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Video

Beyond MPG: Characterizing and Conveying the Efficiency of Advanced Plug-In Vehicles 

2011-11-08
Research in plug in vehicles (PHEV and BEV) has of course been ongoing for decades, however now that these vehicles are finally being produced for a mass market an intense focus over the last few years has been given to proper evaluation techniques and standard information to effectively convey efficiency information to potential consumers. The first challenge is the development of suitable test procedures. Thanks to many contributions from SAE members, these test procedures have been developed for PHEVs (SAE J1711 now available) and are under development for BEVs (SAE J1634 available later this year). A bigger challenge, however, is taking the outputs of these test results and dealing with the issue of off-board electrical energy consumption in the context of decades-long consumer understanding of MPG as the chief figure of merit for vehicle efficiency.
Video

Comparison of Powertrain Configuration Options for Plug-in HEVs from a Fuel Economy Perspective

2012-05-25
The first commercially available plug-in hybrid electric vehicle (PHEV), the General Motors (GM) Volt, was introduced into the market in mid-December 2010. The Volt uses a series-split powertrain architecture, which provides benefits over the series architecture that typically has been considered for use in electric-range extended vehicles (EREVs). A specialized EREV powertrain, called the Voltec, drives the Volt through its entire range of speed and acceleration with battery power alone and within the limit of battery energy, thereby displacing more fuel with electricity than a PHEV, which characteristically blends electric and engine power together during driving. This paper assesses the benefits and drawbacks of these two different plug-in hybrid electric architectures (series versus series-split) by comparing component sizes, system efficiency, and fuel consumption over urban and highway drive cycles.
Video

Impact of Technology on Electric Drive Fuel Consumption and Cost

2012-05-25
In support of the U.S Department of Energy's Vehicle Technologies Program, numerous vehicle technology combinations have been simulated using Autonomie. Argonne National Laboratory (Argonne) designed and wrote the Autonomie modeling software to serve as a single tool that could be used to meet the requirements of automotive engineering throughout the development process, from modeling to control, offering the ability to quickly compare the performance and fuel efficiency of numerous powertrain configurations. For this study, a multitude of vehicle technology combinations were simulated for many different vehicles classes and configurations, which included conventional, power split hybrid electric vehicle (HEV), power split plug-in hybrid electric vehicle (PHEV), extended-range EV (E-REV)-capability PHEV, series fuel cell, and battery electric vehicle.
Technical Paper

Simulation Tool Chain for the Estimation of EMC Characteristics of ECU Modules

2007-04-16
2007-01-1591
Electromagnetic Compatibility (EMC) requirements and the effort to fulfill them are increasing steadily in automotive applications. This paper demonstrates the usage of virtual prototyping to efficiently investigate the EMC behavior of a gasoline direct injection system. While the system worked functionally as designed, tests indicated that current and especially future client-specific EMC limits could not be met. The goal of this investigation was to identify and eliminate the cause of EMC emissions using a virtual software prototype including the controller ASIC, boost converter, pi filter, injection valves and wire harness. Applying virtual prototyping techniques it was possible to capture the motor control system in a simulation model which reproduced EMC measurements in the frequency ranges of interest.
Technical Paper

Efficiency-Optimized Operating Strategy of a Supercharged Hydrogen-Powered Four-Cylinder Engine for Hybrid Environments

2007-07-23
2007-01-2046
As an energy carrier, hydrogen has the potential to deliver clean and renewable power for transportation. When powered by hydrogen, internal combustion engine technology may offer an attractive alternative to enable the transition to a hydrogen economy. Port-injected hydrogen engines generate extremely low emissions and offer high engine efficiencies if operated in a lean combustion strategy. This paper presents experimental data for different constant air/fuel ratio engine combustion strategies and introduces variable air/fuel ratio strategies for engine control. The paper also discusses the shift strategy to optimize fuel economy and contrasts the different engine control strategies in the conventional vehicle environment. The different strategies are evaluated on the urban driving cycle, then engine behaviors are explained and fuel economy is estimated. Finally, the paper projects the potential of hybridization and discusses trends in powertrain cycle efficiencies.
Technical Paper

Characterization and Comparison of Two Hybrid Electric Vehicles (HEVs) - Honda Insight and Toyota Prius

