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Technical Paper

A Model Based Definition of a Reference CO2 Emissions Value for Passenger Cars under Real World Conditions

2018-05-30
2018-37-0031
Abstract With the adoption of the Worldwide harmonized Light Vehicles Test Procedure (WLTP) and the Real Driving Emissions (RDE) regulations for testing and monitoring the vehicle pollutant emissions, as well as CO2 and fuel consumption, the gap between real world and type approval performances is expected to decrease to a large extent. With respect to CO2, however, WLTP is not expected to fully eliminate the reported 40% discrepancy between real world and type approval values. This is mainly attributed to the fact that laboratory tests take place under average controlled conditions that do not fully replicate the environmental and traffic conditions experienced over daily driving across Europe. In addition, any uncertainties of a pre-defined test protocol and the vehicle operation can be optimized to lower the CO2 emissions of the type approval test. Such issues can be minimized in principle with the adoption of a real-world test for fuel consumption.
Technical Paper

Extended Target Weighing Approach - Estimation of Technological Uncertainties of Concept Ideas in Product Development Processes

2018-05-30
2018-37-0028
Abstract The “Extended Target Weighing Approach” (ETWA) presented here describes a holistic, cross-subsystem, function-based lightweight design method - in terms of conceptual lightweight design - for the identification and evaluation of lightweight design potentials in the concept phase of product development. It systematically extends the existing “Target Weighing Approach” (TWA), in order to balance key factors mass, costs and CO2 emissions. During the application of the method, concept ideas are generated which have to be evaluated with regard to their potential. The selection of concept alternatives to be pursued in the early phase of product development often depends on the experience of the product developer. Therefore, the potential of some concepts is not recognized correctly or the risk according to the intended solution caused by missing knowledge or uncertainties is misjudged.
Technical Paper

FCA Full Scale Wind Tunnel: WLTP and Coast Down Test Performed With Wind Tunnel Method

2018-05-30
2018-37-0017
Abstract The effect of pollutants emission on health and environment is a problem that has become even more important with time: WLTP represents the harmonization of test procedures that aims to characterize all vehicles predicting their emissions, depending on coast down road test results and new different driving cycles. UN GTR technical regulation allows the use of wind tunnel to perform a bench coast down with the use of dynamometer or flat belt to calculate the whole vehicle drag (aerodynamic, mechanic and rolling resistance). During 2013, FCA Italy made an upgrade to wind tunnel facility installing a new balance with 5 moving belts: one central belt and four wheels flat belts, each one connected to a specific balance. This upgrade is very important because wheel spinning unit balances allow the calculation of rolling resistance as required by UN GTR.
Technical Paper

Lightweight Automobiles ALLIANCE Project: First Results of Environmental and Economic Assessment from a Life-Cycle Perspective

2018-05-30
2018-37-0027
Abstract In the last years the research activities in the field of lightweighting have been advancing rapidly. The introduction of innovative materials and manufacturing technologies has allowed significant weight reduction. Despite this, novel technologies and materials have not reached a wide distribution. The reasons for this are mainly high production costs and environmental impacts of manufacturing that do not compensate benefits during operation. The paper deals with the AffordabLe LIghtweight Automobiles AlliaNCE (ALLIANCE) project which has the goal of developing novel advanced automotive materials and production technologies, aiming at an average 25% weight reduction over 100 k units/year, at costs of <3 €/kg. The article is focussed on Work Package 1 (WP1) of the project, aimed at estimating the full attributes of innovative design solutions by assessing costs, energy demand and GWP over the entire vehicle Life Cycle (LC).
Technical Paper

A Comprehensive Approach for Estimation of Automotive Component Life due to Thermal Effects

2018-05-30
2018-37-0019
Abstract Due to stringent environmental requirements, the vehicle under-hood and underbody temperatures have been steadily increasing. The increased temperatures affect components life and therefore, more thermal protection measures may be necessary. In this paper, we present an algorithm for estimation of automotive component life due to thermal effects through the vehicle life. Traditional approaches consider only the maximum temperature that a component will experience during severe driving maneuvers. However, that approach does not consider the time duration or frequency of exposure to temperature. We have envisioned a more realistic and science based approach to estimate component life based on vehicle duty cycles, component temperature profile, frequency and characteristics of material thermal degradation.
Technical Paper

