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The U.S. Environmental Protection Agency (EPA) contracted with FEV, Inc. to estimate the per-vehicle cost of employing selected advanced efficiency-improving technologies in light-duty motor vehicles. The development of transparent, reliable cost analyses that are accessible to all interested stakeholders has played a crucial role in establishing feasible and cost effective standards to improve fuel economy and reduce greenhouse gas (GHG) emissions. The FEV team, together with engineering staff from EPA's National Vehicle and Fuel Emissions Laboratory, and FEV's subcontractor, Munro & Associates, developed a robust costing methodology based on tearing down, to the piece part level, relevant systems, sub-systems, and assemblies from vehicles ?with and without? the technologies being evaluated.

The U.S. Environmental Protection Agency (EPA) contracted with FEV, Inc. to estimate the per-vehicle cost of employing selected advanced efficiency-improving technologies in light-duty motor vehicles. The development of transparent, reliable cost analyses that are accessible to all interested stakeholders has played a crucial role in establishing feasible and cost effective standards to improve fuel economy and reduce greenhouse gas (GHG) emissions. The FEV team, together with engineering staff from EPA's National Vehicle and Fuel Emissions Laboratory, and FEV's subcontractor, Munro & Associates, developed a robust costing methodology based on tearing down, to the piece part level, relevant systems, sub-systems, and assemblies from vehicles “with and without” the technologies being evaluated.

Beginning in 2010, implementation of on-board diagnostics (OBD) is mandatory for all the heavy-duty engine applications in the United States. The task of developing OBD strategies and calibrating them is a challenging one. The process involves a strong interdependency on base engine emissions, controls and regulations. On top of that the strategies developed as a result of the regulatory requirements need to go through a stringent and time-intensive process of software implementation and integration. The recent increasing demands to minimize the development process have been pushing the envelope on the methodologies used in developing the strategies and the calibration for robust monitoring. The goal of this paper is to provide a concise overview of a process utilized to help the development, testing and calibration of the OBD strategies on a 2010 model year heavy-duty diesel engine.

The use of biodiesel and its blends with ultra low sulfur diesel (ULSD) is gaining significant importance due to its ability to burn in conventional diesel engines with minor modifications. However the chemical and physical properties of biodiesel are different compared to the conventional ULSD. These differences directly impact the injection, spray formation, auto ignition and combustion processes which in turn affect the engine-out emissions. To understand the effect of fueling with B-20, tests were conducted on a single cylinder 0.42L direct injection research diesel engine. The engine is equipped with a common rail injection system, variable EGR and swirl control systems and was operated at a constant engine speed of 1500 rpm and 3 bar IMEP to simulated turbocharged conditions. Injection timing and duration were adjusted with B-20 at different locations of peak premixed combustions (LPPC) and two different swirl ratios to achieve 3 bar IMEP.

Beginning in 2007, heavy-duty engine manufacturers in the U.S. have been responsible for verifying the compliance on in-use vehicles with Not-to-Exceed (NTE) standards under the Heavy-Duty In-Use Testing Program (HDIUT). This in-use testing is conducted using Portable Emission Measurement Systems (PEMS) which are installed on the vehicles to measure emissions during real-world operation. A key component of the HDIUT program is the generation of measurement allowances which account for the relative accuracy of PEMS as compared to more conventional, laboratory based measurement techniques. A program to determine these measurement allowances for gaseous emissions was jointly funded by the U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and various member companies of the Engine Manufacturer's Association (EMA).

With the advent of advanced diesel after-treatment technologies, sophisticated sensors are becoming a critical cost challenge to OEMs. This paper describes an approach for replacing the engine out NOx sensor with an artificial neural network (ANN) based virtual sensor. The technique centers around inferring NOx concentration from readily available engine operating parameters, eliminating the need for physical sensing and the cost associated with it. A multi-layer perceptron network was trained to estimate NOx concentration from engine speed, load, exhaust gas recirculation, and air-fuel ratio information. This supervised learning was conducted with measured engine data. The network was validated against measured data that was excluded from the training data set. The paper details application of this technique to both a heavy duty and light duty diesel engine. Results show good agreement between predictions and measured data under the steady state conditions studied.

