Light-duty Trucks Research Articles

Development of the New Light-Duty Hybrid Truck

Hino Motors, Ltd., developed the new light-duty hybrid truck whose traction motor, inverter, and traction battery were completely redesigned for maximizing output and efficiency. It also succeeds in balancing low fuel economy and low exhaust emissions by utilizing a combination of a new hybrid system control with a specially developed diesel engine.

Quantifying the external costs of vehicle use: Evidence from America’s top-selling light-duty models

Vehicle externality costs include emissions of greenhouse and other gases (affecting global warming and human health), crash costs (imposed on crash partners), roadway congestion, and space consumption, among others. These five sources of external costs by vehicle make and model were estimated for the top-selling passenger cars and light-duty trucks in the US. Among these external costs, those associated with crashes and congestion are estimated to be the most practically significant. When crash costs are included, the worst offenders (in terms of highest external costs) were found to be pickups. If crash costs are removed from the comparisons, the worst offenders tend to be four pickups and a very large SUV: the Ford F-350 and F-250, Chevrolet Silverado 3500, Dodge Ram 3500, and Hummer H2, respectively. Regardless of how the costs are estimated, they are considerable in magnitude, and nearly on par with vehicle purchase prices.

Vehicle-type choice and neighbourhood characteristics: An empirical study of Hamilton, Canada

The popularity of light-duty trucks has increased with important implications for air quality, traffic accidents and gasoline demand. While previous studies have shed light on vehicle-type choice at the household level, little work has been done that examines the role of the built environment on these choices. This paper reports empirical findings on the relationship between vehicle-type choice and neighbourhood characteristics within the Census Metropolitan Area of Hamilton in Canada. The analysis incorporates proximity and urban form measures derived from high-resolution spatial data and geographic information systems technology. Estimates from discrete choice models of households’ latest vehicle-type choice suggest that preferences for less fuel-efficient vehicles are marginally affected by the diversity of land-uses at the place of residence, after controlling for travel to work attitudes and socio-demographic characteristics of individuals and households.

Development of dimethyl ether engines for light-duty trucks using a large exhaust gas recirculation system

A light-duty truck diesel engine fuelled with dimethyl ether (DME) using a jerk-type in-line DME injection system, which meets the Japan 2009 Emission Regulation, was developed. It includes lower exhaust emission technology such as a large exhaust gas recirculation system with air-throttled and inter-cooled turbocharging. The National Traffic Safety Office, Environment Laboratory, and Bosch Corporation have demonstrated low-emission engines which reduce NO x emission levels to about 50 per cent of the 2009 emissions regulation without an NO x reduction catalyst system.

A technique for developing a high accuracy durability test for a Light Truck on a Six Degree-of-Freedom Road Test Simulator

A technique for developing a high accuracy laboratory durability test for a light-duty pickup truck on an MTS Six Degree-of-Freedom Light Truck (LT) Road Test Simulator (RTS) is presented. On the vehicle being studied, various transducers were instrumented. On-road data was acquired for drive file development on a RTS. Vehicle transducer responses from the road were used as targets to be achieved on the simulator. Several simulation schemes using different vehicle transducer configurations as control channels were attempted and the correlation of transducer responses between those achieved on the simulator and the on-road data was analysed. The configuration that produced the best correlation with on-road responses was adopted to develop the drive files used for subsequent vehicle durability testing.

Fuel Economy Improvement Strategy for Light Duty Hybrid Truck Based on Fuel Consumption Computational Model Using Neural Network

This paper describes a strategy for fuel economy improvement of light duty truck with parallel hybrid system. The main objective of this paper is to develop a new hybrid controller which optimizes the torque distribution among various running situations and driver's characteristics with on-line simulation, computing fuel and electric current consumption by using neural network models of the hybrid ECU. Then, fuel and battery current consumption computational models with respect to battery state of charge (SOC), engine and motor torque and engine speed are synthesized by using neural network, and the models are based on experimental data. Finally, the new hybrid controller including the above mentioned models is developed, and its effectiveness on fuel economy improvement is verified by using computer simulation.

Size and Composition Distributions of Particulate Matter Emissions: Part 1—Light-Duty Gasoline Vehicles