Real-Time Measurement of the Piston Ring Gap Positions and Their Effect on Exhaust Engine Oil Emission

2018-05-05
2018-01-5006
Abstract Measurement techniques for piston ring rotation, engine oil emission and blow by have been implemented on a single-cylinder petrol engine. A novel method of analysis allows continuous and fast real-time identification of the piston ring rotation of the two compression rings, while the mass-spectrometric analysis of the exhaust gas delivers the cylinder oil emission instantly and with a high temporal resolution. Only minor modifications to the piston rings were made for the insertion of the γ-emitters, the rings rotate freely around the circumference of the piston. The idea of this setup is that through online observation at the test bench, instant feedback of the measured variables is available, making it possible to purposefully select and compare measurement points. The high time resolution of the measurement methods enables the analysis of dynamic effects. In this article, the measurement setup and evaluation method is described.
Technical Paper

Experimental Investigation on Effect of Compression Ratio, Injection Pressure and Engine Load on Cyclic Variations in Diesel Engine Using Wavelets

2018-05-05
2018-01-5007
Abstract Higher cycle to cycle variations in combustion results in adverse effects on efficiency, power, drivability, and emissions. Present study investigates the effect of compression ratio, injection pressure and engine load on cycle-to-cycle combustion variations in a diesel engine using statistical methods and wavelets. Cycle to cycle variations of different combustion parameters are analyzed using continuous wavelet transform. Experiments are conducted on a diesel engine at constant engine speed at different engine loads for three compression ratios and injection pressures (170, 200 and 220 bar). Combustion parameters are calculated from measured cylinder pressure data for 2000 consecutive engine cycles. Wavelet power spectrum and global wavelet spectrum is used to analyze the variations in combustion parameters. Highest cycle to cycle variability is found for compression ratio 16 at no load condition.
Technical Paper

Passive Metal Hydride Module Concept for Enhanced Low-Temperature Catalyst Performance

2018-05-04
2018-01-5001
Abstract A technology concept applicable to stoichiometric and lean burn engine operation-a metal hydride (MHx) module for the generation of H2 via reaction with gaseous H2O-was evaluated for the introduction of low levels of H2 (ca. 500 ppmv) into internal combustion engine exhaust for the enhancement of catalyst performance at low temperatures, such as during cold-start. Projected MHx module packaging volume, replacement frequency, and costs over the lifetime of a light duty vehicle are excessive, and considered prohibitive to technology viability.
Technical Paper

Modeling Cruise Control Initiated Wheelspin in Rear Wheel Drive Vehicles

2018-05-04
2018-01-5000
Abstract There are driving situations in which a rear-wheel-drive vehicle, operating with an active closed-loop cruise control, can experience wheelspin and a subsequent oversteer/loss of control. The situations involve low-μ surfaces (ice), weather-related phenomenon (rear-wheel hydroplaning), slope-climbing or a combination of these external effects. Although traction control and stability control, depending on the sophistication of the system, can negate many of these situations, the active fleet contains many vehicles not equipped with these features. In the present work, we calculate the conditions under which cruise-control-initiated rear wheel spin can occur.
Technical Paper

EcoRouting Strategy Using Variable Acceleration Rate Synthesis Methodology

2018-04-16
2018-01-5005
Abstract This paper focuses on the analysis of an EcoRouting system with minimum and maximum number of conditional stops. The effect on energy consumption with the presence and absence of road-grade information along a route is also studied. An EcoRouting system has been developed that takes in map information and converts it to a graph of nodes containing route information such as speed limits, stop lights, stop signs and road grade. A variable acceleration rate synthesis methodology is also introduced in this paper that takes into consideration distance, acceleration, cruise speed and jerk rate as inputs to simulate driver behavior on a given route. A simulation study is conducted in the town of Blacksburg, Virginia, USA to analyze the effects of EcoRouting in different driving conditions and to examine the effects of road grade and stop lights on energy consumption.
Technical Paper

