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The introduction of alternative fuels is crucial to limit greenhouse gases. CNG is regarded as one of the most promising clean fuels given its worldwide availability, its low price and its intrinsic properties (high knocking resistance, low carbon content...). One way to optimize dedicated natural gas engines is to improve the CNG slow burning velocity compared to gasoline fuel and allow lean burn combustion mode. Besides optimization of the combustion chamber design, hydrogen addition to CNG is a promising solution to boost the combustion thanks to its fast burning rate, its wide flammability limits and its low quenching gap. This paper presents an investigation of different methane/hydrogen blends between 0% and 40 vol. % hydrogen ratio for three different combustion modes: stoichiometric, lean-burn and stoichiometric with EGR.

To meet LEV and EU Stage III emission requirements, it is necessary for new catalytic converters to be designed which exceed light-off temperature as quickly as possible. The technical solutions are secondary air injection, active heating systems such as the electrically heated catalytic converter, and the close coupled catalytic converter. Engine control functions are extensively used to heat the converter and will to play a significant role in the future. The concept of relocating the converter to a position close to the engine in an existing vehicle involves new conflicts. Examples include the space requirements, the thermal resistance of the catalytic coating and high temperature loads in the engine compartment.

Although hydrogen ICE engines have existed in one sort or another for many years, the testing of fuel consumption by way of exhaust emissions is not yet a proven method. The current consumption method for gasoline- and diesel-fueled vehicles is called the Carbon-Balance method, and it works by testing the vehicle exhaust for all carbon-containing components. Through conservation of mass, the carbon that comes out as exhaust must have gone in as fuel. Just like the Carbon-Balance method for gas and diesel engines, the new Hydrogen-Balance equation works on the principle that what goes into the engine must come out as exhaust components. This allows for fuel consumption measurements without direct contact with the fuel. This means increased accuracy and simplicity. This new method requires some modifications to the testing procedures and CVS (Constant Volume Sampling) system.

The study of oil emission is of essential interest for the engine development of modern cars, as well as for the understanding of hydrocarbon emissions especially during cold start conditions. A laser mass spectrometer has been used to measure single aromatic hydrocarbons in unconditioned exhaust gas of a H2-fueled engine at stationary and transient motor operation. These compounds represent unburned oil constituents. The measurements were accompanied by FID and GC-FID measurements of hydrocarbons which represent the burned oil constituents. The total oil consumption has been determined by measuring the oil sampled by freezing and weighing. It has been concluded that only 10 % of the oil consumption via exhaust gas has burned in the cylinders. A correlation of the emission of single oil-based components at ppb level detected with the laser mass spectrometer to the total motor oil emission has been found.

Among the existing concepts that help to improve the efficiency of spark-ignition engines at part load, Controlled Auto-Ignition™ (CAI™) is an effective way to lower both fuel consumption and pollutant emissions. This combustion concept is based on the auto-ignition of an air-fuel-mixture highly diluted with hot burnt gases to achieve high indicated efficiency and low pollutant emissions through low temperature combustion. To minimize the costs of conversion of a standard spark-ignition engine into a CAI engine, the present study is restricted to a Port Fuel Injection engine with a cam-profile switching system and a cam phaser on both intake and exhaust sides. In a 4-stroke engine, a large amount of burnt gases can be trapped in the cylinder via early closure of the exhaust valves. This so-called Negative Valve Overlap (NVO) strategy has a key parameter to control the amount of trapped burnt gases and consequently the combustion: the exhaust valve-lift profile.

Nowadays, due to the high competitiveness in the automotive market, the car manufacturers and the engine developers are concentrating as many efforts as possible in order to diminish the lead-time to production and to promote cost reductions of their engine developments. As a consequence, many systems and component tests are being substituted by numerical simulations, allowing a significant reduction in the amount of engine and bench tests. The integration of individual numerical simulation tools generates the philosophy of Virtual Engine Development, which is based on the concept of simulating as much as possible the entire engine as well as its components behaviors. This paper presents the application of Virtual Engine Development (VED) in a PSA 1.4l SI engine development. Theoretical results of engine performance as well as powercell components behavior such as piston, rings, conrod, bearings, liner, engine block and cylinder head, among others, are presented and discussed.

BMW, DaimlerChrysler, Motorola and Philips present their joint development activity related to the FlexRay communication system that is intended for distributed applications in vehicles. The designated applications for powertrain and chassis control place requirements in terms of availability, reliability and data bandwidth that cannot be met by any product currently available on the market under the testing conditions encountered in an automobile. A short look back on events so far is followed by a description of the protocol and its first implementation as an integrated circuit, as well as its incorporation into a complete tool environment.