Size-resolved particulate matter (PM) emitted from light-duty gasoline vehicles (LDGVs) was characterized using filter-based samplers, cascade impactors, and scanning mobility particle size measurements in the summer 2002. Thirty LDGVs, with different engine and emissions control technologies (model years 1965–2003; odometer readings 1264–207,104 mi), were tested on a chassis dynamometer using the federal test procedure (FTP), the unified cycle (UC), and the correction cycle (CC). LDGV PM emissions were strongly correlated with vehicle age and emissions control technology. The oldest models had average ultrafine PM0.1 (0.056- to 0.1-μm aerodynamic diameter) and fine PM1.8 (≤1.8-μm aerodynamic diame ter) emission rates of 9.6 mg/km and 213 mg/km, respectively. The newest vehicles had PM0.1 and PM1.8 emis sions of 51 μg/km and 371 μg/km, respectively. Light duty trucks and sport utility vehicles had PM0.1 and PM1.8 emissions nearly double the corresponding emission rates from passenger cars. Higher PM emissions were associated with cold starts and hard accelerations. The FTP driving cycle produced the lowest emissions, followed by the UC and the CC. PM mass distributions peaked between 0.1-and 0.18-μm particle diameter for all vehicles except those emitting visible smoke, which peaked between 0.18 and 0.32 μm. The majority of the PM was composed of carbonaceous material, with only trace amounts of water-soluble ions. Elemental carbon (EC) and organic matter (OM) had similar size distributions, but the EC/OM ratio in LDGV exhaust particles was a strong function of the adopted emissions control technology and of vehicle maintenance. Exhaust from LDGV classes with lower PM emissions generally had higher EC/OM ratios. LDGVs adopting newer technologies were characterized by the highest EC/OM ratios, whereas OM dominated PM emissions from older vehicles. Driving cycles with cold starts and hard accelerations produced higher EC/OM ratios in ultrafine particles.

Impact of Underestimating the Effects of Cold Temperature on Motor Vehicle Start Emissions of Air Toxics in the United States

Analyses of U.S. Environmental Protection Agency (EPA) certification data, California Air Resources Board surveil-lance testing data, and EPA research testing data indicated that EPA’s MOBILE6.2 emission factor model substantially underestimates emissions of gaseous air toxics occurring during vehicle starts at cold temperatures for light-duty vehicles and trucks meeting EPA Tier 1 and later standards. An unofficial version of the MOBILE6.2 model was created to account for these underestimates. When this unofficial version of the model was used to project emissions into the future, emissions increased by almost 100% by calendar year 2030, and estimated modeled ambient air toxics concentrations increased by 6–84%, depending on the pollutant. To address these elevated emissions, EPA recently finalized standards requiring reductions of emissions when engines start at cold temperatures.

Non-dirty dancing? Interactions between eco-labels and consumers

Current studies on eco-labeling have been limited because they either examine the relationship between individual characteristics and eco-behavior or between label characteristics and eco-behavior. We extend this literature by designing and testing a model that explicitly links how the characteristics of the individual and the information simultaneously influence an information program’s success. The specific application studies the potential effects of providing eco-information in the private market for passenger vehicles and light-duty trucks sold in the United States. The results point toward the importance of well-designed labeling practices as they significantly impact individuals’ perceptions of the eco-friendliness of products. Further, the importance of underlying psychological factors; and individuals’ priors of the product and of the environmental problem suggests a strong role for the long-run provision of eco-information, especially in cases where individuals hold incorrect perceptions.

Diesel Aftertreatment Modeling: A Systems Approach to NOx Control

Stringent North American emission regulations present several challenges for lean-burn diesel vehicles that offer significant fuel economy advantages over gasoline vehicles. This article presents a useful systems approach to developing robust models and combining them to analyze diesel aftertreatment (AT) technologies: (1) the diesel oxidation catalyst (DOC) that oxidizes carbon monoxide (CO), unburned hydrocarbons (HCs), and nitric oxide (NO), and stores HCs and (2) the urea-based selective catalytic reduction (SCR) catalyst that hydrolyzes aqueous urea to ammonia (NH3), which, in turn, reduces nitrogen oxides (NOx). The DOC and SCR models integrate information from multiple sourcesdetailed thermal balances, laboratory performance data, phenomenological descriptions of adsorption and desorption in the catalyst, and experience-based correlationsusing optimization and statistical tools. The DOC model predicts cumulative HC and CO tailpipe vehicle emissions as well as DOC NOx outlet composition (NO vs NO2). The SCR model uses the exotherm and NO2 information from the DOC model to predict NOx conversion and NH3 slip. System-level analyses that have resulted in important insights are highlighted using case studies, including (1) extrapolation of the downstream injection exotherm vehicle data for a fresh DOC to an aged DOC; (2) analysis of the effects of NO2 produced in the DOC, SCR aging conditions, and NH3 storage capacity on the NOx reduction performance of the SCR on a 6000-lb light-duty truck, and (3) development of urea injection strategies based on a tradeoff between NOx reduction and NH3 slip.

