (EV) and charging stations which can be monitored and controlled in in real time. In the year 2015 this hardware should be extended by a Micro Smart Grid (MSG). A local photovoltaic and wind plant in combination with local energy storages should allow the usage of local produced electrical power for charging the EV. The reference architecture of EcoGuru, the realised IVAS in relation with their benefits found out in the LLEF together with the purpose of game mechanics to influence the user behaviour and the mobility system dynamics (Gamified Corporate Carsharing) are presented in the following chapters. 218

Dionysios Satikidis, Kavivarman Sivarasah, Kristian Lehmann, Ilko Hoffmann, Gabriele Scheffler
Security in vehicle networks of connected cars

More than 20 years ago, the invention of the CAN bus built the basis of our today’s cars networks. At the beginning, only two to three ECUs (electronic control units) were connected. But nowadays we have complex networks of sensors and actors with different bus systems like CAN, LIN, FlexRay, MOST or Ethernet. The interaction of functions in this distributed network is an essential part for our today’s modern cars with all features for safety and comfort. Besides the further development of innovative sensors like radar and camera systems and the analysis of the signals in highly complex ECU systems, the connected cars will be a driving factor for tomorrow’s innovation. Internet connections will not only provide the need for information to the passenger. Functions like eCall or communication between cars or car to infrastructure (car2x) shows high potential to revolution the individual traffic. This includes the improvement of the traffic flow controlled by intelligent traffic lights, OEM backend systems to provide latest mapping data, warnings from roadside stations or brake indication of adjacent cars. This builds the basis for enhanced driver assistant systems and automated driving. But the connection to the outer world bears also the risk for attacks to the car.

Armin Happel, Christof Ebert
Advantages and challenges of lean operation of two-stroke engines for hand-held power tools

Today, hand-held power tools facilitate specific jobs in many application areas, e.g. garden/landscape maintenance, construction industry and forestry. This market is highly diversified and demands special tools which are optimized for each application purpose (brush cutters, chain saws, etc.). Most of them are driven by two-stroke SI (spark ignition) engines equipped with a carburetor. High specific power, simplicity, low weight, low costs and compact design are characteristics of these two-stroke engine powered tools. The use of piston control or reed valves, oil-in-gasoline lubrication and loop scavenging is well established. Significant improvements regarding emission behavior have been achieved in recent years due to stratified scavenging systems which have become a standard. In order to respond to future challenges like continuing emissions and fuel consumption reduction the present engine technology has to be further developed. Several research areas are considered in order to improve the overall product, i.e. injection systems, ECU hardware and functionality, exhaust gas after-treatment and combustion systems [1, 3, 4, 5]. To date, the research on combustion systems for hand-held power tools tended to focus on rich mixture setting. The demands for high power and quick engine response are met by a rich mixture in part load and WOT (wide open throttle) operation. Moreover, the rich mixture reduces NOx formation and reduces thermal stress.

Stephan Meyer, Armin Kölmel, Tim Gegg, Alexander Trattner, Helmut Grassberger, Oliver Schögl, Stephan Schmidt, Roland Kirchberger, Helmut Eichlseder
Quality characteristics of hydraulic injection quantity measurements – Transferability of non-engine tests to real systems

In the development of future engine technologies with continually lower emissions in connection with rising performance requirements, the injector represents a key component. In today’s common rail systems, high rail pressures and multiple injections are state of the art. Requirements for a precise and reproducible metering of quantities injected, particularly in the field of microquantities, are therefore continually increasing. These demands require high quality measuring techniques for injection systems. Injection quantity measurements are performed in a laboratory, which can recreate the real conditions in the engine only within certain limits. In addition, the measuring device affects injection. The measurement of injectors is the basis for testing singlecylinder and multi-cylinder engines and input parameters for simulations. In order to guarantee good transferability of laboratory measurements to real systems, any influencing variables that must be taken into account here will be investigated. The aim is to minimize the deviations of the systems from one another and thus to improve the quality of the results.

Kerstin Rensing, Thorsten Hergemöller, Franz-Paul Gulde
Software system control of a dual-injection system for future emission standards

In order to meet future emission standards for gasoline vehicles, several complex approaches have been developed in the recent past by original equipment manufacturers (OEMs). A dual-injection system, which has a combination of a port fuel injection and a direct injection, is counted among these increasing numbers of complex developments for which new and extensive software implementations are required [1]. Bosch Engineering GmbH has developed a software control in the Bosch Engine Management System (EMS) ME17 for a dual-injection system with the main challenge of meeting future emission standards. Whereas each single-injection system is well-known and established in its individual use in a vehicle and its corresponding software implementation, the combination is still rarely available, much less with the increased emission limits of future emission standards (EU6 and later). While a port fuel injection offers better fuel management compared with a direct-injection system, the advantages of a direct injection have to do with responsiveness and overall fuel efficiency [2]. Compared with the previous emission standards, the amount of particles is significantly reduced in the EU6 limits and will be more decreased in the EU6c limits from 2017 on. This strict emission request has not been reached before with a dual-injection system. The following shows how to solve this challenge in the software system.

Anja Blau, Oliver Abendroth, Jan-Christian Arnold, Markus Hummel, René Passon
Product development at Opel – A synthesis of CAE and test

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Henning Holzmann
Uncompromised design – Changing the vehicle development process to meet rising design and engineering requirements

The engineering demands affecting automotive aerodynamics are rising significantly, due to requirements to reduce global carbon emissions coupled with an increasingly competitive and consumer-driven marketplace. These demands touch every aspect of the vehicle development process, requiring more innovative engineering solutions, bolder designs, and more complex trade-offs between vehicle attributes. In response to these demands, digital models allow collaborative design with rapid iterations. They also enable a transformational shift in the testing process, away from the sequential “build-and-test” approach using physical prototypes, and toward a purely digital design process enabled by accurate digital simulations of vehicle performance attributes.

Stephan Remondi, Brad Duncan
Porsche vehicle dynamics development – Virtual approval of car model derivatives in collaboration with road testing

Nowadays car manufacturers tend to increase the number of model variants in order to offer to the customer a wider range of “customized” vehicles. On the one hand this increased variety is driven by the desire to distinguish the car models from the body style point of view. On the other hand there is often also a wide range of technical differences between the car models like drive layout, combustion engine specifications, hybrid concepts, suspension systems and others. Porsche has a long history of offering sports car models with a big number of car derivatives. From the driving behavior point of view, i.e. vehicle dynamics, steering feel and ride comfort, such a diversification requires a thorough analysis and approval of the various models in order to guarantee a high-level handling performance. Virtual methods can help to cope with such an increased number of car variants and/or non-availability of real car specifications during the development phase but this requires a lot of experience and smart approaches in order to combine the virtual results with real life and draw the right conclusions. In this paper we want to give a general overview of combined vehicle dynamics testing and simulation approaches which are used to guarantee maximum performance for the example of a front-engine luxury sports sedan. This process is thought to be straightforward and to allow a deep understanding of the relationships between the component properties and their influence on the driving behavior of the vehicle.

Thomas Maulick, Gauthier Boisdequin, Maurice van de Weerd
Advanced diesel technology to meet multi-dimensional challenges of the diesel engine

The modern Common-Rail Diesel engine is no more a European phenomena while the long-term prognosis shows growth of about 9% in India and China. In India the Diesel engine has already a high share in the market due to the need of low operating cost while in China there is not only an ever increasing demand for light commercial vehicles but also for Passenger Cars. These two markets need robust and cost attractive Diesel Injection Systems, which must also be capable to fulfill the new emission norms like BS5 (Bharath Stage 5) or CN5 (China 5), while facing challenging environmental conditions, fuel quality and OEM requirements different to Europe. On the other hand the requirements for the European High-End Segment are not only to consume less fuel with the same power output – but to have the same noise and comfort level like a comparable DI-Gasoline-engine. Key enablers are a multiple injection capability with very short hydraulic dwell times combined with excellent mixture formation and more system injection pressure of up to 3000bar to achieve power output targets above 100 kW/l. Based on broad system competences in terms of Diesel combustion and control, Bosch offers tailored solutions for all segments and markets and adopts a modular approach, which actively builds upon the achieved maturity of functional groups and concepts. The resulting portfolio of Solenoid injectors and Piezo injectors are presented herein.

Thomas Wintrich, Jürgen Hammer, Dirk Naber, Michael Raff
Untersuchungen zur Zylinderabschaltung an einem Dieselmotor für den Einsatz in mobilen Arbeitsmaschinen

Im Rahmen dieses Projektes konnten mit Hilfe von experimentellen Untersuchungen die Auswirkungen einer Zylinderabschaltung am Dieselmotor untersucht werden. Es sollten die Darstellbarkeit und das Vorhandensein eines direkten Potentials hinsichtlich Kraftstoffverbrauchseinsparung untersucht werden. Aber auch das durch das höhere Abgastemperaturniveau gegebene, indirekte Potential der Zylinderabschaltung zur Kraftstoffeinsparung sollte aufgezeigt und bewertet werden.

Wolfgang Monschein, Peter Grabner, Helmut Eichlseder, Marcus Quasthoff, Pascal Kiwitz
Investigations in using higher FAME-blends in DI-CR-Dieselengines

Due to international market’s demand for higher blending rates of biogenic fuels, these fuels came more and more into the focus of development requirements. Currently, the biogenic components in diesel fuel mainly contain fatty acid methyl esters (FAME). By now, in using these biofuels with higher blending rates (up from 7%) various problems have been observed in the field, which are primarily caused by the lower oxidation stability of FAME [1]. For this reason, the problem areas in motor operation caused by highly advanced oxidation of the fatty acid chains in the biodiesel have been systematically evaluated as part of a funded research project at the Institute for Powertrains and Automotive Technology (IFA) of the Vienna University of Technology in cooperation with a partner from the automotive industry. The special focus of this paper lies in the main problematic aspect in using FAME fuels with higher blending rates: the fuel aging. This oxidative ageing causes a possible polymerization of the fatty acid structure which transforms these components in the fuel into a phase characterized as viscous liquid or even solid [2]. As a result, the function of the fuel supply system in the car – from the tank to the injectors – can be severely affected, or at worst a total damage of the internal combustion engine can occur.

Clemens Roßboth, P. Hofmann, Berhard Geringer
Machining technologies for multi-materials

The weight reduction in the automobile industries is one of the major motivations for the implementation of lightweight construction materials. Today, these materials have become an essential component, not only for luxury class cars, but also for mid-size and compact cars. Furthermore as design plays an increasing part in purchase decisions, new materials and production processes are enabling innovative car body shapes. Nowadays every single of the construction stages requires high-quality of the manufacturing processes. The complex properties of lightweight structures present however diverse challenges for the manufacturing processes and at the same time, the increasing demands for light materials involves higher material and tooling expenses. Therefore the optimal selection of the machining technologies in compliance with the production demands represents a high economic impact on the current industrial demands. Multi-material designs integrate conventional steels, high strength steels, light metals, composites or laminate stacks in body structures. Here the manufacturing processes of car body parts of sheet metals are handled with high process reliability, while the series production of composites and stacks still deals with the measures to decrease the machining costs and the operation times and provide high process reliability. The present article gives an overview over latest innovations and fields of research in the machining of these materials.

Andreas Gebhardt, Hector Vazquez Martinez, Tim Mayer, Robert Beckenlechner, Philipp Esch
Joining technologies for multi-materialdesign

From an industrial point of view, joining technologies play a key role nowadays, due to the continuously increasing applications of multi-material-design. The different properties of the used materials lower the number of possible (suitable) joining technologies. Fiber-Reinforced-Plastics (FRPs) make it even more difficult to choose the right technology because of their anisotropic behavior. Bonding is currently the most common technology for joining FRPs. Furthermore, hybrid joining processes are applied in order to combine the positive properties of other joining technologies with bonding. Nevertheless a blatant disadvantage of bonding FRPs is the fact, that there are no fibers in the direct area of the join which leads to a weakened structure and lower mechanical properties. Friction Stir Welding can avoid this disadvantage when joining short fiber-reinforced thermoplastics by stirring fibers into the joining area. To be able to apply the Friction Stir Welding technology to thermoplastic materials, certain changes in the process parameters are necessary because the technology has its origin in the metallurgy.

