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In einer sich rasant verändernden Welt sieht sich die Automobilindustrie fast täglichmit neuen Herausforderungen konfrontiert: Der problematischer werdende Rufdes Dieselmotors, verunsicherte Verbraucher durch die in der Berichterstattungvermischte Thematik der Stickoxid- und Feinstaubemissionen, zunehmendeKonkurrenz bei Elektroantrieben durch neue Wettbewerber, die immer schwierigerwerdende öffentlichkeitswirksame Darstellung, dass ein großer Unterschiedzwischen Prototypen, Kleinserien und einer wirklichen Großserienproduktion besteht.Dazu kommen noch die Fragen, wann die mit viel finanziellem Einsatz entwickeltenalternativen Antriebsformen tatsächlich einen Return of Invest erbringen, wer dienotwendige Ladeinfrastruktur für eine Massenmarkttauglichkeit der Elektromobilitätbauen und finanzieren wird und wie sich das alles auf die Arbeitsplätzeauswirken wird.Für die Automobilindustrie ist es jetzt wichtiger denn je, sich den Herausforderungenaktiv zu stellen und innovative Lösungen unter Beibehaltung des hohenQualitätsanspruchs der OEMs in Serie zu bringen. Die Hauptthemen sind hierbei,die Elektromobilität mit höheren Energiedichten und niedrigeren Kosten der Batterienvoranzutreiben und eine wirklich ausreichende standardisierte und zukunftssichereLadeinfrastruktur darzustellen, aber auch den Entwicklungspfad zum schadstofffreienund CO2-neutralen Verbrennungsmotor konsequent weiter zu gehen. Auch dasautomatisierte Fahren kann hier hilfreich sein, weil das Fahrzeugverhalten dann –im wahrsten Sinne des Wortes - kalkulierbarer wird.Dabei ist es für die etablierten Automobilhersteller strukturell nicht immer einfach,mit der rasanten Veränderungsgeschwindigkeit mitzuhalten. Hier haben Start-upseinen großen Vorteil: Ihre Organisationsstruktur erlaubt es, frische, unkonventionelleIdeen zügig umzusetzen und sehr flexibel zu reagieren. Schon heute werdenStart-ups gezielt gefördert, um neue Lösungen im Bereich von Komfort, Sicherheit,Effizienz und neuen Kundenschnittstellen zu finden. Neue Lösungsansätze,gepaart mit Investitionskraft und Erfahrungen, bieten neue Chancen auf dem Weg derElektromobilität, der Zukunft des Verbrennungsmotors und ganz allgemein für dasAuto der Zukunft.

Inhaltsverzeichnis

Frontmatter

Automotive landscape 2030+ – Pole position for Germany in autonomous driving

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

Steffen Gänzle

Make or break – Automotive business models at crossroads

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

Ralf Kalmbach

Digital value chain 2030+ – 360°

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Jörg Gnamm

Analysis of rollover behavior of SUVs in the early phase of chassis development

With increasing complexity of vehicle systems, the trends towards decreasing development time and requirements for reducing the number of prototype vehicles, virtual development starting in the early phase has gained significant importance. However, in chassis development of SUVs (Sport Utility Vehicles), rollover stability as a significant aspect of vehicle safety has traditionally been ensured late in the development process, normally shortly before the SOP (Start of Production). Realizing the rollover risk at this phase, chassis design changes to ensure rollover stability have to be taken, which often impairs the preliminary design targets with respect to vehicle dynamics and ride comfort from the early phase. Therefore it is necessary to consider rollover behavior in the early stage.For limousines, development is focused on typical vehicle dynamics and has been intensively investigated in the past. But in the development of SUVs with high CoG (Center of Gravity), the prediction of rollover behavior makes more challenges because of non-linear and highly dynamic characteristics in the limit range. Furthermore, BEVs (Battery Electrical Vehicles) with new design features demand a new consideration of rollover stability, which expands an unexplored area.This paper aims for achieving a better understanding of untripped rollover as well as a systematic methodology to analyze rollover behavior in the early phase. The paper is organized as follows. Chapter 2 presents a summary of state of art and literature to get an insight of the rollover stability indictors and models. Following a brief description of an existing transient nonlinear two-track model as well as its extension, the model verification to interpret the model limitation is presented in chapter 3. Subsequently, a systematic validation process including parameter validation and operational validation is executed in chapter 4. Based on the above mentioned, an example of chassis design with consideration of rollover in early phase is presented in chapter 5.

Fan Chang, Günther Prokop, Sebastiaan van Putten

Next generation 3D vehicle dynamics test system – Software and control concept

Vehicle developers face steadily decreasing development times and increasing system complexity. New control concepts like integrated vehicle dynamics control aiming to improve handling quality and ride comfort usually influence longitudinal, lateral and vertical dynamics at the same time. Therefore, holistic 3D vehicle dynamics and the accompanied research become more important. New tools and test methods are required to support and accelerate the research and development process.Today, two main possibilities exist to design, optimize and test the holistic 3D dynamics of a vehicle. One is through CAE and simulation, based on design data or results from component and subsystem test benches. The other is through track testing. Both possibilities are state of the art within the vehicle dynamics development process. With a new vehicle dynamics test system, the so called Handling Roadway (HRW) that will become available in 2018, IVK/FKFS will supply an alternative to track testing when it comes to evaluation of 3D dynamics of the real vehicle. The new HRW will enable a realistic overall vehicle response to control and disturbance input, featuring the well-known advantages of a fully controlled test bench environment. The new test system will be described in the next chapter.The intended role of the HRW in the development process is to provide an additional link between simulation and road testing as indicated in Figure 1. While driving simulators allow human-in-the-loop testing within a safe and fully controlled environment, the HRW will now allow full vehicle testing under these conditions.

Alexander Ahlert, D. Zeitvogel, J. Neubeck, W. Krantz, J. Wiedemann, F. Boone, R. Orange

Driving dynamics in the Formula Student

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

Marc Möckl, Christian Lichtenberg

High-level phlegmatization of an ICE for the use in a series hybrid powertrain

The electrification of power trains offers high potential for fuel savings. Furthermore, the use of a series hybrid technology allows simplifying the internal combustion engine due to fewer requirements concerning dynamics, power, and torque – it is possible to phegmatize the internal combustion engine. In this project a simulation model of a series hybrid is presented where an internal combustion engine is only working as a generator. The basic engine is a 4-cylinder direct injecting turbocharged spark-plug engine. Variable valve-timing as well as throttle and wastegate control are removed. The internal combustion engine is only working at its optimum point. Phenomenological thermal models of the engine and the transmission are presented. Furthermore, thermal models of the electrical components were developed. A thermal management system is shown as well as a hybrid operating strategy. The power train model is calculated in the WLTC and fuel savings are investigated.

Bojan Jander, R. Baar

Combustion engine concepts with extended expansion in hybrid powertrains

This work describes Gasoline engine concepts designed for the use within hybrid powertrains. By utilizing 0D/1D-simulations, three Extended Expansion engine concepts are investigated. With this alternative process, a significant increase in the expansion ratio while retaining the compression ratio is achieved, resulting in an increase in engine efficiency.The concepts are being derived from conventional turbocharged four-cylinder engines. The Atkinson concept has a Multi-Link cranktrain to provide an asymmetric piston motion. The Miller concept uses a valve train strategy with early inlet valve closure combined with a high stroke/bore ratio. In the 5-Stroke concept, the two inner cylinders are replaced by a large expansion cylinder. A post-expansion takes place in the expansion cylinder, thus extending the expansion phase.All concept-specific effects that influence fuel consumption are taken into account in the simulation. The simulated fuel consumption maps are subsequently used in a simulation of hybrid powertrains. A Mild-Hybrid with P2 topology and a Plug-In Hybrid with P2/4 topology are examined. The calculation of fuel consumption is based on driving cycles. The influence of the hybrid topology on the utilization of the engine’s sweet spot range is illustrated. It is shown that the P2/4 topology enables a significant increase of the mean effective engine efficiency during the driving cycle.

Morris Langwiesner, C. Krüger, S. Donath, Michael Bargende

Adaptive energy management strategy for a heavy-duty truck with a P2-hybrid topology

The efficiency of a Hybrid Electric Vehicle (HEV) depends significantly on the quality of the implemented Energy Management Strategy (EMS). To achieve optimal efficiency for different driving situations, an adaption of the EMS regarding the changing boundary conditions e.g. payload, driver behaviour, geodetical data, etc. is recommended. This paper presents an approach for an adaptive EMS based on the Equivalent Fuel Consumption Minimization Strategy (ECMS) for a heavy-duty truck with a P2- Hybrid topology. The first approach to realize an adaptive ECMS takes a variation of the payload into account. The presented Adaptive-ECMS (A-ECMS) is compared to a simple Rule Based (RB) Strategy. The evaluation criteria for both EMS is an equivalent fuel mass reduction potential. In contrast to previous research, this paper considers not only a driving cycle that is used for chassis dynamometer testing but also a real driving cycle from a measurement campaign. It can be shown that the A-ECMS with only one adaption parameter outperforms the simple RB Strategy by up to 1.9 % regarding equivalent fuel consumption in the driving cycle used for chassis dynamometer testing. In the real driving cycle the reduction of equivalent fuel mass realised by the A-ECMS amounts up to 0.43 %.

Sven Schulze, M. Mühleisen, G. Feyerl, S. Pischinger

Modeling of a map based turbocharger in a three dimensional engine environment

The ongoing trend towards downsized engines with turbocharger intensifies the need for development tools capable of simulating complex engine layouts with a level of details that only multidimensional models offer. This is strongly driven by stringent emission limits and the effort to reduce CO2 emissions while ensuring the concurrently demanded vehicle performance. In turbocharged engines the coupling of the combustion chamber and turbocharger forms a complex system in which the components influence each other remarkably causing e.g. the well-known turbo-lag.3D-CFD simulations of cylinders with parts of the runner or airbox have become practicable several years ago and will remain a valuable tool in virtual engine development; however the next logical step is to extend this approach from the cylinder to the full engine domain. This paper presents an approach that combines a three dimensional representation of the entire engine, including the complete air path, with a 0D-turbocharger.The approach, is used to model a two-cylinder engine which is compared to measurements from the test bench. The interaction between turbocharger and engine within a working cycle is analyzed under constant load conditions. The benefits of the chosen approach are highlighted by comparing it to a conventional approach of using one dimensional pressure traces as boundary conditions.

Andreas Kächele, Marco Chiodi, Michael Bargende

Impact of compressor induced acoustic excitations on the accuracy of the air flow measuring signal

The result of advancing development targets for new engine projects is a continuously increasing demand on improvements of the components of the engine. A prospective instance for increasing efficiencies is the new OM656 diesel engine from Mercedes- Benz [1] which shows a better acceleration and maximum power performance combined with decreased fuel consumption and emissions.To reach the development targets the improvement of the thermodynamics is an important parameter. The components of the air system like compressor, charge air cooler, low pressure pipe, and filter need to be developed towards low pressure loss. Nevertheless the air system has also to fulfill more functional requirements like the injection of the EGR and the blow-by flow, the filtration of the air, the damping of acoustics as well as the measurement of the mass air flow which is essential for many controlling functions of the engine.

Matthias Hamann, L. Erbig, M. Matt, Y. Bogachik, O. Kalkan, M. Onischke

CFD simulation of scroll compressors with axial and radial clearances and thermal deformation

Scroll compressors are positive displacement machines which compress the gas in size-changing working chambers while transporting it from the suction side to the discharge side. The working chamber size results from the movement of an orbiting scroll around a fixed scroll. Scroll compressors are used in the automotive industry for air-conditioning and turbochargers while scroll expanders are used for heat recovery systems.This paper shows transient 3D CFD results of a scroll compressor used as a dry scroll vacuum pump (DSVP) including clearance flow, turbulence effects and conjugated heat transfer between gas and solids. The setup steps and results for the simulation of a DSVP are shown and compared to theoretical and experimental results. The timevarying working chambers are meshed for each time step before the CFD simulation with special hexahedral meshing software for positive displacement machines which can handle small clearances around 10 μm. The CFD results are used for a mechanical simulation to get the thermal deformation of the scroll compressor. The deformation has an impact on the clearance size and can be used to optimize the CFD model.Numerical simulation is one important part of the scroll compressor development to get an optimized machine. By using special meshing software, high-quality simulations can be done capturing all clearance flow effects. Thermal deformation should be taken into account to get the clearance size depending on the operating point.

Jan Hesse, A. Spille-Kohoff, R. Andres, F. Hetze

Towards a standardized reference architecture for vehicle-to-backend platforms: Motivation and benefits

The European Commission has regulated that an automatic emergency call (eCall) facility must be provided in every new vehicle that is manufactured with effect from the end of March 2018 [1]. In the event of an accident, eCall will autonomously call an emergency call center and transmit the current position of the car, and at the same time establish a voice connection to speed up and improve rescue.Future vehicles will be equipped with wireless cellular network technologies, but not just because of the required eCall system. As these technologies will connect the vehicle to the Internet permanently, the vehicle will be a so called connected vehicle. This article discusses the connected vehicle from two perspectives. Based on these, the development of a standardized reference architecture for vehicle-to-backend (V2B) platforms is motivated. Afterwards, a case study of the oneM2M Service Architecture as enabling technology for a V2B platform is presented. Finally, conclusions about the proposed approach of a standardized reference architecture are discussed considering also related work in the automotive domain.

Markus Glaab

Safe computing with central ECUs

Nowadays the complexity of E/E systems tends to increase due to the appearance of new technologies and functionalities interacting across domain boundaries. The examples of advanced driver assistance systems (ADAS) and highly automated driving (HAD) are being implemented inside already complex systems, themselves evolving at a high pace in new powertrain architectures, body controllers, gateways or infotainment systems.As described by Navale et al. [1], Stolz et al. [2] and presented by Haas and Langjahr at Stuttgart Symposium 2016 [3], E/E architectures are undergoing an evolution from pure mechanical systems to highly centralized E/E vehicle architectures, see Figure 1. Central element and core of the systems are electronic control units (ECU). ECUs evolved from modular one-box one-function units to systems with higher integration level to reduce the overall number of controllers in the vehicle. Each domain, like powertrain or brake system (ABS/ESP), is today usually controlled by one domain specific central ECU acting as master. With increasing requirements and interaction between these domains, for instance for the cruise control function acting on the brake system and on the powertrain, ECUs acting at overall vehicle level come into play.

