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Technical Paper

“Pedestrian in the Loop”: An Approach Using Augmented Reality

A large number of testing procedures have been developed to ensure vehicle safety in common and extreme driving situations. However, these conventional testing procedures are insufficient for testing autonomous vehicles. They have to handle unexpected scenarios with the same or less risk a human driver would take. Currently, safety related systems are not adequately tested, e.g. in collision avoidance scenarios with pedestrians. Examples are the change of pedestrian behaviour caused by interaction, environmental influences and personal aspects, which cannot be tested in real environments. It is proposed to use augmented reality techniques. This method can be seen as a new (Augmented) Pedestrian in the Loop testing procedure.
Technical Paper

Vibration Comfort Control for HEV Based on Machine Learning

Hybrid electric vehicles (HEVs) with a power-split system offer a variety of possibilities in reduction of CO2 emissions and fuel consumption. Power-split systems use a planetary gear sets to create a strong mechanical coupling between the internal combustion engine, the generator and the electric motor. This concept offers rather low oscillations and therefore passive damping components are not needed. Nevertheless, during acceleration or because of external disturbances, oscillations which are mostly influenced by the ICE, can still occur which leads to a drivability and performance downgrade. This paper proposes a design of an active damping control system which uses the electric motor to suppress those oscillations instead of handling them within the ICE control unit. The control algorithm is implemented as part of an existing hybrid controller without any additional hardware introduced.
Technical Paper

Validation of the PC-Crash Pedestrian Model

The pedestrian model in PC-Crash is based on a multi-body system, where several bodies are interconnected by joints. Each of these bodies can have different properties to represent the different parts of the human body. The joint properties can be specified independently as well. The theoretical background of the pedestrian model has been introduced in SAE 1999-01-0445 and the model shows to give a good correlation of the gross movement of the pedestrian compared to crash test data. As there are many parameters, which can and have to be specified for the pedestrian model as input parameters, an in depth validation of the different parameters has to be done to validate this model. This paper describes in detail the validation process for the pedestrian model. A significant number of crash tests (approx. 30) was used as a basis to compare the results of the simulations and the real movement of the test subjects.
Technical Paper

Thermodynamic Loss Analysis of a High Power Motorcycle Engine with Focus on Alcohol Blended Fuels

The development of future internal combustion engines and fuels is influenced by decreasing energy resources, restriction of emission legislation and increasing environmental awareness of humanity itself. Alternative renewable fuels have, in dependency on their physical and chemical properties, on the production process and on the raw material, the potential to contribute a better well-to-wheel-CO2-emission-balance in automotive and nonautomotive applications. The focus of this research is the usage of alcohol fuels, like ethanol and 2-butanol, in motorcycle high power engines. The different propulsion systems and operation scenarios of motorcycle applications in comparison to automobile applications raise the need for specific research in this area.
Technical Paper

Thermodynamic Limits of Efficiency Enhancement of Small Displacement Single-Cylinder Engines

Millions of small displacement single-cylinder engines are used for the propulsion of scooters, motorcycles, small boats and others. These SI-engines represent the basis of an affordable mobility in many countries, but at the same time their efficiency is quite low. Today, the limited fossil fuel resources and the anthropogenic climate require a sustainable development of combustion engines, the reduction of fuel consumption being an important factor. A variety of different strategies (turbo-charging, cylinder deactivation, direct injection, etc.) are investigated here to increase the efficiency of multi-cylinder engines. In the case of small displacement single-cylinder engines, other strategies are required because of their special design and the high pressure on costs. In the context of this paper different layout parameters which have an influence on the working process are investigated, with the aim of increasing the efficiency of small displacement single-cylinder engines.
Technical Paper

The Potential of New Vehicle Concepts For Transport Optimization and GHG Emission Reduction in Urban Areas

Increasing urbanization, the growing degree of motorization and traffic performance in urban areas and environmental aspects like greenhouse gas emissions (GHG) are the motivation for a detailed analysis of personal individual mobility in urban areas, which is presented in this study. In the first step, the publication examines a study of market potential of new small and lightweight vehicle concepts. A mobility inquiry conducted in a mid-sized European city enables an estimation of the potential user groups for alternative vehicle concepts for individual urban traffic. In a second step, the CO2 reduction potential of urban car concepts is simulated for a generic vehicle fleet. This fleet consists of conventional vehicles of various classes (subcompact, compact, mid-sized …) as well as new lightweight urban car concepts. A novel vehicle concept for urban transportation will be presented as well.
Technical Paper

The Potential of Key Process/Performance Indicators (KPIs) in Automotive Software Quality Management

A steady increasing share and complexity of automotive software is a huge challenge for quality management during software development and in-use phases. In cases of faults occurring in customer’s use, warranty leads to product recalls which are typically associated with high costs. To avoid software faults efficiently, quality management and enhanced development processes have to be realized by the introduction of specific analysis methods and Key Process/Performance Indicators (KPIs) to enable objective quality evaluations as soon as possible during product development process. The paper introduces an application of specific analysis methods by using KPIs and discusses their potential for automotive software quality improvement. Target is to support quality evaluation and risk-analysis for the release process of automotive software.
Technical Paper