Manuel Schuster, Michael Stroka
Multi-material design for the optimization of the automotive production process

The automotive industry and thus the automobile production processes have to face new challenges constantly. Changing mobility concepts, alternative approaches to mobility, urbanization and demographic change lead to alterations of the buying behavior of potential customers. This results in a higher rate of product diversity, which increases steadily. Through the constant growth of Asia and China, in particular as automotive manufacturing sites, and the gain in purchasing power of the population of emerging and developing countries, new markets appear, developing with high growth rates. This process has also impacts on the production technology. A key issue is the transition from finite fossil fuels to alternative fuels and drive systems. Significant rating values are CO2 and pollutant emissions. Downsizing conventional combustion engines and the use of alternative fuels are means to achieve minimization of emissions. Innovative electric motors, solar and fuel cells or hybrid solutions are other approaches to realize a pure electric vehicle. Requirements for that are suitable energy sources and storage systems. Another approach to reduce emissions is the application of new types of materials in the engine, chassis or body. These measures lead to weight reduction and therefore lower fuel consumption. Such materials require the development of entirely new process chains, which includes recycling, manufacturing processes and logistics concepts. Due to the availability of modern methods and materials, coming automobile generations will be realized by multi-material mixing. In this concept, the materials are combined and can be optimized according to the operational demands. The manufacturing, working and processing as well as the calculation of such structures and the development of associated process chains are enormous challenges for future car generations.

Noelia González Vila, Jochen Burkhardt, Christoph Birenbaum
Highest measurement and calibration performance through cooperation of OEM, Tier1, μC, Tool-Supplier

Due to the rapidly increasing complexity of software in engine control units, there is a demand for ever increasing measurement and calibration data rates and more comprehensive functions for development and calibration. At the same time, space for installing the measurement hardware is decreasing. The familiar methods based on bus protocols such as XCP on CAN and XCP on FlexRay are no longer sufficient, resulting in the need for connection of high-performance measurement and calibration hardware between the ECU and the measurement and calibration tool. There is a strong demand on the part of both vehicle manufacturers and ECU suppliers for solutions that use the XCP protocol standardized by ASAM with different transport protocols between the measurement and calibration hardware and the measurement and calibration tool. Because the XCP standard assumes that the ECU is connected directly to the measurement and calibration tool, the XCP standard must be expanded for this application. This presentation will describe how an innovative high-performance hardware device for measuring, calibrating, bypassing, rapid prototyping, and Flash programming can be connected to the existing measurement and calibration tool. The connection to the latest microcontroller generation (e.g. Freescale MPC57xx, Infineon Aurix, Renesas RH850) is realized for this using a standardized XCP-on-Ethernet interface.

Alfred Kless
ETAS LABCAR-XiL: Bridging the gap between development phases by harmonizing concepts and tools

Virtual reality has been named as one of the engineering challenges of the 21st century (www.engineeringchallenges.org). In automotive software (SW) development, its instantiation is perceivable as the endeavor of replacing real artifacts, e.g., electrical or combustion engines, or activities carried out on those real artifacts, e.g., testing and validation of real vehicles, through virtual artifacts, i.e., virtual representations on computers of real artifacts, usually called “models”, and activities carried out on those virtual artifacts, e.g., model-based verification and validation. Following this major engineering trend, we are facing the challenge to realize seamless transitions between all test and validation steps used to develop automotive controls. Closing the gaps between Model-, Software-, and Hardware-in-the-Loop (MiL/SiL/HiL) tools by an appropriate XiL environment will enable developers to homogenously conduct analyses by using appropriate tooling throughout the development process.

Christoph Störmer, Corina Mitrohin, Andreas Thuy, Ghizlane Tibba
Experimental and numerical study of wind noise caused by cowl area on Volvo XC60

The paper presents a detailed experimental and numerical study of aerodynamically produced noise which occurs due to turbulent structures created by the cowl cavity and side mirror. The study aims to answer the question about how much turbulence in the cowl area contributes to the overall wind noise level on Volvo cars. Measurements were carried out at the Volvo wind tunnel on a Volvo XC60. Configurations considered were: rear view mirror On/Off with the cowl cavity open/closed. The results discussed in this paper include intensity probe measurements in the flow as well as standard measurements in the car. The experimental results are compared to numerical data, which are presented as isocontours of λ

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criterion and pressure fluctuations.

Olga Roditcheva, Dragos Moroianu, Holger Bernhardsson
On the aerodynamic performance of two Silver Arrows from the thirties

Two typical Silver Arrows from the thirties, one Mercedes-Benz W25 and one Auto Union Type C, were used to illustrate the simplicity and the capabilities of modern commercial CFD (Computational Fluid Dynamics) tools to mimic and compare the flow fields around these cars. In a Bachelor thesis carried out during the spring 2014 at Chalmers University of Technology, Bondesson et.al. (2014), six students with no prior CFD experience performed the computations presented in this paper. Since no CAD (Computer Aided Design) data was available on the full-scale cars, 1:18 scale model-cars from CMC-models were used, see Figure 1. The two models were 3D-scanned and reconstructed in order to obtain a detailed geometry needed for CFD simulations. Of course, the performance of these vintage race-cars is always of great general interest, and if these computations could increase the knowledge on the German Silver Arrows it would be an added bonus of this work.

Lennart Löfdahl, Teddy Hobeika, Alexey Vdovin
Upgrade of the full-scale aeroacoustic wind tunnel of Stuttgart University by FKFS

FKFS has operated the full-scale aeroacoustic wind tunnel of University of Stuttgart for many years. One task is to keep this wind tunnel as one of the most modern ones of its kind. In 2014, the wind tunnel has again been upgraded significantly. The aerodynamic as well as the aeroacoustic performance have been improved significantly and the operational processes have been accelerated. Also new innovative features have enlarged the test capabilities to a significant extent. A new modular belt system (FKFS first®), which is patented, allows high performance measurements in a 3-belt mode e.g. for race cars as well as precise and efficient measurements for production vehicle development in a 5-belt mode. A new, larger turntable houses the belt system and a new under-floor balance which enables highaccuracy measurements of forces and moments also for a high resolution in time. Parasitic forces which are generated at the wheel drive units, are eliminated by a specific correction procedure which is also patented (FKFS pace®). The enhanced road simulation is rounded up by a new type of boundary layer conditioning system. A unique, active side wind generator (FKFS swing®) enables investigations of unsteady aerodynamics and aeroacoustics. It consists of 8 wing-like profiles with independent drives which can deflect the whole airflow around the car in the test section with a frequency of up to 10 Hz. Acoustic linings in the first diffuser and other measures have improved the acoustic performance of the wind tunnel. Low frequency pulsations of the open jet are suppressed very efficiently by special patented profiles in the nozzle (FKFS besst®) and a Helmholtz resonator. The profiles also reduce the high-frequency noise of the wind tunnel.

Armin Michelbach, Reinhard Blumrich
Predictive planning of the battery state of charge trajectory for hybrid-electric passenger cars

To achieve efficient usage of hybrid power-trains, predictive operational strategies can be developed, which take into account future driving situations by knowledge of driving cycle. The algorithm presented in this paper calculates a State of Charge (SoC) trajectory, which minimizes fuel consumption by using a trip preview and the corresponding power demand of the vehicle. This trajectory can be used together with instantaneous operational strategies with no or only short prediction (e.g. an adaptive Equivalent Consumption Minimization Strategy (ECMS)). The algorithm explicitly takes into account the limits of the battery and therefore avoids situations, in which the power-train would be operated inefficiently without prediction due to the constraints. The effectiveness of the algorithm is shown by comparing it with operational strategies without prediction and an offline potential analysis.

Gunter Heppeler, Marcus Sonntag, Oliver Sawodny
Enhanced online thermal modeling for power electronic temperatures in (hybrid) electric vehicles

In electric and hybrid electric vehicles, the power losses of the semiconductors within power modules lead to strong self-heating. The resulting thermal stresses are major factors regarding critical overload and lifetime reliability. The relevant temperatures and temperature profiles are important design parameters. Additionally, it is necessary to monitor these temperatures during operation of the vehicle. However, if the number of relevant temperatures is larger than the number of sensors or the point of interest is not accessible for sensor placement, it is advantageous to use a model-based method to estimate these temperatures and use the given sensor information to correct the model. A so-called feedback observer can be used to reconstruct the non-measureable temperature. The capability of such an observer is based on the size and structure of the implemented model. In this paper multiple models and model structures are presented, which can be used to meet different requirements: Asymmetrical load distribution within the modules; coolant inlet and outlet estimation and/or the adaption of those models for the situation if the coolant flow rate of the inverter is variable. However, every extension of the model results in an increase of complexity and therefore in an increase of computational effort. Hence, to model as compact as possible is another requirement that has to be met. The result is a systematic approach which allows to combine those modeling methods within a modular construction system for thermal modeling of power converters. The presented models are compared regarding capability and computational effort.

Manuel Warwel, Gerd Wittler, Michèle Hirsch, Hans-Christian Reuss
Modeling of the electrical DC-link in fuel cell vehicles for DC-DC converter control design

High-Power DC-DC converters are used in hybrid fuel cell vehicles to control the power flow between battery and fuel cell and therefore have an important impact on the design and the dynamics of the electrical drive train [1]. Controller design for such converters might become more and more important in the future as it not only assures the desired power flow in the system but also affects the amount of low-frequency disturbances seen by fuel cell and battery. Furthermore converter control significantly impacts the voltage dynamics of the drive train which have to respect strict bounds to prevent severe damage to components such as semiconductors. Converter control is therefore related to voltage stresses, filter design as well as lifetime considerations. The complexity of the electrical drive train interfacing with the converter as well as the range of operating conditions require a detailed analysis of the complete system and its various dynamics to allow for more sophisticated control approaches as well as assessment of the controller’s impact on the drive train. In this paper, an analytical model of a possible drive train configuration will be derived step by step. After setting forth an adequate model for each component, the complete model will be validated using a detailed simulation model. A similar model and its application to Model Predictive Control have also been presented in [2].

Conrad Sagert, Oliver Sawodny
Generation 2 Lithium-Ion battery systems – Technology trends and KPIs

Currently in series produced Lithium-Ion batteries – so called Generation 1 Lithium- Ion batteries – are used in high voltage battery applications in Hybrid, Plug-In-Hybrid and Electric vehicles. These Generation 1 battery systems proved already in series that Lithium-Ion batteries fulfill the high requirements regarding safety and electrical power in automotive applications. The real proof of the requested minimum 10 years life time requirement is not done yet. However, based on results from accelerated aging tests in laboratories one can expect that the Lithium-Ion batteries will fulfill the requested life time requirements of automotive field usage, too. Main targets of the development of the second generation of Lithium-Ion battery systems are decreased specific cost in EUR per kWh as well as increased volumetric and gravimetric energy density. Especially cost down will be the barrier to overcome in order to enable a wide use of electric drives in vehicles. Starting with a short overview of the actual status of Lithium-Ion battery technology this paper gives prognoses how the requirements to and the Key Performance Indicators of Generation 2 batteries will develop. Besides the already established high voltage systems used in Hybrid, Plug-In-Hybrid and Electric vehicles applications also new applications with a voltage level lower than 60 V are described. Such systems will be relevant for Boost-Recuperation-Systems (BRS) or Recuperation-Systems (RS). These systems are in direct competition to optimizing measures of conventional combustion engine powertrains. Hence an increased usage of such systems will only be possible when the demanding cost targets will be met. Focus of the paper will be batteries for the applications in Plug-In-Hybrids (PHEV), Electric vehicles (EV) and Boost-Recuperation-Systems (BRS).