Drazen Baic, P. Langjahr, W. Haas, A. Fessard

From the environmental model to the intelligent engine stop start system

Engine Stop Start (ESS) offers an advantage in fuel consumption by automatically switching off the engine during vehicle stops. It is an important module of the BMW Efficient Dynamics Strategy and was introduced in 2007. Today it is a standard configuration within the automobile industry.With the introduction of the Intelligent Engine Stop Start (IESS) function in the new 5 series the BMW AG starts a new evolution step by using environmental data. To recognize relevant situations, data from camera, radar, and navigation system are used to optimize the operation strategy. Potentially short and inefficient stops are avoided to increase the fuel efficiency of the vehicle. In addition, the drivability is improved by keeping the engine running in situations requiring a good acceleration response of the vehicle.This paper starts with a short overview of ESS describing the development steps and focuses on the additional features introduced by IESS. Furthermore, the technical background and proof of concept for IESS are explained.

Elias Wiedemann, M. Karl, C. Ebner, A. Sonntag

Challenges of a safe value-added production logistics of the future

In this article, we present challenges of a safe value-added production logistics for the future. Challenges have been tracked down in the area of collaboration with AGVs, sensors, position detection and real-time decision making. Different concepts and technologies may help to find solutions for these challenges. Pick-by-Voice systems or novel sensors can improve AGV collaboration. Monitoring systems and safety sensors that measures the distance to obstacles reliably and identifies specific objects at the same time are needed to enable autonomous and changeable production logistics systems. In addition, technologies such as Ultra-Wideband-systems (UWB) support safe position detection. Progress in the field of information systems like smart contracts helps utilize real-time decision making. Elaborated safety concepts are required for the implementation of a value-added production logistics.

Karl-Heinz Wehking, D. Korte, M. Hagg

Flexible production systems as an answer to a volatile environment

The production of automobiles and internal combustion engines must be viewed in the context of complex structures with numerous influencing factors. It is bound by current legislation, is influenced by new developments on a technological level, and takes its orientation from the current market situation. These factors are also subject to an increasingly rapid rate of change. [12]In this context, the production of engines involves a large number of changes that influence economic efficiency. For example, the regulations with regard to emission limits and the permitted CO2 emissions of internal combustion engines are becoming increasingly stringent. There are calls for accelerated implementation of these new specifications; the reaction times for manufacturers are falling steadily. In Europe, the CO2 fleet limit value is to be lowered to 95 g/km - and thus by 38% - from 2015 to 2020/21. [4] Associated with this is a significant tightening of the emission regulations (real driving emissions, RDE). Further reductions over and above this are under discussion. A similar tightening of regulations can be seen in the USA, China, and Japan. Furthermore, the growing desire for individuality leads to an increasing variety of versions as a result of ″mass customization″ [2]. The driving factors behind the variety of versions include not only internal combustion engine technology or the number of cylinders but also to an increasing extent local emission variants and additional technologies that have repercussions for the internal combustion engine. Moreover, in the last few years the BMW Group has developed into one of the highest-volume provider of electrified vehicles and the continued spread of eMobility is imminent. [7, 8]

Werner Köhl, C. Siedelhofer, G. Siegmund, C. Schuster, S. Mayer, A. Bloemer

Basic principles of agile assembly in the automotive industry

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

Petra Foith-Förster, T. Dietz, T. Bauernhansl

Homogeneous lean burn engine combustion system development – Concept study

TMG (TOYOTA Motorsport GmbH) and FEV have jointly conducted a concept study on environmentally friendly engine with indicated thermal efficiency (ɳinet) of 46% and low emissions while fulfilling high-performance criteria i.e. specific power of 103 kW/l and low end torque (LET) of 2.3 MPa BMEP at 2000rpm. An ultra lean-burn combustion concept has been designed by means of 1D and 3D MBD (Model Base Development) methods and subsequently validated experimentally by a single cylinder TC GDI engine as a technology demonstrator in order to fulfill the requirements of both environmental sustainability and fun to drive in passenger cars.FEV has developed the concept with TMG by using FEV’s scatter-bands and Charge Motion Design (CMD) approach. Based on the concept layout, TMG has designed the single cylinder engine (SCE) and conducted the validation tests. Additionally, optical diagnostics of flow, mixture formation as well as combustion have also been carried out. In order to meet contrasting demands of enhanced in-cylinder charge motion necessary for ultra-lean burn and high flow performance for high specific power, a variable charge motion (VCM) system has been implemented.This feature, in combination with high compression ratio (CR) and adapted gas exchange enabled to demonstrate the achievement of ɳinet = 46% at λ=1.90. Furthermore, the efficiency and nitrogen oxides (NOx) engine-out emission trade-off has been analyzed in details with the underlying mechanisms described.

Pawel Luszcz, K. Takeuchi, P. Pfeilmaier, M. Gerhardt, P. Adomeit, A. Brunn, C. Kupiek, B. Franzke

AUDI h-tron – A key-technology to meeting the requirements for sustainable drive concepts

The automotive industry is facing a change, which in the future calls for sustainable mobility programs with global and local zero emissions. AUDI meets this challenge with a wide range of drive concepts to meet global emissions targets. In addition to conventional combustion engines, PHEV technologies and battery electric vehicles, the fuel cell drive represents a reasonable addition to the strategy portfolio.Refueling times of 3-4 minutes and long ranges - the 5th generation of the fuel cell system at Audi offers a usage behavior that is similar to that of a vehicle with a conventional drive.Introduced at the Detroit Motor Show in 2016, the h-tron quattro concept combines a highly efficient 110kW fuel cell system with a powerful battery that can temporarily provide an additional 100kW. Thanks to its optimized design, the fuel cell stack has room in the front end and achieves an efficiency of over 60%.For a successful market establishment, there are various challenges to accomplish. In addition to the identification of cost reduction potentials in the fuel cell system and progress towards a full industrialization of the technology, H2 production from renewable energies as well as the provision of appropriate infrastructure are key factors that should help to gain widespread public acceptance. Accordingly, Audi is involved in numerous German and international initiatives to promote hydrogen technology.

Jürgen Jablonski, P. Hackenberg-Wiedl, S. Rank

The new Porsche GT engine family: The perfect link between motorsports and road car engines

The new Porsche GT engine family connects the racetrack DNA of the RSR powertrain with the GT-road car engines. The successful development strategy on the racetrack combined with the transfer of technical details such a central oil feed in the crankshaft, an oil centrifuge and shimmed solid lifters were the key factors for the introduction of this engine family. This family covers the needs of the high professional works motorsports in the GT class and the ones of the road car – the 911 GT3 of the second generation.

Roland Sargenti, W. Buck, T. Mader, M. Hendess, D. Raabe

Development of an innovative combustion process: Spark-assisted compression ignition

--------------------------------------------------------------------------------------------------------This manuscript, according to publishing restrictions, is available only as a summary of the following parts: introduction, motivation, conclusions and outlook. Thank you for your understanding. --------------------------------------------------------------------------------------------------------Motorsports has always been an optimal environment for innovative solutions. Highly motivated by competition, the solutions can be tested, implemented and validated within minimal development time, thus establishing Motorsports as a genuine innovation driver. But the way how to achieve gains in engine performance has remarkably changed in the last years. Today, due to different regulations – e.g. the introduction of an air restrictor in the World Rally Championship or the limitation of the fuel consumption in the Formula 1 World Championship –, engine power can be raised only by increasing engine efficiency. Accordingly, the development targets in Motorsports have changed. Thus, new solutions may become increasingly interesting for mass production engines in the future, too.

M. Chiodi, Andreas Kächele, Michael Bargende, D. Koch, G. Wachtmeister, D. Wichelhaus

Measures to fulfill

The first stage of the regulations on real-driving emissions (RDE) has become effective in Europe in September 2017. Now compliance with the EU6d_temp stage is required in order obtain a type approval. This regulation aims to limit the nitrogen-oxide and particulate emissions. With residual emissions from diesel cars having only very small contribution to finedust in cities due to the broad-based use of particulate filters, further development activities are now geared towards effectively limiting nitrogen-oxide emissions.For several years Robert Bosch GmbH has been conducting comprehensive studies in order to support OEMs in meeting the emission targets by defining technical measures that will effectively limit and reduce real-driving emissions. Respective progress reports were presented at the previous FKFS conferences in 2016 /1/ and 2017 /2/. At last year’s symposium we were able to demonstrate that the requirements of the EU6d_final stage applicable as of 2020 (new types) and 2021 (all types), respectively, can be met in particular through an intelligent combination of engine-related measures and exhaust-gas after-treatment. This year’s presentation focuses on further improvements for remaining emission-related driving modes and on the increased emission robustness even during driving maneuvers which can hardly be considered ″normal driving″.This paper demonstrates that undercutting the limits set forth in the EU6d_final stage with a high degree of robustness is possible through a further optimization of the interaction between the engine and the exhaust-gas after-treatment and in particular by an improved temperature management of the exhaust-gas after-treatment system. The improvements over the status presented last year /2/ can be achieved without any additional hardware. Furthermore, approaches to further optimize the emission behavior will be discussed.As the studies had not been finalized when this paper was written, some of the following results are preliminary that may be updated during the oral presentation.

Dirk Naber, S. Bareiss, A. Kufferath, M. Krüger, H. Schumacher

Additive manufactured open cell structures: Promising substrates for automotive catalysts

Catalyst technologies for automotive after-treatment systems require constant developments to comply with the latest regulations concerning real driving emissions. Apart from the current benchmark in catalyst substrates of honeycombs (HCs), the research is focusing on open cell structures, which show promising properties [1]. The network of solid struts of the open cell lattices overcomes the limits of laminar flow in HCs and enhances higher conversion efficiencies [2][3], lower cold start emissions and higher flow uniformity, which is a key factor for catalyst durability [4][5][6][7]. Open cells allow more flexibility in the geometrical configuration of the reactor [8], but they show also a higher pressure drop per unit of length [9][10], decreasing engine efficiency. Thus, to have a fair comparison between HC and open cells, the performance index I has been introduced [2], which evaluates catalyst efficiency by weighting conversion and pressure drop. CFD analysis suggested that the trade off is in favour of open cell structures when the porosity is high enough [11][1]. Here open cells are studied as regular polyhedral structures, which literature have shown to be more performant than randomized foams [12]. Several works conducted numerical analysis of open cell foams consisting of regular cells [2] [13] [14]. Regular structures are easier to handle because they require only two parameters (for example the characteristic pore dimension and its ratio with the strut diameter) to be defined and mathematical expressions allow the derivation all the other geometrical properties [1]. Often the Kelvin cell has been used as a typical elementary cell.

Panayotis Dimopoulos Eggenschwiler, V. Papetti, F. Lucci, A. Ortona

CFD framework for the modeling of aftertreatment systems: Application to the study of an electrically heated DOC for Diesel e

In this work, a state-of-the-art 48 V electrical heated catalyst is considered to investigate its effect in increasing the abatement efficiency of a standard DOC. The electrical heating device considered is based on a metallic support, arranged in a spiral layout, and it is heated by the Joule effect due to the passage of the electrical current. As a result of the spiral arrangement, the distribution of the heat source on the heating section is not uniform, determining a certain spatial distribution of the temperature of the gas entering the DOC section. To simulate the after-treatment system, a suitable CFD framework has been implemented on the basis of the open-source OpenFOAM code. Firstly it is validated resorting to experimental data. Then, it is applied for the investigation of the effects of the electrical heating on the pollutant abatement, with particular focus on the effects of the non-uniform temperature distribution related to different layouts of the heating spirals.

A. Della Torre, Gianluca Montenegro, A. Onorati

How to compare global and local pollutant emissions

The reduction of pollutants like nitrogen oxides or particulate matter is currently one of the drivers for the development of better power train concepts. Additionally, stricter regulations on CO2 emissions will become active in the next years. One big question is, how to compare the impact of pollutants, which act locally and short-term, with the impact of global greenhouse gases like CO2, acting on a long-term base. Which of both has to be seen as more harmful? Is it possible to develop a comparative factor to rate the ecological fingerprint of both? In our work an approach is proposed to estimate a common ″damage indicator″ based on the monetary calculation of the ″followup costs″ (external costs). Such calculations have been done up to now either for the local pollutant emissions or for the impact of global acting greenhouse gases. Our attempt is, to combine these two fully different classes of emission with the damage cost estimation. Although parts of these estimations contain significant uncertainties, already interesting preliminary conclusions can be drawn. As an example, the ecological impact of real-drive emissions of some passenger cars will be discussed comparatively. It is estimated that the resulting external costs are in the order of 1 ct/km based on realistic real drive emissions, where the CO2 contribution is the dominant factor for the non-diesel driven cars.

Friedrich Dinkelacker, F. Galli

Suspension influences on a steer-by-wire torque vectoring vehicle

Conventional steering systems with a mechanical connection between steering wheel and road wheels are limited in terms of adapting the steering ratio and the steering torque in dependence of the current operating condition. Steer-by-wire systems enable to decouple the mechanical connection of the steering wheel and the road wheels, thus enabling situation-dependent feedback to the driver’s steering inputs and also the possibility of autonomous steering interventions for automated driving. Because of the high safety requirements for steering systems, steer-by-wire systems require either a fail-safe system with a mechanical fallback solution e.g. actuated with a clutch, or a fail-tolerant system, [1]. These fail-tolerant systems can be achieved for example with full redundancy of all safety-critical components, but also by using torque vectoring (TV) as a redundant steering function, [2].TV allows individual torque distribution on wheels to stabilize the vehicle in a critical driving situation like electronic stability control (ESC), or to influence the yaw motion of the vehicle in non-critical driving situations, e.g. to improve driving enjoyment, [1]. Since TV does not only influences the lateral dynamics significantly through the different longitudinal forces, but in addition different longitudinal forces can also generate a torque around the kingpin axis. This effect can also be used as a failtolerant system for a steer-by-wire system. However, the amount of torque that is required to steer the vehicle depends to a high amount on the suspension kinematics.There are several requirements on suspension kinematics that have to be considered during the design process, with steering by TV not being the main optimization target. To still ensure an optimum performance of steering by TV under given constraints, an investigation is presented in this article to quantify influences of suspension kinematics and geometry on steering by torque vectoring. Based on a multi-body vehicle model which is described in Section 1.2, two different three-dimensional suspension models for the front axle were implemented, see Section 2, and validated using measurement data, see Section 3. Using these models, a parameter study was conducted to compare the influence of two selected suspension parameters on the steering behavior of a TV steered vehicle and a conventionally steered vehicle. The results of this parameter study are presented in Section 4. Finally, a discussion and outlook are given in Section 5.

