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The importance of autonomous vehicle operation to satisfy future safety and productivity requirements is emphasized by the current National plans for IVHS and AHS development and deployment. Daimler-Benz Research, in cooperation with Freightliner Corporation, is developing a research vehicle VECTOR (Vision Enhanced/Controlled Truck for Operational Research) which currently is undergoing testing of a vision-based control system for lateral guidance. This effort is building on experience from prior Daimler-Benz and PROMETHEUS projects, including the test vehicles VITA (VIsion Technology Application) and OSCAR (Optically Steered CAR). The paper describes this work and future expansion plans to incorporate longitudinal control systems in VECTOR.

Quantitative Laser-Induced Incandescence (LII) has been applied to investigate the soot formation in a combusting Diesel jet for various conditions. For the quantification of the LII signal the local soot volume fraction of a diffusion flame burner was measured using laser beam extinction. These data were used for the calibration of the LII signal. The investigation of the soot formation in a combusting Diesel jet was performed in a high pressure, high temperature combustion chamber with optical access. A wide range of pressure (up to 10 MPa) and temperature (up to 1,500 K) conditions could be covered using a hydrogen precombustion, which is initiated inside the chamber before fuel injection. The influence of different gas atmospheres have been investigated by varying the gas composition (H2, O2 and N2) inside the chamber.

In conjunction with throttle-free load control on a 4-valve, single-cylinder spark-ignition engine, the influencing variables of charge cycle, mixture formation and combustion process are presented both as computer calculations and on the basis of test results. The influences of the position of the maximum of the inlet valve stroke, the position of the inlet close, the shape of the valve stroke and the load motion in relation to the maximum power and minimum fuel consumption are investigated in full load by computer calculations and in partial load by engine tests.

The active safety of tractor / trailer-combinations plays an important role in regard to traffic safety in general. For improving the active safety of tractor / trailer-combinations, it is necessary to investigate the interactions between the towing vehicle and the trailer during braking maneuvers. This paper describes the ECE-regulations for the braking force distributions of tractor/full trailer- and tractor / semitrailer-combinations. The influence of different layouts of the braking systems within these regulations on the coupling forces between tractor and trailer and the driving performance of the units during braking is investigated. The dynamical behaviour of a tractor/full-trailer-combination and a tractor / semitrailer-combination are both discussed with the aid of simulations of the ISO-standard testing procedures “Braking in a turn” and “Braking straight ahead”.

The individual development process for distributed, communicating electronic control units hinders the integration of Automotive systems and increases the overall costs. In order to facilitate such applications, services and protocols for Communication, Network Management, and Operating System must be standardized. The aim of the OSEK project is to work out a respective specification proposal in cooperation with several car manufacturers and suppliers. This will permit a cost-effective system integration and support the portation of system functions between different electronic control units.

The combustion process of a heavy-duty DI-Diesel truck engine has been investigated using numerical simulation. The numerical modeling was based on an improved version of the KIVA-2 engine simulation code, employing a modified characteristic time-scale combustion model and a modified Kelvin-Helmholtz spray atomization model. The NO-formation process was modeled using the extended thermal Zeldovich mechanism. The simulation efforts included the effects of different injection characteristics such as varying the injection rate profile or number of injection holes and sizes. The physical sub-models used to improve the simulation of the mixture-formation and the combustion process were validated through comparison with single-cylinder engine experiments. Special attention was given to accurately model the in-cylinder flame propagation of the individual sprays and their effect on thermal NO-formation. All simulations were based on full load cases at medium speed.

Realization of the leanburn SI engine's potential for improved fuel economy strongly depends on precise control of the air-fuel ratio (AFR), especially during transients, for acceptable driveability and low exhaust emissions. The development of an adaptive-feedforward model-based AFR controller is described. A discrete, nonlinear, control-oriented engine model was developed and used in the AFR control algorithm. The engine model includes intake-manifold airflow dynamics, fuel wall-wetting dynamics, process delays inherent in the four-stroke engine cycle, and exhaust-gas oxygen (UEGO) sensor dynamics. The sampling period is synchronous with crank-angle (“event-based”) for more precise control. The controller relies on the engine speed and throttle position for load information. An intake-manifold pressure (MAP) sensor is used for identification of the airflow dynamics, but not for control. The MAP sensor would also be useful for the cold start and for engine diagnostics.

