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Technical Paper

Transmission Oil Degradation Warning Systems and Computing in Agricultural Tractors

2000-06-19
2000-01-1873
This communication examines three strategies of predictive lubricant monitoring and replacement, used for farm tractors or similar vehicles. These strategies optimise the draining periodicity. They are the off-line follow-up, the sensors follow-up and the analytical model follow-up. The implementation of the suggested analytical model will be discussed, on the basis of field collected data (on a series of tractors, either customer's or on loan). Regular oil samples, and significant ones carried out at the end of the study, were taken and analysed in order to predict the evolution of the lubricant characteristics. Extensions to the experimental study were carried out at the end of this work. They are discussed in the paper (FZG gear scuffing, 4 ball wear and EP…).
Technical Paper

Review of Parameters Affecting Stability of Partially Filled Heavy-Duty Tankers

1999-11-15
1999-01-3709
Partially filled tanker trucks are susceptible to rollover instabilities due to fluid sloshing. Due to the catastrophic nature of accidents involving the rollover of tanker trucks, several investigations have been conducted on the parameters affecting stability of partially filled heavy-duty tankers. Since stability of heavy-duty tankers undergoing on-road maneuvers such as braking, and/or lane changing has been an issue that concerned many researchers for a long time, a literature review has been conducted which underlines the most important contributions in this field. This review covers work done in the field of fluid-structure interaction, yaw and roll stability of heavy-vehicles, and fluid-vehicle dynamic interaction. In addition, vehicle stability issues are addressed such as jack-knifing, side slipping, vehicle geometry and container geometry among others.
Technical Paper

A Multibody Approach with Graphical User Interface for Simulating Truck Dynamics

1999-11-15
1999-01-3705
The use of computer simulation of vehicle dynamics as a development tool has come into its own over the past few decades. “Simulated” testing on a computer makes possible a degree of control and repeatability that allows the automotive engineer to determine the influence of design variables on different aspects of dynamic performance in ways that would be difficult or impossible by experimental methods. One of the software tools receiving wide acceptance for simulating trucks and combination vehicles is Truck-Sim™. The attraction of this program arises in part from its foundation of truck modeling methods developed at the University of Michigan Transportation Research Institute over the past two decades, and the use of an advanced graphical user interface to make the software both easy to understand and easy to use by design and development engineers.
Technical Paper

TruCharge™ An Advanced System for Supporting Vehicle Batteries and Eliminating Unscheduled Battery Maintenance

1999-11-15
1999-01-3748
There has been minimal innovation in the area of battery test and diagnostic support over the past 20 years. Battery testing has been limited to measurement of terminal voltage, electrolyte specific gravity measurements and load testing. This paper describes an innovative and newly developed battery analyzer/charger unit. The AlliedSignal TruCharge unit is capable of providing accurate state-of-charge (SOC), capacity as well as providing battery defect data via an automated test sequence that takes less than 20 seconds. It charges the battery quickly while minimizing the generation of hazardous hydrogen gas. The underlying technology is described along with the performance features and specifications of the unit. The unit is also capable of recovering sulfated lead acid batteries. The economic and environmental benefits of battery recovery are discussed. This unit is developed based upon extensive market analysis.
Technical Paper

High-Level In-Vehicle Decision Support

1999-11-15
1999-01-3752
This paper documents the current realities of in-vehicle navigation systems in terms of their functionality, scope and responsiveness. It discusses the evolution of these systems with the advent of wireless communications. Addressed are the issues associated with delivery and utilization of real-time traffic, incident, and weather information to and by in-vehicle navigation systems. Also discussed are other High-level in-vehicle decisions that can be supported by the marriage of wireless communications with in-vehicle navigation. Applications considered range from the choosing of alternate waypoints and destinations (where to get gas, where to park), to the host of nRouteCommerce transactions that can be more efficiently achieved with the support of in-vehicle navigation (reserving a parking space, resetting household thermostats as you approach home). Implications on driver workload, in-vehicle processing, wireless bandwidth and Internet traffic are discussed.
Technical Paper

