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Viewing 151 to 180 of 21553
2015-04-14
Technical Paper
2015-01-1186
Michael Safoutin, Jeff Cherry, Joseph McDonald, SoDuk Lee
While equivalent circuit modeling is an effective way to model the performance and energy efficiency of automotive Li-ion batteries, in some applications it is more convenient to refer directly to round-trip energy efficiency. Energy efficiency of either cells or full packs is seldom documented by manufacturers in enough detail to provide an accurate impression of this metric over a range of operating conditions. The energy efficiency of a full battery pack may also be subject to more variables than would be represented by extrapolating results obtained from a single cell, and can be more demanding to measure in an accurate and consistent manner. Roundtrip energy efficiency of a 22.8-kWh A123 Li-ion (Lithium Iron Phosphate, LiFePO4) battery pack was measured by adding and removing a fixed quantity of charge at currents between 0.2C and 2C and at SOCs between 10% and 90% at an average temperature of 25C.
2015-04-14
Technical Paper
2015-01-1191
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
The parameters of battery electrochemical model based on porous electrode theory are complex, which is suitable for off-line analysis. The parameters of equivalent circuit model (ECM) are few and composed of electrical components (resistances, inductances, capacitances, Warburg impedance, constant phase element…), whose operation is fast, and more suitable for the on-line estimation of the vehicle power battery performance, such as SOC, SOH and temperature. An electrochemical impedance spectroscopy battery model which can comprehensively depict the internal state of the battery is developed in the paper firstly. The model is based on the porous electrode theory, and it can obtain a complete spectrum of the cell impendence. Then the effect of battery key parameters (the radius of particle, electrochemical reaction rate constant, solid/electrolyte diffusion coefficient, conductivity) to the simulated impedance spectroscopy are discussed.
2015-04-14
Technical Paper
2015-01-1188
Seongjun Yun, SungJin Park, Daekwang Kim, Junyong Lee, Sejun Kim, Kwang-yeon Kim
The fuel economy of a vehicle can be improved by recuperating the kinetic energy when the vehicle is decelerated. However, if there is no electrical traction component, the recuperated energy can be used only by the other electrical systems of the vehicle. Thus, the fuel economy improvement can be maximized by balancing the recuperated energy and the consumed energy by electrical systems of the vehicle. Also, suitable alternator and battery management is required to maximize the fuel economy. This paper describes a design optimization process of the alternator and battery system equipped with recuperation control algorithms for a mid-sized sedan based on the fuel economy and system cost. A vehicle model using AVL Cruise is developed for driving cycle simulations and validated with experimental data. The validated model is used for the parametric study and design optimization of the alternator and battery system with single and dual energy storage.
2015-04-14
Technical Paper
2015-01-1180
Letao Zhu, Zechang Sun, Haifeng Dai, Xuezhe Wei
Lithium-ion batteries have been increasingly utilized as the energy storage systems in electric, hybrid electric vehicle and plug-in vehicles (EVs/HEVs/PHEVs). To guarantee batteries in a normal operation scenario, parameters and states such as terminal voltage, current, open circuit voltage (OCV), state of charge (SOC), state of health (SOH), temperature and so on need to be monitored and estimated by battery management systems (BMSs). As a crucial characteristic relationship, the OCV-SOC curve reflects rich information containing SOC, SOH, heat generation, etc. However, due to thermo-dynamic characteristics of Li insertion/extraction process, the OCV-SOC curve exhibits hysteresis (OCV differs between charge and discharge). Generally, this phenomenon can be neglected for some battery types such as LiCoO2 and LiMn2O4, but for LiFePO4 batteries, it is very pronounced and non-ignorable due to the very flat feature of the OCV-SOC curve.