The Potential of Hydrogen Internal Combustion Engines in a Future Mobility Scenario

Focus is pointed on the highly favorable physical properties of hydrogen (H2) with regard to its combustion characteristics in internal combustion engines. Thereby it will be shown in how far the performance of next generation hydrogen engines can be improved by implementing a direct fuel injection system instead of the conventional port injection approach. Results from numerical as well as from experimental investigations will be used to clearly give a vision of the overall future potential of hydrogen for combustion engines in comparison to fuel cell systems.
Journal Article

The Potential of 3D-CAD Based Process – Optimization in the Automotive Concept Phase

The time reduction of the vehicle design and creation process is an important key to reduce development costs. Modern CAD systems offer a wide range of possibilities, not only in the standard field of mechanical design, but also in terms of creating advanced control mechanisms concerning part and assembly structures. Integrated design strategies include miscellaneous scripting and programming possibilities as well as implemented functions. An efficient application of these features can help to decrease the development time and to manage the growing functional complexity of automotive engineering processes. Continuously increasing product variants and functionalities call for design strategies and methods, which are capable to handle a quick data control and data transfer supporting an efficient geometry creation and evaluation.
Technical Paper

The Patch-Transfer-Function (PTF) Method Applied to Numerical Models of Trim Materials Including Poro-Elastic Layers

In automotive industry, acoustic trim materials are widely used in order to reach passenger comfort targets. The dynamic behavior of the poro-elastic materials is typically modelled by the Biot theory, which however leads to expensive numerical finite element calculations. One way to deal with it is to use the Patch-Transfer-Function (PTF) sub-structuring method, which couples subdomains at their interfaces through impedance relations. This was done already for systems including locally reacting poro-elastic materials. In this paper, a methodology is presented allowing to numerically assess the PTF impedance matrices of non-locally reacting trim materials using the Biot based poro-elastic model solved by the finite element method (FEM). Simplifications of the trim impedance matrices are introduced resulting in considerable calculation cost reductions. The associated prediction errors are discussed by means of a numerical case study.
Technical Paper

Technologies to Achieve Future Emission Legislations with Two Stroke Motorcycles

Increasingly stringent emission regulations force manufacturers of two wheelers to develop low emission motorcycle concepts. Especially for small two-stroke engines with symmetrical port timing structure, causing high HC-emissions due to scavenge losses, this is a challenging demand that can only be met with alternative mixture formation strategies and by intensifying the use of modern development tools. Changing from EU4 to EU5, emission legislation will not only have an impact on the improvement of internal combustion but will also drastically change the after-treatment system. Nowadays, small two-stroke engines make use of a simple carburetor for external mixture preparation. The cylinders are scavenged by air/fuel mixtures. Equipped with exhaust gas after-treatment systems, such as secondary air with two or three catalytic converters, the emission limits for EURO 4 homologation can be achieved with carbureted engines.
Technical Paper

Systematic Experimental Creep Groan Characterization Using a Suspension and Brake Test Rig

Vehicle road tests are meaningful for investigations of creep groan noise. However, problems in reproducing experiments and partly subjective evaluations may lead to imprecise conclusions. This work proposes an experimental test and evaluation procedure which provides a precise and objective assessment of creep groan. It is based on systematic corner test rig experiments and an innovative characterization method. The exemplary setup under investigation consisted of a complete front wheel suspension and brake system including all relevant components. The wheel has been driven by the test rig’s drum against a brake torque. The main parameters within a test matrix were brake pressure and drum velocity. Both have been varied stepwise to scan the relevant operating range of the automobile corner system for potential creep groan noise. Additionally, the experiments were extended to high brake pressures, where creep groan cannot be observed under road test conditions.
Technical Paper

System Design Model for Parallel Hybrid Powertrains using Design of Experiments

The paper focuses on an optimization methodology, which uses Design of Experiments (DoE) methods to define component parameters of parallel hybrid powertrains such as number of gears, transmission spread, gear ratios, progression factor, electric motor power, electric motor nominal speed, battery voltage and cell capacity. Target is to find the optimal configuration based on specific customer targets (e.g. fuel consumption, performance targets). In the method developed here, the hybrid drive train configuration and the combustion engine are considered as fixed components. The introduced methodology is able to reduce development time and to increase output quality of the early system definition phase. The output parameters are used as a first hint for subsequently performed detailed component development. The methodology integrates existing software tools like AVL CRUISE [5] and AVL CAMEO [1].
Journal Article

Sulfur Poisoning of a NOx Storage Catalyst - A Comprehensive Modelling Approach

This paper describes the development of a 0-D-sulfur poisoning model for a NOx storage catalyst (NSC). The model was developed and calibrated using findings and data obtained from a passenger car diesel engine used on testbed. Based on an empirical approach, the developed model is able to predict not only the lower sulfur adsorption with increasing temperature and therefore the higher SOx (SO2 and SO3) slip after NSC, but also the sulfur saturation with increasing sulfur loading, resulting in a decrease of the sulfur adsorption rate with ongoing sulfation. Furthermore, the 0-D sulfur poisoning model was integrated into an existing 1-D NOx storage catalyst kinetic model. The combination of the two models results in an “EAS Model” (exhaust aftertreatment system) able to predict the deterioration of NOx-storage in a NSC with increasing sulfation level, exhibiting higher NOx-emissions after the NSC once it is poisoned.
Technical Paper