Gerald Reiter, K. Pohlmans, C. Miano, A. Hackl, C. Lex

Vehicle simulation environment enabling model-based systems engineering of chassis control systems

Modern vehicle and mobility concepts result in an increasing vehicle variety and complexity. Subsystems and -components have to be developed in close connection to assess interaction effects. For this work, only the vehicle chassis and its design and development process is to be considered. A modern vehicle chassis contains numerous active control systems, whose purpose include improvements of the vehicle safety, driving dynamics and driving comfort. These systems rely on valid vehicle state information, road condition information, battery degradation states and many more. Further, these systems depend on each other’s system states to avoid unwanted interference.Considering this, the vehicle sensor technology, the on-board power supply, as well as all chassis control systems to be developed together. Since a state-of-the-art vehicle chassis contains multiple control systems each being parameterised by hundreds of parameters, both complexity and interaction effects exceed the potential of independent, conventional development strategies.

Christopher Braunholz, W. Krantz, J. Wiedemann, I. Scharfenbaum, U. Schaaf, A. Ohletz

Control strategy for electromechanical active roll stabilization

As a part of the chassis, electromechanical active roll stabilization systems increase the spread between driving dynamics and driving comfort. There are several distinct advantages compared to the passive versions: improved driving comfort, increased lateral tire force and adjusted self-steering behavior.Functional upgrading results from the interaction of mechatronic components: actuators, sensors and information processing. Using system control as a functional key component within information processing plays a decisive role in this process.Numerous conflicting goals represent a challenge regarding system development. On the one hand due to the high demand on the dynamics of the set forces in the chassis; on the other hand, because of the typical automotive requirements such as limited power resources, a high operating temperature and the sensitive acoustics.The following paper provides an insight into the system function of the electromechanical active roll stabilization employed in different D-segment vehicles of the Porsche AG.Special focus is placed on the description of a modular-hierarchical structured control strategy as it has already proven its value despite the above-mentioned conflicting goals. The control structure primarily consists of three core elements: the sensor data fusion of external disturbance variables including an internal preview, the modal transformation of the disturbance excitation into axle specific variables as well as a model based subordinate actuator control.

Igor Illg, A. Freuer, M. Eisenbarth, G. Nareyko, T. Koch

Innovative torque vectoring control concept to generate predefined lateral driving characteristics

Active chassis systems offer the possiblity to specifically influence the driving behavior of the passive vehicle [1]. According to Becker et al., the driving behavior of a vehicle is defined by the car’s reaction to driver inputs and to disturbances during a maneuver [2]. In the context of lateral vehicle dynamics, the reaction of the vehicle can be described by the yaw rate and the side slip angle in the center of gravity. Since the latter two quantities are dynamically coupled, Direct Yaw Moment Control or Torque Vectoring is not appropriate to control the vehicle’s yaw rate and side slip angle independently [3]. The proposed innovative Torque Vectoring system in this paper focusses on yaw rate tracking. References to systems with additional active rear steering to control the vehicle’s side slip angle independently are exemplariliy given in [4].On the basis of simulations, this paper discusses to which extent an urban electric compact car equipped with the innovative LEICHT chassis [5] is capable to generate the very same yaw rate behavior as an upper middle-sized class reference vehicle by an intelligent allocation of the electric motor torques. The controller design is based on the sliding mode control technique due to its inherent robustness properties and great potential in the field of vehicle dynamics control [6].

Alexander Fridrich, W. Krantz, J. Neubeck, J. Wiedemann

Image-producing knocking investigations in a two-stroke SI engine

In an effort to reduce the carbon footprint of handheld devices, alcohol blended fuels represent an economically viable option with different alcohols available from renewable sources. On the technical side, it is to be investigated how alcohol-blends affect engine operation, by means of a thermodynamic study.Two-stroke machines exhibit a combustion anomaly called four-stroke-knock. Since the propensity to knocking combustion is affected by alcoholic components in fuel, this effect has been investigated and will be discussed in this paper. A special focus lies on measuring flame propagation and fuel mixture preparation using high-speed visualization techniques under knocking conditions.

Florian Schumann, K.W. Beck, T. Seidel, T. Gegg, J. Weßling, F. Sobek, B. Kehrwald

Analysis of the impact of information about future driving situations on the energy consumption

Locally emission-free driving with plug-in hybrid electric vehicles (PHEVs) demands accurate information about the energy demand for driving in certain areas or for reaching the next charging station. In order to avoid using the internal combustion engine, this study shows the impact of information about future driving situations on the accurate prediction of the required energy demand. To generate realistic data of specific driving situations, a simulation environment has been developed. Due to paramaterizable settings, it enables reproducible analyses of different influences on the energy demand, in particular of the traffic, the traffic control and the driving characteristics. Since especially urban driving is interesting for electric driving with PHEVs, the analyses concentrate on urban driving. The results show that it is more important to know the traffic situation in urban areas than on highways.

Tobias Schürmann, D. Görke, S. Schmiedler, J. Strenkert, K.A. Böhm, Michael Bargende

Investigation of the holistic energy demand of different power train topologies under realistic boundary conditions

This paper presents a novel approach to analyse and compare the auxiliary loads’ impact on the energy balance for different drivetrains considering user behaviours and weather conditions in Germany. To investigate this influence a method containing the German driving performance, derived from the study ‘Mobilität in Deutschland’ in combination with the ‘Artemis’ driving cycles and German climate conditions out of ‘meteonorm’ datasets clustered by the population and weighted by the vehicle distribution is established and explained. With these boundary conditions the drivetrains Fuel Cell Electric Vehicle (FCEV), Battery Electric Vehicle (BEV) as well as conventional gasoline vehicles with an Internal Combustion Engine (ICE gasoline) have been simulated.With the developed methodology the influence of different driving cycles (NEDC, WLTC, Artemis urban, rural and motorway) and the auxiliary loads’ impact for the seasonal, German weather conditions as well as the extreme weather conditions (coldest winter and hottest summer day) were analysed. A significant influence on the energy consumption, the impact on the available driving range and the need to investigate solutions to reduce the auxiliary loads’ consumption in future work is shown.

Benedikt Hollweck, J. Wind, C. Schnapp, F. Stöber, D. Pfeffer

Metal matrix composites in handheld power tools

Husqvarna has with cooperation of Swerea SWECAST been evaluating applications where to use Metal Matrix Composite material to enhance the lightweight construction of handheld power tools.Some inherent problems with MMC material will be discussed and what measures that have been taken to cope with these material properties.Different approaches and methods to cast aluminum silicon carbide MMC is addressed and some of their virtues and drawbacks discussed.Finally test results are presented for a potential new application of MMC material for a Cut-off saw where the replacement of high tension steel with MMC aluminum has the potential to lower the weight of the part to less than 40% and lower the complete product weight by 0.3 kg.

Niklas Enander, Andreas Hillby

Centralized administration of diagnostic and update processes for cloud mirrored vehicles

The ″Internet of Things″ and ″Industry 4.0″ are heavyweight words in today’s world, which is increasingly interconnected and digitized. In many areas of daily life, a networked and centralized management of services has become indispensable. But, as with any technology, the benefits of administrative and maintenance efforts are at stake. Decelerated by long development cycles, this process also takes place in the automotive world. A connection of the vehicle to the internet, including various remote applications, is already standard for many OEMs. In the course of this work, a method is presented, with which a vehicle connected to the internet can be mapped in the cloud and, based on this, can be remotely diagnosed and remotely updated. The approach described uses common IOT protocols, but omits the full integration of the MVCI runtime system (ISO 22900 [1]) and the required diagnostic data (ISO 2290-1 ODX [2]) into the vehicle. It will be discussed on the basis of a use case, how tailormade procedures are generated in the backend and how they are processed and logged in the vehicle. Finally, the approach is implemented prototypically, explained and demonstrated in the overall system comprising backend, data transmission unit and vehicle.

Michael Eberspächer, M. Grimm, Hans-Christian Reuss

Big data for assisted and autonomous driving

If intelligent algorithms are the rockets of self-driving cars, then the data that is used to train and validate these algorithms can be considered the fuel on which these cars are running. Indeed, developing algorithms for self-driving cars requires many iterations on large sets of data which are collected under various real-case driving scenarios, and this is especially so as these algorithms increasingly incorporate deep neural nets.A standard approach to developing and testing algorithms for autonomous driving in a timely and cost-efficient manner is to carry out re-simulations. In re-simulation campaigns, based on the raw sensor data collected in a limited number of physical test drives, many additional virtual test drives are created on which the algorithms are then carried out, optimized and tested against the range of scenarios. The sheer amount of data that is involved in this process poses very new challenges to this standard approach for meeting functional and non-functional requirements.A typical development process requires to carry out many re-simulations, but even a single re-simulation is computationally expensive. In conventional IT environments where re-simulations are carried out on individual workstations one at a time, this implies correspondingly large times to results. Data is collected in test drives world-wide, where even at a single testing site, data volumes exceed the storage and processingcapacities. Typically, because of the large size, data cannot be easily moved from the location of storage to the re-simulation environment, and re-simulation campaigns on cross-site data become extremely difficult.

A. Pawlik, T. Bonfort, N. John, S. Karl, T. Klein, L. Oser, F. Navarrete, J. Ventura, J. Villaveces, A. Villwock, Tobias Abthoff

The connected car and its new possibilities for diagnosis of the internal combustion engine

40-50% of the Engine Control Unit’s (ECU) software consists of diagnosis algorithms [2]. In general, diagnosis can be divided into two main groups: On-Board diagnosis (OBD) and Off-Board diagnosis. The former group is implemented in the vehicle itself and runs during normal driving operation. In contrast, Off- Board diagnosis is performed in the workshop and runs at particular load points of the engine. Now, the Connected Car provides the opportunity to outsource parts of the diagnosis software from the vehicle to the cloud or, in case of need, to download new software from the cloud. Hence, two main advantages can be identified: On the one hand, the amount of diagnosis software on the ECU can be reduced, which offers more resources for control algorithms. On the other hand, it is possible to use more computationally intensive algorithms since a cloud has a many times higher computing power than a vehicle’s ECU. In this paper, an algorithm is presented which shall enable an exact localization (pinpointing) of a fault in the case of an implausibility in the exhaust manifold pressure. For this, an error suspicion is detected by the vehicle’s software, to begin with. Then, the relevant measurement data of the vehicle is sent to the cloud over the mobile network. Afterwards, the diagnosis is executed on the server. At the end, the diagnosis result is transmitted back to the vehicle. The described principle is validated offline in a simulation environment in Matlab/Simulink®.

Lars Hagen, A. Walter, Michael Bargende

Requirements and systems engineering for complex systems

Software-intensive systems are in immense market pressure. While they must be uncompromisingly innovative in terms of technology and safety, markets are demanding ever shorter cycle times and continuous efficiency gains. Traditional development processes that achieve innovation and quality through a cumbersome development and verification/validation process are outdated. For example, our studies show that cost of rework across the product lifecycle can be reduced by 20-50% by improving requirements engineering.Requirements engineering in its connection with systems engineering is the decisive success factor for the efficient development of software-intensive hardware / systems. Systems Engineering supports the continuous development of requirements up to validation. Due to the increased level of abstraction at the beginning in the requirements development and analysis, problem descriptions are much clearer, simpler and less redundant. This not only increases the speed of development, but also ensures clearly understood domain concepts within the project. Models help with consistency from system requirements to software requirements, and then to design and validation.

F. Kirschke-Biller, Christof Ebert

The future of manufacturing: The first modular seat factory in Eastern Europe

Building a seat structure is a process that involves multiple manufacturing processes. After the stamping of most of its single parts, these parts are being MAG1- and Laserwelded together and painted in a dip-coating process. Following the painting, the components are assembled with screws and bolts and a number of additional parts like electrical motors, cables and labels are added. The finished structure tested for functionality and acoustics before packed and shipped in specifically built carriers to our customers.Brose and its seating division have been at the forefront of modern technology since 1990. Brose engineers have driven and further developed the laser welding process for the assembly of seat structures. It is a precise and robust process. Brose now has an installation base of more than 180 laser source across the globe.A seat structure can have a weight of up to 35 kg. It is a safety-critical product, which has to be proof-tested extensively. Numerous poka-yokes in fixtures as well as online process control of all screwing operations are a given standard. The manufacturing requires a lot of capital for welding and paint fixtures, welding machines, automated assembly and testing cells. OEM2-requirements ask for the provision of additional flexible capacity of up to +20% in capacity for each production step while take-rates can fluctuate substantially between different variants.

Lutz Wünn

Challenges for car body shops of electric sports cars

German car manufacturers are currently facing a variety of challenges in order to survive in international competition. On the one hand they have to serve an increasing number of market segments and niches with more and more complex model series and derivatives. On the other hand, the situation is characterized by fluctuating unit numbers per vehicle type, planning uncertainty due to unknown and dynamic market developments, in particular due to the introduction of new electric vehicles. The battery technology, which for example has a strong influence on the underbody structure of the car body, is currently undergoing major changes and rapid developments in the field of battery technology which are difficult to predict. In addition, the situation is getting more complicated by shorter product life cycles and associated frequent product changes and upgrades. [1] [2]

Marian Bichler, T. Böhm, A. Kampker, J. Triebs

48 V by Mercedes-Benz

The introduction of the 48 V on-board power supply brings a new dimension into play both in terms of energy and with regard to power. The hybridization on the 48 V level offers benefits for fuel consumption and performance, coupled with an excellent cost/benefit ratio. This technology not only supports many of the familiar hybrid functions without a high-voltage on-board power supply. It also addresses the constantly growing demand of tomorrow’s vehicles for electric power.

