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As the complexity of current automobiles increases, new and innovative diagnostic methods for car maintenance and diagnostic inspection are greatly needed. This paper introduces a new diagnostic approach, which learns from previous repair cases with the help of neural networks in order to assist future diagnostic inspections. Practical experiments have shown that this approach is able to provide promising results even with the data that is already available today.

The California LEV1 II program will be introduced in the year 2003 and requires a further reduction of the exhaust emissions of passenger cars. The cold start emissions represent the main part of the total emissions of the FTP2-Cycle. Cold start emissions can be efficiently reduced by injecting secondary air (SA) in the exhaust port making compliance with the most stringent standards possible. The thermochemical conditions (mixing rate and temperature of secondary air and exhaust gas, exhaust gas composition, etc) prevailing in the exhaust system are described in this paper. This provides knowledge of the conditions for auto ignition of the mixture within the exhaust manifold. The thus established exothermal reaction (exhaust gas post-combustion) results in a shorter time to light-off temperature of the catalyst. The mechanisms of this combustion are studied at different engine idle conditions.

Due to the introduction of new safety and comfort systems in modern automobiles, stability of the vehicle electrical system is increasingly important. The increasing number of electrical components demands that additional electrical energy be provided from robust, reliable supply sources in vehicles. When designing such systems, simulation is the development tool that is used to quickly obtain information regarding electrical system stability, battery charge level, and the distribution of power to the consumer systems. This paper describes how the Saber simulation environment from Synopsys Corporation helps develop increasingly demanding and complex vehicle power systems. A Volkswagen vehicle power net serves as an illustration.

This paper presents a complete methodology for performing finite-volume-based detached-eddy simulation for the prediction of aerodynamic forces and detailed flow structures of passenger vehicles developed using the open-source CFD toolbox OpenFOAM®. The main components of the methodology consist of an automatic mesh generator, a setup and initialisation utility, a DES flow solver and analysis and post-processing routines. Validation of the predictions is done on the basis of detailed comparisons to experimental wind-tunnel data. Results for lift and drag are found to compare favourably to the experiments, with some moderate discrepancies in predicted rear lift. Point surface-pressure measurements, oil-streak images and maps of total pressure in the flow field demonstrate the approach's capabilities to predict the fine detail of complex flow regimes found in automotive aerodynamics.

In the new century the automotive industry is transforming itself from an entirely mechanical industry to an industry that is driven by electronics and services. The companies who will be most successful are those who are able to control, drive and renew the architectural concepts enabling the introduction of state-of-the-art information technology to the car and its supporting infrastructure. This paper will first define the term architecture and will elaborate about the increasing relevance of architectural thinking in the automotive domain. Architectural leadership will be defined to mean control (proprietary ownership of components and/or interfaces), creation of a de-facto or legal standard as well as renewal (creation of new products and markets utilizing new linkages of existing architectures). In the second part examples of successful and less successful approaches for establishing architectural leadership in the automotive industry are discussed.

The prevention of any brake noise or brake-induced body vibrations is a key development target firmly integrated in the car development process. Emphasis is placed here on disc brake judder that is attributable to thickness variations in the disc. These deviations from the ideal plane surface can be caused either by wear and corrosion or by thermal stresses (changes within the microstructure of the disc material). They are termed “cold judder” and “thermal judder” respectively. During braking, possible vibration excitation passes through a wide frequency band due to the coupling between the judder frequency and the wheel rotational speed, and thus, resonant frequencies of many vehicle components can be excited. This includes wheel suspension components and the steering column. In this paper, it is reported on extensive investigations into the topic of “cold judder”.

Due to the increase in demand for comfort and safety features in today's automobiles, the internal vehicle communication networks necessary to accommodate these features are very complex. These networks represent a heterogeneous architecture consisting of several ECUs exchanging information via bus systems such as CAN, LIN, MOST, or FlexRay buses. Development and verification of internal vehicle networks include multiple design layers. These layers are the logical layer represented by the software application, the associated data link layer, and the physical connection layer containing bus interfaces, wires, and termination. Verification of these systems in the early stages of the design process (before a physical network is available for testing) has become a critical need. As a result, the need to simulate these designs at all their levels of complexity has become critically important.