Holger Fink, Stephan Rees, Joachim Fetzer
E-Mobility – Voltage classes, challenges and technical solutions

The CO

2

limitation decided by the European Commission challenges the Automotive OEM’s to further improve the conventional powertrain with regard to CO

2

Emission reduction. Thermal Engine concepts alone need to be supported by alternative propul-sion solutions in order to meet the fleet average CO

2

limits in order to get benefits from the utilization of the transient driving conditions in term of electrical boost and break recuperation. Most of the current hybrid vehicles in the market match these requirements technically. From a commercial point of view there is the need to further attractiveness – means price improvements. Besides the value add for the Battery the additional cost of hybrids are mainly influenced by the implementation of HighVoltage systems that need extensive technologies for electrical safety requirements. The new 48 Volt Voltage level could be a solid solution to improve CO

2

emissions aligned with cost optimization within hybridization. Technically the application of various different voltage levels within a vehicle needs investigation from an electrical systems and component point of view. The presentation explains the technical challenges and offers an overview on possible solutions and gives a comprehensive insight to hybridization.

Edmund Erich
Conception and implementation of a charging station for electric buses in public transport

The idea for fully electric bus operation following the DockingPrinciple was conceived at the Fraunhofer IVI over ten years ago. The term DockingPrinciple stands for a new way of supplying energy for electric vehicles used in public transport, with an on-board energy storage unit as the vehicle’s sole source of energy. This storage unit takes in energy from fast charging stations (docking stations) installed along the way and releases it according to the demands of the vehicle propulsion system and the electric auxiliaries. From the current point of view, there are two feasible concepts for recharging the vehicle’s storage unit. Firstly, the energy needed for the upcoming tour can be provided during a fast charging process of several minutes’ length with a power of typically 250 kW. Secondly, considering the currently available storage technologies, it is sensible to install additional charging stations at bus stops. Doing so allows for longer routes while avoiding disproportionately high costs for the on-board energy storage units. At selected stops, a time slot of 15 seconds is available during which the energy storage can be recharged with a power of 700 kW. This process is called pulse charging.

Stefan Büchner, Sven Klausner, Martin Engel
Reduction of CO2 emissions – Optimization approach: vehicle vs. fleet

The global average temperature increased about 0.6°C since the beginning of the 20th century, caused by burning of fossil resources and the resulting CO

2

emissions. In 1997 the Kyoto-Protocol was adopted to reduce the greenhouse gases from 2008 to 2012 at around 5% in comparison to the value of 1990, [1]. Hereby figure 1 shows that in Europe 12% of the CO

2

emissions are caused by the traffic of passenger cars.

Michael Martin
Simulation and new correlation method of crash sensor signals in misuse tests

To achieve optimal occupant protection in the event of a vehicle crash, the restraint systems (belt pre-tensioner and airbag) need to be deployed at the precise right time. This point in time depends on the crash severity, the direction of impact and the capability of the vehicle’s structure to absorb the energy. The task of the sensing system is to determine whether and when the safety measures need to be deployed. Therefore, several sensors are positioned at vehicle’s front, center and side (see Figure 1). These are measuring acceleration in the indicated direction. The sensors at the outer position are here called “main sensors”. The sensor sitting in the center of the vehicle is called “confirmation sensor”. The sensors send signals to the Sensing Diagnostic Module (SDM), located at the same position as the confirmation sensor. The signals of these sensors are processed in the SDM by an algorithm which decides whether, when and which component of the restraint system shall be deployed.

Robert Murmann, Lothar Harzheim, Stefan Dominico
Innovative Ansätze zur Ressourceneffizienz in der Fahrzeuglackierung

Die hier dargestellten Ergebnisse und Erkenntnisse sind zu einem großen Teil im Rahmen des Verbundprojekts InnoCaT 5 sowie im Rahmen der nachfolgenden Weiterentwicklungsarbeiten entstanden. Das InnoCaT 5-Projekt war Teil der 30 Projekte umfassenden Innovationsallianz Green Carbody Technologies

InnoCaT

. Ziel der von zwei Automobilherstellern gemeinsam mit Anlagen-, und Lackherstellern sowie dem Fraunhofer IPA durchgeführten Forschungs- und Entwicklungsarbeit des InnoCaT 5- Projekts war die Reduzierung des hohen Energiebedarfs der Automobillackierung. Dabei wurden die Prozessschritte Lackapplikation- und Trocknung näher betrachtet, bei denen die bedeutendsten Energie- und Ressourceneinsparpotenziale der Karosserielackierung liegen. Weitergehende Informationen zu den Projektergebnissen sind in dem Abschlussbericht [1] zu finden.

Oliver Tiedje, Ulrich Strohbeck
Design of functional automotive components with requirements for cleanliness

The technical developments that have taken place in the automotive industry over the last few years explain why the issue of technical cleanliness has become so important in the manufacture of functionally-relevant components nowadays. Together with the customer’s growing demand for safety and driving comfort, the trend towards increasing performance densities whilst simultaneously adhering to ever-stricter environmental requirements remains unbroken. In consequence, the tolerances of aggregates built into vehicles are now very low and the parts are subjected to higher and higher stress levels, making them increasingly sensitive to particulate contamination. In some cases, a single particle just a few 100 micrometers in length may suffice to impair the function of a complex hydraulic system or even cause it to fail completely. A diesel injection system with an injection pressure of 2500 bars, an ESP system with valve diameters of just a few millimeters, a turbocharger with speeds of well over 100,000 revolutions per minute or a hydraulically-controlled camshaft phaser located in the engine oil circuit are all systems which could fail because of a so-called killer particle. Nozzles becoming blocked, valves jamming, damage to bearings or conductor paths in control devices shorting are only some of the reasons why such functional failures occur. As a result, component cleanliness has become a quality feature that is now specified in customer-supplier agreements and has to be measured.

Markus Rochowicz
Managing of quality and safety continuously through development into production

As the opening titles to the Stuttgart International Symposium “Automotive and engine technology” show: “Safe, efficient, connected – On the way to future mobility” Prof. Herbert Kohler, Daimler AG and “Mobility solutions for future scenarios” Wolf- Henning Scheider, Robert Bosch GmbH [1]; key automotive companies are addressing the opportunities provided by modern electronics and connectivity solutions. The discussion about legal understandings concerning is currently heading to a precise set of definitions for systems providing intelligent functions to the classic driving task, compare [2]. It still counts that “the arrival of new intelligent functions, allowed by the availability of powerful and low-cost electronics, is bringing a complete new line of market potentials for the automobile manufacturers and their suppliers [3].

Stefan Gerstmayr
Improving the turbocharger acoustics of a four-cylinder gasoline engine using CFD

The turbocharger is particularly important for today’s gasoline engines. Considering the compressor the special flow conditions close to surge are the focus of attention. In addition to the challenges related to mechanics and engine performance the acoustic issues have great importance in this operating range. The turbocharger acoustics are investigated by numerical simulations and the improvements achieved are validated experimentally. The acoustic flow simulation using CFD is proven worth in different engine applications.

Matthias Seltsam
Control concept for the partial admission of a turbocharger turbine

One of the main challenges in turbocharging an internal combustion engine (ICE) is the controlling of the turbocharger. Through the power balance of the turbine and compressor mounted on the same shaft, both components run dependently from each other. Further the operation of the turbocharger depends on the operation of the ICE. At low engine speeds, the turbocharger should produce a steep and large pressure increase in the compressor to reach a fast power increase of the ICE. At this state however, the ICE delivers low exhaust gas mass flow to drive the turbocharger turbine, which results in low rotational speed of the turbocharger and consequently low pressure increase. On the other hand, there is a surplus of exhaust gas energy at high ICE speeds because of high temperatures and large mass flow rates of the exhaust gases resulting in excessive turbine power. State-of-the-art to solve this problem is using a Waste-Gate turbocharger. As a part of the exhaust gas mass flow is bypassed around the turbine, a smaller turbine is utilized to drive the compressor. This leads to a reduced inertia of the rotor allowing a more rapid speed-up of the turbocharger and as a consequence more engine power output at low engine speeds. However, the energy of the bypassed mass flow is wasted at high ICE speeds.

Frederic Heidinger, Thomas Müller, Mirko Ilievski, Damian M. Vogt
A design methodology for combined turbo and supercharger applications

The significant growth forecasted in gasoline boosted engines and the more challenging regulatory requirements for emissions and fuel economy are leading to an aggressive engine downsizing trend. Two technology leaders have partnered in order to offer an optimized design in dual boosting systems which combine superchargers and turbochargers. The result is an air delivery boosting system that can accommodate high BMEP at all engine speeds without compromising transient response. Combining the skills of both companies, the advanced engineering groups joined efforts to perform an extensive simulation study over the course of a year aimed at defining a superior system design methodology. This study explored and analyzed the benefits of each boosting device. Two main configurations were considered based on the relative sequence of each device in the air path, namely: supercharger (SC) + turbocharger (TC) and TC + SC.

Roberto Rastelli, John Shutty, Brandon Biller
Engine temperature management and control: Improvements and benefits linked to the replacement of map-controlled thermostat with a mechatronic part

In order to cope with new regulations and find a better compromise between fuel consumption, pollutant emissions and comfort, thermal management technologies are getting more complex. This is especially true when it requires replacing a basic passive solution or an open-loop control one with a mechatronic system. The latter enables the optimal setups to improve performance in cold/hot, transient/stable, partial/full load operation. A new Active Cooling Thermal-management valve concept has been developed to specifically replace map-controlled thermostat whilst keeping the same packaging and cost range. The system delivers a quick and precise close-loop control of the temperature to solve the main drawbacks of classic solutions such as a temperature-sensitive response time or hysteresis and temperature overshoots.

Haitham Mezher, Mickael Cormerais, D. Chalet, Thierry Marimbordes, Pierre Emmanuel Prétot, Q. Montaigne, Heinz Fuchs, Antoine Bouedec
A switching Moving Boundary Model for the simulation of ORC plants in automotive applications

Waste heat recovery is a promising approach to improve fuel economy and emissions of thermal engines for stationary and mobile applications. Among recent solutions, Organic Rankine Cycles (ORC) seem to join effectiveness and technological readiness for the application to Internal Combustion Engines (ICE), both Spark Ignition (SI) and Diesel. Significant reductions in fuel consumption have been reported, but – especially in automotive applications – further improvements in the ORC plant matching and performance in transient operations are required. This paper presents a lumped-parameter model of an ORC system for exhaust waste heat recovery in automotive engines. The heat exchangers dynamics is accounted for by modeling the behavior of the working fluid through the Moving Boundary Method (MBM), which is based on a lumped-parameter representation of the conservation laws for single and two-phase fluid flows. An original switching technique has been implemented to account for variations in the fluid properties and heat transfer during transient operations of the ORC plant. Grey-box models for the pump and expander have been developed starting from steady-state characteristic maps. The behavior of the comprehensive model in transient operating conditions has been significantly improved also during start-up process, usually a threatening situation for mathematical models.

Marco Crialesi Esposito, Nicola Pompini, Agostino Gambarotta, Marcello Canova
A redundant sensor system with driving dynamic models for automated driving

The knowledge of the current motion of the vehicle plays a central role for driving dynamics control. The over ground velocity and side slip angle for stability systems and the lane accurate position for automated driving must be available even when sensors fail or they must be accurate enough until the driver undertakes the control of the car again. This task is called dead reckoning in the navigation community. To estimate position, velocities and parameters of driving dynamics an Extended Kalman Filter (EKF), that includes a nonlinear two track model, is used. Inputs are steering wheel angle and wheel speeds. The states of the horizontal driving dynamics are position, yaw angle, longitudinal and lateral velocity and yaw rate. To make the filter adaptive to changing road conditions or tire wear, parameters of a modified Pacejka tire model are modeled as states too. To get realistic uncertainties in the model, some nuisance factors are modeled as nuisance states, which is a novelty in driving dynamic state estimation. The measurements contain the ESC sensors (yaw velocity, long. and lat. accelerations) and one sensor that can measure the absolute position and velocity in a fixed coordinate system, e.g. by a GPS.