Introduction of an array of new electrical and electronic features into future vehicles is generating vehicle electrical power requirements that exceed the capabilities of today's 14 volt electrical systems. In the near term (5 to 10 years), the existing 14V system will be marginally capable of supporting the expected additional loads with escalating costs for the associated charging system. However, significant increases in vehicle functional content are expected as future requirements to meet longer-term (beyond 10 years) needs in the areas of emission control, fuel economy, safety, and passenger comfort. A higher voltage electrical system will be required to meet these future requirements. This paper explores the functional needs that will mandate a higher voltage system and the benefits derivable from its implementation.

In this paper a systematic approach is presented for the design and optimization of forced liquid cooled electronic modules with high power dissipation. The steps of the design cycle include hydrodynamical evaluation of the heat sink, thermal management, thermomechanical optimization and especially lifetime prediction of soldered joints. Utilized engineering tools comprise Computational Fluid Dynamics, Finite Differences and Finite Element programs. These are coupled via software interfaces in order to enable data exchange as well as efficient cooperation of the designers. Applying these means performance, reliability and costs of a certain module have been optimized. By use of a design-for-reliability procedure substantial savings with regard to development time, prototyping effort and consequently costs can been achieved.

During the design, evaluation and optimization process of automotive brake systems brake torque measurements are often crucial. Known brake torque sensors lead to differences in terms of mass, inertia, stiffness and brake cooling compared to a vehicle without measurement equipment. In this contribution a new brake torque sensor is described which proved to be superior to known systems. Either the hub itself is turned into the sensing element or is replaced by a sensing element. Thus mass, inertia, stiffness and cooling conditions are nearly unchanged. A modification of this sensor allows measurement of residual brake torques in a low range (20....50 Nm) with high sensivity and features at the same time a high range (up to 2.000 Nm) with lower sensivity. The application of the sensor in a study to lower energy loss caused by residual brake friction in a passenger car is described.

Particulates were collected from the exhaust of a single cylinder diesel engine at different speeds and fuel-air equivalence ratios. The filters were rated to capture 99.99% of all particulates >0.3 microns in diameter. Samples were taken at 1500 RPM and equivalence ratios varying from about 0.2 to 0.7, and at an equivalence ratio of about 0.3 and engine speeds varying from 1000 to 2500 RPM. A base point with an equivalence ratio of 0.3 with an engine speed of 1500 RPM was repeated several times to establish the expected test variation of the particulate data. The particulate properties investigated were the total mass of particulate produced per mass of fuel burned, the mass fraction of extractable organic material in the sample, and the mutagenic potency of the extract as measured by a bacterial bioassay. Variation in fuel-air ratio (engine load) affected the particulate and extractable organic production much more than variations in engine speed.

The experience which has been gained in more than ten years with vehicles for the U.S.A. and Japan forms the basis of the catalytic converter systems for application in Europe. We are talking about the improvement of the mechanical and chemical endurance of catalytic converters and oxygen sensors. Special attention is paid to various substrate materials (e.g. steel) and coatings concerning their properties with regard to high-temperature stability and power loss. Moreover we are dealing with the increased application of electronics in the engine. The paper mainly refers to the Mercedes-Benz 190 E 2.3-16. This vehicle is used as an example to show the development of an emission concept for European requirements.

The design of automotive electronics is a highly cooperative, distributed process between car manufactures and suppliers. Due to significant increase of quality, cost, and time to market demands, several initiatives have been founded over the last years to address the increasing demand for standardization both for automotive electronics and vehicle based software. The German MSR consortium has concentrated on design tools and information exchange between manufacturers and suppliers, whereas the OSEK/VDX consortium has concentrated on the establishment of basic software components for open system architectures. To address future demands, these activities have to be consolidated and complemented by initiatives addressing the systematic improvement of the concurrent design processes as well as the appropriate qualification of engineering personnel.

