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Comparison studies have been conducted on a 1:16th scale model and a full scale tractor trailer of a variety of sealed aft cavity devices as a means to develop or enhance commercial drag reduction technology for class 8 vehicles. Various base cavity geometries with pressure taps were created for the scale model. The studies confirmed that length has an important effect on performance. The interaction of the boat-tailed aft cavity with other drag reduction devices, specifically side skirts, was investigated with results showing no discernable drag performance interaction between them. Overall, the experiments show that a boat-tailed aft cavity can reduce the drag up to 13%. Full-scale tests of a commercially derived product based on these scale tests were also completed using SAE Type II testing procedures. Full-scale tests indicated a fuel savings of over 6.5%.

Currently, all heavy-duty on-road engines in the USA are certified for emissions compliance using the Federal Test Procedure (FTP) heavy-duty transient cycle. The engine in a hybrid drive system, on the other hand, is controlled at a more steady-state level to reduce emissions over conventional drive systems. In this study, Allison Electric Drive seeks a better standardized emissions test cycle to certify (in the near term) engines which will be used in parallel and series hybrid drive systems. Actual revenue service data from a transit hybrid electric vehicle (HEV) was compared to several standard engine test cycles including the US FTP, ISO 8178 (a collection of many steady-state cycles), the Euro III (ESC) 13-mode cycle, and the Japanese 13-mode cycle. Graphical analysis of actual hybrid engine data revealed that the ESC cycle reflects field data better than other cycles, including the US FTP, which has little correlation.

Frequency domain testing has had limited use in the past for durability evaluations of automotive components. Recent advances and new perspectives now make it a viable option. Using frequency domain testing for components, test times can be greatly reduced, resulting in considerable savings of time, money, and resources. Quality can be built into the component, thus making real-time subsystem and full vehicle testing and development more meaningful. Time domain testing historically started with block cycle histogram tests. Improved capabilities of computers, controllers, math procedures, and algorithms have led to real time simulation in the laboratory. Real time simulation is a time domain technique for duplicating real world environments using computer controlled multi-axial load inputs. It contains all phase information as in the recorded proving ground data. However, normal equipment limitations prevent the operation at higher frequencies.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

A correlation study of vehicle exhaust emissions measurements was conducted by the West Virginia University (WVU) Transportable Heavy-Duty Vehicle Emissions Testing Laboratory and the Los Angeles County Metropolitan Transportation Authority (MTA) Emissions Testing Facility. A diesel fueled transit bus was tested by both chassis dynamometer emissions testing laboratories. Exhaust emissions were sampled from the tested vehicle during the operation of the Federal Transit Administration (FTA) Central Business District (CBD) testing cycle. Data of gaseous and particulate matter emissions was obtained at each testing laboratory. The emissions results were compared to evaluate the effects of different equipment, test procedures, and drivers on the measurements of exhaust emissions of heavy-duty vehicles operated on a chassis dynamometer.

A method has been developed which allows prediction of the field performance of structural components based on prototype vehicle test procedures and results. Component designs can then be optimized by selecting prototype durability test objectives which more accurately reflect actual field usage. This procedure, which is based on fatigue damage calculations from component strain histories, has been successfully applied to non-safety related body, frame and suspension structural components of light trucks and vans.

During the past decades the public acceptance of the actual environmental legislation has gradually turned into an active support of the same. Test methods have anyhow become more cost heavy and time consuming, underlining the need of simplified tests with reasonable correlation to the legal methods. Generally, the emissions under static and semistatic load conditions are gradually eliminated, why the heavy pollution now comes from transient periods of the driving pattern. Consequently a transient test procedure must satisfy the quality requirements on a short test applicable to vehicles from cars to heavy trucks and busses. The INertia COLLection system described here is developed to enable low cost and well repeatable measurements of the emission characteristics of engine systems in light and heavy vehicles under transient load. The system is easy to adopt and does not need any chassis dynamometer.