2001-03-05
2001-01-1335
Two limited-production hybrid electric vehicles (HEVs) - a 1988 Japanese model Toyota Prius and a 2000 Honda Insight - were tested at Argonne National Laboratory to collect data from vehicle component and systems operation. The test data are used to analyze operation and efficiency and to help validate computer simulation models. Both HEVs have FTP fuel economy greater than 45 miles per gallon and also have attributes very similar to those of conventional gasoline vehicles, even though each HEV has a unique powertrain configuration and operation control strategy. The designs and characteristics of these vehicles are of interest because they represent production technology with all the compromises for production included. This paper will explore both designs, their control strategies, and under what conditions high fuel economy was achieved.
Technical Paper

Analysis of Performance Results from FutureTruck 2001

2002-03-04
2002-01-1209
The 2001 FutureTruck competition involved 15 universities from across North America that were invited to apply a wide range of advanced technologies to improve energy efficiency and reduce greenhouse gas impact while producing near-zero regulated exhaust emissions in a 2000 Chevrolet Suburban. The modified vehicles designated as FutureTrucks demonstrated improvements in greenhouse gas emissions, tailpipe emissions, and over-the-road fuel economy compared with the stock vehicle on which they were based. The technologies represented in the vehicles included ICE-engines and fuel cell hybrid electric vehicle propulsion systems, a range of conventional and alternative fuels, advanced exhaust emissions controls, and light weighting technologies.
Technical Paper

Assessing and Modeling Direct Hydrogen and Gasoline Reforming Fuel Cell Vehicles and Their Cold-Start Performance

2003-06-23
2003-01-2252
This paper analyzes fuel economy benefits of direct hydrogen and gasoline reformer fuel cell vehicles, with special focus on cold-start impacts on these fuel cell based vehicles. Comparing several existing influential studies reveals that the most probable estimates from these studies differ greatly on the implied benefits of both types of fuel cell vehicles at the tank-to-wheel level (vehicle-powertrain efficiency and/or specific power), leading to great uncertainties in estimating well-to-wheel fuel energy and/or greenhouse gas (GHG) emission reduction potentials. This paper first addresses methodological issues to influence the outcome of these analyses. With one exception, we find that these studies consistently ignore cold-start and warm-up issues, which play important roles in determining both energy penalties and start-up time of fuel cell vehicles. To better understand cold-start and warm-up behavior, this paper examines approaches and results based on two available U.S.
Technical Paper

Integration of Time Triggered CAN (TTCAN_TC)

2002-03-04
2002-01-0263
Time Triggered CAN (TTCAN) is an extension of the well-known CAN protocol, introducing to CAN networks time triggered communication and a system wide global network time with high precision. Time Triggered CAN has been accepted as international standard ISOCD11898-4. The time triggered communication is built upon the unchanged standard CAN protocol. This allows a software implementation of the time triggered function of TTCAN, based on existing CAN ICs. The high precision global time however requires a hardware implementation. A hardware implementation also offers additional functions like time mark interrupts, a stopwatch, and a synchronization to external events, all independent of software latency times. The TTCAN testchip (TTCAN_TC) is a standalone TTCAN controller and has been produced as a solution to the hen/egg problem of hardware availability versus tool support and research.
Technical Paper

Evaluating Commercial and Prototype HEVs

2001-03-05
2001-01-0951
In recent years, vehicle manufacturers have made great progress in developing and demonstrating commercially available and prototyped hybrid electric vehicles (HEVs). These vehicles include commercially available gasoline hybrid cars (Toyota Prius and Honda Insight) and Partnership for the Next Generation Vehicle (PNGV) diesel hybrid prototypes (Ford Prodigy, GM Precept, and DaimlerChrysler ESX3). In this paper, we discuss tested and claimed fuel benefits and performance of these commercial and prototyped HEVs relative to conventional vehicles (CVs) that are otherwise similar to these HEVs, except for hybridization. We also describe a reverse-engineering approach to de-hybridize or “conventionalize” these five existing commercial and prototyped HEVs. Because these commercial and prototyped HEVs represent a variety of technological choices, configurations, and development stages, this analysis gives us in-depth knowledge about how each of these vehicles achieves high efficiency.
Technical Paper

Impact of Drive Cycle Aggressiveness and Speed on HEVs Fuel Consumption Sensitivity