Light truck vehicles (LTVs) contribution to rear-end collisions

Light truck vehicles (LTVs), comprising light-duty trucks, vans, and sport-utility vehicles (SUVs) drive higher and wider than passenger cars which could affect the visibility for the following passenger car driver. This paper investigates the contribution of LTVs to rear-end collisions resulting from horizontal visibility blockage using the University of Central Florida sophisticated reconfigurable driving simulator. Indeed, a sudden stop of a leading LTV, in the shadow of the blindness of the succeeding passenger car driver, may deprive the latter of a sufficient response time, which may lead to high probability of a rear-end collision. To investigate this issue, two scenarios were developed in the UCF driving simulator. The first scenario serves as a base scenario where the simulator car follows a passenger car, and the second scenario serves as a test scenario, where the simulator car follows an LTV. The results obtained by comparing the scenarios showed that LTVs produce more rear-end collisions at unsignalized intersections due to horizontal visibility blockage and due to the resulting drivers’ behavior when driving behind an LTV.

Current and future US Tier 2 vehicles program and catalytic emission control technologies to meet the future Tier 2 standards

The Tier 2 vehicles program, defining a variety of emission standards, concepts and provisions, of the EPA in the United States has been phased in for all light-duty vehicles (LDVs), light-duty trucks (LDTs) and medium-duty passenger vehicles (MDPVs) from model year 2004, and this program will be continued until 2009, depending on the vehicle categories. Ultimately, not only should manufacturers of LDVs, LDTs and MDPVs and their importers in the United States meet the new Tier 2 standards, but all exporters outside the United States, such as Korean car makers, must also certify their vehicles by using this standard program. The principal rule for successfully applying this program to all the LDVs, LDTs and MDPVs is the use of the same Tier 2 standards if these vehicles are included in the same weight rating category, irrespective of fuel and engine types being used. This review provides an indepth discussion of key issues and provisions related to Tier 2 vehicles with engine measure strategies for automotive engineers and related academic researchers who are particularly interested in investigating how manufacturers will develop, certify, produce, and market their Tier 2 vehicles. A detailed mechanism for the phase-in of the Tier 2 standards to different vehicle weight categories will be discussed in this review, and the major difference between the US Tier 2 standards during the phase-in years and the EURO ones will be substantially compared. Great roles in meeting the future Tier 2 emission standards using numerous commercial and emerging catalytic technologies and their challenges to future Tier 2 vehicle applications will be extensively discussed.

トラック用自動変速機におけるクラッチ機構(<メカライフ特集>創立110周年記念,つなぐ,つける,はめる)

トラック用自動変速機におけるクラッチ機構(<メカライフ特集>創立110周年記念,つなぐ,つける,はめる)

Structural and Fractal Properties of Particles Emitted from Spark Ignition Engines

Size, morphology, and microstructure of particles emitted from one light-duty passenger vehicle (Buick Century; model year 1990; PM (particulate matter) mass emission rate 3.1 mg/km) and two light-duty trucks (Chevrolet C2; model year 1973; PM mass emission rate 282 mg/km, and Chevrolet El Camino; model year 1976; PM mass emission rate 31 mg/km), running California's unified driving cycles (UDC) on a chassis dynamometer, were studied using scanning electron microscopy (SEM). SEM images yielded particle properties including three-dimensional density fractal dimensions, monomer and agglomerate number size distributions, and three different shape descriptors, namely aspect ratio, root form factor, and roundness. The density fractal dimension of the particles was between 1.7 and 1.78, while the number size distribution of the particles placed the majority of the particles in the accumulation mode (0.1-0.3 microm). The shape descriptors were found to decrease with increasing particle size. Partial melting of particles, a rare and previously unreported phenomenon, was observed upon exposure of particles emitted during phase 2 of the UDC to the low accelerating voltage electron beam of the SEM. The rate of melting was quantified for individual particles, establishing a near linear relationship between the melting rate and the organic carbon 1 to elemental carbon ratio.

Combustion system development for the new diesel engines in light and medium commercial vehicles from Ford and PSA

This is the first engine family specifically designed for light and medium commercial vehicles to be produced under the joint Ford Motor Company/PSA Peugeot Citroen Diesel engine co-operation agreement. Although the new engine is based on an existing engine architecture, it introduces a number of technical innovations, raising the bar even higher for engine technology in the commercial vehicle sector. Part of the engine development has focused on optimising the combustion system and was led by the engineers of the Ford Research and Advanced Engineering Centre FFA in Aachen, Germany. The new engines produce engine-out emissions that are well within the stringent limits given by the EU4 Light Duty Truck (LDT) emissions standard for all of the vehicle applications, whilst maintaining good fuel economy.