Thomas Mundinger, K. Wanner, M. Weber

A modular concept for hybridized manual transmissions

Manual transmissions combine the advantages of lowest weight, highest efficiency and lowest cost compared with all other light vehicle transmission types. This is reflected in the market share and the expected total volume of manual transmissions in the global markets. However, the concept of a manually shifted transmission needs to be adapted to upcoming market requirements:the need to integrate hybrid features in the powertrains to meet future legislated emission limitstightened NOx and particulate emission limits in cities and potential restrictions for the use of Diesel powered vehicles in inner city districtsneed for compatibility of today’s manual transmissions with advanced driver assistance functionsThe GETRAG concept to address this challenge is based on a step-by-step upgrade of the transmission’s function, where each step is building on the previous and provides a functional enhancement on it’s own. All components and functions are fully integrated into the transmission in consideration of the installation package in the vehicle engine bay thus minimizing the complexity and specific effort to offer hybrid and conventional powertrains versions in the same vehicle. The GETRAG hybrid manual transmission (HMT) concept offers specific advantages for small and mid size powertrains as a cost efficient option to create mild hybrid variants on the base of a 48V electric system. By the use of a standardized GETRAG hybrid part kit shared with the GETRAG Hybrid DCT program (6HDT200 / 7HDT300) the cost are held low while technical and development risks are minimized. For vehicle assembly the integrated solution offers the benefit of a fully tested unit ready to be mounted into the vehicle. The modularity of the system enables upgrade opportunities to automated hybrid transmissions (AHT) and – package neutral - to high voltage hybrid units for PHEVs and therefore purely electric driving in restricted inner cities.

Frank Casimir

Development of a 48V P0 demonstration vehicle with eBooster® air charging

A demonstration vehicle is presented where improvements to the electrical and air induction systems are made which provide increased performance with improved fuel economy. This is made possible by a 48 V architecture which enables the deployment of new components, specifically a belted motor generator unit (MGU) and electricallydriven compressor (eBooster®). The synergy between these components enables energy efficient means to collect regenerated energy and provide added torque, faster engine response, and extended engine off operation among a list of added features. Control features and strategy are highlighted along with simulation and vehicle test data. Resultant performance and fuel economy benefits are reviewed which support the contention of 48 V being a cost effective architecture to enable CO2 reduction relative to a high voltage hybrid.

M. Grill, P. Keller, Sara Mohon, Keith van Maanen, Wolfgang Wenzel, L. Xiaobing, V. Negandhi

Development of 48V powertrain systems at Mercedes-Benz

Technical solutions to conventionally reduce the fuel consumption and CO2 emissions of combustion engines have been largely exhausted. In order to cope with continually increasing requirements via legislation and customers’ expectations, more costly and technically complex solutions must be investigated and introduced to meet these requirements. These technical and legislative challenges are also constrained by providing the customer the high level of performance and comfort they are accustomed to in a premium segment vehicle from Mercedes-Benz, while keeping the additional costs for the customers to a minimum. The 48V electrification of the powertrain and a number of auxiliaries has a great deal of potential to achieve these goals. Introducing a 48V system can be a cost-efficient, entry-level hybridization offering a large amount of the functionality of high voltage hybrids at a fraction of the cost. This makes it an attractive step in lowering the overall fleet consumption of a vehicle manufacturer for customers who are not interested in a plug-in hybrid or an electric vehicle at this time.In additional to fuel consumption improvements, the increase of the voltage level allows for additional electric power which can be used to electrify auxiliaries which are currently mechanically powered. Furthermore, the additional electrical power can be used to satisfy the ever increasing power requirements for comfort, infotainment and safety or autonomous driving systems.There are numerous topologies for the hybridization of a powertrain with a 48V system, two systems introduced at Mercedes-Benz with the newest motors will be discussed in detail and their functionality will be compared. Following this, further applications will be evaluated and the future compatibility of 48V systems will be characterized.

Michael Timmann, R. Inderka, T. Eder

Double injection SCR – Bosch’s development for future emission regulations

For OEMs the diesel engine plays an essential role in achieving their CO2 fleet targets and it will continue to do so in the future. The requirements regarding NOx emissions have increased with the introduction of the RDE legislation (Real Driving Emissions) in Europe and the LEVIII-ULEV regulation in den US; complying with these regulations will require further actions to be taken on the engine and the exhaust system. SCR-based exhaust-gas after-treatment with closed-coupled exhaust system layouts and an intelligent temperature management are the methods of choice to support OEMs in achieving the future emission requirements.In BOSCH’s view the double-injection SCR technology represents an efficient, robust and targeted method to achieve this goal. AdBlue® is injected separately by a closecoupled SCR (coated DPF) and a second SCR located away from the engine. Amongst others, this layout offers benefits regarding the thermal de-coupling of the SCR catalysts and an improved, demand-based AdBlue® injection. In addition it simplifies catalyst monitoring (OBD).This paper discusses these benefits of a double-injection system. To this aim theoretical considerations as well as proofs based upon real measurements will be presented.

Tobias Bayer, D. Samuelsen, S. Bareiss, M. Chaineux

Reduction of perturbations on spray force measurements for quantification of Diesel sprays

Over the last two years the diesel engine has lost the better part of its reputation in the public opinion. In spite of legitimate criticism, it still is an indispensable drive solution for all applications where reliability, flexibility and efficiency are key values. While state of the art exhaust aftertreatment can fulfil the demand for ultra-low emissions ‘under real driving conditions, the legal CO2 target values cannot be reached without a further development of the combustion.The injection system is one of the key components to an efficient combustion. The better its potential influencing factors are understood, the more possibilities on enhancing future combustion processes are available. Conventional methods of examining injectors are high-speed imagery and hydraulic determination of the injection rate. While hydraulic measurements can only describe the mass flow coming out the whole nozzle, high-speed imagery can detect unequal distribution between the individual holes but only in a qualitative manner.Thus, spray force or momentum flux measurement is an important link between those two techniques as it provides information related to mass flux on a hole to hole basis which helps to understand the processes within the combustion and helps to identify their leverage. The momentum flux can also be a valuable boundary constraint for computational fluid dynamics (CFD) simulations. The measurement principle consists in determining the force component the spray applies onto a rotationally symmetric transducer in direction of flow.However, the value in use depends on the accuracy of the obtained data. In order to determine the momentum flux to be correct, the assumption of a rectangular deflection of the spray on the transducer’s surface has to be met. Previous investigations have shown two effects which interfere with this idealistic consideration. One is the formation of a moving eddy on the surface of the transducer, the other is the rebound of spray droplets especially under conditions of low backpressure, which lead to an overestimation of the spray’s momentum.This paper introduces an alternative geometry for the transducer’s shape which helps to minimize or eliminate the mentioned effects.

Hans Römisch, T. Hergemöller, Michael Bargende

Validation of designand development-tools for Diesel injectors with measurements from a single cylinder research engine

All sectors of diesel engines are facing challenges and require ongoing optimization. While for smaller engines, latest emission legislation comes in the form of real driving emissions, marine engines are subject to the sulphur cap in 2020 set by the International Maritime Organization. Not being affected by the trend of full electrification due to limitations in energy storage, large engines in particular will remain subject to optimization for a long time to come. Considering the rising need for global transportation and the resulting share of large engines regarding worldwide soot, NOX and CO2 emissions these engines will also stay in the center of public attention.In the near future the rise of new applications like Dual Fuel Engines and high pressure methane direct injection causes an increase in engine complexity. Especially in Dual Fuel Engines, the wish to integrate main and pilot injector leads to challenges regarding the stability and symmetry of the pilot injection in order to guarantee a reliable engine operation [4]. Further challenges can arise from the necessary reduction of greenhouse gases, which will create a market for E-Fuels [8]. Fuel systems of the future will have to be flexible and react dynamically to the type of synthetic fuel chosen by the owner.

Martin Drescher, F. Pinkert, I. Najar

Investigation on the influence of nozzle geometry variations on Diesel jets

The internal combustion engine is currently the most important cornerstone of mobility. To ensure that it also remains competitive with other drive concepts in the future, further development is unavoidable to comply with the ever-stricter requirements as they pertain to environmental compatibility.When it comes to diesel-powered internal combustion engines, the injection system in particular is critical for mixture formation and is therefore the focus of research aimed to reduce emissions before after treatment and increase engine efficiency. Characterizing the injectors used and acquiring a comprehensive understanding of the spray behavior are imperative for deriving further combustion-relevant injection variables. This knowledge lays the foundation for identifying optimization potentials and delicate variables.The standard measuring technology used to investigate injectors illuminates merely one aspect of the injection process. This is why, during previous research work, efforts were already undertaken to evaluate the results of the different measuring technologies in combined fashion in order to acquire a more comprehensive picture of the mechanisms behind the spray disintegration and the resulting fuel spray [1][2].The focus of this paper is to investigate geometry variations of the nozzle hole of passenger car diesel injectors and their effects on the behavior of the spray. The overarching objective is to leverage the evaluation of the partial results of three measuring technologies to obtain a holistic analysis of the injectors and, thus, to understand the correlation between the nozzle hole geometry and the ensuing properties of the fuel spray.

Corina Slocinski, T. Hergemöller, Michael Bargende

The automotive digitalization – The way from driving yourself to highly automated driving

Some 7 million years ago a creature, later to be known as “homo sapiens“, began to rise up and turned his gaze towards mobility.10 000 BC man began to domesticate animals like horses and put them before towed carts. Approximately 4000 BC the carts became enhanced by putting wheels on them, thus being evolved to coaches. This kind of locomotion by muscular power could be named “ Mobility 1.x“1801 modern traffic began with a mobile steam road locomotive (“Puffing Devil“) followed 1870 by the well-known Marcus-Wagen and shortly after by a fuel-powered carriage-like vehicle by Gottlieb Daimler. In consequence these vehicles powered by an engine have been developed evolutionary until now, leaving the basic principle “a motor for drive“, be it fuel, diesel or electricity, mostly untouched. As early as in the middle of the 19th century the increasing mobility caused traffic problems in London. In 1868 the first manually operated gas lit signals for carriages were put into operation, 1920 the first electric three colour traffic light was installed in the motor city of Detroit. In the end the automobile covers the basic human requirement to travel from one place to another independently, quickly and safely. One could consider this era as the second generation of mobility – “Mobility 2.x”.

Thomas Stottan

Cognitive ergonomics: Extravagance or mandatory functional safety requirement

60% to 80% of all critical incidents during the use of automobiles can be ascribed to human behaviour (Schaub, 2017). The question about human failures is ubiquitous after traffic accidents, but the human behaviour is not only a safety risk: it is an even larger factor for more safety. Also, in 60% to 80% of all technical failures in automotive systems, the human behaviour is responsible for the recovery of the safe state bevor a critical situation arises (Schaub, 2017). The main subjects of cognitive ergonomics are the human behaviour and how humans individually react to different tasks and situations, while interacting with technical systems (e. g. automobiles, aircrafts, trains). Research activities in terms of cognitive ergonomics follow up with the design of human-machine interfaces with respect to the diversity of processes in human behaviour and human information processing (Smith & Hoffman, 2018). In accordance with ISO 26262-2:2018, the Functional Safety lifecycle of the automotive product development process roughly considers the human behaviour in the so-called controllability. controllability is one of three dimensions of the description and quantification of potential risks and hazards and quantifies the ability of the driver to control a failure and recover a save state (ISO 26262-2:2018). Due to the unclear derivation as well as the missing link to underlying cognitive processes of drivers, the definition of controllability is not sufficient enough to allow its comprehensive description and rating in the analysis of automotive systems.

Marc Schneider

Framework for interactive testing and development of highly automated driving functions

With the emergence of autonomous driving, a rapidly increasing number of new vehicle functions is needed, which must be checked by numerous vehicle tests regarding their functionality. Due to the increasing complexity of these systems, this requires an expanded use of virtual developmental and test methods. Therefore, software environments that enable the generation and implementation of various test cases are needed.

Martin Kehrer, J. Pitz, T. Rothermel, Hans-Christian Reuss

Definition of critical traffic scenarios to evaluate trigger criteria for collision avoidance

This contribution examines the parameters, which influence a critical situation in road traffic decisively. For this purpose, sets of simulations are performed to evaluate the impact. By this knowledge, a trigger criteria for collision avoidance, which take all parameters into account is defined. The criteria utilizes an easy planning method to assess if an evasive maneuver or braking intervention will lead to collision free driving.

Andreas Homann, T. Bertram, M. Buß, M. Keller, Karl-Heinz Glander

Requirements on driving dynamics in autonomous driving with regard to motion and comfort

Today, the active driver is considered as reference for the development of driving dynamics. However, with the ongoing development of autonomous vehicles, at automation level three according to VDI, the active driver becomes an inattentive passenger. Depending on the changed level of attention and the possible new activities of the occupants in an autonomous car, such as reading, sleeping or working, the requirements for the driving dynamics of vehicles will change as well. So far, different attempts have been made to set these requirements as acceleration limits for the vehicle body derived from empirical studies with conventional cars. In a new approach, acceleration requirements could be derived for the occupant instead of the vehicle body. Thus, in the future the vehicle controller may not only control its driving dynamics with respect to the vehicle itself, but also with respect to its occupants.A driving simulator study, described in this paper, examines the influence of the degree of attention of an occupant, with respect to his movements in the vehicle while cornering. Acceleration measurements are taken directly at the body of the passenger. The study shows that inattentive occupants, distracted by other activities during autonomous driving, will move more compared to attentive ones who observe their environment. In addition, it has been shown that an attentive occupant moves more uniform compared to an inattentive one. It is also expected that the inattentive passenger of an autonomous car will move much more compared to an attentive driver today. This results in new requirements on ride comfort in autonomous vehicles. In this context, the capture of motion of the occupants during autonomous driving could be a good indicator for the experienced driving comfort. The passenger movements caused by accelerations of the body must be in a range, where the occupants are able to follow their requested activities undisturbed, but still provide enough feedback of the driving activities if desired. Its fulfillment is an essential pre-requisite for the ride comfort of autonomous vehicles.