Optimal Tank Geometry to Enhance Static Roll Stability of Partially Filled Tank Vehicles

1999-11-15
1999-01-3730
A generic tank cross-section is formulated to describe the geometry of currently used tanks in transportation of fuel oils and bulk liquids, and to explore optimal tank geometry for enhancement of roll stability limit of tank vehicle combinations. The tank periphery, composed of 8 circular arcs symmetric about the vertical axis, allows more design flexibility in view of the roll stability limits than the conventional tank shapes. A shape optimization problem is formulated to minimize the overturning moment imposed on the vehicle due to c.g. height of the liquid load, and the lateral and vertical movement of the liquid bulk within the partly filled tank. Different optimal tank cross-sections are proposed corresponding to varying fill conditions, while the total cross-sectional area, overall height and overall width are constrained to specified values.
Technical Paper

Design of a Multilink Independent Front Suspension for Class A Motor Homes

1999-11-15
1999-01-3731
Motorized recreational vehicles with front axle load ratings that exceed 4,086 kilograms, or 9,000 pounds, are traditionally equipped with rigid I-beam type axles. These axles are used in this application because of their ability to carry high axle loads at a reasonable cost, and their durability history in truck usage. Recently, several manufacturers have used independent type front suspension designs. A multi-link type suspension offers some unique solutions in optimizing the front suspension design. This paper describes the performance goals (i.e. Suspension Design Factors) and tradeoffs in pursuit of the final design. Establishing these SDF’s, achieving them and their relationship to vehicle performance are the focus of this paper. Plots of the kinematic and elastic characteristics are included to illustrate some of the unique features of this multi-link suspension.
Technical Paper

Environmental Standards for Biodegradable Hydraulic Fluids and Correlation of Laboratory and Field Performance

2000-09-11
2000-01-2543
Biodegradable hydraulic fluids have been introduced relatively recently and, initially, acceptable environmental performance and technical performance were neither well specified or controlled. Over the past few years, many standards and specifications have been written, especially in the area of biodegradability and ecotoxicity. Technical performance test requirements are emerging more slowly, however, and there is still some doubt over appropriate tests and limits for some performance areas. The proliferation of standards is confusing to both the product developer and fluid user. This paper summarizes the common biodegradability and ecotoxicity elements in the main environmental performance standards. It also discusses appropriate laboratory performance tests for oxidation stability, hydrolytic stability and wear, and sets acceptable limits in these tests, based on correlation of lab and field performance of two synthetic ester based hydraulic fluids.
Technical Paper

A Picture is Worth a Thousand Lines of Code

2000-09-11
2000-01-2571
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.
Technical Paper

Anhydrous Polyalkylene Glycol Hydraulic Fluids

2000-09-11
2000-01-2557
There is an ongoing interest in identifying new biodegradable hydraulic fluid compositions that may be used as alternatives to mineral oil in many hydraulic applications such as mobile off-highway equipment. To date, many basestocks have been proposed including: vegetable oils, polyol esters, diesters, synthetic hydrocarbons and others. One basestock is gaining interest as alternative, biodegradable, fire-resistant hydraulic fluid; anhydrous poly(alkylene glycol) (PAG) fluids. However, the use of these fluids is not new; they are simply being rediscovered. The objective of this paper is to provide an overview of the discovery and development of anhydrous PAGs as hydraulic fluids. This discussion will include: an overview of PAG chemistry, properties and hydraulic pump performance.
Technical Paper

Estimating the Expected Effectiveness of Enhanced Ground Proximity Warning Systems in Reducing Controlled Flight Into Terrain by Aircraft Operating under Part-135