The investigation of vehicle soiling by improvement of vehicle parts to optimize the surrounding airflow is of great importance not only because of the visibility through windows and at mirrors but also the functionality of different types of sensors (camera, lidar, radars, etc.) for the driver assistance systems and especially for autonomous driving vehicles has to be guaranteed. These investigations and corresponding developments ideally take place in the early vehicle development process since later changes are difficult to apply in the vehicle production process for many reasons. Vehicle soiling is divided into foreign soiling and self-soiling with respect to the source of the soiling water, e.g., direct rain impact, swirled (dirty) water of other road users and own rotating wheels. The investigations of the soiling behavior of vehicles were performed experimentally in a wind tunnel and street tests.

The consideration of vehicle soiling in the development process becomes ever more important because of the increasing customer demands on current vehicles and the increased use of camera and sensor systems due to autonomous driving. In the process of self-soiling, a soil-water mixture is whirled up by the rotation of the car’s own wheels and deposits on the vehicle surface. The validation of the soiling characteristics in vehicle development usually takes place in an experimental manner, but is increasingly supported by numerical simulations. The droplet field at the tyre has been investigated several times in the past. However, there are no published information regarding the physical background of the droplet formation process and the absolute droplet sizes considering the position at the tyre and the behaviour at different velocities.

Once the adaptive cruise control systems are already in the market in Japan and Europe, the evolution of these comfort systems is logically going towards implementing new additional functions and safety strategies in order to detect and actuate in case of emergency. This transition has to be done in clear and precise steps to assure an easy adaptation to each improvement. Driver assistance systems will play a major role in the future to minimise the risk and consequences of accidents and to increase the driving comfort level. The impact of such systems on traffic and society is briefly commented. This paper discusses the need of new driver assistance systems and a possible roadmap for them. After a short introduction of present Adaptive Cruise Control (ACC), and based on them, next possible functions are described.

The accelerated processes in vehicle development require new technologies for function development and validation. With this motivation, Function-in-the-Loop (FiL) simulation was developed as a link between Software-in-the-Loop (SiL) and Hardware-in-the-Loop (HiL) simulation. The combination of real Electronic Control Unit (ECU) hardware and software in conjunction with virtual components is very well suited for function development and testing. This approach opens up new possibilities for mechatronic systems that would otherwise require special test benches. For this reason, an Electric Power Steering (EPS) was transferred to a virtual environment using FiL simulation. This enables a wide range of applications, from EPS testing to the development of connected driving functions on an integrated platform. Right from the early development phases, the technology can be used purposefully with short integration cycles.

The need to reduce weight of large and heavy components used by the automotive and aerospace industries such as engine block, cylinder head cover and helicopter gearbox housing has led to the development of new Mg gravity casting alloys that provide adequate properties and cost effective solution. The new Mg gravity casting alloys are designed for high stressed components that operate at a temperature up to 300°C. These new alloys exhibit excellent mechanical properties and creep resistance in T-6 conditions. The present paper aims at introducing three new Mg gravity casting alloys designated MRI 201S, MRI 202S and MRI 203S, which were recently developed by the Magnesium Research Institute of DSM and VW. Apart from the excellent high temperature performance of these alloys, they provide adequate castability and dimension stability along with good weldability and corrosion resistance.

Two optical techniques were developed and combined with a CFD simulation to obtain spatio-temporally resolved information on air/fuel mixing in the cylinder of a methane-fueled, fired, optically accessible engine. Laser-induced fluorescence (LIF) of anisole (methoxybenzene), vaporized in trace amounts into the gaseous fuel upstream of the injector, was captured by a two-camera system, providing one instantaneous image of the air/fuel ratio per cycle. Broadband infrared (IR) absorption by the methane fuel itself was measured in a small probe volume via a spark-plug integrated sensor, yielding time-resolved quasi-point information at kHz-rates. The simulation was based on the Reynolds-averaged Navier-Stokes (RANS) approach with the two-equation k-epsilon turbulence model in a finite volume discretization scheme and included the port-fuel injection event. Commercial CFD software was used to perform engine simulations close to the experimental conditions.

A recently developed Laser Raman Scattering system was applied to measure the in-cylinder air-fuel ratio and the residual gas content (via the water content) of the charge simultaneously in a firing spark-ignition engine during cold start and warm-up. It is the main objective of this work to elucidate the origin of misfires and the necessity to over-fuel at cool ambient temperatures. It turns out that the overall air-fuel ratio and residual gas content (in particular the residual water content) of the charge appear to be the most important parameters for the occurrence of misfires (without appropriate fuel enrichment), i.e., the engine behaviour from cycle to cycle becomes rather predictable on the basis of these data. An alternative explanation for the necessity to over-fuel is given.