Georg Burkhard, S. Vos, N. Munzinger, E. Enders, D. Schramm

Process for early prediction of noise induced by damper struts

Rattle noise induced by vehicle dampers at the rear axle is often detected only rather late in the vehicle development process during test drives. Thus, resolving the problem in the last phase is costly and sometimes even not possible before delivering the first series-production cars. Therefore, the paper investigates how the risk of rattling can be predicted already earlier without performing any test drives. To achieve this goal, damper struts are measured on a component test rig and the inertance of the car body in the damper connection area is identified from modal analysis. It is shown that the risk of rattling can be predicted from these measurements. In order to predict the risk of rattle noise also without any vehicle testing of a real prototype, possibilities of modern simulation methods are investigated as well. Especially the finite element method is used for determining the inertance of the car body in the damper connection area. It turns out that a combination of strut measurement and finite element analysis of the car body are a promising concept of predicting the risk of rattle noise without the need of a finished prototype. The deviations between measurement and simulation are comparable to variations occurring between different vehicles from the production line.

T. Brenner, Timo Hofmann, J. Hupfeld, D. Bestle

Simplified model for self-excited rear-axlevibrations

Vehicles are subject to a variety of requirements, of which the technical objectives are only a partial area. In addition, different sub-areas increasingly interact, whereby the complexity of the development process of a vehicle continuously increases.In the design phase, the vehicle characteristics are determined on a largely virtual level. In this phase no detailed final vehicle data is given. Instead, there are parameter ranges that are being progressively refined. Due to the available scope for development in the early phase, changes in vehicle parameters can still be achieved with arguable effort and manageable additional costs. However, complex full vehicle models that could be used to assess the effects of parameter changes with high accuracy are not yet available.During the testing phase, the vehicle functions and characteristics on the virtual vehicle are checked and assessed with regard to their goals. If target conflicts are discovered only during this late development phase, changes are associated with great efforts concerning engineering time and high costs due to the largely defined vehicle parameters.This conference paper presents a simplified simulation model with which statements regarding the self-excited oscillation phenomenon wheel shimmy can be made. With the help of a modified quarter-vehicle model unstable vibrations of the rear axle can be calculated. The instability assessment is done by an eigenvalue analysis.

Sebastian Wagner, G. Vena, D. Schramm

Generation of optimal shim stacks for valves in automotive dampers

Today, tuning of hydraulic vehicle shock absorbers is still mainly an empirical and iterative process performed in ride tests. The used valve systems are based on shim stacks which provide a wide behavior variety by millions of different shim combinations where, however, many shim stack variants have rather similar stiffness or flexibility characteristics. In this paper, a strategy based on finite element analysis and numerical optimization is presented for finding an optimal stacking. It allows to automatically identify shim stacks with similar flexibility characteristics taking into account limitations for specific design parameters which may for example improve and cheapen the serial production process. This strategy can also be exploited by transforming the shim stacks resulting from the physical tuning dampers used in ride tests into more robust shim stacks regarding the influence of manufacturing tolerances which are always present in mass production.

Timo Hofmann, Tobias Brenner, J. Hupfeld, D. Bestle

Sensor fault-tolerance for the actuator of an electric power steering system

Electric Power Steering (EPS) systems should be fault-tolerant. Therefore this contribution describes an estimation method to reconstruct the position signal and the current signals of a permanently excited synchronous motor (PMSM) if there sensors are faulty. An extended Kalman filter is used which operates in the whole speed range, also for low speed shortly before standstill, without the need of added test signals on the set point current. The approach works with a detailed process and adaptive noise model to allow an operation in the whole speed range.

Philipp Keßler, R. Isermann

Rotational speed sensor for high temperature

A new sensor concept for future wheel speed applications in trucks based on a series resonant circuit with a sensor coil is proposed. This sensor is not only able to cover the whole rotational speed range beginning at standstill but also the temperature range up to more than 200°C. In addition a digital current interface, self-diagnosis-capability and additional information about airgap and temperature can be provided in order to enhance the reliability of the system. With this sensor concept it is possible to replace the currently used inductive sensors with rotational symmetry (TIM: Twist Insensitive Mounting) and a diameter smaller than about 15 mm. Additional electronics and signal processing are required to provide all capabilities mentioned above.

Klemens Gintner

Synthetic oil filter media facing present challenges in mobility

One of the most frequently discussed mobility topics is the future of drivetrains. In internal combustion engines (ICE), oil filtration has always played a role and has largely contributed to a long lifetime of engines, transmissions and cooling cycles. Beyond that, oil filtration will play a major role in future drivetrain concepts. In lubricating and cooling, contaminants like particles and water have to be removed to assure a long lifetime also of future drivetrain components. Modern drivetrain concepts and trends are pointing towards hybrid motors or e-drives with e-axles, bio fuels, downsized components and new, more efficient lubricants or coolant oils. During operation in present and future drivetrains, the quality of oils is chemically as well as physically influenced in a way that ageing can occur faster or more intense. This brings up increased challenges on the oil filter media during the operation. Oil filter media made of synthetic fibers, fully or partially, are facing these challenges.This contribution focusses on filter media that are made of synthetic fibers, to face the present and future requirements of oil filtration – from engine oil over coolant oil to transmission oil applications, also in alternative drivetrain applications like e-mobility. Oil filter media designed of synthetic fibers are discussed to be optimized regarding their filtration properties, chemical resistance, influence of water, differential pressure, and small installation spaces.

B. Meister-Magsino, F. van Uffelen, N. Werchner, A. Kilian, A.-L. Winkler, H. Banzhaf, Richard Bernewitz

Innovative filtration solutions for electric mobility

Climate change is a major threat to mankind. Acknowledging this, the COP21 Conference in Paris has set a target of maximum 1.5°C temperature rise compared to the preindustrial levels to limit the negative effects of global warming [1]. As transport-related CO2 emissions share account for 23% of the total globally [2], passenger cars also have to bring their contribution. The agreed targets will be transferred into national legislation on CO2 emissions which will become more stringent. To comply with upcoming emission legislation, electrification of the powertrain is necessary. As CO2 reduction potential and cost for electrification go in parallel, powertrains with a lower degree of electrification will gain significant market shares first, with tighter emission requirements pushing for higher degrees of electrification in the future.

Michael Harenbrock

Seamless simulation toolchain for virtual engineering and virtual commissioning of smart factories

Over the last years the number of products in automotive industries dramatically increased. Each product is manufactured in ever-growing variance. Additionally their complexity has grown tremendously. Plants for manufacturing engineering need to produce a large number of different models and thus need to be more flexible. Ramp up has to be performed frequently and has to be much more efficient.At the same time, smart factories are highly automated and have become much more complex themselves. Many variants of one product can be produced in one production line. Therefore setting up a production line has become a very involved task as the change of one process parameter influences many variants.Any occurring problem in the production line has serious consequences. But as the plant is much more intricate, once ramp up of a plant has started, the adaption of parameters is complicated and rapidly increases ramp up time. Thus the planning of production plants has to be performed as detailed as possible to reduce the need for adjustments during the phase of constructing the actual plant. To achieve such detailed planning the predictive power of virtual design has to be increased.

Jos Höll, C. König, Y. Ritter, F. Auris, T. Bär, S. Süß, M. Paul

Manufacturing Smart Services for automotive production lines

The intelligent exploitation of sensor data and order parameters from modern production systems is one of the biggest challenges in the context of Industry4.0. Currently, data from single machines are processed individually and not integrated with upstream or downstream processes. This case is prevalent in automotive assembly lines. Here, numerous machining tools from different vendors prohibit a smooth collaboration. However, only the aggregation of the entirety of available data sources permits a comprehensive and intelligent analysis and optimization of production lines. This approach leads to the regulation and behavior prediction of single components and finally of whole production systems. Such an intelligent assessment can be realized by Smart Services which are self-contained application containers allowing for efficient data analytics in modern production lines. The SePiA.Pro project develops and investigates a self-describing and secure packaging format for Smart Services facilitating their automatic provisioning. The project implements an open, standard- and cloud-based platform consisting of a modelling environment for Smart Services; a repository for the exchange of Smart Services; and a provisioning engine for automated deployment of Smart Services. Said platform opens up modern data analytics capabilities for anyone, as both customers and suppliers of analytics services. Use cases from automotive manufacturing demonstrate the value of the developed solution.

Ulrich Odefey, F. Baumann, G. Grünert, S. Hudert, M. Zimmermann, M. Falkenthal, F. Leymann

A container-based architecture for the flexible coupling of communication protocols

In the context of Industry 4.0 [1], components of production facilities are getting increasingly connected. Therefore, communication between multiple devices from different manufacturers with different communication protocols is necessary. This task is solved by protocol converters and gateways. The communication at the shop floor, where real-time communication is required, is implemented using industrial fieldbus protocols. The communication to the office floor on the other hand, has no real-time requirements and is implemented using protocols, like MQTT, AMQP, or OPC UA. The communication between shop floor and office floor requires a mapping of parameters and data models, which is done manually during commissioning of the devices in the shop floor.The integration effort increases with the number of protocols used (see Figure 1). If a protocol should be replaced in a 1-to-2 architecture, each interface (number n) to that protocol must be changed. In case of a bidirectional communication, the implementation of each interface must be changed in both devices, which result in a quadratic increase of configuration effort. A common strategy to reduce the integration effort is to limit the number n of protocols in a production facility. However, limiting the number of protocols means also limiting the amount of available devices, because not every device supports every protocol. On the other hand, having many different protocols on the shop floor increases the configuration effort to change the protocol in the office floor.

Timur Tasci, A. Schmidt, Matthias Milan Strljic, A. Verl

A data model for data gathering from heterogeneous IoT and Industry 4.0 applications

Industry 4.0 (I4.0) offers the opportunity to gain a detailed insight into the current production process by means of an increased networking of production plants. This crosslinking makes it possible to record the entire state of a production plant and to trace it within a later analysis. The aim of this analysis is to optimize the monitored production process resulting from analyses of I4.0 value-adding services [1, 2]. Figure 1 schematically visualizes the information flow for such a scenario. Data from the various levels of production are collected, stored in a data storage facility and evaluated by a valueadding service pipeline. The results are integrated back into the production process as optimizations. In this work, first the requirements for such a value-adding service pipeline are determined, which results in a total of five requirements and is abbreviated with R1 to R5. Subsequently, a suitable system architecture from the Big Data area is selected in order to meet the previously established requirements and thus implement a value-adding service pipeline. The requirements R1 - R5 and the system architecture will then flow into a data model for data acquisition and transmission within the shop floor of the production.

Matthias Milan Strljic, Timur Tasci, A. Schmidt, T. Korb, O. Riedel

Automated driving at BMW – Solutions for today and tomorrow

On board of the latest BMW models there are the most diverse ranges of driver assistance systems available. Innovative functions in the areas of driving comfort, driving safety, and parking represent the highest level of automotive technology [1]. While autonomous driving will be the topic for the coming years, a high level of automation can already be experienced today. The driver is supported and relieved from stress in many situations. Nevertheless, the driver always maintains responsibility and observes the surrounding environment. The driver can completely takeover control at any time. The next level of automation is close.Developments for highly automated driving are in full throttle worldwide. The offer of fully automated mobility is interesting and lucrative for many industries. Solving this highly complex development task and mastering the technology is a new challenge for every player in the game.BMW established close cooperation with partners and has consequently changed the working model. Agile development methods and optimal infrastructure are key factors to succeed.

Claus Dorrer

Challenges for the vehicle dynamics development of sporty BEV vehicle

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

Gauthier Boisdequin, T. Maulick, J. Haug

Method for analysing the feeling of safety at high speed using virtual test drives

The interaction between vehicle and driver within the close-loop perception and control process is a very important research aspect in the development of new vehicles. Previous investigations indicated the increasing importance of the feeling of safety in conventional and severe driving situations. A typical European situation is fast driving on autobahn or highway with simultaneous effects of lateral dynamics and vertical disturbances. Especially in this case the impression of safety influences the overall driver’s vehicle assessment. For vehicle manufacturers it is essential to provide an adequate feeling of safety, whereby the vehicle has to be stable and comfortable and has to meets customers’ expectations [1]. Most investigations and test definitions related to vehicle stability are focusing on critical driving situations such as maneuvers defined in the ISO standards. Apart from these situations, customer-oriented driving maneuvers in everyday driving situations become increasingly important and have to be defined. In [2] it is described, that especially driving safety, well feeling and comfort are important criteria for customers’ decision-making to buy a new car. Other aspects are smooth vehicle movements and consequently a higher ride comfort. This causes a good subjective impression of the level of safety at higher speeds. Furthermore, a harmonious roll behavior contributes to a good feeling of safety [3]. However, not only in the role as a driver, trust in the vehicle is particularly important. All other vehicle occupants on the passenger and the back seats should feel comfortable without disturbances by unusual or annoying vehicle movements. Considering new driving scenarios such as autonomous driving, special attention must be paid to vehicle motions as reaction from uneven road surfaces or lateral and vertical dynamics control systems. Again, in this situation the human sense of safeness and trust in the vehicle and its body movements is particularly important.

Martin Heiderich, S. Leonhardt, W. Krantz, J. Neubeck, Jochen Wiedemann

Development of novel vehicle structures for automotive series production

The development of novel vehicle concepts is, amongst other, driven by the following trends in the mobility sector [1]:Electrification,connectivity and automationindividualization and flexibilizationsafetyThe German Aerospace Center (DLR) addresses these challenges within the research metaproject “Next Generation Car” (NGC), which serves as multiplier for DLR system and technology competence by networking and integrating research institutes, infrastructures and demonstrators in the transport sector based on three vehicle concepts: Urban Modular Vehicle (UMV), Safe Light Regional Vehicle (SLRV) and the Interurban Vehicle (IUV) (Figure 1).

Christoph David, S. Vohrer

Safety and light integration of alternative powertrains with innovative material concepts

Parallel to the development of the automobile with combustion engines at the end of the 19th century, researchers also developed successfully on electric vehicles. As two substantial examples Werner von Siemens with his electrically powered carriage (1882) or the electric cars developed by Ludwig Lohner und Ferdinand Porsche for the world exhibition 1900 in Paris can be pointed out. Because of their significant expanded range, availability and price of the fossil fuels as well as the quick refuel process, passenger cars with combustion engines dominate the 20th century. During the last years, the frame conditions like the increased price and limitedness of fossil fuels but also the social desirability changed. Therefore, electric vehicles experience a renaissance [1].This trend is reinforced by simultaneously staged megatrends like autonomous driving, car sharing, regions inside Asia and Africa with increased needs for transportation concepts or the topic of “last-kilometre” transportation for goods, which result in turn into demands for application-specific material concepts. As the main requirements for the mentioned application field of transportation, the topics of lightweight, safety (resistance against impact), ability for multi-material-design (joinability) but also recyclability and the material-specific CO2-footprint (life cycle engineering) can be highlighted [2, 3].