2007-04-16
2007-01-0281
Hybrid Electric Vehicle (HEV) owners have reported significantly lower fuel economy than the published estimates. Under on-road driving conditions, vehicle acceleration, speed, and stop time differ from those on the normalized test procedures. To explain the sensitivity, several vehicles, both conventional and hybrid electric, were tested at Argonne National Laboratory. The tests demonstrated that the fuel economy of Prius MY04 was more sensitive to drive-cycle variations. However, because of the difficulty in instrumenting every component, an in-depth analysis and quantification of the reasons behind the higher sensitivity was not possible. In this paper, we will use validated models of the tested vehicles and reproduce the trends observed during testing. Using PSAT, the FreedomCAR vehicle simulation tool, we will quantify the impact of the main component parameters, including component efficiency and regenerative braking.
Technical Paper

Analyzing the Uncertainty in the Fuel Economy Prediction for the EPA MOVES Binning Methodology

2007-04-16
2007-01-0280
Developed by the U.S. Environmental Protection Agency (EPA), the Multi-scale mOtor Vehicle Emission Simulator (MOVES) is used to estimate inventories and projections through 2050 at the county or national level for energy consumption, nitrous oxide (N2O), and methane (CH4) from highway vehicles. To simulate a large number of vehicles and fleets on numerous driving cycles, EPA developed a binning technique characterizing the energy rate for varying Vehicle Specific Power (VSP) under predefined vehicle speed ranges. The methodology is based upon the assumption that the vehicle behaves the same way for a predefined vehicle speed and power demand. While this has been validated for conventional vehicles, it has not been for advanced vehicle powertrains, including hybrid electric vehicles (HEVs) where the engine can be ON or OFF depending upon the battery State-of-Charge (SOC).
Technical Paper

Testing and Analysis of Three Plug-in Hybrid Electric Vehicles

2007-04-16
2007-01-0283
Current-production hybrid electric vehicles (HEVs) have shown a measurable improvement in fuel economy, in comparison with conventional vehicles, by using the internal combustion engine in a more efficient operating region, which therefore reduces petroleum consumption. These HEVs operate with a charge-sustaining control strategy. Plug-in HEVs (PHEVs) show the potential to further decrease petroleum consumption by operating in a charge-depletion control strategy, in which the energy stored in the battery pack in used during normal driving and recharged through stationary, off-board vehicle charging. This charge-depletion strategy uses more electrical energy to propel the vehicle, which displaces more petroleum. This paper discusses the testing and analysis of a Hymotion Prius PHEV, an Energy CS Prius PHEV, and a Renault Kangoo PHEV.
Technical Paper

Expansion Devices for R-744 MAC Units

2005-05-10
2005-01-2041
In mobile R-744 A/C units mechanical expansion devices (e.g. orifice tubes) or electronic valves (e.g. PWM-valves) can be used. Besides the costs, aspects like coefficient of performance (COP), cooling capacity or control behavior - especially for extreme conditions - influence the choice of the valve type. This paper will present a comparison between an ideal electronic valve and a two stage mechanical orifice tube under full load and part load conditions. The influence of the expansion valve on COP and cooling capacity in different ambient conditions can be sufficiently described with steady-state simulations. The simulation tools used for this work are based on Modelica/Dymola. The simulation results show that for European climate conditions the use of two-stage orifices might increase fuel consumption.
Technical Paper

Ultrafast X-Ray Phase-Enhanced Microimaging for Visualizing Fuel Injection Process

2005-09-11
2005-24-093
Propagation-based and phase-enhanced x-ray imaging was developed as a unique metrology technique to visualize the internal structure of high-pressure fuel injection nozzles. We have visualized the microstructures inside 200-μm fuel injection nozzles in a 3-mm-thick steel housing using this novel technique. Furthermore, this new x-ray-based metrology technique has been used to directly study the highly transient needle motion in the nozzles in situ and in real-time, which is virtually impossible by any other means. The needle motion has been shown to have the most direct effect on the fuel jet structure and spray formation immediately outside of the nozzle. In addition, the spray cone-angle has been perfectly correlated with the numerically simulated fuel flow inside the nozzle due to the transient nature of the needle during the injection.
Technical Paper

Development of Guidelines for the Use of Commercial CFD in Tractor-Trailer Aerodynamic Design