The automakers that comprise MOST® describe the reasons for this decision. First, they present the automobile industry's needs relative to multimedia networks in vehicles. Then, they present the different aspects of the MOST® technology. Multimedia networks are used in the electronics market, but they do not meet the technical and industrial constraints of the automobile electronics, which is why six automakers are working on most technology under the aegis of ""Most Cooperation.'' The transmission rate is a decisive aspect in the selection of a multimedia network. The rate of sound and video applications require fiber optics. The multimedia network rate must be adequate for a vehicle equipped with the maximum number of options, but the maximum rate is limited by the number of passengers.

The optimization of the vaporization and mixture formation process is of great importance for the development of modern gasoline direct injection (GDI) engines, because it influences the subsequent processes of the ignition, combustion and pollutant formation significantly. In consequence, the subject of this work was the development of a measurement technique based on the laser induced exciplex fluorescence (LIF), which allows the two dimensional visualization and quantification of the in-cylinder air/fuel ratio. A tracer concept consisting of benzene and triethylamine dissolved in a non-fluorescent base fuel has been used. The calibration of the equivalence ratio proportional LIF-signal was performed directly inside the engine, at a well known mixture composition, immediately before the direct injection measurements were started.

A new phenomenological model of injection and auto-ignition is established in a 4-cylinder DI diesel engine of the production size class equipped with an inclined 5 holes injector. Measurements are performed at representative engine conditions for partial load. The penetration of the liquid phases is visualized in the whole combustion chamber by simultaneous Laser-Induced Fluorescence (LIF) and Mie scattering techniques. The autoignition and combustion are analyzed by a time-resolved direct imaging of the chemiluminescence process. Experiments based on the correlation of two separated images of the combustion phenomena in a single cycle have allowed a detailed comprehension of spatial and temporal description of the autoignition and reaction zones development. Several autoignition sites are revealed in the vicinity of the injector nozzle. The reaction zone is shown to develop independently and then to merge to a unique one in the whole combustion chamber.

An individual cylinder AFR estimator using a single proportional oxygen sensor (UEGO) situated at the confluence point of the exhaust manifold has previously been described ([1],[2]). As this model is nonlinear, it proposes a linear slicing by zone [3], enabling it to apply the estimator to the entire range of engine speeds. However, several problems remain; the model [3] is complicated and therefore difficult to program in an electronic engine control, the model is no longer valid with the ageing of sensors, injectors, or the motor, it is impossible to diagnostic the defaulting organ or one which deviates. The work set out in this article describes a model, and the conditions for its identification, which resolve these. The resultats obtained on engine tests show that the model is robust, precise and capable of estimating cylinder AFR as well as diagnosticing an injector or UEGO sensor deviation.

In automotive NVH, the noise generated by a powertrain is still one of the major noise sources especially at low and mid vehicle velocity. For this reason automotive OEMs are continuously focusing on methods to efficiently analyze this noise source. For this purpose, a well-established simulation methodology can provide results thoroughly, within a limited amount of time and with a reduced cost contrary to experiments which are involved in late design phases and are more expensive. This paper aims at presenting an approach to simulate efficiently the acoustic radiation from automotive components. With this aim in mind, the acoustic response of a realistic powertrain unit subjected to working conditions ranging from 1000 RPM to 4500 RPM is studied until 3000 Hz. Several radiating boundary conditions will be assessed in order to detect the most efficient set-up for this kind of problem and to extract the optimized modeling guidelines.

A local Gaussian process regression approach is presented, which allows to model nonlinearities of internal combustion engines more accurate than global Gaussian process regression. By building smaller models, the prediction of local system behavior improves significantly. In order to predict a value, the algorithm chooses the nearest training points. The number of chosen training points depends on the intensity of estimated nonlinearity. After determining the training points, a model is built, the prediction performed and the model discarded. The approach is demonstrated with a benchmark system and air charge test bed measurements. The measurements are taken from a turbocharged SI gasoline engine with both variable inlet valve lift and variable inlet and exhaust valve opening angle. The results show how local Gaussian process regression outmatches global Gaussian process regression concerning model quality and nonlinearities in particular.