Stefan Lindner, T. Fröhlich

Methods and processes for robust weight management in the automotive industry

The development of successful automobiles requires the consideration of customer, business and public interests. Especially public interests like legislation, environment and regulations challenge the automotive industry today [1, 2, 3]. In order to achieve all desired requirements, an intelligent overall system of objectives is indispensable [4].The vehicle weight is a crucial part of the system of objectives because it influences the vehicle design as well as customer-relevant characteristics like fuel consumption, range and driving dynamics. Therefore, the definition of the vehicle weight target is a fundamental milestone in the vehicle development process [1].The extensive influence of the vehicle weight on various characteristics leads to challenging and fixed weight targets throughout the project. The high volatility of vehicle developments due to the system’s complexity and tightening regulations can lead to target adjustments during the development process. As a result, time and cost intense measures are inevitable, which get more and more expensive the later they are applied [2].For that reason, the demand for a structured and continuous weight management consisting of several suitable methods is derived. The goal is to set up an elaborate weight target system which ensures a robust achievement of challenging weight targets.

Marcus Stegmiller, A. Albers, N. Bursac

Laser geometry detection in the Porsche wind tunnel – Base for 3D beamforming and deformation measurements

Especially in the early stages of the automotive development process, a quick and reliable rating of aero-acoustic sound sources is important to fulfil the challenging requirements. For the localization and a detailed investigation of these aero-acoustic sources a complex system, consisting of three microphone arrays (acoustic cameras) has been established in the Porsche wind tunnel [1][2].By the system basically 2D source maps are calculated and overlaid with a camera image for each array referring to a virtual focus plane in a certain distance.For complex source situations and in case of highly 3D-structured surfaces, however, the missing “depth information” can lead to misinterpretations. With 3D Beamforming, it is possible to calculate and display the acoustic source map using the correct distances on the entire surface of the measurement object and the merged acoustic information of all three arrays [3].The basis is a 3D model of the measurement object whose position and orientation to the coordinate system of the microphone array must be known.Above all, at higher car speeds, the forces resulting from the vehicle flow can lead to considerable component deformations (for example door out-boarding) and thus to aerodynamic and acoustic issues. In order to evaluate the correlations and develop corresponding measures, it is necessary to measure and analyze the deformations under wind load exactly.The state-of-the-art 3D laser scan system installed in the Porsche wind tunnel allows the determination of the geometry models required for 3D beamforming, the vehicle position relative to the microphone array and the deformations of planar components.For the deformation measurements, a much higher accuracy than the absolute single point measurement accuracy of the 3D scanners used is achieved using a special statistical evaluation method.

Jörg Ocker, L. Paul

Acoustic characterization of electrical motors based on magnetomechanical and drivesystem issues

Performing detailed vibration and acoustic analyses for electrical traction motors with high efficiency and routine is indispensable in automotive engineering. Hence, acoustic engineering tasks are related with high demands on acoustic simulation workflows. For traction drive applications the derivation of acoustic models which feature a high numerical efficiency and reliability for a routine applicability in product development has proven to be a challenging scientific task in recent years. To meet industrial requirements, simulation environments and scientific methods for acoustic models need to be characterized by 1.embedding the simulation into a drive-system environment for dynamic mechatronic simulations and analyzing speed-variable electrical motors under realistic operating conditions. That is, inverter and control influences in timedomain need to be taken into account. This is mandatory for numerical testing of control-based acoustic countermeasures.2.Numerical algorithms for modeling of motors with arbitrary topology have to be represented by a generic mathematical architecture. The algorithms must be independent of the underlying physical models, whether they are 2D-Finite- Element-(FE), 3D-FE- or analytically based.3.Hence, a unified data structure with generic interfaces between physical models and modules within the simulation environment needs to be used. This yields an efficient data handling between different physical or technical domains.4.Finally, a routine comparability of simulation to measurement results must be guaranteed with high reliability for entire operation cycles.

Philipp Kotter, C. Köpf, J. Berkemer, O. Zirn, K. Wegener

Legal requirements and design of exterior sounds for electric vehicles

According to legal requirements, vehicles with an electric engine (electric and hybrid vehicles) have to be equipped with a device to warn pedestrians (AVAS, Acoustic Vehicle Alerting System). Corresponding regulations are or will be in force in the coming years more or less worldwide. The regulations differ for the different regions, complicating the Sound development and vehicle adaptation.For the OEMs the generation of exterior sound offers the opportunity to implement a recognizable, typical Brand Sound. But, the sound emitted to the exterior is partly also audible in the interior. It thus has to be avoided that it reduces the interior Sound Quality and NVH performance and causes strange interior sound effects, since the exterior sound only has to be active up to 20 or 30 km/h.The creation of a sound that fulfills the different legal requirements, implements a Brand Sound and does not reduce interior Sound Quality is a challenging task. In order to do so, complex and sophisticated sound generation algorithms have to be applied, and a proper process has to be used for the design and vehicle adaptation process. For most OEMs the target Brand Sound for AVAS systems is not yet defined, and the standard process only allows to check whether a sound fulfills the legal requirements when a vehicle is equipped with a device and measured according to the legal specifications. This process is tedious, time-consuming, inefficient and costly.In order to solve the conflict between the required fulfillment of legal requirements on the one hand and the wish to implement a Brand Sound on the other hand, plus an easy vehicle adaptation of AVAS an assessment of the conformity of an actually designed sound is directly integrated into the Sound Design Process.

Markus Bodden, T. Belschner

SCODE: Designing and verifying functionally safe systems in conformance to IEC61508 and ISO26262

The motivation to have safe products could be as old as the product development itself. The safety of a product is an implicit expectation from almost, perhaps all the stakeholders of any product. In fact, the safety of a product is an obligation even more so than an expectation, going by the requirements of the product liability. In a general context, IEC 61508 covers the aspects to be considered during the development of E/E/PE systems. For functional safety of the road vehicles, ISO26262 defines the requirements of functional safety in the system-, hardware-, and software development.While the standards are comparatively precise for the development phases like verification and validation, the requirements for the design phase are more generic, leaving the details very much to the implementer. For a design to be functionally safe, the standards requires to avoid complexity. The use of formal methods and principles like stateless design are encouraged. The examples given in the standards are either very domain specific like Calculus of Communicating Systems (CCS) or are difficult to apply like the formal language Z.

Sriram Vasu, O. Kust

Hybrid-surrogate-based automatic calibration in rapid-prototyping

Embedded software rapid-prototyping technique gains in importance in the development of automatic transmission control software. However, tuning the software parameters in rapid-Prototyping-environment is time consuming. Hence, a novel automatic universal calibration method is proposed in this paper. This method is derived from surrogate-based optimization and employs two types of surrogate models: Kriging models and neural networks. Such hybrid-surrogate-structure can not only optimize constant parameters, but also identify dependency functions of state variables.

Jianbin Liao, J. Schröder, C. Gitt, H.-C. Reuss

A quasi-dimensional charge motion and turbulence model for Diesel engines with a fully variable valve train

With the increasingly strict emission regulations and economic demands, variable valve trains are gaining in importance in Diesel engines. A valve control strategy has a great impact on the in-cylinder charge motions, turbulence level, thus also on the combustion and emission formation. In order to predict in-cylinder charge motions and turbulence properties for a working process calculation, a zero-/quasi-dimensional flow model is developed for the Diesel engines with a fully variable valve train. For the purpose of better understanding the in-cylinder flow phenomena, detailed 3D CFD simulations of intake and compression strokes are performed at different operating conditions with various piston configurations. In the course of model development, global in-cylinder charge motions including swirl, squish and axial flows are assigned to idealized flow fields. Among them, swirl formation during intake is estimated dependent on the stationary swirl number route that is determined by the valve actuation. Swirl losses during compression and expansion are ascribed to wall friction, turbulent conversion as well as piston motion. In conjunction with the charge motion model, a quasi-dimensional turbulence model is developed based on the k-ε turbulence model. Turbulence production and dissipation are determined through submodels. The results from the performed validations demonstrate, the proposed flow model accurately predicts the temporal change of in-cylinder flow quantities and also responds correctly to the variations of piston configuration as well as operating conditions such as engine speed, charging pressure and valve actuation. Further application of the model in other Diesel engines is feasible by tuning certain model parameters.

Qirui Yang, M. Bargende, M. Grill

Alignment of simulation methodology and measurement techniques to predict the HC distribution at catalyst inlet

Injection of fuel into the exhaust system is increasingly being used to support the operation of exhaust gas aftertreatment systems. When injecting a fluid into the exhaust system, one major challenge is to define an optimum position of the injector and its spray hole configuration along with an appropriate injection pressure. Simulation techniques are a suitable means to support the corresponding development process. Hence, the project “Exhaust Fuel Injection” was initiated. Project target is the alignment of simulation methods and measurement techniques to predict the HC distribution in radial and axial direction at the inlet of a catalyst. This includes the development of suitable measurement techniques to determine the hydrocarbon concentrations upstream and downstream of a catalyst.Transient 3D Computational Fluid Dynamics (CFD) simulation was used to model the fuel injection into a purpose-built exhaust system. The simulation results of the distribution of hydrocarbons at catalyst inlet in radial and axial direction are compared with measurements performed at an engine test bench. The measurements include optical techniques using Mie-scattering to determine whether droplets occur or not and Laser- Induced Liquid Fluorescence (LIF) measurements, where a tracer indicates the HC concentration in the gas phase. Additionally, the HC-concentration was measured using an HC exhaust gas analyzer (Fast FID).A total of 21 parameter variations were simulated and measured showing high comparability with the measurements (deviation below 2 %) regarding the uniformity index (radial uniformity) as well as peak gradient and duration (axial uniformity) in 13 variations. Only four of the 21 simulated cases showed poorer conformity (deviation above 3 %). Especially simulations in operating points with comparably low exhaust temperatures (340 °C – 395 °C) matched well. Also, the influence of different injection pressures (5-50 bar) was modeled with good accuracy. Highest deviations between simulation and measurement were found with high exhaust temperatures and low exhaust mass flow rates and in the variations with mixers.

Verena Huth, A. Dhongde, D. Klein, M. Günther, S. Pischinger, T. Fukuma

Investigations on PN formation and emission from passenger car GDI engines

To meet the future CO2 limits, several engine manufactures increase their proportion of gasoline engines equipped with direct injection systems (GDI). However particle number emissions of GDI engines is much higher than of port fuel injection (PFI) engines. Reasons for particle emissions are nonhomogeneous mixture formation, the presence of local rich zones and liquid fuel in the combustion chamber [1; 2]. Downsizing and Downspeeding are promising solutions to reduce the fuel consumption. In context with the new emissions regulations the reduction of particle number emissions at high engine loads is becoming increasingly important. The higher engine loads at lower engine speeds lead to more fuel injection in a lower in-cylinder charge motion environment. Both are negative for the mixture formation and the evaporation of the liquid fuel.In previous work, a single cylinder research engine was operated to measure the particle number emissions at high engine loads [3]. In this work, a CFD-Model was used to analyze the mixture formation process. Therefore, a cold simulation was performed up to the point of ignition. The CFD simulations provide an insight into the mixture formation process, the fuel evaporation process and the creation of liquid film in the combustion chamber. The simulations are performed at boundary conditions of the experimental work and are thus directly comparable to the measurements. To validate the simulations, optical in-cylinder measurements were done at the same operation points. The focus is on high engine loads with an IMEP of 1.4 MPa and an engine speed of 2000 rpm. The variation in this paper will be Start of injection (SOI) for two different injectors with different injection pressure and charge motion variations. At the end a short summary about the overall project results is given.

Denis Notheis, M. Bertsch, A. Velji, T. Koch

Applying industrial data analytics in automotive test bed environments

Modern automotive test beds do not only produce the measurement data they are operated for, but also a lot of auxiliary data which is generated by sensors and software. This data is a byproduct of the testing process and not directly related to the unit under test. Nevertheless, its size can be enormous. A prototypical example of this data are software log-files that contain not only information about connected hardware devices and their current statuses, but also records of generated warnings and errors.If the information contained in these logs is used at all, then mostly by manual inspection of the files by engineers to track down certain errors and their root causes. Currently this inspection and service process is hardly supported by computational approaches.In our contribution we demonstrate how new methods of industrial big data analytics, data-mining, and visualization can be put to use in order to generate knowledge and new insights from the available data. This can help machine vendors, test bed equipment vendors and OEMs to avoid expensive downtimes.We will shine a light on the whole analytics process: How the data looks like, what information is contained, how it needs to be prepared to enable analyses and what difficulties can arise at each step. This will provide a deep view on how industrial data analytics projects should be set up and conducted while also mentioning potential obstacles and how to overcome them.

A. Festl, F. Michitsch, P. Priller, Michael Schmeja

Process optimization in press shop by using vacuum handling devices with integrated intelligence

Digitalization is transforming industry. It is changing processes, making them more flexible and transparent. The main target is to reach the vision of “Smart Factory” with autonomous production units. The units organize themselves on an ad hoc basis, the employees benefit from intelligent assistance systems; production is individualized so that even for the batch size 1 the efficient high volume production conditions can be reached. This vision will soon be possible; the only question is where to start.This study makes Industry 4.0 a practical reality by using an example of a tooling in a press line for the production of car body panels. Intelligent compact ejectors allow both efficient product operation and control of the entire process. All of the parameters that are relevant to energy and performance throughout the vacuum system are recorded, monitored, and analyzed via IO-Link here. Besides, process data is displayed on the smartphone together with maintenance and service information via NFC. Compatible systems and services connected through IO-Link, such as intra clouds or cloud services, are used to make the information visible in the different integration stages and output channels. This enables a higher degree of transparency and productivity in automated processes in automotive industry. The energy monitoring function guarantees optimal energy consumption throughout the system. The system status is monitored using condition monitoring, which increases system availability substantially. The predictive maintenance function improves the performance of the tooling. The user can initiate scheduled predictive maintenance even before the system ceases operation. Compact vacuum ejectors continuously monitor the tooling status, detect subtle changes or imminent malfunctions and report them to the system’s controller via IO-Link and NFC communication. The result is significant reduction in down time and increase in system availability.