Jakob Bechtloff, R. Isermann
Real time minor damage identification system and its validation in a fleet test

The demand for mobility in modern communities is rising. As a result, car rental and car sharing companies have been growing rapidly during the last years. As a consequence, also the number of car sharing customers is increasing constantly and very fast. In September 2014 the total number of car sharing customers in Germany exceeded 1 million [1] ‒ compared to 760,000 at the beginning of 2014, an increase of approx. 240,000 in only 9 months. Hence, a further growth can be expected in the upcoming years. Some information on car sharing is given in table 1.

Andre Kneifel, Sergai Gontscharov, Klaas Hauke Baumgärtel
Progress in determining the safety of traction batteries for electric vehicles

Rechargeable Lithium-ion batteries are electrochemical storage components characterized by long cyclic and calendar lifetimes, high gravimetric and volumetric energy densities and high energy efficiency. Their price has fallen significantly in recent years. This lowered the price of traction batteries. For the use of lithium-ion batteries in the drive train of electric and hybrid vehicles, high growth rates are predicted for the next 15 years, the presence of electric cars on the road will increase significantly. Therefore the present safety consideration is limited to lithium-ion batteries.

Detlef Hoffmann
Modern chassis development as a result of skilfully combining testing and simulation

Chassis development involves a host of requirements for the performance and efficiency of chassis components. These include costing, weight, CO2 emissions, the capability to fit into the module strategy, packaging, and strength requirements, in addition to vehicle dynamics and ride comfort. In respect to the full vehicle, the chassis is responsible for approximately 25% of the vehicle weight and 20% of the vehicle costs. Taking these factors into account, it is essential to make the chassis development process as efficient and systematic as possible. This means that the tools that are available in development process, i.e. hardware-based testing and simulation-based testing, must be linked as closely as possible in order to generate the maximum benefits. Whereas in the past vehicle and component releases were the product of testing (and still are today), the rapid development of simulation tools, together with increased computing performance, means that a few tests could be replaced by simulations and that the boundary conditions for real-life testing can be more accurately established by means of targeted, preliminary simulations. Reduction of hardware and respectively better test results achieved by preliminary parameter studies in simulation have become essential if we look at the increasing number of derivates based on a certain vehicle platform. Thus less time within development process per derivate is available because resources have not grown in the same way. This means that the reduction of development loops per derivate is compensated by simulation techniques. However, it is not the intention of the authors of this paper to have testing replaced in its entirety by simulations at some point in the future. The authors rather wish to achieve a targeted interaction of both methods in order to bring them together within development process. This paper provides a number of examples which highlight the extent to which testing and simulation have merged and grown together over the past few years, a trend that will continue and become more pronounced in the future.

Thomas Kersten, S. Gies
The new aerodynamic and aeroacoustic wind tunnel of the Porsche AG

Porsche has built a new wind tunnel in its central R&D Center in Weissach. Significant improvements of this wind tunnel over the existing one include augmented ground effect simulation technologies, increased wind speed and suitability for aeroacoustic testing. Beyond this, the new wind tunnel is part of an integrated building complex, also comprising of a new automotive design facility and extensive model workshops. The present publication describes the fundamental ideas driving this concept, as well as technical key features of the new wind tunnel.

Hauke Stumpf, P. Röser, T. Wiegand, B. Pfäfflin, J. Ocker, R. Müller, W. Eckert, H.-U. Kroß
A modern continuous development process – an example of interaction between computer/test stand/road for thermal management

This manuskript is not available according to publishing restriction. Thank you for your understanding.

Raimund Siegert
PLUG-IN Hybrid from Mercedes-Benz – The next generation PLUG-IN Hybrid with 4-cylinder gasoline engine

The modularly structured hybrid system from Mercedes-Benz has been available in combination with gasoline and diesel engines since 2012. Previous experiences in the hybrid series production development have shown that although batteries of higher capacity enhance the electric driving experience, there are no further benefits in terms of efficiency and package. For this reason, Mercedes-Benz made a decision on the combination of increased electrical capacity with the option of external recharging. To this end, the S500 plug-in hybrid was initially launched in 2014. For the first time a variant with 4-cylinder gasoline engine has subsequently emanated from the modular hybrid system. In combination with an electrical range of 31 km, this downsizing allows previously unknown certification of 48 g CO2/km in this class. Furthermore, agility values on the 6-cylinder level could be implemented with very direct driving characteristics due to the increased capacity of the battery, the selected powertrain topology and the direct response of the electrical machine.

Uwe Keller, Stefan Schmiedler, Jochen Strenkert, Norbert Ruzicka, Franz Nietfeld
Investigation of raw exhaust and diluted exhaust emission measurement systems with different modern plug-in hybrid electrical vehicles

The continuous trends of the more efficient use of resources and the reduction in pollution from vehicles are reflected in a wide range of modern propulsion concepts for the transportation of passengers and goods. Different regions in the world follow similar trends but with individual strategies and designs. One global approach is the implementation of the bridge technology of powertrain hybridization in passenger cars. The technology of the so-called Plug-in Hybrid Electrical Vehicle (PHEV) is widely known among consumers and a variety of designs are commercially available. The variety of combinations of internal combustion engines (ICE) with an electric motor and the associated measurement challenges has been described in a number of papers. This paper discusses the measurement accuracy for raw and diluted exhaust sampling (CVS) and PM/PN measurement during the typical numerous engine stop and start periods. The question is: can a single, optimized exhaust emission measurement system be capable of coping with the variety of hybrid vehicle concepts and test regulation requirements?

Matthias Schroeder, Harald Kurz, Philipp Baumann, U. Strehl
Analysis of serial plug-in hybrid-drives by interconnection of component specific simulation tools

In comparison between today’s vehicles and former times, many of the vehicle components were nearly independent of each other. But in the meantime some of them are closely connected. Many of the mutual interactions between powertrain, driving dynamics and electric, later also electronics, were initially either not existing, or they were not took into detailed consideration during vehicle development. This independency of the components subsystems was still popular when computer simulations arrived in vehicle development. As a result, the simulation tools turned out in an independent way for a long time. However, in modern vehicle concepts result a deeper networking of the individual vehicle subsystems. With this increase of networking, further interactions between vehicles components arise, which did not exist in the past in this scale. For hybrid vehicles this applies in a special extent. Because of the combination of two different drives, there result many additional degrees of freedom with regard to possible powertrain configurations and operating strategies. Furthermore changes at single vehicle components partially have an extensive impact to the entire vehicle. At the same time, there comes along a great optimization potential to get closer to the goal of a highly efficient use of energy and minimization of emissions.

Andreas Schmidt, Hans-Christian Reuss, Michael Grimm
Ergonomic lightweight design for workers in automotive production

Additive Manufacturing Technology offers a unique design flexibility due to its layer based construction approach. This provides a new potential for lightweight construction. Bionic lightweight structures, integrated functionality and topology optimized structures are now possible to be manufactured. The process also offers the possibility for producing personalized products, individually fitted to human physiology. Ergonomic workplace design can benefit from this technology, through individualized lightweight design, like handling tools for example. Baraldi and Kaminski could show benefits to the worker and the company, resulting on ergonomic workstations in the assembly line. The company benefits by improved productivity, product quality and workers’ quality of live. The workers don’t overstress their body and do better work with higher motivation and less sickness. Finally the design and production process of an ergonomic lightweight stool for an assembly line is shown. Using topology optimization, a material combination of carbonfiber- reinforced (CFRP) tubes and additive manufactured polyamide parts an individual advice with over 50% weight reduction compared to the previous solution could be achieved.

Raphael Geiger, Steve Rommel
Assistive technologies for workers in the automotive industry

In many working fields, like for example the automotive production industry, ergonomic unfavorable working positions are not avoidable. Working in “overhead”- position for example is still quite normal in many automotive assembly yards. Although “Overhead-Working-Positions” are known to cause chronical diseases of the musculoskeletal system. Working in bent over position in the car is another often seen situation in car assembly lines. Picture 1 is showing a worker at the production side of Opel in Bochum.

Urban Daub, Bernhard Budaker, U. Schneider
Optimization of global production network structures

In recent years, companies have experienced several waves of internationalization [19]. As a result, production networks have been developed into global and complex entities [13], which, in turn, are suboptimal and fragmented [4]. “The challenge companies are facing now is to optimize these production networks within the existing location structures by redesigning the value-added activities” [19]. The optimization of production network structures heightens the risk of wrong decisions. This is reflected in the massive failure of relocation schemes in general, but particularly of internal relocations of value-added processes. In 2012, one-fourth of all offshoring projects in the manufacturing sector resulted in reshoring projects [23]. The causes of such a high number of wrong decisions go back to a merely cost-based decision behavior. The reasons for reshoring, listed in figure 1, show what is currently going wrong in planning [10]. It highlights that those qualitative criteria that cannot be evaluated in monetary terms, such as flexibility or quality, are presently not or not appropriately considered in the decision-making process when structuring production networks [22].

Andrea Prinz, Thomas Bauernhansl
An effective method to identify thermodynamic tire characteristics through driving maneuvers

The optimal tire temperature is a determining factor to get quick lap times in motorsport, because the tire rubber compound characteristics decay very rapidly outside a given temperature range. The characteristics of road car tires also vary with temperature, although such a variation is smaller than the one of racing cars; however, the performance of sport cars is still massively influenced by tire temperatures. The heat coming out of high performance driving is transferred in different ways throughout the tires, resulting in very big temperature variations within the tire parts. The tire surface in contact with the road can get warm very quickly because of friction energy in the contact patch, and can also cool down rapidly because of air convection and heat conduction into the track. On the other hand, the inner liner has much smaller and slower variations in temperature, partly because of the relatively low thermal conductivity of the rubber compound. These two spots where the tire temperature is usually detected have an influence on tire characteristics which are relevant for vehicle dynamics: the surface temperature correlates with grip, the inner liner temperature with cornering stiffness [1]. The measurement of these quantities requires additional (and reliable) sensors, setting a tough task.

F. Büttner, Michael Unterreiner, P. Bortolussi
Valid vehicle dynamics prediction by objective description of tyre behavior under real operating conditions

This manuskript is not available according to publishing restriction. Thank you for your understanding.

Sebastiaan van Putten, Günther Prokop, S. Einsle, A. Wagner
Dynamic measurements and simulation of road surface characteristics

Driving simulators often use fictitious roads for different vehicles and driver analysis. However, sometimes models of real roads are better depending on the scope of research. For that purpose, a method to transfer the geometry of real roads and their surface characteristics into the format of driving simulators was developed. In the next step, the effects of some of these road surface characteristics on drivers should be simulated with the help of models and real-time transfer functions in the simulator. For the measurement of roads and their surface characteristics, a car has been equipped with different sensors. With the help of a purpose-made software, the postprocessing of the measured data occurs offline and semi-automated. This software converts the measured data into the formats “OpenDRIVE®” and “OpenCRG®”, which are widely used in driving simulators, as well as in the driving simulator of the Research Institute of Automotive Engineering and Vehicle Engines Stuttgart (FKFS).