2000-04-11
2000-01-2105
In order to reduce “Controlled Flight Into Terrain” (CFIT) accidents the FAA proposed, in 1998, the regulation that Enhanced Ground Proximity Warning Systems (EGPWS) should be installed in all turbine powered aircraft with 6 or more seats for passengers, operating under Federal Aviation Regulation Part-135 (commuter and charter operations). We analyzed all Part-135 crashes of this type using NTSB aviation accident data from 1983 to 1998. There were 15 crashes involving CFIT. We asked 26 experienced pilots to examine the brief narratives of the crashes and to estimate the probability that had the aircraft been equipped with EGPWS, the crews would have avoided the crashes. Based on the ratings, the median probability that Part 135 crashes would be avoided using EGPWS was 59%. We describe the nature of the crashes, the human factors involved and the reasons why the enhanced terrain warning is only partly effective.
Technical Paper

Emission Control Research to Enable Fuel Efficiency: Department of Energy Heavy Vehicle Technologies

2000-06-19
2000-01-2198
The Office of Heavy Vehicle Technologies supports research to enable high-efficiency diesel engines to meet future emissions regulations, thus clearing the way for their use in light trucks as well as continuing as the most efficient powerplant for freight-haulers. Compliance with Tier 2 rules and expected heavy duty engine standards will require effective exhaust emission controls (aftertreatment) for diesels in these applications. DOE laboratories are working with industry to improve emission control technologies in projects ranging from application of new diagnostics for elucidating key mechanisms, to development and tests of prototype devices. This paper provides an overview of these R&D efforts, with examples of key findings and developments.
Technical Paper

TRAFFIC SAFETY OF HEAVY VEHICLES, (ACCIDENT ANALYSIS, ACCIDENT RECONSTRUCTION)

2001-06-04
2001-06-0244
This paper provides an overview of safety situations of commercial vehicles on the basis of databank concerning more than 4500 accidents. Different safety points of view are analysed and evaluated. A special accident reconstruction program (CARAT) is interpreted which is able to solve the traffic and accident questions in practical approach. It summarises conclusions and proposals on road safety of heavy vehicles in Europe.
Technical Paper

THE ANALYSIS OF DUTCH NATIONAL DATA ON HEAVY TRUCK ACCIDENTS: THE NECESSARY EXTENSION OF TRADITIONAL FREQUENCY COUNTS WITH LOGISTIC REGRESSION ANALYSIS

2001-06-04
2001-06-0014
For the 1993–1997 Dutch national accident data, logistic regression analysis was used to find the most important factors, that influenced the outcome of an accident with a truck involved. Frequency counts were used to identify factors that occurred most frequently. The combination of these two methods led to the most important factors influencing the number and severity of truck accidents. An important extension with respect to only frequency counts is that significance levels were taken into account to check whether differences are really distinguishable. It was concluded that the combination of frequency counts and logistic regression is a necessary extension to prevent the presentation of artefacts when basing conclusions solely on frequency counts and to find factors with high risk. Furthermore, it was found that national statistics are not detailed enough to find the real underlying causes and can therefore hardly be used to find points for improvement on vehicle and road design.
Technical Paper

Natural Gas as a Future Fuel for Heavy-Duty Vehicles

2001-05-14
2001-01-2067
In addition to their significant environmental impacts, medium-duty and heavy-duty (HD) vehicles are high volume fuel users. Development of such vehicles, which include transit buses, refuse trucks, and HD Class 6-8 trucks, that are fueled with natural gas is strategic to market introduction of natural gas vehicles (NGV). Over the past five years the Department of Energy's (DOE) Office of Heavy Vehicle Technologies (OHVT) has funded technological developments in NGV systems to support the growth of this sector in the highly competitive transportation market. The goals are to minimize emissions associated with NGV use, to improve on the economies of scale, and to continue supporting the testing and safety assessments of all new systems. This paper provides an overview of the status of major projects under a program supported by DOE/OHVT and managed by Brookhaven National Laboratory.
Technical Paper