Eda Gökcimen

Possibilities of deep learning for automated driving with focus on environmental perception

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

Heinrich Gotzig

Simulation in development and testing of autonomous vehicles

On the first glance, autonomous vehicles seem to be just a simple continuation of the development of assistance systems which help the driver keeping the lane, holding the distance to other vehicles and avoiding accidents, with the vision of avoiding 80% of all accidents, because they are mainly caused by human errors. However, there is huge challenge with respect to the requirements on system performance and reliability for this step. As Herrtwich mentioned in [1], human drivers do quite well in driving a vehicle without accident, with statistically 7.5 million km between accidents on the German Autobahn network; if an assistance system helps a driver to avoid such accidents in (just for example) 9 out of 10 times, it does a good job by reducing the number of accidents by a factor of ten. However, autonomous vehicles with SAE level 3 or higher face the challenge to avoid or control any critical situation within a statistical distance of 75 million km between accidents, in order to achieve a similar performance compared to a level 2 (driver assisted) system. That includes many situations, which have traditionally been handled by human drivers easily, but might be difficult for automation.As Winner points out in [2], it would need test driving without accidents for hundreds of millions of kilometers to prove statistically, that the risk of autonomous vehicles is low enough to argue the safe operation; this kind of straight forward system verification would not lead to a practical implementation (because of time and cost issues) and furthermore would still leave gaps in an exhaustive safety argument. As in other industries with low risk requirements (aerospace, power supply systems, automated production systems, etc.), other methods have to be used to prove the safety performance of automated vehicles [3]. System design for such systems relies on redundant subsystems with well understood, logic-based safety arguments. But functional safety (based on robust and uncorrelated subsystems) is only one part of the design; functional completeness, i.e. the proof that any conceivable situation can be handled by the system, needs a very systematical system design and thorough verification and validation procedures. For this part of the development and testing task, simulation plays an important role [6].This paper shall focus on the goals, the required tools and components, and the approaches of simulation for development and testing of autonomous vehicles.

Hans-Peter Schöner

Technology meets human: Travel behavior in the age of autonomous driving

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

Barbara Lenz

Challenges in thermal management for electrified vehicles

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

Heike Schönerstedt

Coupled simulation as part of the energy management of electrified vehicles

The limited driving range of battery electric vehicles is one of the major challenges of the vehicle development. Legal test cycles take driving ranges at 23°C without air conditioning only into consideration. But the power required for heating the car cabin in winter or cooling the car cabin in summer can reduce the driving range up to 40% [1]. Figure 1 shows the average ambient temperature in Graz, Austria. The illustration highlights that mainly temperatures below 23°C are happening. Thus, heating of the car cabin is required for most of the time. Therefore, the interest of development is not focused on the driving range described by the legal test cycles (e.g. NEDC) but on how far the vehicle can be driven in winter or under any other real conditions.

Michael Martin, I.M. Cuenca Jaén

Adaptive cabin air filter system for energy efficient filtration for e-vehicles

One of the key challenges for e-mobility is to increase the cars driving range. Heating and cooling of the cabin air drains energy from the battery, which cannot be used for the powertrain of the car. Simultaneously the demands on the quality of the cabin air are significantly increasing. The protection of the passengers from ultrafine particles by HEPA filters or harmful gases by adsorption leads to filtration products that no longer can be implemented in the air conditioning system (HVAC). New installation spaces in electric cars offer the opportunity to adapt an intelligent filter system upstream of the air conditioning system. The system consists of three, individually adjustable filter stages that are activated depending on the air pollution level of the environment and driving conditions (traffic jam, tunnel, city, outback).Sensors continuously monitor the quality of indoor and outdoor air in terms of particles, gases, temperature and humidity. As a result, the proportion of the outside air supply and the necessary filtration performance can be regulated if required. This always ensures the best air quality in the interior of the car and reduces energy consumption of the air conditioning system. Therefore, the high-quality HEPA filter is only activated when needed, which increases the lifetime and reduces service costs.

Jérôme Migaud, M. Lesage, D. Chalet, T. Heininger, B. Bauer, M. Heinzmann, C. Krautner, M. Klein

Design space exploration for the model-based design of the power distribution system in vehicles

The existing energy supply network reaches its limits due to the rapidly increasing electrical consumption with a simultaneously high legacy share in the design. This article therefore shows a possibility of how different designs can be investigated with the aid of a generic model approach considering real driving conditions. Such a generic model allows a flexible adaptation of the examined freedoms such as topology or component placement and the boundary condition e.g. the environment parameters during the evaluation. This allows to make well-founded statements about the advantages and disadvantages of alternative architectural designs in the early stages of development.

Lisa Braun, E. Sax, Kurt Kruppok

Reliability design for passive power semiconductors in electrical machines

The automotive industry is currently experiencing an unprecedented amount of innovation and introducing new technologies in almost every field. Even with all of these exciting new developments, one of the most important points is to maintain or improve the reliability and lifetime of cars. In response to these demands, automotive manufacturers and suppliers have worked to strengthen their expertise in this area.This paper gives you useful hints and shows the general process for reliability design using the example of passive power semiconductors in alternators. Alternators are used in vehicles to transform mechanical energy into electrical energy. It doesn’t matter, if the mechanical energy comes from the combustion engine itself or from braking phases during driving, so called recuperation.Driven by the current demands of automotive technology, electrical drives will gain more and more importance and market share in the market. The general approach to develop electrical drives including electronics, is similar to how most mechanical parts are designed and developed. After fixing the requirements and topology, the electromagnetic layout is in the lead. This physical domain defines the main geometries of the machine and the currents as well as the voltage level. Having this information, you have to decide about the best technology and according topology for your mechanical, electromagnetic, circuitry and electronic components. Design for reliability (DfR) in reference to BERTSCHE [1] should be considered during the whole development process.

Christopher Grießhaber, R. Schroth, M. Kopp

Next gen electric drive unit for passenger cars and light duty vehicles

This paper presents an advanced EDU family (Electric Drive Unit) with high system performance. Electric Motor, a new innovative gear set, differential, shift mechanism, dual inverter and cooling are integrated into one compact unit. Gear set and E-Motor inner cooling and lube are realized by a low power, cost effective centrifugal oil pump. The EDU features a water cooling for inverter and stator jacket.The compact gear set is realized as ring gear-less planetary structure with unique design. The complete reduction gear set is captured in one cage and is completely free of axial and radial forces (different than most today´s solutions). The gear set also includes a neutral shift and park lock system. Both systems are actuated by one electromechanical actuator. The park lock is in base principle a conventional park lock with claw, but realized with a multi claw pole in axial actuation to reduce weight and package space of the system.The high end version is equipped with a dual inverter. This allows the usage of a multiphase E-Motor (6 phase Motor is intended solution). In this way cogging torque can be improved without sacrificing efficiency. This gives even better prerequisites for good NVH behavior. As a further side effect the availability and scalability is improved by this approach.This next-gen EDU family shows very high specific values on System level. To achieve this many small and larger innovations were incorporated into the EDU system.

Peter Janssen, G. Hellenbroich, H.-P. Lahey

Connected testbeds – Early validation in a distributed development environment

The automotive industry is currently driven by three major trends - electrification, automation and connectivity [1]. These lead to an increasing complexity of the overall system and more interaction of the subsystems. In addition, there is a progressive shift from development tasks to suppliers, which goes hand in hand with parallel development of the subsystem. To cope with the challenges described above, development tasks should be frontloaded to earlier stages, while simultaneously maintaining the system context. This applies in particular to the validation activities.Validation is the central activity in the development process, since only in validation knowledge evolves [2]. As depicted in the following figure 1 engineers can choose from a broad landscape of validation environments, reaching from pure simulation to component testbeds to on-road testing. With the increasing share of physical components costs for validation typically rise. But also accuracy rises because modeling errors can be eliminated by replacing simulation modules with physical components. However, reproducibility and flexibility decrease due to the effort it takes to modify a physical setup in comparison to a parametrized model [3].

David Nickel, M. Behrendt, K. Bause, A. Albers

Powertrain calibration based on X-in-theLoop: Virtualization in the vehicle development process

Powertrain development in the automotive industry has changed significantly over the recent years and is forecasted to alter even more in the near future. For many decades, the internal combustion engine was the only propulsion system for passenger cars and commercial vehicles. The need to minimize CO2 emissions from the transportation sector to limit global warming as well as the new requirements to reduce real driving emissions (RDE) to further improve air quality, specifically in urban areas, forced OEMs, Tier1 suppliers and engineering service suppliers to also develop electrified powertrains. The portfolio of vehicle propulsion systems in the future will include pure electric vehicles, full (plug-in) hybrid vehicles, mild electrified (48V) hybrid powertrains but also vehicles still only using conventional combustion engines. This enlarged variety in powertrain configurations requires enormous engineering efforts in the development and testing of the full bandwidth of powertrains. To allow a parallel development of the different technologies, it is essential to keep the costs of calibration and testing to a minimum in order to ensure affordable products. To achieve this, a synthesis of advanced simulation methods and modern testing equipment is the suitable solution. It generates a variety of new test procedures and methods for the efficient development of complex propulsion system architectures. The Institute for Combustion Engines at the RWTH Aachen University presented a method to couple a conventional internal combustion engine installed in one test cell via a virtual shaft with an electric machine and / or a transmission installed on another test bench. [1] Another approach is to virtualize individual elements or sub-systems of the powertrain and the environment around the test object. In this case, physical components of the powertrain (e.g. engine, transmission, electric machine) or control units will be connected to virtual systems / components (e.g. vehicle, hybrid powertrain, environment, etc.). [2] This allows the calibration of the full target system while only one part / component is physically available and operated on a test bench. The FEV Group has defined and implemented a consistent strategy for virtual calibration using multiple X-in-the-Loop systems and integrated this approach into the established, quality-guided standard calibration process. Representative examples of characteristic use cases are presented in this paper and the pertaining challenges and benefits are described in more detail.

Matthias Kötter, B. Lindemann, D. Bergmann, M. Ehrly, T. Jung, M. Nijs, S. Thewes, T. Körfer, S. Trampert, T. Drecq, P. Gautier

Model-based combustion analysis for the development of control functions at the EiL-test bench

A methodology of model-based combustion analysis for the development of control functions at the test bed is considered. One focus is hereby the usage of semi-physical models, which are obtained by combination of theoretical physical models with experimental models in order to adjust the overall model to the actual, nonlinear behavior. In the context of engine modeling, the physical model structure offers a priori knowledge and physical interpretability. The experimental part ensures model adaption to real engine behavior, which is realized by using online parameter-estimation methods. Furthermore, the combination of both allows the transferability to other engines. The resulting modeling approach is particularly intended for online applications.Conventional model-based combustion analysis can be extended by semi-physical real time models. These models support the application engineers, especially for the calibration of dynamic engine behavior at the test bench. As an example, an analysis method based on a crank-angle-synchronous semi-physical combustion model is presented, which gives additional insight into the fast and highly time-resolved combustion processes and provides characteristic parameters, which make the effect of different optimization measures comparable.

Alexander Weber, R. Isermann

Measuring and modeling of rolling resistance

Limited resources and the higher awareness of the influence of CO2 emissions on global warming have led to stricter legal regulations. The aim of 20 % cut in CO2-emissions until 2020 compared to levels of 1990 was declared by the European Union [1]. Transportation has a share of 26 % on these emissions. Therefore different regulations including fleet consumption levels for passenger car manufacturers have been introduced and increase the pressure to develop more efficient cars.Besides the development of more efficient or ideally CO2 neutral drivetrains (which are only possible for 100 % regenerative generation of power), the reduction of driving resistances is one of the main instruments to achieve this objective. The external driving resistances consist of Air resistanceRolling resistanceAcceleration resistanceClimbing resistance Rolling resistance, acceleration and climbing resistance depend on the mass of the vehicle. However, increased safety and comfort requirements together with production costs specifications limit the opportunities for more efficient cars due to mass reduction. On electrical powered vehicles, kinetic and potential energy can be regenerated to a large extend. Therefore acceleration and climbing resistance can be compensated partly and air drag and rolling resistance are more important than for conventionally powered vehicles. Furthermore, electrical powered vehicles are often used in urban surroundings at relatively low speeds, at which rolling resistance becomes the dominant driving resistance.

Roman Sauer, J. Wiedemann, W. Krantz, J. Neubeck

Experimental validation of different approaches for thermodynamic simulation of passenger car tyres

Due to the intensified integration of simulation and modelling into the development of automotive vehicles and their assistance systems, the expectations of accuracy and computational efficiency in simulation are increasing rapidly. In addition, simulation finds more and more application in the process of vehicle homologation, which were a pure experimental discipline in the past. In any case, not only demands affecting vehicle modelling but also refined tyre modelling become more important. In recent years, with continuing refinement in tyre simulation, the needs for coping with tyre temperatures and the resulting influences on the tyre characteristics have been considered important.These effects include, amongst other things like tyre wear, the temperature dependent behaviour of the tyre-road grip and the loss of cornering stiffness with increasing temperature. To consider those effects, it will become mandatory to reliably estimate the tyre temperatures as one additional input into any enhanced tyre model for vehicle dynamics and handling. In the sense of balanced modelling, the temperature submodel should not exceed the computational effort of the respective tyre model.For studying heat flow modelling of tyres, the present work aims to generate a comparative basis by investigating three different temperature models in regard of the fulfilment of the mentioned requirements. Furthermore, the easiness of identifying a model’s parameters is quite an important aspect from the engineering point of view. It is known that models which are based on more or less simple physical relations, where their parameters do have physical meaning (so-called semi-physical models) are able to facilitate parameterisation than e.g. pure empirical or phenomenological models. In particular, the latter ones require expensive a-priori measurements in general. Therefore, in the following special attention is paid to their abilities of integration into any adequate tyre model for vehicle dynamics and handling.