Wolfram Ressel, Marcos Manuel Sanchez, K. Tejkl
Experimental investigation of urea-water sprays in selective catalytic reduction (SCR) systems

Urea-SCR (selective catalytic reduction) is currently the state-of-the-art NOx reduction technique for Diesel engines. The main challenges for the implementation of mobile urea-SCR systems include rapid decomposition and homogeneous distribution of urea and the mitigation of deposit formation. A key affecting these performance factors is the injection of the urea-water solution (UWS). However, urea-water sprays under exhaust flow conditions have not been studied extensively so far. The present study is a comprehensive analysis of the behavior of the UWS spray. The investigation was conducted with a 3-hole commercial SCR injector. The spray properties under exhaust flow conditions are described by non-intrusive optical techniques: shadow imaging and Mie scattering. The spray cooling effect on the exhaust channel wall is analyzed based on the temporal and spatial evolution of the wall temperature using infrared thermography. This work is also complemented with the investigation of the specific behavior of UWS droplet during the wall impact over a wide range of temperatures and urea concentrations. This fundamental study provides information on the characteristics of UWS droplets evaporation time, the boiling regimes and the wetting conditions, which enhances the understanding of the wall impingement of urea-water sprays.

Yujun Liao, L. Nocivelli, P. Dimopoulos Eggenschwiler, A. Spiteri
The influence of organometallic additive in gasoline on the exhaust gas aftertreatment components

As a rule, metal containing additives are not used in fuel in the European Union. A limit of up to 6 mg of manganese per liter of gasoline was introduced in the revised Fuel Quality Directive in 2011. In this paper, the influence and risk of metal containing additives on the aging of exhaust system components over full useful life of 160,000 km is verified, using the example of an additive containing 6 mg of manganese per liter as a basis. The investigations were carried out on a certified roller dynamometer by means of two endurance tests with vehicles running on metal-free fuel and fuel containing metal. Both vehicles were equipped with a typical state-of-the-art downsizing gasoline engine with a Euro 5 application. Euro 5 reference fuel was used as the basis for gasoline. The exhaust emissions were analyzed at fixed intervals over the endurance run. In order to a better understanding of the NEDC emissions results, the characterization of the exhaust system was supported by measurements of the oxygen storage capacity (OSC), an endoscopy and a computed tomography of the catalytic converter. The results of the investigations are presented and discussed. It is shown that the increasingly strict emission limits require improved fuel grades. Using metal containing additives in fuel poses a risk to modern engines and highly efficient exhaust aftertreatment systems and therefore also to the environment.

Wolfgang Reiser, D. Wiese, A. Binde
Impacts of Diesel-HEVs on exhaust gas aftertreatment systems for future emission legislations

The ongoing electrification of Diesel powertrains along with the introduction of new test procedures by the European Union creates new challenges for the development of the next generation of exhaust gas aftertreatment systems. The electrification leads to changed operating conditions of the combustion engine resulting in temporarily higher engine-out emissions and simultaneously lowered exhaust gas temperatures. Additionally, the exhaust gas aftertreatment system will have to deal with higher exhaust gas mass flows, due to the upcoming new test procedures and real driving emission tests. Therefore the boundary conditions at Diesel-HEVs require a close coupled positioning especially of the DeNO

x

function to ensure high conversion rates over wide range of operating conditions and engine out emissions. The DeNO

x

potential of different exhaust gas aftertreatment systems for the use in Diesel-HEVs will be discussed in this paper. On the one hand, the applied testing methodology includes tests at the Engine-in-the- Loop (EiL) testbed. With the EiL testbed the simulation of different powertrain configurations is used to show the influence of these configurations on the thermal conditions in the exhaust gas aftertreatment system and to evaluate the emissions and their conversion. On the other hand, on road and vehicle dynamometer measurements with state of the art Diesel-HEVs are used to determine the NO

x

emissions and thermal conditions during real driving scenarios.

Christoph Rathgeber, Christian Beidl, P. Spurk, U. Göbel
A quasi-dimensional charge motion and turbulence model for engine process calculations

This paper describes the development of an in-cylinder turbulence model for use in an engine process calculation. The model calculates (zero-dimensional) turbulence quantities for a predictive burn rate model (homogeneous SI engine). The model is based κ-ε turbulence model. As a key feature, a quasi-dimensional tumble model is presented. Tumble generation and respectively turbulence production and decay of the tumble are modeled on a physical basis. Tumble generation is calculated as a function of stationary tumble numbers and boundary conditions obtained from a 1D-CFD calculation. A calculation of tumble spin-up is discussed. For the in-cylinder turbulence production, tumble, inflow, piston motion and compressibility are taken into account. Dissipation is calculated on the basis of turbulence length scales defined by cylinder geometry and intake valve lift. In addition, during intake an inhomogeneous distribution of turbulence in the cylinder is taken into account. A connection of the developed turbulence model to a predictive burn rate model is presented in the second part of this paper.

Christoph Bossung, Michael Grill, Michael Bargende, O. Dingel
Alteration of fuel properties at extreme conditions – Formation of deposits in common-rail injectors

Engine and FIE manufacturers are facing an increased number of complaints on abnormal engine functioning related to internal diesel injector deposits (IDID). Possible consequences are increased emissions, rough engine running and misfiring due to impairments in the timing of the injector or modified injection quantities as well as serious engine damage by permanently incorrect injection or sticking needles/valves. It is expected that the introduction of more complex injection strategies and highly accurate but sensitive injection components into future engine generations will exacerbate the risk of dysfunctioning. Yet, there is still uncertainty about the detailed chemical structure of the deposits and the mechanisms involved in its formation. In the literature certain additives, biofuel components or metal traces are held responsible for being the root cause of deposit formation.

Christian Fink, Svetlana Crusius, Ulrike Schümann, R. Junk, Horst Harndorf
Impact of H2-admission to natural gas on gas engines

The increasing amount of renewable energies, to be specific solar and wind power, will lead to a further increasing difference between the production and consumption of electrical energy. One possible solution to handle this discrepancy is to store the excess electrical energy in form of chemical energy. In this particular case storing energy in form of hydrogen in the natural gas grid will be considered in more detail. The target of the literature survey is to identify the possible amount of hydrogen addition into the gas network and the consequences for the operation of combustion engines. Therefor the possible future scenarios of the energy supply were investigated. Then a closer look was taken at the natural gas infrastructure to derive limits for the hydrogen concentration. In addition current technologies to store energy and their future development were considered. Afterwards the impacts of the hydrogen admixture on the operation of combustion engines were examined in the scientific research. To summarize, the natural gas grid is not the limiting factor for the hydrogen concentration in natural gas. And thereby it is not possible to predict exactly the future limitations, because it will be a compromise between the three parties politics, gas suppliers and customers. The principal effects of hydrogen/natural gas-mixtures on the combustion process and operation of engines were identified in the literature survey.

Stefan Weber, L. Baumgartner, G. Wachtmeister
Electronic horizon: Flexible implementation of predictive driver assistance features

Digital maps and navigation systems are not only a great assistance for the driver himself. An increasing number of vehicle functions in the domains of energy efficiency, safety and comfort, called ADAS (Advanced Driver Assistance Systems), use information about the driving route and its environment from the digital maps. The map data thereby dispose of a much greater range and complete the information provided by the usual radar, video and ultrasound sensors. For example, digital maps can provide the topography and curvature of the route ahead over several kilometres in order to efficiently control engine and gearbox. This so-called electronic horizon provides the developer with the possibility of looking ″around the corner″, among others. The camera installed behind the windshield for traffic sign recognition can only register objects in the field of view of the vehicle. If however, the driver wants to turn at the intersection, indicating this with his turn lights, the maximum admissible speed after the turn may be determined from the map data before the camera even has the opportunity to register the relevant sign.

Jürgen Ludwig
Robust estimation of vehicle sideslip angle from variables measured by ESC system

The vehicle sideslip angle β is one of the most important variables for evaluating vehicle dynamics. In particular, several studies has shown that its knowledge may allow the design of ESC systems having significantly better performances over the standard ones based on yaw rate control, see e.g. [1,2]. However, direct measurement of β requires the use of complex and expensive devices (based on optical or inertial+GPS technologies) which cannot be used in production cars. Therefore, the estimation of the sideslip angle from signals measured from standard ESC sensors (steering angle, longitudinal speed, yaw rate, lateral and longitudinal accelerations) has been intensively studied in the last years, see e.g. [3,4,5,6] and the references therein. All these investigations are based on a Two-Step design procedure: a suitable model of vehicle dynamics is first identified making use of experimental data measured on a testing vehicle; then one of existing observer/filtering method (Kalman Filter, Sliding Mode Observer, Moving Horizon Estimator, …) is used for designing the estimator, here called TSVS/SA (Two-Step Virtual Sensor of Sideslip Angle), see Figure 1A.

Mario Milanese, C. Novara, I. Gerlero
Application of haptic signals for driver to car communication during autonomous driving

Numerous data sets revealed that there are diverse expectations regarding the use of highly or fully automated driving. Hereinafter, for “fully automated driving” the term “autonomous driving” will be used. For example, a survey published by Ernst & Young [5] stated that people expect higher efficiency, more safety, a better traffic flow and more time for doing something else while driving. Especially the latter, “having more time for doing something else” indicates a change in the general understanding of “how car driving has to be” or the way it should be once autonomous driving is available. Until recently research focused mainly on the active role of the driver with regard to driving and to vehicle control in general, etc. Nowadays, however, there is a new component in automotive research, pointing towards a more passive role of the driver in which s/he still wants to use a car without focusing all one’s attention on driving. Instead, the current mindset favors using a vehicle simply for getting from A to B. A “driver” meanwhile (who does not actually do much driving anymore) can perform secondary tasks.

Christoph Liedecke, G. Baumann, Hans-Christian Reuss
Exploiting the potential of eye movements analysis in the driving context

Driving is a complex and highly visual task. With the development of high-end eyetracking devices, numerous studies over the last two decades have investigated eye movements of the driver to identify deficits in visual search patterns and to derive assistive, informative, and entertainment systems. However, little is known about the visual behavior during autonomous driving, where the driver can be involved in other tasks but still has to remain attentive in order to be able to resume control of the vehicle. This work aims at exploiting the potential of eye movement analysis in the autonomous driving context. In a pilot study, we investigated whether the type of the secondary task in which the driver is involved, can be recognized solely from the eye movement parameters of the driver. Furthermore, we will discuss several applications of eye movement analysis to future autonomous driving approaches, e.g., to automatically detect whether the driver is being attentive and – when required – to guide her visual attention towards the driving task.

Christian Braunagel, W. Stolzmann, E. Kasneci, T. C. Kübler, Wolfgang Fuhl, Wolfgang Rosenstiel
System design and optimization of The Ohio State University Electric Motorcycle for the 2014 Isle of Man TT Zero Race

The Ohio State University Buckeye Current Team was formed in 2010 at the Center for Automotive Research, to provide our students a practical experience in designing and building electric motorcycles to compete in national and international races. The mission of the team is to teach students about electric vehicles, promote electric vehicle events, and give them an engaging educational work environment through real-world experiences. The Team achieved international recognition with a prestigious 3rd place finish in their inaugural effort at the 2013 Isle of Man TT Zero race. The all-electric motorcycle RW-2, designed and built entirely by OSU engineering students, raced on the Snaefell Mountain Course averaging 90.43mph. This paper illustrates the design and engineering process that the Buckeye Current Team followed with the objective of participating again to the TT Zero race in 2014. The paper details the technical solutions that have been implemented, including vehicle energy simulation and scenario analysis, mechanical and electrical design, control development and data logging system.

A. Bonnell-Kangas, P. Brodsky, J. Cline, N. Lord, Marcello Canova
Venturi Formula E Team in the 100 % Electric New FIA Championship

This manuskript is not available according to publishing restriction. Thank you for your understanding.

