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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.

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.

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.

Extensive crash sled testing and analysis has recently led to the development of a new HANS prototypes for use in FIA F1. The performance of HANS prototypes has been studied with various conditions of HANS design geometry and impact direction. The new HANS prototypes have been found to substantially reduce injurious motions and forces of the head and neck, and the new HANS is lighter, more compact, and performs better than the currently available HANS. Use of HANS by FIA F1 drivers has been initiated.

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.

The Daimler-Benz Driving Simulator is a tool for research and development. It was put into operation 1984/85 and was enhanced since that time in many details, having gained a lot of experience with its use in many different applications. During a main modernization from autumn '93 until summer '94, the driving dynamics computer system as well as the visual system have been exchanged and the hydraulic motion system has been extended in lateral direction for improving motion simulation quality.

A road simulation method has been developed to investigate ride comfort and fatique strength in the laboratory. A short description is given of the road profile generation technique used. The road to be simulated is recorded by driving the vehicle on the road and measuring the vertical accelerations and the forces of each spindle. In the laboratory the transfer behavior of the vehicle is determined with the aid of an identification technique. An iteration process is used. The simulation of the road profile and the forces is realised in the laboratory with multi-channel electrohydraulic equipments. Laboratory test results are shown and compared with road signals.

Daimler-Benz considers safety belts as the fundamental and essential restraining system. The company began offering a Supplemental Restraint System option consisting of a driver airbag system and an emergency tensioning belt retractor for the passenger in December 1980. The functional reliability of the system has proven satisfactory.

Among many tasks of car development, safety, economy, environmental benefits and convenience, safety should have a high priority. One of the main goals is the reduction of the number of accidents. Environment and situation recognition by autonomous vehicle-electronic systems can contribute to the recognition of problems together with information to the driver or direct intervention in the car's behaviour. This paper describes some techniques for environment recognition, the status of a present project, and the goals of some PROMETHEUS (Program for a European Traffic with Highest Efficiency and Unprecedented Safety) projects.

The ultimate goal of drive-line management is low fuel consumption as well as providing the highest possible driving performance within the bounds of good driving safety. This can only be achieved by shifting the operating region on the performance diagram. In order to do this the technical characteristics of the drive-line components must be taken into account. The development of drive-line optimization can be separated into two phases. In the first phase the driver is partially or entirely integrated into the control circuit via external visual and acoustic feedback inputs. In the second phase automatic controls take-over the drive-line management without putting stress on the driver so that the vehicle in effect controls itself.

Information on the driving stability can be obtained in the form of oversteer or understeer tendencies and acceleration limits on a circular path. Up to now the calculations have only been made on an ideal, even roadway. Significant dynamic characteristics, such as the tuning of the shock absorbers, which also play a role in evaluating the stability of a vehicle in a driving test, are thereby not included in the calculations. In this paper the unevenness of the roadway is taken into consideration in calculating steady state cornering tests. Different vehicle models can be evaluated in regard to their handling or active safety with the aid of the driver's steering actions required to keep the car on course.

In order to reduce the severity of injuries to pedestrians and cyclists, the sheetmetal contact zones of Mercedes-Benz cars are constructed of a yielding, smooth-surfaced design. Unfortunately, contradictory demands are made on some components. This is particularly true for the bumper in which avoiding or reducing the cost of repair requires a greater bumper height, overhang, and stiffness, which run counter to the requirements of pedestrian protection. Despite this conflict, however, the bumpers of recently developed Mercedes-Benz cars offer a high degree of pedestrian protection since they are faced with rigid foam. To assist in both mathematical and experimental pedestrian impact simulation, standard test dummies should be modified by reducing the stiffness at the waist in order to achieve a higher degree of faithfulness to human behaviour.

Daimler-Benz have developed an automatically/electronically controlled traction system, the 4MATIC. Great store has been set by active safety. This paper deals with the problems involved in 4-Wheel drive and analyzes the reasons which led to the 4MATIC concept. Depending on the conditions encountered, the drive components engage automatically one after the other in the sequence front-wheel drive - interaxle differential lock - rear axle differential lock. The engagement, and thus the approaching limits of driving dynamics, is indicated to the driver by an indicator lamp so that he can adjust to the deteriorated conditions in time. A further important advantage of this system is the automatic disengagement of the differential locks when braking so that the anti-lock braking remains fully effective.

This report deals with the development and use of the Daimler-Benz Isohuman Simulation Model for the mathematical simulation of dummy behaviour in an impact environment. Designated ISM, this computer program package is capable of handling both automobile occupant and pedestrian kinematics. Daimler-Benz safety engineers use the ISM to evaluate new safety designs before performing actual laboratory tests. The ISM code uses the theoretical algorithm of Prof. Wittenburg. The dummy is represented by 11 rigid body elements. Realistic and accurate simulations are assured by the fact that a considerable number of functional and sophisticated algorithms were developed to involve the different interactions of dummy-to-belt or dummy-to-vehicle. In particular, considerable work is being done to introduce a more precise and realistic dummy and vehicle geometry.

Multi-dimensional modelling of the flow and combustion promises to become a useful optimisation tool for IC engine design. Currently, the total simulation time for an engine cycle is measured in weeks to months, thus preventing the routine use of CFD in the design process. Here, we shall describe three tools aimed at reducing the simulation time to less than a week. The rapid template-based mesher produces the computational mesh within 1-2 days. The parallel flow solver STAR-CD performs the flow simulation on a similar time-scale. The package is completed with COVISEMP, a parallel post-processor which allows real-time interaction with the data.