Abstract This article proposes a novel approach of a hybrid system of physics and data-driven modeling for accurately estimating the state of charge (SOC) of a battery. State of Charge (SOC) is a measure of the remaining battery capacity and plays a significant role in various vehicle applications like charger control and driving range predictions. Hence the accuracy of the SOC is a major area of interest in the automotive sector. The method proposed in this work takes the state-of-the-art practice of Kalman filter (KF) and merges it with intelligent capabilities of machine learning using neural networks (NNs). The proposed hybrid system comprises a physics-based battery model and a plurality of NNs eliminating the need for the conventional KF while retaining its features of the predictor-corrector mechanism of the variables to reduce the errors in estimation.

Biofuel can enable a sustainable transport solution and lower greenhouse gas emissions compared to standard fuels. This study focuses on biodiesel, implemented in the easiest way as drop in fuel. When mixing biodiesel into diesel one can run into problems with solubility causing contaminants precipitating out as insolubilities. These insolubilities, also called soft particles, can cause problems such as internal injector deposits and nozzle fouling. One way to overcome the problem of soft particles is by filtration. It is thus of great interest to be able to quantify fuel filters’ ability to intercept soft particles. The aim of this study is to test different fuel filters for heavy-duty engines and their ability to filter out synthetic soft particles. A custom-built fuel filter rig is presented, together with some of its general design requirements. For evaluation of the efficiency of the filters, fuel samples were taken before and after the filters.

Abstract The 2010 Environmental Protection Agency (EPA) Emission Standard for heavy-duty engines required 0.2 g/bhp-hr over certification cycles (cold and hot Federal Test Procedure [FTP]), and the California Air Resources Board (CARB) standards require 0.02 g/bhp-hr for the same cycles leading to a 90% reduction of overall oxides of nitrogen (NOx) emissions. Similar reductions may be considered by the EPA through its Cleaner Trucks Initiative program. In this article, aftertreatment system components consisting of a diesel oxidation catalyst (DOC); a selective catalytic reduction (SCR) catalyst on a diesel particulate filter (DPF), or SCR-F; a second DOC (DOC2); and a SCR along with two urea injectors have been analyzed, which could be part of an aftertreatment system that can achieve the 0.02 g/bhp-hr standard.

Measurement of emissions from small utility engines has usually been accomplished using steady-state raw emissions procedures such as SAE Recommended Practice J1088. While raw exhaust measurements have the advantage of producing modal exhaust gas concentration data for design feedback; they are laborious, may influence both engine performance and the emissions themselves, and have no provision for concurrent particulate measurements. It is time to consider a full-dilution procedure similar in principle to automotive and heavy-duty on-highway emission measurement practice, leading to improvements in many of the areas noted above, and generally to much higher confidence in data obtained. When certification and audit of small engine emissions become a reality, a brief dilute exhaust procedure generating only the necessary data will be a tremendous advantage to both manufacturers and regulatory agencies.

The objective of this paper is to delineate the importance of pictures, i.e., graphical models, in documenting and communicating the high level functionality of a complex system, primarily for embedded software requirements and specifications. An overview is given of various graphical techniques and methodologies for modeling complex systems. The aspects (advantages and disadvantages) relating to different categories of modeling are outlined. Discussion of complex systems extends beyond the functional/software aspects of product design to both process and project modeling. The author shares personal observations and experiences with modeling, and tools used.

In the conventional approval test method of fuel consumption for heavy-duty diesel vehicles currently in use in Japan, the fuel consumption under the transient test cycle is calculated by integrating the instantaneous fuel consumption rate referred from a look-up table of fuel consumptions measured under the steady state conditions of the engine. Therefore, the transient engine performance is not considered in this conventional method. In this study, a highly accurate test method for fuel consumption in which the map-based fuel consumption rate is corrected using the transient characteristics of individual engines was developed. The method and its applicability for a heavy-duty diesel engine that complied with the Japanese 2009 emission regulation were validated.