Nicolas Mauduit, G. Pastor
The fastest electric vehicles on earth: A history of electric land speed racing and of the Venturi Buckeye Bullet program

For more than two decades the Buckeye Bullet landspeed racing team at The Ohio State University’s Center for Automotive Research has pushed the absolute limits of electric vehicle racing. From batteries to hydrogen fuel cells, the team holds every national and international speed record in the unlimited weight class, with top speeds well into the 300 MPH range. The mission of the team is to push the automotive technologies of tomorrow to their maximum performance limits, while training the next generation of automotive engineering leaders in a new and exciting way. With this mission in mind the team is currently developing the ultimate landspeed electric vehicle, the Venturi Buckeye Bullet 3. The VBB3 is powered by more than 2.5 megawatts of the latest generation of lithium ion batteries, cutting edge IPM motors and variable frequency drives. For the first time since the Jamais Contente in 1899, an electric vehicle has been designed with the intent of directly competing with its fossil fueled counterparts. The team hopes to push the electric landspeed record over 400 MPH and eventually set the ultimate wheel driven record in excess of 450 MPH. This paper illustrates the model based design of the vehicle architecture, vehicle packaging and aerodynamic design strategy, selection of a battery technology and development of the pack, integration of the electric powertrain, and the testing results to date. The paper concludes with an overview of the work to be carried out in 2015 as the team prepares for 400 MPH world record attempts.

Giorgio Rizzoni, D. Cooke, G. Pastor
Development of a four-wheel drive electric racecar

Formula Student is the first racing series where combustion cars race against electric ones. We will highlight the competiveness of the electric concept. Furthermore you will be introduced in the development of such a four-wheel driven electric racecar.

Benedikt Bauersachs, D. Mitrovic, S. Schmidt
Automotive industry without conveyer belt and cycle – research campus ARENA2036

The main driver within the framework of integrated industry (Industrie 4.0) is a holistic and integrated resource efficiency. The production of the future is based on flexible and highly qualified staff which will operate intelligently automated processes. The future of the digital factory is distributed, decentralized and smart – and this complex production will organize itself on the base of real time information and cyber-physical systems (CPS). Complexity in this environment must not only be handled, mastered and administered but downright be operated and actively managed. In the University of Stuttgart’s cooperative research campus ARENA2036 this notion is integrated into an innovative smart research factory for lightweight automotive production.

Thomas Bauernhansl
Robots as enablers for changeability in assembly applications

After giving an introduction into the basic concepts of changeability and recent developments in industrial robotics, the paper analyses the requirements for change-enabling robot systems based on three transformation scenarios: lot size change, product geometry change and process change. As a result, change-enabling robot systems that can cope with the mentioned transformation scenarios must support integration into manual work stations and must be highly modular to allow adaptation of hardware and software with little effort. The remaining paper describes a door module assembly use case, develops a concept of a change-enabling robot system for this use case and evaluates the robot system applied to this use case with regard to cycle time, costs and the three transformation scenarios.

Martin Naumann, M. Fechter
Changeable and reconfigurable assembly systems – A structure planning approach in automotive manufacturing

The ability of a manufacturing system to cope with frequently changing or increasing product variants and changing production volumes is a key competitive factor in today’s volatile operational environment. After giving an introduction into the concept of changeability and explaining the interdependence of production system structures and changeability, the paper describes a planning approach for the structure of changeable and reconfigurable assembly systems in automotive manufacturing. The planning approach uses flexibly linked process modules as structural feature of the assembly system’s structural concept. Types of process modules, classified by characteristics of the assembly parts, are designed to perform assembly operations not taking into account product structure restrictions on assembly sequence. Process modules are then located in a layout of chessboard-like pattern under flow-oriented consideration of the product precedence graph. The paper presents a door module assembly use case, for which the assembly system structure was developed using the described planning approach.

Petra Foith-Förster, Thomas Bauernhansl
Changes in production logistics for automobile manufacturing

Changes in the production of automobile will be needed in the next years. This observation is based not only on the higher amount of variations and car models but also on the different power unit alternatives. These transformations can take place only if production logistics changes their processes and workflows. In the context of the research environment ARENA2036, new concepts are being developed at the Institute for logistics and material handling (IFT) in Stuttgart. In this paper we give an overview of these new concepts, their specific operating resources and the results of initial simulation studies.

Karl-Heinz Wehking, J. Popp
A model based system approach to innovative smart intake products: CO2 savings and specific performance

On modern combustion engines, air induction systems are evermore evolving into more complicated elements with an objective to find the best trade-off between fuel consumption, pollutant emissions and engine performance. This pursuit has led to the emergence of the downsized turbocharged engine. For such an engine, it’s necessary to reinforce the low end torque. This is because, at low operating speeds and loads, the lack of enthalpy at the exhaust side causes a poor behavior of the turbocharger which leads to a poor boost pressure and consequently a deficit of engine performance. The proposed idea in this case would be to benefit from an optimized ‘smart’ air intake system to solve this issue while assuring other interesting functions as well. First, cylinder filling can be enhanced by assuring acoustic resonance conditions at the intake. The result is an increase of air flow leading to a better torque response and vehicle responsiveness. Pressure waves induced boosting can also help to reduce the thermal stress on the turbocharger as well as the size of the charge air cooler. Secondly, pressure waves can help to save energy by ‘de-throttling’ at part load operation on an SI engine. This has the effect of reducing the pumping loop and thus enhancing specific fuel consumption. Mechatronic integration into smart systems at the intake is necessary to achieve such goals. The Active Charge Air Duct (ACAD) and the active air intake manifold presented in this paper are innovative plastic products that aim to reduce fuel consumption. This is achieved through geometries with a high flexibility of thermoplastic processes.

Jérôme Migaud, H. Bühl, Vincent Raimbault, A. Korn, D. Chalet, H. Mezher, Q. Montaigne, Pierre Emmanuel Prétot
Electrical 48V coolant pump for highest thermal management requirements

The EU parliament’s regulation sets the average threshold for CO

2

-emissions at 95 grams per kilometer for new vehicles starting in 2020/2021 - in comparison with 130 g/km in 2015. This trend is continuing not only in Europe but in other regions of the world as well. Thresholds for CO

2

emissions in 2020 have been set to about 121 g/km in the USA (then 93 g/km starting in 2025), 117 g/km in China, and 105 g/km in Japan. In order to achieve this level, many mechanically driven components have already been replaced with electrical systems. The rising proportion of hybrid vehicles promotes the trend toward electrification. With regard to the development of the combustion engine, simplification or even elimination of the belt drive for engine auxiliaries characterizes efforts for future vehicles. Eliminating of the belt drive allows the friction in the combustion engine to be minimized, thus increasing its efficiency. This opens the door for fuel savings and therefore results directly in lower CO

2

-emissions.

Michael Krappel, Claire Heidecker, Simon Streng, Alfred Elsäßer
Aspects of engine start/stop comfort

In this paper, the start/stop process of combustion engines is considered as a functional chain from excitation over amplification mechanisms acting on the vehicle body and finally on the passengers. The functional chain is lined up in three fields to display the causality of the different influencing parameters: “Engine Excitation at Start/Stop”, “P/T Body Oscillation System” and “Vehicle Body”. For each field, exemplarily parameters are chosen to improve the start/stop behaviour. In the thematic field “Engine Excitation at Start/Stop” a comparison between a conventional key start to a re-start of a gasoline engine is shown. The excitation mechanisms are depicted and a countermeasure is derived to reduce the excitation in the shown example. In the field “P/T Oscillation System”, the eigenfrequency shift of the most critical P/T body mode as countermeasure has proved effectivity in vibration reduction. Further on, the advantage of a 24V/48V starter regarding vibration reduction is outlined. The last chain element “Vehicle Body” provides an explanation of vehicle sensitivity in different directions of the vehicles´ coordinate system. Finally, the human perception of vibrations is projected on the engine start/stop event. The relevant weighting functions, which take the frequency depending perception into account are outlined. A comparison of two NVH metrics to objectify the sense of vibration is conducted.

F. Wolter, G. Eisele, Christoph Steffens, T. Wellmann, K. Govindswamy
Autonomous driving and e-mobility, technical challenges and benefits

From a first perspective, there are no functional differences between electrically driven vehicles and conventional fossil fuel vehicles with respect to automatic driving. The machine perception of the vehicle’s surroundings is enabled by various sensors, such as camera or radar sensors, fully integrated into the vehicle (see Fig. 1). Additional information about the static driving environment is usually provided by a highly precise digital map. However, these maps can only be used when the vehicle exactly knows its global position. Therefore, an automated vehicle also requires a selflocalization module for map matching. The result of the machine perception is referred to as environment model. It comprises of the dynamic state of the vehicle itself as well as objects of the surroundings, embedded in a static environment. It should also contain all the relevant infrastructure elements such as traffic signs and traffic lights, as well as structuring elements like traffic islands, curbstones, road markings, closed areas or pedestrian crossings.

Klaus Dietmayer, Michael Buchholz, Jürgen Wiest
The impact of the introduction of DoIP and Ethernet for the development of electric vehicles – Use cases and benefits

In recent years, automotive development has been driven by major trends such as new powertrain concepts (e.g. for electric or hybrid vehicles), new exhaust systems (e.g. SCR emission treatment) and extended functionalities (e.g. start/stop systems, kinetic energy recovery and batteries for the storage of drive energy). These developments have led to an extension of the complexity of these systems and thus of the diagnostic functionality. Accordingly, the algorithms used in the self-diagnostics of control units represent a significant proportion of the source code. In current control units, this fraction can already reach 50% of the source code. Increasingly, stringent requirements for the accuracy of OBD functions together with the requirement for more comprehensive monitoring of vehicle operation (in-use monitoring) and permanent fault logging has led to functional extensions of the control unit software. The increasing complexity of the electronic control systems has led to a huge number of tunable parameters in the used algorithms. And this seems to be further increasing in the future. Also the amount of data that has to be programmed into the electronic systems at the end of the production line is continuously increasing. And as the time is critical during production, high bandwidth flashing technologies are necessary to run an efficient process.

Thomas Kotschenreuther, A. Rupalla
Prüfung eines Batterie-Management-Systems mittels Batteriezellen-Simulator und Testautomatisierung

Die Batterie für den Antrieb eines Elektrofahrzeugs besteht i.d.R. aus 96 bis 120 Einzelzellen und einem Batteriemanagementsystem (BMS), welches die Einzelzellen überwacht. Ein Defekt einer einzigen Batteriezelle führt zum Ausfall der Gesamtbatterie. D.h., die Gesamtbatterie ist nur so gut wie deren schlechteste Batteriezelle. Batterieausfälle können durch Überladung, Tiefentladung, eine zu niedrige oder zu hohe Umgebungstemperatur oder schlechte chemische Eigenschaften auftreten. Die wesentliche negative Beeinflussung ist jedoch, dass durch Produktionstoleranzen und Alterung die Zellen in ihrer Spannungslage auseinander driften. Für eine lange Lebensdauer und damit verbundene längere Reichweite auch nach einer gewissen Zeit, müssen die Spannungs-Niveaus aller Zellen gleich gehalten werden. Mit Hilfe von sog. Balancing-Verfahren werden schlechte Zellen „regeneriert“. Das Batterie- Steuergerät sorgt damit nicht nur für die Sicherheit der Batterie, sondern auch den Ausgleich der Zell-Spannungen. Um nun sämtliche Sicherheitsmechanismen, aber auch Algorithmen wie das Zell-Balancing prüfen zu können, wird ein Batteriezellen- Simulator/Emulator mit benötigt. Die emulierten Batteriezellen sind in all ihren Eigenschaften parametrierbar und können so für das Batteriemanagementsystem alle notwendigen Zustände bzw. Störungen emulieren. Um sowohl die Ladung als auch die Entladung einer Batteriezelle nachbilden zu können, werden am Batteriemanagementsystem pro Zelleingang jeweils eine Quelle und eine Senke benötigt.