The use of CNG in modern spark ignition turbocharged engine offers many advantages such as high knocking resistance, low CO₂ emissions and high specific power outputs. On the other hand, compared to gasoline, the volumetric efficiency is significantly decreased when CNG is port-injected due to its low energy density. In order to address this issue, recent studies have successfully highlighted the advantages on port-injection engines of the CIGAL™ concept (Concomitant Injection of Gas And Liquid fuels) from IFP Energies Nouvelles. However, the combination of port-injection of CNG with direct injection of gasoline remains unexplored. This paper investigates this novel injection concept on the four-cylinder 1.6L turbocharged GDI engine with inlet variable valve timing resulting from the cooperation between PSA Peugeot-Citroen and the BMW Group.

The successful design and especially the control of the SCR system is a challenging process that can be supported by the application of simulation tools. As a first step, we employ physico-chemically informed ‘off-line’ models that are calibrated with the help of targeted small- and full-scale tests. Despite their high level of sophistication, this SCR model is able to be integrated in a control-oriented simulation software platform and connected to other powertrain simulation blocks. The target is to use this simulation platform as a virtual environment for the development and optimization of SCR control strategies. The above process is demonstrated in the case of a passenger car SCR. The model is calibrated at both fresh and aged catalyst condition and validated using experimental data from the engine bench under a wide variety of operating conditions. Next, the calibrated model was coupled with embedded control models, developed for Euro 6 passenger car powertrains.

Air conditioning acoustics have become of paramount importance in electric vehicles, where noise from electromechanical components is no longer masked by the presence of the internal combustion engine. In a car HVAC systems, the coolant compressor is one of the most important sources in terms of vibration and noise generation. The paper, the generated structural noise is studied in detail on a prototype installation, and the noise transmission and propagation mechanisms are analyzed and discussed. Through ”in situ” measurements and virtual point transformation, the rotor unbalance forces and torque acting within the component are identified. The dynamic properties of the rubber mounts, installed between the compressor and its support, are identified thanks to matrix inversion methods. To assess the quality of the proposed procedure, the synthesized sound pressure level is compared with experimental SPL measurements in different operational conditions.

The use of micro controllers in automotive systems renders the coordination of about 150 actors (70 electric motors, 15 magnetic valves and 50 relays). The resulting complexity of those systems as well as the requested zero defects demands time consuming testing. This work describes a method of performing test-scenarios, starting from a zero defect running specification, modeled by finite state machines. The test-scenarios are intended to determine whether a given system meets all specification requirements. First, a kind of structured modelling reactive automotive systems is deduced. Next, some important test selection methods, developed for the case the specification is given in the form of a finite state machine, are considered. Finally, a procedure and method for performing minimized complete test-scenarios for automotive systems are presented.

The improvement of low-speed MUX-systems in car-body areas gets important in a scenario where on one hand, the possible number of integrated local control units (LCU's) gets larger and on the other hand, the possible versions of a car range from basic to top-of-the-line. Cost and developement time can be reduced if the same MUX-System is used throughout this whole range. A possibility to realize this is the use of data-compression (DC) for data-transmission. Basic configurations integrating only a small number of LCU's of a car-MUX can communicate without using data-compression, whereas for the top-of-the-line versions, the performance can be enhanced using DC only for communication processes between additional control units causing critical peak load situations. Specifically, the use of adaptive algorithms in automotive multiplex systems is a promising way to improve the MUX's capacity performance by minimizing redundant symbols/information in peak-load situations.

The production of the BMW ALPINA B12 5.7 with Switch-Tronic transmission provides the markets of Europe and Japan with an exclusive, luxury-orientated, high performance limited series limousine. This is the first vehicle worldwide to be fitted with the progressive exhaust gas aftertreatment technology known as the Electrically Heated Catalyst (EHC), in which the effectiveness of the power utilized is increased significantly by an alternating heating process for both catalytic converters. Only since this achievement has the implementation of the EHC been viable without extensive modification to the battery and alternator. With this exhaust gas aftertreatment concept, the emissions of this high performance vehicle will fall to less than half the maximum permissible for compliance with 1996 emission standards.

To simultaneously reduce wear and friction in automotive valve train systems, a technique for measuring the rotational speed of tappets by placing radionuclide markers in their surfaces has been developed. Using an electrically driven test rig, counting rate variation during camshaft rotation is traced, allowing a mean value of the tappet's rotational speed to be determined. Measurements were performed on a V6 Peugeot engine cylinder head for various geometrical combinations of the cam-to-tappet contact (crown radius of the tappet, cam taper angle), and the dependence of the tappet's rotational speed upon functional parameters (lubricant pressure and temperature, angular speed of the camshaft) was determined. Tappet rotation was found to be strongly affected by camshaft operating speed and the design of the cam-to-tappet contact, and less by lubrication conditions (off pressure and temperature).