Development of a Measurement Technology in Order to Determine the Dynamic Behavior of a Two-Stage Variable Connecting Rod

2018-04-15
2018-01-5002
Abstract Variation of the geometric compression ratio in gasoline combustion engines during engine operation enables potential for decreasing fuel consumption as well as emissions. One way to achieve a variable geometric compression ratio (VCR) is the application of a connecting rod with a variable effective length between its large end and its small end. Such a system consists of a connecting rod body with an eccentrically supported piston pin and a linkage which is supported hydraulically. Therefore, the connecting rod evolves from a solid part to a complex assembly of mechanical and hydraulic parts. In order to deploy this system in the most efficient way, an understanding of the physics and the dynamic behavior of the VCR connecting rod is necessary. This includes the mechanical subsystem as well as the hydraulic subsystem. This paper describes the experimental examination of a two stage variable connecting rod.
Technical Paper

Marker Ink Impact on Prototype Catalyst Performance

2018-04-15
2018-01-5009
Abstract Inks periodically used to mark the inlet faces of prototype catalyst substrates before testing were analyzed by a variety of methods to identify and quantify inorganic atomic constituents. The dominant inorganic constituents in these inks were Al and Ti, which would likely be in the form of Al2O3 and TiO2 after ink application and firing in air, and thus relatively inert as these are often already constituents in many catalyst washcoats. However, potential catalyst poisons, such as S, Cl, Cr, Zn, and Na were also detected in some inks. A simple model was developed to quantify the possible impact of the potentially irreversible catalyst poisons (such as Si, Cl and Na) based on ink loading during application, constituent concentration in the ink, and catalyst active site density.
Technical Paper

Structural Optimization of Rollcage Using Finite Element Analysis and Design of Experiments Approach

2018-04-15
2018-01-5014
Abstract Finite Element Analysis (FEA) is a numerical method to find solutions to real world problems and is now commonly used for product development. Various finite element analyses are performed to validate the system performance. Many finite element codes are also available for this purpose. Now-a-days, product development not only deals with the validation of design performance, but also focuses on design optimization. Methods such as one-factor-at-a-time (OFAT) experiments are generally used in which one input factor is varied at a time and its effect on system performance is studied. Design of Experiments (DOE) is a systematic approach in which more than one input factors are purposefully varied to study their effect on system performance. Finite Element Analysis and Design of Experiments approach can be used in combination for design optimization. This paper deals with the process for design optimization that can be followed using FEA and DOE in conjunction.
Technical Paper

Closed-Loop Control Strategy and State Estimator for Diesel Engine SCR After-Treatment System

2018-04-15
2018-01-5004
Abstract With the development of the vehicle and Diesel engine technology, the selective catalytic reduction (SCR) technology has been paid more attention recently, which is one of the most effective approaches for reducing the nitrogen oxides (NOx) emissions of Diesel engine exhaust. The control strategy of the ammonia coverage ratio of SCR catalyst is vitally important, which directly influences the NOx reduction efficiency and ammonia leakage. To solve such a challenging task, some assumptions are given firstly based on the understanding of the SCR nonlinear dynamic characteristics, and then the SCR nonlinear model is established by the Continuous Stirred Tank Reactor (SCTR) method. The ammonia storage characteristics are studied based on the established model. Then, the stability and observability of the SCR model are analyzed. For the unmeasurable ammonia coverage ratio and storage capacity of catalyst, a state observer based on the extended Kalman filter (EKF) is proposed.
Technical Paper