This paper presents an approach to the design of automotive applications based on the client/server architecture, which has been well established in office automation. The basic client/server model is first discussed in the context of automotive requirements. This new function oriented approach is then compared to the previous, device oriented approach. After the introduction of basic components the communication mechanism is discussed with regard to the fundamental procedures, data representation and protocol implementation. Its usage is then explained by an example. Finally, after presenting the results of this study, there is an outlook to future work as well as to possible collaboration with others partners in order to achieve further standardization.

Chemiluminescence imaging has been applied to a parametric investigation of diesel autoignition. Time-resolved images of the natural light emission were made in an optically accessible DI diesel engine of the heavy-duty size class using an intensified CCD video camera. Measurements were obtained at a base operating condition, corresponding to a motored TDC temperature and density of 992 K and 16.6 kg/m3, and for TDC temperatures and densities above and below these values. Data were taken with a 42.5 cetane number blend of the diesel reference fuels for all conditions, and measurements were also made with no. 2 diesel fuel (D2) at the base condition. For each condition, temporal sequences of images were acquired from the time of first detectable chemiluminescence up through fully sooting combustion, and the images were analyzed to obtain quantitative measurements of the average emission intensity.

The awareness concerning environmental issues and the economical need for fuel savings leads to the introduction of new, highly efficient Diesel engines for passenger cars. An engine with common rail injection system could meet this target and, with the help of an advanced diesel exhaust aftertreatment system also fulfilled the new legislative emission regulations. Besides the efficient oxidation of carbon monoxide (CO), hydrocarbons (HC) and diesel particulates, such a system also requires a moderate reduction efficiency for nitrogen oxides (NOx) under excess oxygen conditions. The present paper illustrates the further progress in catalytic NOx-reduction under excess of oxygen by hydrocarbon enrichment using the common rail injection system.

The paper shows the completely new designed concept for electronics in the Mercedes-Benz Actros. The basic rules are explained, and on the example of the engine management the advantages of such an entire-vehicle promise are shown. At last it is pointed out, that the presented concept will be the basis for future developments on integration of electric's and electronics.

By-wire systems have been established for several years in the area of aircraft constructions. There is the visible trend to realize by-wire applications without mechanical or hydraulic backup systems in vehicles. The required electronic systems must evidently be available and safe. This paper addresses a new automotive architecture approach using the time-triggered fault-tolerant TTP protocol that has been designed for class C safety related control applications, like brake-by-wire or steer-by-wire, due to the SAE classification [1]. As an example we present this approach within a brake-by-wire research car (case study) without mechanical backup. The intention of this architecture is to tolerate one arbitrary fault - excepting faults of actuators - without any effects of the brake performance. For this purpose we use redundancy in communication (TTP) and electric components like sensors, actuators and power supply.

The two major problems of diesel emission control are the reduction of nitrogen oxides and particulates. This paper describes experimental investigations to achieve both a separation of soot particles as well as a catalytic NOx reduction with hydrocarbons under lean diesel exhaust gas conditions. For that purpose a diesel particle trap is coated with a catalyst based on a Pt containing zeolite. Preliminary studies have been performed on the catalytic NOx reduction to evaluate the efficiency of a Pt/zeolite system as well as to establish the impact of operation conditions on the catalyst performance. The activity of the prepared samples (catalytic coating on particle trap) has been determined under model gas test conditions. Much attention has been focussed on the steady-state kinetics of the surface processes. Another aspect considered is the N2O formation which can be reduced, when alkali-earth or rare-earth oxides are added to the catalyst system.

The development of a leanburn engine is described, in which optimized engine design, innovative engine management and exhaust gas aftertreatment using a special NOx-storage catalyst were combined to yield a significant improvement in fuel economy with reduced NOx emissions. To achieve stable combustion near the lean limit a swirl system was used and the appropriate parameters of the 2.2 I 4-cyIinder 4-valve SI engine were optimized. As a result, the mixture formation was improved and the lean limit was extended to higher air-fuel ratios. An adaptive lambda controller which was based on the evaluation of engine-smoothness calculated from the RPM-sensor was implemented to control each cylinder individually close to the lean limit. A model-based control system was developed to achieve extremely accurate air-fuel ratio control during transients.