2015-04-14
Technical Paper
2015-01-1179
Christopher J. Brooks, Eric Kreidler
Vehicle drivetrain electrification is one of the many future challenges that automakers face. While there are many different EV system configurations, the one constant is the need for better electrochemical storage. Initially, this paper will discuss existing electrochemical systems and their potential to meet future vehicle requirements. We will then examine beyond Li-ion systems and their potential to replace current technology. Lithium-O2 batteries form lithium peroxide (Li2O2). This product formed on the electrocatalyst happens to be a wide band-gap semiconductor/insulator. This has ramifications for discharge, charge, and battery design. During discharge, the poor electronic conductivity of Li2O2 limits the amount and rate at which product can be formed. Under a constant discharge, the resistance of the electrode increases, causing a voltage drop that becomes sufficiently large and stops any further reaction.
2015-04-14
Technical Paper
2015-01-1192
Xudong Xu, Xuezhe Wei, Hong Gao, Jiangong Zhu, Jing Yang, Yaofeng Liu
Lithium-ion battery charging strategy affects the charging time of electric vehicles, energy efficiency of the entire vehicle, service life and safety. This paper focuses on the lithium iron phosphate battery, based on the battery internal mechanism and the working conditions, taking charging time, effective full-charge capacity and energy efficiency in charging process as the evaluation indexes. Firstly, through a lot of comparative experiments, the evaluation indexes’ variations of the constant-current constant-voltage charging strategy in different temperatures and charging currents have been studied in the paper, analyzing the respective characteristics of constant current charging phase and constant voltage charging phase in the whole charging process and their own contributions, finding out the superiority of the constant current charging strategy.
2015-04-14
Technical Paper
2015-01-1223
Masood Shahverdi, Michael S. Mazzola
An approach is being pursued for a series hybrid electric vehicle (SHEV). The twin goals of maximizing Fuel Economy (FE) and improving consumer acceptance has led to a SHEV powertrain using energy storage as a means for filtering drive cycle power demands on the engine, rather than an energy source for supplying all-electric range. The concept is intended to minimize, if not eliminate, the battery in the SHEV without resorting to full range proportional control of the engine and generator. An initial optimization study reported for a cross-over SUV SHEV showed a 3.5 kWh Li-ion battery pack was still required. In new research, a sports car class SHEV was studied, which is the topic of this manuscript. The challenge with this vehicle is to reduce the ESS size even more because the available space allocation is only one fourth of the battery size in the SUV. In this manuscript, a controller is developed that allows a hybridized Subaru BRZ to be realized with a light ESS.
2015-04-14
Technical Paper
2015-01-1197
Chao Chen, Franz Diwoky, Zoran Pavlovic, Johann Wurzenberger
A Linear and Time-invariant (LTI) Reduced Order Method (ROM) has recently been proposed for battery thermal problems in system-level simulations. In this method, a couple of Foster networks or state space models are applied to estimate the volume-averaged module/cell temperature or local temperature at specific positions in a battery pack. When the parameters prescribed to the Foster network or state space model are identified by Computational Fluid Dynamics (CFD) solutions, it has been shown that the LTI ROM is able to provide identical results as those from CFD. In this work, an LTI model of a fluid-cooling EV battery module with twelve series connected Li-Ion cells is presented. The model consists of two LTI sub-systems: one is called self-heating sub-system which describes the temperature response to the heat dissipated from the reaction layers and electrodes of the cells.
2015-04-14
Technical Paper
2015-01-1196
Jeremy S. Neubauer, Eric Wood
Fast charging is attractive to electric vehicle (EV) drivers for its ability to enable long-distance travel and quickly recharge depleted batteries on short notice. However, such aggressive charging and the sustained vehicle operation that results could lead to excessive battery temperatures and degradation. Properly assessing the consequences of fast charging requires accounting for disparate cycling, heating, and aging of individual cells in large EV packs when subjected to realistic travel patterns, usage of fast chargers, and climates over long durations (i.e. years). The U.S. Department of Energy’s Vehicle Technologies Office has supported NREL’s development of BLAST-V—the Battery Lifetime Analysis and Simulation Tool for Vehicles – to create a tool capable of accounting for all of these factors. Herein the authors shall present on the findings of applying this tool to realistic fast charge scenarios.