Andreas Hackl, C. Scherndl, W. Hirschberg, C. Lex

Tire contact patch pressure distribution model for the static parking maneuver

A high priority in vehicle development is the precise definition of the steering characteristics. One crucial parameter for the design and correct dimensioning of the steering components is the maximum steering wheel moment, which occurs at the static parking maneuver. The static parking maneuver is characterized by zero vehicle velocity with applied brakes, large steering wheel angle along with high camber angles. The main contributions to the steering wheel torque in this maneuver are the tire forces and moments that are caused by the friction between the tire and the road. Next to the friction coefficient between tire and road, these forces depend dominantly on the pressure distribution in the tire contact patch. The current tire models, which are used for simulations in the early development stage, calculate inaccurate pressure distributions in the contact patch that do not correspond with measurements. Consequently, the predicted friction forces are inaccurate and an exact design of the steering components is currently not possible.The main objective of this contribution is the development of a model, which allows calculating the tire contact area and pressuring distribution considering vertical load, inflation pressure, tire properties and high camber angles. To achieve this goal, the present paper provides an analysis of comprehensive measurements of the pressure distribution in the contact patch and an evaluation of its dependency on the most relevant influencing parameters such as wheel load, inflation pressure and camber. These findings are then used to propose a new and more accurate model to calculate the pressure distribution. For this purpose, a new approach is being pursued to describe the tire contact patch by the use of a super ellipse. Furthermore, the calculation of the pressure distribution is developed within this contact area. A regression model is used to identify the model parameter’s sensitivity to the constraints of the parking maneuver.

Mario Weinberger, J. Becker, D. Schramm

Development of smart interior systems for connected cars

From connected cars to agile software development methods, the automotive industry is constantly evolving. In the highly competitive automotive industry of today, suppliers, development partners and OEMs need to keep up with trends and technologies and should be prepared to adapt quickly to changes. The amount of digital intelligent systems in a vehicle is constantly increasing and the networking of vehicles is also becoming more significant with regard to intelligent driver assistance systems and semiautonomous driving.

Bernhard Budaker, M. Geiger, K. Fernandes

Automotive systems engineering – Enabled by virtual prototypes

As part of the increasing complexity of today’s vehicle systems, the development departments of OEMs and suppliers constantly face new challenges. Traditional methods for development and application which are based on processes with real prototypes reach their limits here. In addition to an unreasonably high effort involved in the testing of all subsystems as well as the high costs that arise in this context, there are other, more fundamental difficulties.First, the lack of availability of real prototypes needs to be mentioned. This problem applies both to later stages within the development process in which prototypes are usually on hand as well as the number of available real prototypes that is simply too limited to ensure access for all development engineers at the required time. The interaction of the diverse range of subcomponents can only be tested sufficiently if all subsystems are available as real prototypes. However, according to the automotive systems engineering approach discussed here, systems should be tested within their networks and under realistic test conditions. The requirements for this can only be met if virtual prototypes can be used early in the development phase.

Steffen Schmidt, M. Elbs

The future cyberphysical car

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

Thomas Dietz, T. Bauernhansl, B. Budaker, M. Hossfeldq

From traditional navigation maps to future high-definition life maps for automated vehicles

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

Ralf G. Herrtwich

The BAIC BJEV view of autonomous driving in China

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

Marcus Hafkemeyer

The new German bill on automated vehicles – and the resulting liability changes

On 21 June 2017, Germany enacted a bill legalizing automated vehicles (hereinafter referred to as “AV Bill”). The AV Bill modified the German Road Traffic Act (Straßenverkehrsgesetz, “StVG”) and defined the requirements for highly and fully automated vehicles to use public roads. It further addressed the rights and duties of the driver when activating the automated driving mode.The AV Bill did not change the general liability concept under German law. Therefore, both the driver and the “owner” (Halter) remain liable even if the vehicle is in automated driving mode. However, the driver will be able to avoid liability if he/she lawfully used the automated driving mode. Automated vehicles must be equipped with a black box to identify whether the driver or the system had control at the time of an accident. Since this will help the driver/owner (or, in practice, the owner’s insurance company) to prove that the vehicle – and not the driver – caused the accident, the relevance of German product liability rules is likely to increase. As a consequence, the relationship between insurers and car manufacturers will change.In addition to liability issues, many legal questions, especially regarding data privacy, remain to be solved. Finally, since automated driving is permitted within the limits of the “intended use” (as defined by the individual car manufacturer), this will likely be one of the key differentiators between car manufacturers in Germany.

Christian M. Theissen

User requirements for future urban vehicles

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

Matthias Klötzke, G. Kopp, S. Schmid, H.E. Friedrich

Innovative electric vehicle concepts with optimized acoustic performance

Mobility and national wealth are closely connected [1]. Growing national wealth leads to a growth of Transportation of goods and people. Moreover, mobility is also one of the human basic needs in our society. Growing demands on mobility has yet its negative impacts on environment (e.g. greenhouse effect, air pollution, lack of fossil fuels etc.) and on our society (exhaust gas and noise emissions, accidents, etc.).In order to reduce CO2 emissions and air pollution, stricter air quality laws have been issued by the governments all over the world, e.g. the European Union legislation sets mandatory emission reduction targets for new cars: The fleet average to be achieved by all new cars is 95 g/km by 2021, phased in from 2020 [2]. On June 30th 2015, the National Development and Reform Commission of the People’s Republic of China (NDRC) submitted its Intended Nationally Determined Contribution (INDC), including the target to peak CO2 emissions by 2030 at the latest and increase the share of non-fossil carriers of the total primary energy supply to around 20 % by 2030 [3]. Shortage of fossil fuels is another global issue faced by all humanity. According to [4], until 2040, transportation will still be the sector in which fossil fuels are mostly consumed.

Weijun Lu, T. Vietor, R. Blumrich, J. Wiedemann

Optimization of electric vehicle exterior noise for pedestrian safety and sound quality

Without the noise of a running combustion engine, electrically driven vehicles are very quiet, sometimes even too silent to be noticed by other road users, especially pedestrians, putting their health and lives at risk. Therefore, authorities recommended the introduction of artificial exterior noise signatures to be emitted by vehicles with electric powertrains to ensure detectability and pedestrian safety. In response, many manufactures have already introduced synthesized noise generation systems using exterior loudspeakers.The paper at hand, discusses a systematic approach using exterior and interior simulations to optimize the system sound design. Within the scope of development of the exterior noise signals, the goal is to achieve the minimum required sound levels and transient pitch requirements, while ensuring the sound is both pleasant from the outside of the vehicle and at the same time non-intrusive to the vehicle interior. Utilizing an exterior transfer path approach for potential speaker locations, the sensitivity of variables such as speaker location, noise source routing, exterior noise transfer functions and sound source design can be evaluated to achieve the required sound levels and directivity while minimizing the noise intrusion into the vehicle cabin. A transfer path analysis to the vehicle interior is utilized to assess the influence of the exterior noise sources on the sound quality inside the vehicle.

Adrian Rosplesch, T. Tousignant

Interoperability between charging infrastructure and electric vehicle

The charging interface between grid and electric vehicles is new. Energy and automotive industries have to co-operate for a successful introduction of e-mobility. There are plenty of challenges to provide a proper co-operation of these “two worlds”. From the view of the energy provider integration of e-mobility into smart grid is important, which includes effective dynamic load management and the use of the HV-Batteries in the vehicles to store and feedback energy. The user expects sufficient and reliable charging points to re-charge his electric vehicle everywhere and at any time. Keys for an infrastructure accepted by users are easy to use and secure data transfer of personal data.Basic requirement to provide charging services is a proper a reliable communication between electric vehicles and charging stations.

Ursel Willrett

Calculation of route-dependent energysaving potentials to optimize EV’s range

In order to compensate the range disadvantage of battery electric vehicles, it is necessary to make efficient use of the vehicle’s available energy. Knowing exactly how much energy is needed to drive the upcoming route makes this possible. This paper investigates the extent to which driver behavior and the use of the air conditioning system affect the range of battery electric vehicles taking into account the route, environmental and traffic data. Therefore, a methodology is presented which utilizes different measures based on a predictively determined speed profile and provides a remaining, position-dependent energy-saving potential. The aim is to know the remaining energysaving potential at all times during the route guidance. Thus, an assistance system for extending the range can make use of it if the situation requires it.

K. Kruppok, R. Kriesten, E. Sax

Mastering the future: Agile model-based system design for BMW’s electrified next generation platform

Future mobility systems are becoming more complex. Existing processes for hardware component oriented development reach a limit for highly integrated systems. High quality cannot be efficiently ensured any longer at shorter development cycles and reduced budgets.This article shows an approach to master system design and system verification with two approaches taken over from software industries: digital and agile transformation. Digital transformation of systems engineering based on model based specification with SysML helps to master complexity and agile transformation based on cross-functional teams with domain engineers and computer scientists contributes to sustainable consistency and a test first approach.As a consequence, testing efforts are frontloaded and quality increases due to early stakeholder involvement. Furthermore, this approach supports the know-how exchange between the specialists of different domains at expert level. This enables an efficient high performance large scale development under series project conditions.

Stefan Kriebel, Johannes Richenhagen, C. Schulze, V. Moyses, P. Orth, S. Pischinger, T. Greifenberg, B. Rumpe

Road load determination in a wind tunnel compared to the WLTP wind tunnel method

A new type approval procedure for determination of pollutants, CO2 emissions and fuel consumption was introduced in the EU and various other countries in 2017. The WLTP (Worldwide harmonized Light vehicles Test Procedures) can be used to determine the road load of a vehicle using the wind tunnel method instead of using coast down testing procedures on a proving ground. This method uses the measurement of the aerodynamic drag in a wind tunnel with the remaining components of the road load (mostly rolling resistance and drive train losses) determined by a flat belt or chassis dynamometer. This article investigates, whether it is possible to determine the road load in a wind tunnel as well. The AEROLAB wind tunnel of the BMW Group provides new possibilities which have not been previously investigated. This facility has a single-belt-rolling-road-system, which provides realistic flow conditions below the vehicle underbody and around the wheels. The aerodynamic forces are measured depending on ride height through a horizontal force measurement system in combination with a vehicle fixation at the front wheel hubs. The internal forces like rolling resistance and drive train losses are not be measured. However, with the integration of two other load cells in the vehicle fixation system, the internal forces of the vehicle can be determined in conjunction with the aerodynamic drag. The results and differences of these two measurement methods are discussed.In the following two sections of this chapter at first the reason for the introduction of WLTP and the assigning of the road load determination to the type approval procedure is shortly explained. The composition of the road load of a vehicle is stated in the second section.

Isabell Vogeler, R. Untermaierhofer, R. Petz, T. Schütz

Simulation method for vehicle tire water spraying behavior

The consideration of vehicle soiling in the development process becomes ever more important because of the increasing customer demands on current vehicles and the greater use of camera and sensor systems due to autonomous driving. In the process of self-soiling a soil-water-mix deposits on the vehicle surface which is thrown up by the rotation of the car´s own wheels. The validation of functions in vehicle development usually takes place in an experimental manner, but is increasingly supported by numerical simulations.In these simulations the whirl up process is modelled by a static wheel where the droplets start tangentially from homogenous emitter lines on the tire surface. This represents a significant simplification of the central boundary condition of the whole selfsoiling simulation.This study presents a new approach for the direct simulation of the droplet whirl up process of a single rotating wheel, based on the meshfree Finite Pointset Method (FPM). A more realistic droplet field is thus obtained which consequently leads to a more realistic simulation of vehicle self-soiling. In this study the plausibility of the new approach is evaluated using a down-scaled tire model. The approach is additionally validated in a comparison to experimental results.

Veith Strohbücker, R. Niesner, F. Joos

Evolution of downforce on performance cars

No other attribute has played such an important role in the development of modern high-performance vehicles as downforce. By definition, this is a downward directed force created by the flow around the vehicle with the main goal to produce an enhanced grip for higher cornering speed. In the last fifty years, there has been a remarkable evolution of the downforce concept; ranging from simple wings mounted at different places on the car, into advanced diffuser arrangements that requires total flow optimization. Most of the downforce development has been made in parallel with advances in rubber compounds for high-friction tyres, and together, these two attributes have set new landmarks for increased velocity and safety in all high-speed motoring.

Lennart Löfdahl

Friction power measurements with the piston group of a fired gasoline engine

In addition to a decrease in exhaust gas emissions, a reduction in frictional losses plays a key role in the ongoing development of the combustion engine. This can further increase mechanical efficiency and reduce fuel consumption accordingly.In this context, MAHLE has performed systematic tests on fired passenger car and commercial vehicle engines. The tests are focused on the design parameters of the piston group. The knowledge gained can be used specifically to reduce fuel consumption and therefore CO2 emissions in actual engine operation, even at elevated speeds and loads.The influence on friction of the piston installation clearance, piston pin offset, pin bore geometry (shape and clearance, oil supply), piston skirt geometry (piston skirt contact areas, skirt stiffness, piston profiles), and tangential force of the oil control ring were independently investigated in a turbocharged passenger car gasoline engine. The evaluation took place at warm conditions in the form of the friction mean effective pressure savings potential, which can be converted to savings in CO2 emissions in any desired driving cycle.

Johann Meiser, H. Ehnis, R. Künzel, M. Bargende

Experimental investigations and simulations on cam-roller-friction

Despite the increase in alternative drive solutions for passenger cars, such as plug-in hybrid vehicles or fully electric vehicles, the internal combustion engine will retain its supremacy as the main drive in the next 10 to 15 years. [1] This fact, coupled with the ever-increasing demands of the customers and legislators, especially in regard to fuel consumption and emissions, pushes the thermodynamic and mechanical improvement of the internal combustion engine into the foreground of all engine development projects at the Daimler AG. [2]On the side of the engine mechanics efficiency improvements are mainly achieved by the reduction of frictional losses. Figure 1 shows the frictional losses of a dragged engine at an engine speed of 2000 rpm and 90°C oil and water temperature. It can be seen that at these operating speeds the friction in the crank train (compromised of the piston assembly and crankshaft) dominates.

Sören Herweg, F. Huber, S. Atamer, R. Weller, R. Steiner, B. Sauer, T. Kiekbusch, S. Wiesker, M. Mármol Fernández

The future of automotive radar – Leveraging metamaterial antennas and intelligent algorithms

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

Armin Volkel, C. Marx

K.I.T.T. is real – How conversational AI changes the way we drive (not only for Knight Rider)

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

Patrick Weissert

Sustainable mobility with hydrogen – The internal combustion engine becomes green

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

Thomas Korn
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