A system has been developed which fragments rock by high-pressure gas discharges near the point of ripper penetration of a rock formation. From development tests, it was demonstrated that the system markedly extends the rock fracturing performance of a D7 Caterpillar tractor. The paper is divided into three basic sections. First, a summary of the mathematical analyses and model testing of rock fracturing is presented. Next, the hardware design and development necessary to adapt the FARE principle to rock-ripping requirements is described. Finally, the results and evaluations of tests conducted at various limestone rock test sites are described.

This paper describes the methods employed to attain very low vehicle tare weight in the development of a new line of high entry tilt cab highway tractors. Design criteria mandated no sacrifice in durability or reliability, and substantial improvements in driver space, ride, noise level and aerodynamic drag as compared to the old model. The methods used to define and organize the Engineering program are covered as well as the design and test methods employed. Specific examples are provided to illustrate the design, use of computer aided engineering such as finite element analysis and life prediction, as well as the use of accelerated testing procedures. Finally, the production vehicle is compared to the targets and to competition at introduction time where it placed lightest weight in its class.

Effective requirements elicitation and management is a common need in supplier-OEM relationships, and continues to play a vital role in all aspects of the product development lifecycle. While traditional methods address the business goals for requirements and provide guidance in ensuring the accuracy of the “Descriptive-Prescriptive-Explanatory” outputs for requirements gathering and documentation, engineering organizations continue to encounter challenges with respect to capturing and communicating change, accommodating the addition of relevant design details and efficient propagation to inform development. These challenges become more difficult to overcome in mechatronic systems, which combine mechanical systems with integrated software. As software development can produce an overwhelming volume of information that requires accurate tracking and proliferation, it cannot be effectively managed using traditional hardware-centric systems.

A new facility for the measurement of the compliance, kinematic and coulomb friction properties of heavy vehicle suspensions is described. The facility may test single or tandem and front or rear suspensions. Test procedures for measurement of vertical and roll rates, kinematic and compliant steer effects are presented. Qualitative findings are discussed and example data is appended.

The resistance of passenger cars to corrosion is tested in a three-chamber system, in which the cars are subjected to extreme climatic conditions. A hydropulse installation, a roller dynamometer, blower fans and a ‘gravel gun’ firing stone chippings are used to simulate actual road use. During a 14-week test period, it is possible to obtain corrosion equivalent to that which would have occurred in 6 years of driving in a very corrosive environment.

Standardized driving cycles, such as the New European Driving Cycle (NEDC) in Europe or the Federal Test Procedure 75 (FTP-75) in the U.S. are an important tool to certify new vehicle models. They are used to estimate real world fuel consumption as well as real world emissions. The latter has recently become more important with the stronger focus on green driving, resulting in much stricter emission regulations, while fuel consumption still remains one of the most important aspects in terms of economy and long term costs for the vehicle owner. However these cycles do not reflect the actual behaviour of the driver or regional influences (i.e. topography). Therefore, manufacturers have developed their own usage and test cycles and are able to extract data from the vehicle to analyse the individual driving behaviour and vehicle usage. Apart from that, Naturalistic Driving Observation (NDO) is interested in understanding the driver.

The U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) and the U.S. Army Corps of Engineers (USACE) are improving modeling and simulation technologies in order to predict the performance of Army ground platforms with a high degree of confidence. In order to provide a framework within which to evaluate the simulation technologies and provide a measure of the progress of the effort, a suite of virtual test operating procedures are being implemented. This framework is called the Virtual Evaluation Suite (VES). It is applicable to the study of ground vehicle stability, handling, ride, mobility, and durability over all terrains under all weather conditions. Although developed in order to evaluate simulation technologies, the VES may be considered a simulation that could be used to exercise any ground platform model that meets the VES standard vehicle interface.