2005-11-01
2005-01-3513
With rising oil prices, the issue of energy economy in transportation is getting much attention. At the same time, new emissions standards for tractor-trailer vehicles introduce additional challenges for the manufacturers to achieve improvements in vehicle fuel economy. As part of the U.S. Department of Energy Office of FreedomCAR and Vehicle Technologies' Heavy Vehicle Aerodynamic Drag Consortium, Argonne National Laboratory is currently developing guidelines for the use of commercial computational fluid dynamics (CFD) software to facilitate energy efficiency improvements through improved aerodynamic design of tractor-trailer vehicles. The development of these guidelines requires the consideration of the sensitivity of the accuracy of the analysis to the various modeling choices available to the end user.
Technical Paper

Effect of Injector Nozzle Finish on Performance and Emissions in a HSDI, Light-duty, Diesel Engine

2006-04-03
2006-01-0200
The purpose of this study was to determine the effect of injector nozzle hole size, shape, and finish on performance and emissions in a light-duty diesel engine. Two sets of six-hole valve covered orifice (VCO) nozzles were tested with nearly identical volumetric flow rates but varying geometry and finish. The 17% hydro-erosion (HE) nozzles had a 22% larger discharge coefficient (CD), compared to the 7% HE nozzles. In order to maintain similar volumetric flow rates, the orifice diameter of the 17% HE nozzles were reduced by almost 10%.The nozzles were tested in a 1.7L, four-cylinder, common rail diesel engine, operating on conventional D2 diesel fuel. The 17% HE, conical-shaped nozzles reduced fuel specific particulate matter (PM) and increased fuel specific oxides of nitrogen (NOx) emissions, over the 7% HE, straight-shaped nozzle.
Technical Paper

Impacts of Combining Hydrogen ICE with Fuel Cell System Using PSAT

2006-04-03
2006-01-0037
Because of their high efficiency and low emission potential, fuel cell vehicles are undergoing extensive research and development. However, several major barriers have to be overcome to enable a hydrogen economy. Because fuel cell vehicles remain expensive, very few fueling stations are being built. To try to accelerate the development of a hydrogen economy, the automotive manufacturers developed a hydrogen-fueled Internal Combustion Engine (ICE) as an intermediate step. Despite being cheaper, the hydrogen-fueled ICE offers a lower driving range because of its lower efficiency. The current study evaluates the impact of combining a hydrogen-fueled ICE with a fuel cell to maximize fuel economy while minimizing the cost and amount of onboard fuel needed to maintain an acceptable driving range.
Technical Paper

Investigating Possible Fuel Economy Bias Due To Regenerative Braking in Testing HEVs on 2WD and 4WD Chassis Dynamometers

2005-04-11
2005-01-0685
Procedures are in place for testing emissions and fuel economy for virtually every type of light-duty vehicle with a single-axle chassis dynamometer, which is why nearly all emissions test facilities use single-axle dynamometers. However, hybrid electric vehicles (HEVs) employ regenerative braking. Thus, the braking split between the driven and non-driven axles may interact with the calculation of overall efficiency of the vehicle. This paper investigates the regenerative braking systems of a few production HEVs and provides an analysis of their differences in single-axle (2WD) and double-axle (4WD) dynamometer drive modes. The fuel economy results from 2WD and 4WD operation are shown for varied cycles for the 2000 Honda Insight, 2001 Toyota Prius, and the 2004 Toyota Prius. The paper shows that there is no evidence that a bias in testing an HEV exists because of the difference in operating the same hybrid vehicle in the 2WD and 4WD modes.
Technical Paper

The Challenge of Precise Characterizing the Specific Large-Span Flows in Urea Dosing Systems for NOx Reduction

2008-04-14
2008-01-1028
The reduction of nitrous oxides in the exhaust gases of internal combustion engines using a urea water solution is gaining more and more importance. While maintaining the future exhaust gas emission regulations, like the Euro 6 for passenger cars and the Euro 5 for commercial vehicles, urea dosing allows the engine management to be modified to improve fuel economy as well. The system manufacturer Robert Bosch has started early to develop the necessary dosing systems for the urea water solution. More than 300.000 Units have been delivered in 2007 for heavy duty applications. Typical dosing quantities for those systems are in the range of 0.01 l/h for passenger car systems and up to 10 l/h for commercial vehicles. During the first years of development and application of urea dosing systems, instantaneous flow measuring devices were used, which were not operating fully satisfactory.
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