Anita Athanasas, Kiriakos Athanasas
Integration of modularized battery technology into a stationary storage for electric vehicles

At the Electrical Mobility Laboratory of the University of Applied Sciences Dresden, a smart, versatile applicable and mobile energy storage system has been designed, built and tested in university-owned Light Electric Vehicles (LEV). Based on market research, a battery assembly was dimensioned with commercially available lithiumion batteries. To protect and monitor lithium-ion cells, a circuit has been developed which is able to communicate with other batteries using power-line communication (PLC). Furthermore, a photovoltaic charge controller for the battery system is presented, that can be used in a battery exchange station.

M. Hübner, Felix Gottwald
Mercedes-Benz SLS AMG Coupé Electric Drive NVH development and sound design of an electric sports car

Mercedes-AMG GmbH is known for its high-performance vehicles and driving concepts. In 2009, Mercedes-AMG launched it’s first entirely own car – the Mercedes- Benz SLS AMG. A derivative of the legendary super sports car, a fully electric vehicle was developed and launched in 2013. In this article, the NVH characteristics and sound enhancement system of this electric version are presented. Boasting 751 horsepower, the SLS AMG Coupé Electric Drive is the most powerful electric passenger car on the market (see Figure 1). Considering the new powertrain setup, developing the NVH characteristics is an important challenge. Unlike in conventional cars, road noise or gear whine is not masked by a combustion engine in this car. One focus is on optimizing the auxiliary components for NVH response as well as coordinating the electric motor and transmission. To implement a sound design strategy, a synthetic sound system called ″SLS eSound″ was developed. The target objective is to achieve well-balanced sound enhancement to underscore the powerful presence of a sporty AMG car and the future of electric powertrain technology.

Oliver Engler, Marcus Hofmann, Roman Mikus, Torsten Hirrle
Motion behaviour of ball joints in automotive chassis with respect to structure-borne sound

The dynamic properties of automotive chassis are affected by several different factors. Especially with respect to transmission of structure-borne sound, flexible bearings in chassis play an important role. In contrast to elastomer bushings, friction afflicted ball joints have not yet been studied with regard to this specific aspect [1]. In order to analyse their dynamic properties, a component test bench was developed, which is used to measure the rotational motion behaviour of ball joints in-depth. Based on vehicle test runs, a specific excitation range was defined to meet realistic boundary conditions for the experimental examinations. The experimental results show conditions of sticking and sliding due to specific operating states depending on low frequency vibrations. These results form the background of the ball joint model. In this context, the biggest challenge is to describe the nonlinear component characteristics in time domain simulation. To identify parameters and to improve the understanding of mechanisms in moving ball joints, a numerical model approach was further developed which considers nonlinear effects. The comparison of experimental and simulation results show the ability of the model to calculate the ball joint behaviour in time domain simulation. Figure 1.1 shows the structure of the used approach.

Thomas Jeglitzka, Jochen Wiedemann, D. Schulze-Fehrenbach
Determination of acoustic contributions of car components to the far field using transfer functions

The exterior noise of a vehicle is an increasingly important criterion for the homologation of road vehicles. According to DIN ISO 362-1, it is measured by a standardized procedure, where numerous perturbations exist. Therefore, the aim of the current research is the transfer of this procedure into acoustic chambers with roller test benches, the so called simulated pass-by. In this contribution, a new method for the determination of the exterior noise of vehicles in an early stage of the development process is presented. For that matter, a virtual acoustic vehicle model, based on measurements on a roller test bench in an acoustic chamber is to be developed. By the use of a modular structure, it allows conlcusions about the influences of modifications of single components of the vehicle. Therefore, the airborne transfer functions from dominant sound sources of the vehicle to the microphone positions in the far field are determined reciprocally, using a dodecahedral speaker and a vehicle on the roller test bench at IPEK – Institute of Product Engineering. The vehicle measurements and the airborne transfer functions are used to establish a virtual acoustic vehicle model in the time domain using digital filters. The playback of this model is carried out in the flexible audio-visual stereo projection system at the competence center virtual reality at TU Ilmenau.

A. Albers, David Landes, Matthias Behrendt, Christian Weber, Antje Siegel, S. Husung
Hybrid TPA method applying measurement and simulation

For correct detection of noise sources and their path into a vehicle Transfer Path Analysis (TPA) is more or less a state of the art method. The basic idea is to evaluate specific potentials of countermeasures to reduce disturbing noise based on results of a TPA. Unfortunately the complexity of a TPA, needing correct specification for all relevant paths and acting forces make this method costly and time-consuming. For this reason in many cases it is not first choice once acoustical problems occur on a vehicle in testing. It is very common that project management, once faced with costs and duration for a complete TPA, requests to go ahead with simpler, heuristic “try-out”-methods. Based on our experiences in several projects, we implemented a very efficient TPA method to enable a quicker analysis. A key to success was to join the potentials of simulation with efficient measurement methods to get results for the most important noise paths into the vehicle quickly. We called our method of TPA “hybrid”, due to the fact that both, measurement and simulation, is applied. As rolling noise TPA is a very complex topic, and reduction of rolling noise becomes more important in time of electrification and hybridization of vehicles, we focus on rolling noise TPA. This paper describes the method Magna Steyr Engineering developed and shows some examples of successful application.

Alexander Rabofsky, W. Reinalter, T. Eggner
Driving with fire – Ways to CO2 free mobility

Since the Copenhagen Climate Change summit in 2009 the UN agreed not to exceed a 2o global warming. A 50% chance to achieve this goal is to reduce the worldwide (ww) greenhouse gas (GHG) emissions by 2050 to 50% of the 1990 level with an emission peak not later than 2020. Industrialized countries have to reduce GHG emissions by 80 to 95% in this timeframe while emerging countries have to return to the 1990 level by 2050. As fig. 1 shows we are actually far above the target line on a worldwide basis.

Rolf Leonhard
The future of the diesel engine as a means of propulsion in passenger cars

BMW meets future mobility requirements with a dual development. In addition to the introduction of alternative drive concepts, intensive work is under way on the enhancement of more efficient combustion drives. As a CO2 avoidance concept, diesel engines play an important role here. In Europe, this drive principle has captured very high market shares in the last 20 years – at BMW, more than 75%. Diesel vehicles are also well accepted in regions outside of Europe. The opportunity as a CO2 avoidance concept, however, faces stiff challenges in the form of future exhaust emissions legislation (RDE, US SULEV). This discussion points out the relevant challenges and technological solution approaches. In addition to approaches involving internal engine measures, possible exhaust re-treatment systems, a balanced engine portfolio (right-sizing), as well as efficient electrification approaches for diesel engines will also be discussed. Different packages to effectively address the challenges of the future can be compiled from the above-mentioned technology fields. With the required development boost, future passenger car diesel engines will become ’Blue Performance’ drives over the long term.

Fritz Steinparzer, P. Nefischer, W. Stütz
The future of gasoline engines

Both the future test cycles and more fuel-efficient transmission and electrification concepts are shifting the ICE operation towards higher engine loads. Whereas in the past, FE measures with Gasoline Engines were mainly concentrated on the reduction of throttle losses, in future the extension of the sweet spot area becomes decisive. Consequently, a complete re-evaluation of existing technologies as well as new technology approaches are required also in view of the simultaneously aggravated limits for pollutant emissions. Highly differentiated market demands will result in an increasing differentiation of specific power between “Top Performance / Image Concepts” heading up to 200 kW /l and “Fuel Economy Concepts” targeting a minimum BSFC of 200 g/kWh. In spite quite different boundaries, various base elements like knock resistant combustion systems, highly efficient charging devices, optimized friction, etc. can be utilized both for highest power and for best efficiency.

Günter Fraidl, P. Kapus
Worldwide Harmonized Light-Vehicles Test Procedure (WLTP) und Real Driving Emissions (RDE) – aktueller Stand der Diskussion und erste Messergebnisse

Die Abgasemissionen von Pkw und leichten Nutzfahrzeugen in Europa werden mit Hilfe des Neuen Europäischen Fahrzyklus (NEFZ) unter definierten Umgebungsbedingungen im Labor ermittelt und bewertet. Dabei wird nur ein Teil der im realen Verkehr auftretenden Fahrzustände erfasst. Zurzeit werden verschiedene neue Verfahren zur Bestimmung der Abgasemissionen und des Energieverbrauchs von Pkw und leichten Nutzfahrzeugen diskutiert. Die Expertengruppe „Abgas und Energie“ der Vereinten Nationen (UNECE) erarbeitet eine neue Testprozedur, um die Bewertung der Abgasemissionen und des Energieverbrauchs von Pkw und leichten Nutzfahrzeugen weltweit zu harmonisieren (Worldwide Harmonized Light Duty Test Procedure; WLTP). Im Mittelpunkt stehen die Entwicklung des Fahrzyklus und der Prüfprozedur. Auf EU-Ebene wird diskutiert, wie man die im realen Straßenverkehr auftretenden Emissionen (Real Driving Emissions = RDE) ermitteln und bewerten kann. Eine Möglichkeit zur Messung von Real Driving Emissions ist die Verwendung von mobilen Messsystemen. Ein Portable Emission Measurement System (PEMS) wird in das Fahrzeug eingebaut und ermöglicht die Messung der Abgasemissionen im Straßenverkehr.

Helge Schmidt
The new generation of rear-wheel-drive transmissions at Mercedes-Benz

Mercedes-Benz developed a new generation of rear wheel drive manual transmissions due to increased CO2-requirements as well as increased shift comfort expectations. The new generation of manual six-speed transmissions was developed together with ZF Friedrichshafen and is based on there already known MT10 transmission. The modified architecture enables fuel savings of up to 8g CO2/km (NEDC cycle). The focus of developing the new transmission generation is based on reduced weight as well as a reduction in fuel consumption and on the new innovative Mercedes-Benz Clutch Protection System. Beyond this, Mercedes-Benz especially focused on an improvement of shift comfort, which will set a new benchmark in the premium segment. The new generation of rear wheel drive manual transmissions will be seen in various rear-wheel-drive models. The rollout already started with the new generation of the C-Class in March 2014.

Ralf Koesling, Tobias Gödecke, K. Mühlebach, A. Franke
Quality assurance of adhesive processes in the body shop

The need for a suitable joining technology for multi-material combinations in car bodies of the future has been constantly growing. Here, adhesive technologies offer a number of advantages as well as a great development potential. In order to ensure the performance of the entire vehicle, especially in relation to crash safety, rigidity and corrosion, quality assurance methods are required that ensure the efficiency of adhesive bonds, both in applicability and costs. Present-day conventional destructive test methods must be supplemented by non-destructive methods. A preventive quality management which is already used in the early stages of development by means of simulation methods can help reduce inspection costs and expensive reworking in the prototype phase. For this purpose it is necessary to analyse the processes employed in the manufacturing process of the car body in order to improve simulation with the aid of appropriate laboratory experiments. Initially, basic reaction kinetics tests are presented to demonstrate the heating rate dependency of glass transition temperature and the reaction process of a 1K epoxy adhesive. Finally, the requirements for an advanced testing methodology are defined in order to ensure and improve the quality of adhesive bonding in vehicles.

Jaan Mattes Reiling, P. Middendorf, Manfred Sindel
Next generation car – Lightweight design through function integration in vehicle structures

The „Next Generation Car” (NGC) project combines the research activities of the German Aerospace Center (DLR) in the area of road vehicles. The aim is the development of vehicle concepts and structures, with a high energy efficiency. Under the roof of NGC the DLR develops different vehicle concepts. The concepts have different aims and requirements, e.g. driving distance, number of passengers or maximum speed and should give answers for future vehicle structures. The challenge is to fulfill opposed requirements, e.g. mechanical performance (e.g. crash) and economical values (e.g. costs). At the example of the concept of the „Safe Light Regional Vehicle“ (SLRV) we will show the development of a light and safe body in white (BIW) structure. The BIW realizes special requirements, e.g. packaging, fatigue strength, stiffness and crash performance within a 2 passenger vehicle concept with a mass lower than 500 kg. The BIW design is a sandwich structure with a resulting structural mass of only 90 kg. Simulations indicate that the crash performance is very good, even if the mass of the BIW is so light. The simulations are validated by component crash tests. The result will be shown in this paper.