2015-04-14
Technical Paper
2015-01-1199
Zhenli Zhang, Anthony Rick, Brian Sisk
The microhybrid electric vehicle (MHEV) has increasingly received attention since it holds promise for significant increases in fuel economy vs. traditional gasoline vehicles at a lower price point than hybrid vehicles. Passive parallel connection of the traditional 12V lead acid battery and a high power lithium ion battery has been identified as a potential architecture that will facilitate fuel economy improvements with minimal changes to the electrical network. Enabling a passive dual-battery connection requires a design match between the two batteries, including characteristics such as battery size and resistance, so that the performance can be optimized. In this work we have developed a hybrid model that couples electrochemical model of lithium ion battery (NMC-Graphite as an example) and an equivalent circuit model of lead acid battery in order to study the behavior of 12V dual-battery microhybrid architectures.
2015-04-14
Technical Paper
2015-01-1226
Michael Bassett, Bruno Brods, Jonathan Hall, Stephen Borman, Matthew Grove, Simon Reader
In 2012 MAHLE Powertrain developed a range-extended electric vehicle (REEV) demonstrator, which is based on a series hybrid configuration, and uses a battery to store electrical energy from the grid. Once the battery state of charge (SOC) is depleted a gasoline engine (range extender) is activated to provide the energy required to propel the vehicle. As part of the continuing development of this vehicle, MAHLE Powertrain has developed control software which can intelligently manage the use of the battery energy through the combined use of GPS and road topographical data. Advanced knowledge of the route prior to the start of a journey enables the software to calculate the SOC throughout the journey and pre-determine the optimum operating strategy for the range extender to enable best charging efficiency and minimise NVH. The software can also operate without a pre-determined route being selected.
2015-04-14
Journal Article
2015-01-1426
Drew A. Jurkofsky
Photogrammetry from images captured by terrestrial cameras and manned aircraft has been used for many years to model objects, create scale diagrams and measure distances for use in traffic accident investigation and reconstruction. Due to increasing capability and availability, Unmanned Aircraft Systems (UAS), including small UAS (SUAS), are becoming a valuable, cost effective tool for collecting overhead images for photogrammetric analysis. The metric accuracy of scale accident scene diagrams created from SUAS imagery has yet to be compared to conventional measurement methods, such as total station and laser measurement systems, which are widely used by public safety officials and private consultants. For this study, two different SUAS were used to collect overhead imagery for photogrammetric processing using PhotoModeler software.
2015-04-14
Technical Paper
2015-01-1435
Jeffrey Wirth, Enrique Bonugli, Mark Freund
Google Earth is a map and geographical information application created and maintained by Google Corporation. The program displays maps of the Earth using images obtained from available satellite imagery, aerial photography and geographic information systems (GIS) 3D globe. Google Earth has become a tool often used by accident reconstructionist to create scene drawings and obtain dimensional information. In some cases, a reconstructionist will not be able to inspect the scene of the crash due to various circumstances. For example, a reconstruction may commence after the roadway on which the accident occurred has been modified. In other cases, the time and expense required to physically inspect the incident site is not justifiable. In these instances, a reconstructionist may have to rely on Google Earth imagery for dimensional information about the site. The accuracy of the Google Earth is not officially documented.
2015-04-14
Technical Paper
2015-01-0490
Ryosuke Saito
We discuss the achievement of accurate and rapid appearance evaluation of a commodity from a design perspective. In design development, it is important to evaluate the quality of products in accordance with the customer’s viewpoint. Appearance evaluation using an actual model, such as a Mock-Up Model, is the optimal means. However, in order to respond to flaws or design changes quickly, we use a digital model. Therefore, we developed a graphic tool, TOPS, which can be used to obtain correct rendering results equivalent to an actual model, enabling a high level of precision and efficiency in digital design development.