Road Dynamic Simulation for Vehicle Driveline Experiments

2018-04-15
2018-01-5016
Abstract The dynamic simulation technology for a powertrain test bench is discussed in this paper. Dynamic emulation of mechanical loads is the key technology of laboratory tests in cases when the test site is moved from the road to an indoor laboratory test bench. The combustion engine is replaced by an electric drive motor, which replicates the torque and speed signature of an actual engine. The road load resistance of the vehicle on a real test road is accurately simulated using a load dynamometer motor. In this study, we analyzed and compared the advantages and disadvantages of the inverse dynamics model and the forward model based on the speed closed loop control method, from the perspective of the high-order, nonlinear, and multi-variable characteristics of the test bench system. We developed a load simulation method based on the speed adaptive predictive control (SAPC).
Technical Paper

A New Method of Comprehensive Evaluation Research and Application on Vehicle Engine Exhaust System

2018-04-15
2018-01-5011
Abstract During current design process of vehicle engine exhaust system, the frequently-used approach mainly concerns an individual component, which usually results in not meeting the overall design requirements or unreasonable design parameters. Here a concept of comprehensive evaluation metrics for vehicle engine exhaust system was established, of which a new weight factor assignment method was proposed, named change rate method, as the core of evaluation system to be especially studied. Taking muffler as an instance, six weight factor assignment schemes were adopted to compare with each other. And the rationality and practicability of the change rate assignment method was verified by the muffler noise experiments. The results show that, the change rate method makes the weight assignment more scientific and rigorous. And the new method can reflect the wishes of designers and completely displays the performance comparison and evaluation between schemes.
Technical Paper

Virtual Prototyping with Rigid Body Concept for the Development of Internal Combustion Engine

2018-04-15
2018-01-5013
Abstract The recent surge in the demand for the virtual application has led to the need for prototype testing that control the associated problem to a great extent. Consequently, a reduction in the costs of operating the actual prototype is envisaged. However, in some cases, just by adjusting input parameters alone could increase the success rate of these prototypes. During the design process, the functional prototyping is mainly used to evaluate the appearance of product and simulate its system level functioning. Multi-body dynamics analysis involves the simulation of rigid body systems under the application of forces or motions. Virtual prototype can substitute the physical prototype to perform a system level functioning of the product. The Internal combustion engine mechanism is considered for simulating the system level working with real time dynamic responses.
Technical Paper

Steering Feedback Perception of Average Drivers

2018-04-15
2018-01-5015
Abstract Electromechanical steering systems (EPS) provide assisting steering force through an electric motor, often paired with a screw drive. The combination of an electric motor and a screw drive lead to high inertia and thus to a reduced feedback of tire force behavior at the steering wheel. This force behavior contains information about driving conditions and road surface. However, the electric motor can be used to actively enhance and manipulate steering feedback. This article describes the driver perception of modified steering feedback. The presented data is collected carrying out a driving simulator study with average drivers as test subjects. In this study the driver experiences a modified steering feedback at a change of road friction coefficient. Based on the test subjects ratings the perception, acceptance and controllability of the presented steering feedback modifications are assessed.
Technical Paper

Virtual Functional Testing of a Mechatronic Active Roll Control

2018-04-15
2018-01-5012
Abstract Compared with the traditional bench testing approach, the virtual validation on a PC is more time-saving and cost-effective. However, the control software of an electronic control unit is typically developed together with suppliers and original equipment manufacturer, and each owns parts of the source code. So it is impossible to set up a simulation based on the original C code. Alternatively, to set up an equivalent model is usually time-consuming and less effective. In this work, Schaeffler describes how to develop a virtual testing method based on chip simulation for the series produced mechatronic active roll control system.
White Paper

The Use of Imaging for Powder Metal Characterization and Contamination Identification

2018-04-05
WP-0008
As AM technologies are being used with higher frequencywithin the automotive and aerospace industries, the interest in powder characterization and contaminant identification is growing—especially for suppliers looking to gain entry into these highly regulated industries. Standards for powder materials and methods used for aerospace applications are still be developed, and regulatory agencies such as the Federal Aviation Administration have been requesting that standards be developed as guidance for the industry. Methods such as CCSEM and HLS could be viable options for suppliers needing to adhere to a powder specification by demonstrating compliance. Solutions exist to integrate such methods into a production environment as exemplified by RJ Lee Group.
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