Mixture formation analysis in the combustion chamber of a slightly modified mass-production SI engine with port-fuel injection using nonintrusive laser measurement techniques is presented. Laser Raman scattering and planar laser-induced tracer fluorescence are employed to measure air-fuel ratio and residual gas content of the charge with and without spatial resolution. Single-cycle measurements as well as cycle-averaged measurements are performed. Engine operation parameters like load, speed, injection timing, spark timing, coolant temperature, and mean air-fuel ratio are changed to study whether the effects on mixture formation and engine performance can be resolved by the applied laser spectroscopic techniques. Mixture formation is also analyzed by measurement of the charge composition as a function of crank angle. Clear correlations of the charge composition data and engine operating conditions are seen.

Even though a number of developed countries enjoy a high level of vehicle safety, more than 1.2 million fatalities still occur each year on roadways worldwide. There remains a need to continue improving vehicle and road safety. New technologies in sensors and electronic control units, and the growing knowledge of car-to-car and car-to-infrastructure technologies have led to a fusion of the previously separated areas of accident avoidance (popularly known as active safety) and mitigation of injuries (popularly known as passive safety) into the newer concept of integrated vehicle safety. This new approach represents a further step toward lowering accident rates. This book, written by two of the foremost automotive engineering safety experts, takes a unique and comprehensive approach to describing all areas of vehicle safety: accident avoidance, pre-crash, mitigation of injuries, and post-crash technologies, providing a solutions-based perspective of integrated vehicle safety.

The EPEFE study (European Programme on Emissions, Fuels and Engine Technologies), /1/ and other programmes have identified an increase in tailpipe NOx emissions with reduced gasoline aromatics content for modern 3-way controlled catalyst vehicles. This effect occurs with fully warmed-up catalyst under closed-loop operation. In order to understand the reasons for this effect VW and Shell have mechanistically investigated the effects of fuel properties on EMS (engine management system) and catalyst performance. Fuels with independent variation of oxygen, aromatics and mid-range volatility were tested in different VW engines. λ was monitored using sensors located both pre and post catalyst. The results confirmed that reducing gasoline aromatics content reduced engine-out emissions but increased tailpipe NOx emissions. It could be shown that differences in H/C ratio led to differences in the hydrogen content of engine-out emissions which affected the reading of the λ sensor.

This paper reports on a non-intrusive method for measuring the liquid fuel film thickness in the intake manifold of a series production SI engine with multi-point fuel injection. The technique is based on laser-induced fluorescence. The optical set-up uses a bifurcated optical fibre bundle for transmission of the laser light for excitation of the fluid and for detecting of the fluorescence light. Due to the special design of the optical probe head it is highly sensitive for thin film measurements and it allows the accurate determination of the fuel film thickness even between a few and 100 μm. Special emphasis is placed on the selection of an adequate tracer added to the iso-octane fuel to achieve the correct film thickness even under vaporizing conditions, and on a detailed study of the parameters influencing the evaluated film thickness.

In direct-injection gasoline (GDI) engines with charge stratification, minimizing engine-out nitrogen oxide (NOx) emission is crucial since exhaust-gas aftertreatment tolerates only limited amounts of NOx. Reduced NOx production directly lowers the frequency of energy-inefficient catalyst regeneration cycles. In this paper we investigate NO formation in a realistic GDI engine. Quantitative in-cylinder measurements of NO concentrations are carried out via laser-induced fluorescence imaging with excitation of NO (A-X(0,2) band at 248 nm), and subsequent fluorescence detection at 220-240 nm. Engine modifications were kept to a minimum in order to provide results that are representative of practical operating conditions. Optical access via a sapphire ring enabled identical engine geometry as a production line engine. The engine is operated with commercial gasoline (“Super-Plus”, RON 98).

Dry dust testing of vehicles on unpaved dust roads plays a crucial role in the development process of automotive manufacturers. One of the central aspects of the test procedure is ensuring the functionality of locking systems in the case of dust ingress and keeping the dust below a certain concentration level inside the vehicle. Another aspect is the customer comfort because of dust deposited on the surface of the car body. This also poses a safety risk to customers when the dust settles on safety-critical parts such as windshields and obstructs the driver’s view. Dust deposition on sensors is also safety critical and is becoming more important because of the increasing amount of sensors for autonomous driving. Nowadays, dust tests are conducted experimentally at dust proving grounds. To gain early insights and avoid costly physical testing, numerical simulations are considered a promising approach. Simulations of vehicle contamination by dry dust have been studied in the past.