2015-04-14
Journal Article
2015-01-0488
Andreea Elena Balau, Dennis Kooijman, Ignacio Vazquez Rodarte, Norbert Ligterink
The goal of this work is to develop a tool that stochastically generates drive cycles based on measured data, with the purpose of testing light duty vehicles in a simulation environment or on a test-bench for type approval testing. The WLTC database was used as input data. This database was created with the help of a number of European countries that collaborated and provided real world driving measurements. Consequently cycles that contain typical accelerations per velocity and road types are generated, such that these cycles are representative to real driving behaviour. The stochastic drive cycle generator is developed in Matlab and is based on Markov processes. Two different stochastic generators are used: one for generating the road type and one for generating the vehicle acceleration.
2015-04-14
Technical Paper
2015-01-0498
Matt Gynn, Jamie Steele
This study explores the process changes and challenges encountered during the transition to Virtual Automotive maintenance and service operations—for example, training existing manpower on new tools, the overall schedule adjustments, and to check the item applicability. The confirmation process was reworked significantly, while the final evaluation and reporting process was able to be maintained. Problems were encountered with the organization of the digital part data, the increase in workload of Virtual simulations over physical checks, and the limitations of current simulation technologies. Virtual tools are much slower than physical checks. Ideas for future enhancements of Product Lifecycle Management (PLM) and simulation systems are explored.
2015-04-14
Journal Article
2015-01-0500
Emilio Larrodé, Alberto Torne, Alberto Fraile
This paper is collaboration between the Research Group on Sustainable Means of Transport and Systems (SMITS) of the University of Zaragoza (Spain) and the Spanish company, Zytel Automotive S.L. (ZYTEL). The analysis and decision making on design, behaviour and use of a prototype electric vehicle is the main focus has been pursued in this paper. It was modelled a prototype electric vehicle, called Gorila EV, as from the software tool Adams/Car (MSC Software Corporation). The way it decided to tackle this paper was by Computer Aided Engineering (CAE). Conduct an analysis of the vehicle by CAE allows increasing the quickness and convenience when getting results and reduce costs incurred testing with real prototypes. In this study it considers urban driving, where the vehicle trajectory is constrained by the infrastructure (road signs) and other vehicles (traffic).
2015-04-14
Technical Paper
2015-01-0493
Ying Wang, Ye Wang, You Qu, Sumin Zhang, Weiwen Deng
Abstract Vision-based Advanced Driver Assistance Systems has achieved rapid growth in recent years. Since vehicle field testing under various driving scenarios can be costly, tedious, unrepeatable, and often dangerous, simulation has thus become an effective means that reduces or partially replaces the conventional field testing in the early development stage. However, most of the commercial tools are lack of elaborate lens/sensor models for the vehicle mounted cameras. This paper presents the system-based camera modeling method integrated virtual environment for vision-based ADAS design, development and testing. We present how to simulate two types of cameras with virtual 3D models and graphic render: Pinhole camera and Fisheye camera. We also give out an application named Envelope based on pinhole camera model which refers to the coverage of Field-of-Views (FOVs) of one or more cameras projected to a specific plane.
2015-04-14
Journal Article
2015-01-0892
Alastair Smith, Rod Williams
The formation of deposits within injector nozzle holes of common-rail injection fuel systems fitted to modern diesel cars can reduce and disrupt the flow of fuel into the combustion chamber. This can lead to a reduction in power output because of reduced or less efficient combustion; hence there is a great deal of interest in studying these deposits with the ultimate aim of controlling them. Through previous experimentation [1], a chassis dynamometer test method was developed which combined high fouling operating conditions with zinc doped fuels to give measureable and repeatable fouling rates within a 36 hour test, whilst remaining representative of real world driving by incorporating >50% of the test drive cycle at typical motorway road loads.