Gundolf Kopp, S. Brückmann, M. Kriescher, M. Ruff, H. E. Friedrich
Optimization of DPF regeneration with a cylinder pressure based combustion control

Due to steadily tightening exhaust emission legislations and average fleet consumption the optimization of Diesel engines and its after-treatment is necessary more than ever. Therefore, an optimized interaction between combustion and exhaust after treatment is getting more and more important for meeting further emission legislation targets and reducing fuel consumption. Due to its effective filtration efficiency of particulate matter, the wall-flow Diesel Particulate Filter (DPF) has been established as a basic technology of exhaust after-treatment. With increasing accumulation of particulate matter the exhaust back pressure rises, which necessitates a regeneration of the DPF at regular intervals. As the engine exhaust temperatures required for DPF regeneration are not achieved in normal combustion mode, except during full-load operation, the engine management system has to take different measures to raise the exhaust temperature, if no fuel additives are used. This is usually done by a special combustion mode with intake throttling and a modified injection profile. In order to make the combustion inefficient the fuel is injected as late as possible. The latest possible crank angle is limited by combustion stability. Exceeding this stability limit leads to unstable combustion and in the worst case to misfire.

Nikolaus Held, T. Betz, F. Duvinage, P. Lückert
Trigger wheel based misfire detection for sports cars with eight or more cylinders

Whether 4 or 12 cylinders, small load or high load, even the best engines can experience misfire. If the engine “misfires”, there has been a very weak combustion or no combustion at all. Without a well functioning misfire detection system there is a risk of critical damage to important parts such as the catalyst in case of engine misfire. Additionally the negative influences of misfire on the car’s emission levels are harmful for the environment and violate legislative provisions. Especially in California there are very strict legislations by the Air Resources Board concerning misfire monitoring. Not meeting those means that the car does not get a technical approval. From a hardware point of view, there are three common misfire detection techniques. Sorted by commonness starting with the highest they are: Trigger wheel based, ion current and pressure indication. The trigger wheel based approach does not need additional hardware and therefore is favored over the others if it allows a sufficient detection. Using this method in sports cars to avoid the expensive ion current solution has proven more and more challenging in modern drivetrains. Providing development, calibration and consulting for a vast variety of especially sports cars over the past years, Bosch Engineering GmbH has established a broad experience in this topic to be able to meet the challenges of the future. This paper gives an overview over the basic functionality of a trigger wheel based misfire detection system as well as the newest developments regarding calibration support by simulation and variable parameterization.

Christoph Junker, Heiko Schmid
Intelligent control of the automated calibration of engine management systems by using a new calibration process scheduler

The development of engine management systems of the last two decades was characterized by an exponential increase of functionality driven by the increasing emission laws from the legal authorities. This increasing complexity included mainly new control functions and diagnostic functions. Model based functions for closed- and open loop systems have been developed in order to increase the quality of the control quality. In order to adapt those functions easily at different vehicles, engines, transmission and other electronic control systems in the vehicle, the concept of “calibration” of those functions has been established. Based on maps, curves and scalar parameter, the adaptation can be calibrated with those parameters to the characteristic behaviour of the respective actuators and sensors of the system.

Sven Meyer
Increase in range of a battery electric vehicle by means of predictive thermal management

Battery electric vehicles (BEV) allow local emission free travelling and are also capable of reducing the anthropogenic emission of CO2. Since the waste heat of a BEV is much smaller than in any combustion engine driven car the energy for the heating of the cabin has to be taken from another source. If the energy is drawn from the traction battery the driving range is affected severely. Hence, offering more comfort and extending the driving range become counteracting development strategies. To predict how the driving range is influenced by the need for comfort a predictive simulation tool was developed. The paper will show how the range of the battery electric vehicle can be increased by thermal management strategies. The objective of the presented investigations is to quantify the potential of optimizations of the thermal management system. Therefore, the thermal management system is configured in a modular way. Thus, it is possible to attribute savings achieved via single alterations in the system, such as the addition of a cabin heat exchanger or a heat pump. For the use in a BEV the capability of the thermal management system has been increased to be able to include predictive strategies and adapt to the driver’s demands. Furthermore, the effect of preconditioning on the total energy balance and range is analyzed and depicted. This shows the importance of including preconditioning in thermal management to increase the range of a BEV. The paper is a summary of the results of the FVV project “Wärmemanagement an batteriebetriebenen Elektrofahrzeugen (WBEF)”.

Markus Auer, T. Kuthada, N. Widdecke, Jochen Wiedemann
Improving 1D simulations of thermal management systems with embedded 3D CFD

1D simulation tools have been proven to be very powerful and efficient when dealing with sophisticated cooling systems. They allow thermal analysis of engine cooling or air conditioning systems that incorporate several different components such as radiators, condensers, evaporators, thermostats, coolant pumps, batteries and different cooling cycles. A drawback is the limited simulation of the airflow distribution within a cooling module, as illustrated in figure 1. Simulating the flow through a setup with an obstacle and a heat exchanger in 1D would lead to multiple independent flow paths. However, the obstacle would block the path completely, see fig. 1b, since the flow around the obstacle cannot be considered, due to the path segmentation, see fig. 1c. This can partially be compensated by a pressure loss element for the obstacle or by an inflow profile. But these approaches are still limited, provide only a rough estimate and they are error prone, since the necessary parameters are usually not known and profiles must be measured, pre calculated or extrapolated. This leads to more constraints on the simulation and becomes worse considering a real module. The engine, pipes, bumper, crossbars, shroud, fan, header etc. all interact with the flow field and might result in flow separation, cross flows, increased mixture, recirculation and pressure drop etc., see fig. 1d. For a non trivial case a 3D CFD simulation is necessary to fully consider all relevant effects.

Christoph Janssen, M. Effenberger, R. Gneiting, A. Kleber, S. Larpent, R. Stauch
Impact of visual preconditioning on the comfort rating of the vehicle interior

In this paper the impact of visual and haptic information on the comfort rating of the vehicle interior is presented. Comfort and discomfort factors as well as relevant areas for the impression of room in the cockpit are specified. Related perception modes and visual conditioning of the user lead to a mental image of the vehicle and its properties. The vehicle ergonomics test bench and the parametric vehicle model reproduce the impression of the vehicle cockpit. Finally, a user-centered comfort model of room perception in the vehicle is introduced and discussed.

Roland Mandel, J. Klarzyk, T. Maier
Thermal management of Li-ion batteries and its influence on electrical performance

The current development activities for hybrid (PHEV/HEV) or full electric driven vehicles (FEV/BEV) focus on Li-ion batteries as energy storage. Since the amount of storable energy inside an automotive battery pack still prevents longer distances in the electric driving mode, the available energy has to be used as extensively as possible and high power throughput and maximum utilization of the nominal capacity are key development goals. Nevertheless, safe operation is limited to a certain temperature range which makes operation of Li-ion batteries in automotive application without reducing the battery’s life span and without exceeding recommended temperatures a challenging task. The temperature is one of the key factors that influence the electrical behaviour and the ageing characteristics of Li-ion batteries. At low temperatures the output power is significantly reduced [1, 2, 3] and high charging rates cannot be applied. The deposition of metallic lithium at the anode as a result of charging at lower temperatures can cause internal short circuits and can even initiate a thermal runaway of the battery [4]. However, charging at low temperatures occurs while decelerating a cold started electric vehicle with a thermally unconditioned battery pack. Batteries in adequate thermal state on the other hand facilitate a high power output because of reduced ohmic resistances [5] and raised diffusion coefficients inside the battery cell respectively. Whereas charging at higher temperatures is more feasible, the storage of Li-ion batteries (on stock, but also in the parked car) under elevated temperatures has a detrimental effect on the battery’s long-term endurance. More precisely, the calendar life ageing, which reduces the battery’s capacity and increases its ohmic resistances, intensifies with temperature [6, 7].

Daniel Werner, A. Loges, Oliver Heeg, Nic Sautter, Achim Wiebelt, T. Wetzel
Model based software development – solutions for series software

The claim for fast and efficient implementation of functional requirements grows as fast as the complexity of the systems. To cope with these requirements and allow early availability of software, model based methods of software development for embedded systems have been established. Of course these methods influence the whole development process of the software. To answer the question, if model based software development has additional benefits we need a common concept, covering all phases of developing process. By using the example of electric transmission development we show tools and processes used by ZF in this lecture. It makes efficient work possible throughout the whole development process. Quality is mentioned mainly because safety functions are model based as well. The base is a strong orientation on the process attended by quality assurance. To control the growing complexity ZF additional makes use of reuse. This brings a further challenge to model based software development.

Oliver Schneider, Tobias Mindel, Jörg Liebmann, Ricardo Gonzalez Ramos
Vom konduktiven zum induktiven Laden – Herausforderungen für die Software des OnBoard Chargers Steuergeräts

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Dirk Großmann
Physical modeling of environment detection sensors, based on GPU-supported shader technology

Advanced driver assistance systems are mainly based on interpreting traffic situations using the sensor data they get. During the development and trial of the algorithms, it is crucial to provide data sets that are as realistic as possible. There are countless different situations in traffic; to reproduce each of them by doing a test ride is very costly. Therefore the simulation of these situations with virtual sensor models can save effort, time and even replace the test ride in some situations. Flexibility can be achieved by deterministic models, which need very high computation power which complicates the real-time simulation. Sensor physics can be broken down to sending of rays or waves which are reflected by their environment and measured afterwards. The ideal hardware for this kind of real-time simulation already exits – the graphics processing unit (GPU). GPUs are designed for high-grade parallel processing and they include methods for calculating reflections through so called shaders. The challenges are identifying the analogies between shader based light calculation and sensor physics, as well as using them in order to develop a realistic model that can be run in real-time. Ultrasonic sensors used in parking aid systems will benefit most from deterministic simulation. Thus, this work concentrates on these kinds of sensor.

Sebastian Hafner
Contactless energy transfer for main-line rail vehicles

In the context of an increasing importance of electric mobility with the aim to reduce greenhouse gas and noise emissions, railway operators intensify efforts to replace diesel vehicles with locally emission-free electric traction. Therefore more and more tracks need to be electrified. These electrified lines are the primary object of this paper. In 2010, the total electrified track length worldwide amounted to 262,000 km. For main-line electric rail vehicles the power is almost exclusively transmitted through a sliding contact between roof-mounted pantographs and overhead catenary systems. In main-line railway networks both alternating current as well as direct current is applied. Direct current systems (DC systems) hold a share of about 37 % of electrified railways worldwide. However, due to the comparatively low level of nominal voltages of not more than 3 kV, one has to consider that DC systems are inappropriate for high performance main-line operation and especially in high-speed applications. For alternating current systems (AC systems) frequencies of either 16.7 Hz or 50 Hz are applied. Worldwide AC systems using 50 Hz at a nominal voltage of 25 kV are predominant. The global share of 25 kV AC systems is approximately 46 % of the electrified railway networks.

Sebastian Streit, Joachim Winter
BPLE – brake pipe length estimation (detection of brake pipe consistency for freight trains)

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Benjamin Kumpfe
Metadaten
Titel
15. Internationales Stuttgarter Symposium
herausgegeben von
Michael Bargende
Hans-Christian Reuss
Jochen Wiedemann
Copyright-Jahr
2015
Electronic ISBN
978-3-658-08844-6
Print ISBN
978-3-658-08843-9
DOI
https://doi.org/10.1007/978-3-658-08844-6

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