Examination of Car to Light Truck Compatibility in Frontal Crashes

2001-03-05
2001-01-1165
In the United States, the National Highway Traffic Safety Administration (NHTSA) routinely measures the force exerted on the rigid barrier in frontal crash tests. Thirty-six load cells on the barrier face measure the distribution of the crash forces. This study examined the load cell barrier data collected during recent years to assess the geometric distribution of the crash forces and the variation in stiffness across the vehicle width. The location of the Center of Force was proposed as a metric for quantitatively describing the geometric properties of the crash forces. The Center of Force location was calculated for each column of load cells. Variations in the Center of Force location across the width of the barrier were examined for typical vehicles. This study applies the aggressiveness metric to a frontal crash from NASS/CDS 1997 in which a passenger car collided with a light truck.
Technical Paper

Basic Considerations for the Concepts of Wheeled off-Road Vehicles

2000-06-12
2000-05-0387
The demand for greater mobility on unprepared terrain in all seasons by agriculture, construction, and the military has stimulated interest in the study of off-road vehicles. Thus the use of automobiles for cross-country movements and the potential for building more efficient automobiles and vehicles with high off-road mobility has also increased significantly. The engineers and designers of off-road vehicles face a lack of generally recognized theories. Usually, the concept of terrain vehicles are developed very empirically and are based on principles of mechanics and land locomotion. The author presents a general overview on models and considerations for wheeled off-road vehicle concepts. First vehicle and soil are defined, then the interaction between these two elements is discussed. Based on these models, methods to predict and measure traction of off-road vehicles are evaluated. The relevant elements of off-road vehicles and their influence on mobility are presented.
Technical Paper

Diffusion-Flame / Wall Interactions in a Heavy-Duty DI Diesel Engine

2001-03-05
2001-01-1295
Over the past decade, laser diagnostics have improved our understanding of many aspects of diesel combustion. However, interactions between the combusting fuel jet and the piston-bowl wall are not well understood. In heavy-duty diesel engines, with typical fuels, these interactions occur with the combusting vapor-phase region of the jet, which consists of a central region containing soot and other products of rich-premixed combustion, surrounded by a diffusion flame. Since previous work has shown that the OH radical is a good marker of the diffusion flame, planar laser-induced fluorescence (PLIF) imaging of OH was applied to an investigation of the diffusion flame during wall interaction. In addition, simultaneous OH PLIF and planar laser-induced incandescence (PLII) soot imaging was applied to investigate the likelihood for soot deposition on the bowl wall.
Technical Paper

Evaluation of the effect of air bags in multi-year light truck NCAP tests

2001-06-04
2001-06-0095
The New Car Assessment Program (NCAP) has evaluated the crashworthiness of numerous vehicles since 1979. Each year selected models were frontally crashed at 35 mph into a fixed barrier. Due to increased interest by the public in vehicle safety as part of their car-buying decisions, NHTSA has recently undertaken an expanded program of consumer information on vehicle safety issues. As part of this program, an analysis was performed to determine the effectiveness of light-truck driver air bags to reduce the risk of severe injury as measured by the head and chest injury responses of selected NCAP tests. The light trucks tested most frequently were analyzed to obtain reliable estimates of air bag effectiveness. The vehicles were tested with all the restraints available on that model, which in the case of the early years were safety belts, and in the latter years were a combination of safety belts and air bags.
Technical Paper

Front underrun protection systems for trucks. Considerations about the bullet and target vehicles for a test procedure

2001-06-04
2001-06-0108
The present paper describes the activities of the INSIA (University Institute for Automobile Research) for the definition of the test procedure for the validation of a Front Underrun Protection System for trucks. After a review of the activities of the EEVC Working Group 14 in this field, the possible configurations of the test are discussed. This includes a proposal for the definition of the target and bullet vehicles to be used in dynamic tests, and a first approximation to the type of parameters to be measured.
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