2015-04-14
Journal Article
2015-01-0906
Xin Yu, Xi Luo, Marcis Jansons, Doohyun Kim, Jason Martz, Angela Violi
A systemic experimental fuel surrogate validation approach is proposed for a compression ignition application, and applied to validate a Jet-A POSF4658 fuel surrogate. The approach examines agreement of both physical and chemical properties in a real engine environment during four sequential but distinct combustion phases. Evaporating spray measurement using Mie Scattering are applied to compare the in-cylinder spray behavior of the surrogate, its target fuel, and for reference, n-heptane. Early mixture formation and low temperature reaction behavior were investigated using 2-D broadband chemiluminescence imaging. The high temperature ignition and combustion chemistry were studied using OH chemiluminescence imaging. Engine-out UHC, NO and soot emission characteristics were compared at different intake conditions, injection pressures and injection strategies.
2015-04-14
Technical Paper
2015-01-0131
Nick Smith
Abstract Demand for increased functionality in automotive electrical/electronic (E/E) systems is being propelled by both customers and various governmental regulations and requirements. This demand for more capabilities also introduces new challenges for OEMs who are responsible for implementing these functions. Of course, the cost of system development and manufacturing are considerable, but there are challenges beyond cost that the OEM must deal with, such as increased weight, reliability and quality concerns, exponentially-increasing complexity, and the government requirements. From the point of view of the electrical system platform as a whole, it provides the unique role of integrating all the individual E/E systems. When integrated, unanticipated problems can emerge that require design modifications. Often, these are discovered way down the design path, which results in delays in the program that can lead to missed deadlines and costly rework.
2015-04-14
Technical Paper
2015-01-0148
Georg Macher, Harald Sporer, Eric Armengaud, Christian Kreiner
Abstract Increasing demands for safety, security, and certifiability of embedded automotive systems require additional development effort to generate the required evidences that the developed system can be trusted for the application and environment it is intended for. Safety standards such as ISO 26262 for road vehicles have been established to provide guidance during the development of safety-critical systems. The challenge in this context is to provide evidence of consistency, correctness, and completeness of system specifications over different work-products. One of these required work-products is the hardware-software interface (HSI) definition. This work-product is especially important since it defines the interfaces between different technologies. Model-based development (MBD) is a promising approach to support the description of the system under development in a more structured way, thus improving resulting consistency.
2015-04-14
Technical Paper
2015-01-0176
Karsten Schmidt, Denny Marx, Jens Harnisch, Albrecht Mayer, Udo Dannebaum, Herbert Christlbauer
The implementation of innovative features in the areas of electric-drive systems, chassis and driver assistance systems as well as the introduction of new networking architectures and mostly the increasing in-house software developed by car manufacturers result in new ECUs integrating high numbers of application software components. For such ECUs the software integration scenarios become more complicated, as more constraints with regards to timing, safety and security need to be considered. Multi-core microcontrollers offer even more potential variants for integration scenarios. Understanding the interaction between the different software components, not only from a functional but also from a timing view, is a key success factor for high integration scenarios. Currently, the applied approaches like sending debug messages over CAN or FlexRay need to be enhanced by further approaches. It is important to accept that timing is a crucial aspect.
2015-04-14
Technical Paper
2015-01-0180
Karsten Schmidt, Denny Marx, Kai Richter, Konrad Reif, Andreas Schulze, Torsten Flämig
Transitioning from single-function to multi-function ECUs poses new challenges to the software integration, especially the design, verification and optimization of the software architecture with the OS schedule. We must maximize the CPU utilization and run all functions according to their specific timing needs (CPU load, cycle time, execution time, jitters, etc.). In single-function systems, the relation between function/software development and software integration/test is simple: one function, one ECU, one test system. When timing issues are detected, we can identify their root cause and take appropriate action, either in the function or in the platform software.
2015-04-14
Technical Paper
2015-01-0184
James Price
AUTOSAR is a well established standard for automotive ECU and network design. This session will walk through a demonstration project, using a full AUTOSAR 4.x run-time stack. Attendees will learn how design tools are used in the development process together with the Basic Software stack to develop a specific ECU application.