Subjective Evaluation of Advanced Driver Assistance by Evaluation of Standardized Driving Maneuvers

Advanced Driver Assistance Systems (ADAS) for collision avoidance/mitigation have already demonstrated their benefit on vehicle safety. Often those systems have an additional functionality for comfort to assist the driver in non-critical driving. The verification of ADAS functionality using different test scenarios is currently investigated in many different projects worldwide. A harmonization of test scenarios and evaluation criteria is not yet accomplished. Often, these test scenarios focus on objective collision avoidance and not on the subjective interaction between driver and vehicle. The present study deals with the development of an experimental validation plan for the systems Automatic Cruise Control (ACC), Lane Departure Warning (LDW) and Lane Keeping Assist (LKA). Standardized driving maneuvers with two or more vehicles equipped with synchronized measurement are performed by professional test drivers.
Technical Paper

Study of Possible Range Extender Concepts with Respect to Future Emission Limits

The future exhaust emission legislation limits and the procedures for running the test cycles will have an important influence on future range extender concepts. Due to the special steady state operation strategy of the range extender engines, it is possible to create a simple methodology for comparing engine test bench emissions with the emission limits of exhaust gas legislations. Therefore the energy demand of a predefined vehicle was simulated with PHEM, a longitudinal dynamic simulation tool. According to that, the influence of different exhaust gas after treatment systems and preheating options on the tolerated raw emission concentration will be analyzed. With this information, a few chosen range extender engine concepts will be compared concerning their suitability for future exhaust emission legislations. The selection of the range extender concepts was carried out with the methotology of a value benefit analysis.
Technical Paper

Strategies for Emission Reduction on Small Capacity Two-Wheelers with Regard to Future Legislative Limits

Looking at upcoming emission legislations for two-wheelers, it is quite obvious that the fulfilment of these targets will become one of the biggest challenges within the engine development process. The gradual harmonization of emission limits for two-wheelers with existing automotive standards will subsequently lead to new approaches regarding mixture preparation and exhaust gas aftertreatment. Referring to these future scenarios, a state-of-the-art in development of catalytic converters for two- or three-wheeler applications should be presented. After choosing a suitable test carrier, which has already been equipped with EFI components including an oxygen sensor for λ=1 operation mode, a basic injection system calibration was used to optimize the combustion process. Based on this setup, a variable exhaust system was manufactured to be able to integrate different catalyst configurations.
Journal Article

State of the Art and Future Trends of Electric Drives and Power Electronics for Automotive Engineering

Discussions about the optimal technology of propulsion systems for future ground vehicles have been raising over the last few years. Several options include different types of technologies. However, those who are advocating conventional internal combustion engines are faced with the fact that fossil fuels are limited. Others favor hydrogen fuel as the solution for the future, either in combination with combustion engines or as an energy carrier for fuel cells. In any case, the production and storage of hydrogen is an ongoing challenge of numerous research works. Finally, there are battery-electric or hybrid propulsion systems in use, gaining more and more popularity worldwide. Ongoing advances in power electronics help to improve control systems within automotive applications. New developed or designed components enable more efficient system architectures and control.
Technical Paper

Size distribution of particulate matter~Results from roadside measurements

Measurements of ultrafine particles (diameter < 300 nm) and total suspended particulates (TSP) were performed in 2 tunnels (Lundby, Gothenborg, S, and Plabutsch, Graz, A). The measurements in the Lundby tunnel were performed directly in the tunnel tube at the roadside whereas the measurements at the Plabutsch tunnel took place at the top of a 90 m high ventilation shaft. There was good correlation for all diameters (7.91 nm - 300 nm) between ultrafine particles and TSP for the measurements at the Lundby tunnel. At the Plabutsch site a correlation between ultrafine particles and TSP was detected only for particles > 35 nm. The maximum of the particle size distribution function for Lundby was at 30 nm and for the Plabutsch tunnel at 80 nm.
Technical Paper

Simulation-Based Control of Transient SCE Operation

It is critical for gas and dual fuel engines to have improved transient characteristics in order that they can successfully compete with diesel engines. Testing of transient behavior as well as of different control strategies for the multi-cylinder engine (MCE) should already be done on the single cylinder engine (SCE) test bed during the development process. This paper presents tools and algorithms that simulate transient MCE behavior on a SCE test bed. A methodology that includes both simulation and measurements is developed for a large two-stage turbocharged gas engine. Simple and fast models and algorithms are created that are able to provide the boundary conditions (e.g., boost pressure and exhaust back pressure) of a multi-cylinder engine in transient operation in real-time for use on the SCE test bed. The main models of the methodology are discussed in detail.