Spectroscopy Applied to On-Road Mobile Source Emissions

Not to be confused with emission spectroscopy, the detection of mobile source emissions by means of a remote sensing device (RSD) is almost entirely an application of absorption spectroscopy. In this article we discuss the application to measurement of individual vehicle emissions remotely as the vehicle drives by in its normal driving mode. Most studies and commercial implementation have involved automobiles and light duty trucks. However, the same technology has been applied to heavy duty trucks, locomotives, snowmobiles and airplanes in taxi and takeoff modes. The challenge in all these applications is to make precisely collocated absorption measurements at 100 Hz in both the UV and IR regions of the spectrum with low noise. The ability to measure 1/1000 absorbance units is necessary. The only compensating advantage is that an individual vehicle measurement cycle is over in one second or less, such that slow instrument drift becomes unimportant. The results are all measured as a ratio to the measured emission of CO2 and calibrated by means of a certified cylinder with known ratios. Using these ratios, the end result for each vehicle can be expressed as mass emissions per kg or per L of fuel as well as the emissions % which would be measured were the vehicle equipped with a tailpipe probe and emissions measurement system (corrected for any excess air which might be in the exhaust manifold).

Failure analysis of the suspension spring of a light duty truck

In this paper the failure of the rear suspension spring is analyzed in detail. The rear axle suspension system of the truck and fractured flat spring is investigated. Fracture surface, mechanical and chemical properties and microstructure of the spring material is analyzed. Forces acting on the spring is determined and strength calculations are carried out. Later, failure behaviour and cause of fracture is revealed after carefully analysis of microstructure and results of calculations. At the end precautions to be taken to prevent a similar failure is recommended.

3205 ドライバの運転特性を考慮した小型ハイブリッドトラックの燃費ばらつき低減手法 : 駆動トルクの応答性と燃費の解析(OS3-1 人間機械系シミュレーション,OS3 交通・物流システムのダイナミクスと制御,TRANSLOG 2006)

3205 ドライバの運転特性を考慮した小型ハイブリッドトラックの燃費ばらつき低減手法 : 駆動トルクの応答性と燃費の解析(OS3-1 人間機械系シミュレーション,OS3 交通・物流システムのダイナミクスと制御,TRANSLOG 2006)

Neighborhood design and vehicle type choice: Evidence from Northern California

Previous studies have found that suburban development is associated with the unbalanced choice of light duty trucks. The specific aspects of the built environment that influence vehicle choice, however, have not been well-established. Further, these studies have not shed much light on the underlying direction of causality: whether neighborhood designs themselves, as opposed to preferences for neighborhood characteristics or attitudes towards travel, more strongly influence individuals’ decisions regarding vehicle type. Using a sample from Northern California, this study investigated the relationship between neighborhood design and vehicle type choice, controlling for residential self-selection. Correlation analyses showed that neighborhood design has a strong association with vehicle type choice. Specifically, traditional neighborhood designs are correlated with the choice of passenger cars, while suburban designs are associated with the choice of light duty trucks. The nested logit model suggests that sociodemographic and attitudinal factors play an important role, and that an outdoor spaciousness measure (based on perceptions of yard sizes and off-street parking availability) and commute distance also impact vehicle type choice after controlling for those other influences. This study, therefore, supports the premise that land use policies have at least some potential to reduce the choice of light duty trucks, thereby reducing emissions.

Nonparametric factorial analysis of daily weigh-in-motion traffic: implications for the ozone ?weekend effect? in Southern California

Abstract The Ozone Weekend Effect (OWE) has become increasingly more frequent and widespread in southern California since the mid-1970s. Although a number of hypotheses have been suggested to explain the effect, there remains uncertainty associated with the root factors contributing to elevated weekend ozone concentrations. Targeting the time window of the 1997 Southern California Ozone Study (SCOS97), this paper examines traffic activity data for 14 vehicle classes at 27 weigh-in-motion (WIM) stations in southern California. Nonparametric factorial analyses of light-duty vehicle (LDV) and heavy-duty truck (HDT) traffic volumes indicate significant differences in daily volumes by day of week and between the weekly patterns of daily LDV and HDT volumes. Across WIM stations, the daily LDV volume was highest on Friday and decreased by 10% on weekends compared to that on midweek days. In contrast, daily HDT volumes showed dramatic weekend drops of 53% on Saturday and 64% on Sunday. As a result, LDV to HDT ratios increased by 145% on weekends. Nonparametric tests also suggest that weekly traffic patterns varied significantly between WIM stations located close to (central) and far from (peripheral) the Los Angeles Metro area. Weekend increases in LDV/HDT ratios were more pronounced at central WIM sites due to greater weekend declines of HDT relative to LDV traffic. The implications of these weekly traffic patterns for the OWE in southern California were investigated by estimating daily WIM traffic on-road running exhaust emissions of total organic gas (TOG) and oxides of nitrogen (NOx) using EMFAC2002 emission factors. The results support the California Air Resource Board's (CARB's) NOx reduction hypothesis that greater weekend NOx reductions relative to volatile organic compound (VOC) emissions, in combinations with the VOC-limited ozone system, contribute to the OWE observed in the region. The results from this study can be used to develop weekend on-road mobile emission inventories for the purpose of air quality modeling.