2015-04-14
Technical Paper
2015-01-0186
Syed Arshad Kazmi, Jin Seo Park, Jens Harnisch
End of Line tests are brief set of tests intended to evaluate ECU’s in order to ensure correct functioning of intended functionality works as expected. These tests perform two critical functions. 1- Act as a proof of quality for the manufactured ECU and 2 - determine a faulty test object and therefore act as a criterion for rejection. As these tests are executed on the production line, available time to perform these tests is limited. With ever increasing demand of faster production, there is an increasing pressure to design the tests and its execution framework in a time optimized manner without any compromise on the quality of tests or a reduction in functional coverage. On the other hand, OEMs specify increasingly more functionality and complexity in ECU, thus demanding increase in EoL tests functional coverage. Therefore the time taken to execute the tests reaches a critical point in overall ECU production.
2015-04-14
Technical Paper
2015-01-0185
Younho Lee, YangNam Lim, KokCheng Gui, Jin Seo Park, Pawan Reddy, Syed Arshad Kazmi
These days in automotive industry, AUTOSAR has been increasingly used as a standard and unified software platform as vehicle electronics have becoming more variety, more performance and more complicated. MCAL is a software driver which belongs to lowest level in AUTOSAR software structure. MCAL is directly accessing to the microcontroller hardware and is provided by microcontroller supplier like Infineon. To handle microcontroller peripheral for general usage, MCAL is used. And in cases for special dedicated functions of microcontroller or for special requirements, Complex Driver could be used as legacy software instead of MCAL. SPI communication has grown to become a de facto standard for exchanging digital information between MCU and other ICs on the circuit board. One main benefit of SPI is that, a very fast data acquisition can be supported as compared to the other communications means, with very low CPU core load and results in higher performance.
2015-04-14
Technical Paper
2015-01-0190
Mostafa Anwar Taie, Ibrahim El-Faramawy, Mohamed Elmawazini
Estimating the real-time (RT) behavior of software architecture in embedded system is very difficult and critical. Most of the current approaches rely on engineering judgment or actual measurements performed during integration testing. Both approaches are not error proof and can yield to RT constraints violations discovered during simulation of RT architectural design or during product validation. Impact on project could even be a CPU change. In this work, OS process execution time (ET) is used as the basic element of RT architectural design. First, OS process ET is predicted using machine learning (ML) algorithms, based on previous SW releases. Different types of features (e.g. number of static architecture requirements, hardware factor, seniority index), are proposed as inputs (feature vectors) to multiple ML classifiers in order to predict processes ET. Multiple ML techniques (e.g.
2015-04-14
Technical Paper
2015-01-0189
Rolf Schneider, Dominik Juergens, Andre Kohn
A permanent challenge for the development of automotive electronic control units is the steadily rising demand for computing power. One well known reason is surely the trend for co-hosting of functions on a shared hardware platform. But what is also heavily propelling this demand is the raising complexity of innovative functions meant to make the car brand specific driving experience even more unique, extraordinary and/or comfortable. The underlying complex algorithms often accompanied with high safety requirements thirst for faster CPUs. Meanwhile also for the automotive domain silicon vendors try to satisfy those resource demands with new microcontrollers incorporating multiple independent computing cores on one single chip as it is already common for personal computers, server installations, communication infrastructure and even consumer electronics like smartphones or flat TVs for quite some years.
2015-04-14
Technical Paper
2015-01-0202
Armin Wasicek, Andre Weimerskirch
Combatting the modification of automotive control systems is a current and future challenge for OEMs and suppliers. ‘Chiptuning’ is a manifestation of manipulation of a vehicle’s original setup and calibration. With the increase in automotive functions implemented in software and corresponding business models, chip tuning will become a major concern. Recognizing and reporting of tuned control units in a vehicle is required for technical as well as legal reasons. This work approaches the problem by capturing the behavior of relevant control units within a machine learning system called a recognition module. The recognition module continuously monitors vehicle’s sensor data. It comprises a set of classifiers that have been trained on the intended behavior of a control unit before the vehicle is delivered. When the vehicle is on the road, the recognition module uses the classifier together with current data to ascertain that the behavior of the vehicle is as intended.
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