Due to its high efficiency and superior durability the diesel engine is again becoming a prime candidate for future light-duty vehicle applications within the United States. While in Europe the overall diesel share exceeds 40%, the current diesel share in the U.S. is 1%. Despite the current situation and the very stringent Tier 2 emission standards, efforts are being made to introduce the diesel engine back into the U.S. market. In order to succeed, these vehicles have to comply with emissions standards over a 120,000 miles distance while maintaining their excellent fuel economy. The availability of technologies such as high-pressure common-rail fuel systems, low sulfur diesel fuel, NOx adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with the light-duty Tier 2 emission requirements. In support of this, the U.S.

The use of a partial flow sampling system (PFSS) to measure nonroad steady-state diesel engine particulate matter (PM) emissions is a technique for certification approved by a number of regulatory agencies around the world including the US EPA. Recently, there have been proposals to change future nonroad tests to include testing over a nonroad transient cycle. PFSS units that can quantify PM over the transient cycle have also been discussed. The full flow constant volume sampling (CVS) technique has been the standard method for collecting PM under transient engine operation. It is expensive and requires large facilities as compared to a typical PFSS. Despite the need for a cheaper alternative to the CVS, there has been a concern regarding how well the PM measured using a PFSS compared to that measured by the CVS. In this study, three PFSS units, including AVL SPC, Horiba MDLT, and Sierra BG-2 were investigated in parallel with a full flow CVS.

Six heavy-duty diesel engines were tested for exhaust emissions on the ISO 8-mode nonroad steady-state duty cycle and the U.S. FTP highway transient test cycle. Two of these engines were baseline nonroad engines, two were Tier 1 nonroad engines, and two were highway engines. One of the Tier 1 nonroad engines and both of the highway engines were also tested on three transient cycles developed for nonroad engines. In addition, published data were collected from an additional twenty diesel engines that were tested on the 8-mode as well as at least one transient test cycle. Data showed that HC and PM emissions from diesel engines are very sensitive to transient operation while NOx emissions are much less so. Although one of the nonroad transient duty cycles showed lower PM than the steady-state duty cycles, all four of the other cycles showed much higher PM emissions than the steady-state cycle.

This paper describes a method used to compare the emissions from transient operation of an engine with the emissions from steady state operating modes of the engine. Weightings were assigned to each mode based on the transient cycle under evaluation. The method of assigning the weightings for each mode took into account several factors, including the distance between each second of the transient cycle's speed-and-torque point requests (in a speed vs. torque coordinate system) and the given mode. Two transient cycles were chosen. The transient cycles were taken from actual in-use data collected on nonroad engines during in-field operation. The steady state modes selected were based on both International Standard Organization (ISO) test modes, as well as, augmentation based on contour plots of the emissions from nonroad diesel engines. Twenty-four (24) steady-state modes were used. The transient cycle's speed-and-torque points are used to weight each steady state mode in the method.

This paper presents the results of several emission testing programs conducted by the U.S. Environmental Protection Agency. The test vehicles were primarily 1980 and 1981 passenger cars which were obtained at random from private owners. Some 1982 models were also tested. The 1328 vehicles were selected from the Los Angeles area as well as from a number of other low-altitude locations. The test sequence included the Federal Test Procedure, the Highway Fuel Economy Test and several short cycle tests. The primary purpose of the program was to gather information on current vehicles which could be used in calculations and projections of air quality and aid development of programs to improve it. The results of the program indicate that these vehicles are capable of maintaining low emission levels although high levels are also possible due to defects, deterioration, or tampering. Inspection/Maintenance programs are a feasible and effective means for correcting high levels when they occur.