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Technical Paper

100% LPG Long Haul Truck Conversion - Economy and Environmental Benefits

2012-09-24
2012-01-1983
Advanced Vehicle Technologies (AVT), a Ballarat Australia based company, has developed the World's first diesel to 100% LPG conversion for heavy haul trucks. There is no diesel required or utilized on the trucks. The engine is converted with minimal changes into a spark ignition engine with equivalent power and torque of the diesel. The patented technology is now deployed in 2 Mercedes Actros trucks. The power output in engine dynamometer testing exceeds that of the diesel (in excess of 370 kW power and 2700 Nm torque). In on-road application the power curve is matched to the diesel specifications to avoid potential downstream power-train stress. Testing at the Department of Transport Energy & Infrastructure, Regency Park, SA have shown the Euro 3 truck converted to LPG is between Euro 4 and Euro 5 NOx levels, CO2 levels 10% better than diesel on DT80 test and about even with diesel on CUEDC tests.
Technical Paper

16-Channel Portable Data Acquisition and Reduction System

1984-04-01
840764
A Microprocessor Data Acquisition System has been designed to be cab-mounted in vehicles or used in laboratories to acquire up to 16 channels of test data. This data may be acquired as time-at-level histograms in one or two dimensions with min-max-mean data recovery, time histories, or peaks and valleys stored on digital tape. The system includes a microcomputer-based Playback/Support Box that simplifies playback of data tapes for computer analysis or stand-alone data plotting using a graphics terminal.
Book

2018 Ultimate GD&T Pocket Guide 2nd Ed

2020-11-23
The 2018 Ultimate GD&T Pocket Guide explains the most common rules, symbols, and concepts used in geometric dimensioning and tolerancing. This one-of-a-kind reference guide includes more than 100 detailed examples to illustrate concepts. Numerous charts for quick reference provide explanations of each GD&T symbol, modifier, and more. This valuable on-the-job resource clarifies how to interpret standard-compliant technical drawings that use ASME Y14.5-2018.
Technical Paper

4994 Tractor Hydraulic System

1984-09-01
841100
J I Case Company has produced four-wheel-drive agricultural tractors since 1964. In 1984 however, the flagship of the Case fleet changed hands. Rising labor costs and larger farming operations spearheaded the need for a more efficient larger tractor. January 1984 marked the introduction of the largest four-wheel-drive tractor in the history of Case, the 4994, a 400-gross engine horsepower tractor, Figure 1. Sheer horsepower alone however, would not meet the requirements of today's farming operations. Case Engineering realized that tomorrows tractors must have sufficient power to handle the wide variety of attachments available. They also realized that along with the unmatched power must come precise control of the attachment. These advancements in farming have required improvements to the tractor hydraulic system. This paper describes the hydraulic system of the 4994, Case's new flagship.
Journal Article

5.9 GHz DSRC Standards Overview and Status

2008-10-07
2008-01-2651
Over the past several years the Institute of Electrical and Electronic Engineers (IEEE) Standards Association has developed standards for the 5.9 GHz Dedicated Short Range Communications protocols, also known as Wireless Access in Vehicular Environments. These standards consist of IEEE 1609 as well as an amendment to the IEEE 802.11 standard or 802.11p. The 1609 standards were published for Trial Use and these as well as the 802.11p draft have been implemented in a variety of test beds to provide lessons learned and feedback into the standards working groups. Based on ongoing testing, the protocols display a strong capability to address the requirements of crash avoidance and transportation mobility applications. The corresponding test results provide information necessary to update the standards after the first trial phase as industry moves toward commercial implementations.
Technical Paper

50 Years of Agricultural Tractor Development

1966-02-01
660584
The story of Power Farming is the great saga of our times. It is a story of free enterprise, perseverance and endurance of the individual, of vision, idealism and cooperation among men, of the lightening of human toil and the release of millions of workers from farms to feed the ever hungry industrial revolution. By no means least, it is the story of producing food necessary to win two global wars, keep our allies alive and millions of the defeated enemy from starvation. FOREWARD By 1915, the Steam Traction Engine had attained its highest development. It was the forerunner, rather than the predecessor, of the farm tractor. The former was the instrument of expansion; the latter, the instrument of progress. The invention of the tractor, following by only sixteen years Otto's practical embodiment application of the Beau de Rochas power cycle to a heat engine, marked the advent of a new order - - the age of Power Farming.
Technical Paper

A Cartridge Type Pivotal Pin and Bushing Joint

1982-02-01
820636
A cartridge type pivotal pin and bushing joint has been patented and is being tested and refined both in the laboratory and on construction machinery. It features “dry lubricated” (Teflon) bearings which are assembled and sealed prior to installation. It is suitable for heavy unit loads and use under severe wear conditions, such as in crawler track chains and loader bucket pivotal pin joints. A brief history of U. S. manufactured track pin joints is included to show the progress in extending the service life of these devices.
Technical Paper

A Comparative Analysis of WHR System in HD Engines Using Conventional Diesel Combustion and Partially-Premixed Combustion

2012-09-24
2012-01-1930
In the truck industry there is a continuous demand to increase the efficiency and to decrease the emissions. To acknowledge both these issues a waste heat recovery system (WHR) is combined with a partially premixed combustion (PPC) engine to deliver an efficient engine system. Over the past decades numerous attempts to increase the thermal efficiency of the diesel engine has been made. One such attempt is the PPC concept that has demonstrated potential for substantially increased thermal efficiency combined with much reduced emission levels. So far most work on increasing engine efficiency has been focused on improving the thermal efficiency of the engine while WHR, which has an excellent potential for another 1-5 % fuel consumption reduction, has not been researched that much yet. In this paper a WHR system using a Rankine cycle has been developed in a modeling environment using IPSEpro.
Technical Paper

A Comparison Between Micromachined Piezoresistive and Capacitive Pressure Sensors

1997-11-17
973241
Hundreds of millions of micromachined, piezoresistive Manifold Absolute Pressure (MAP) sensors have been produced to reduce pollution and improve fuel efficiency in engine control systems. Other vehicle applications for micromachined pressure sensors include monitoring turbo pressure, barometric pressure, fuel tank leakage, fuel rail pressure and tire pressure. Exhaust gas recirculation and even door compression for side impact detection are employing micromachined silicon pressure sensors. Piezoresistive pressure sensors have dominated the automotive market to date. Practical micromachined capacitive pressure sensors have recently been developed and could replace the piezoresistive sensor in many applications. This paper will examine the advantages of both pressure sensing technologies, and discuss applications that an inexpensive capacitive pressure sensor will open up.
Technical Paper

A Comparison Of The Dynamic Performance Of A U.S. And A European Heavy Vehicle

1988-09-01
885111
Despite the general similarity of U.S. and European heavy trucks, there are differences in design properties that affect braking and turning performance. A European tractor-semitrailer was studied for the purpose of comparing its properties to those of U.S. vehicles and assessing the comparative performance. Mass, suspension, and braking system properties of the European tractor and semitrailer were measured in the laboratory and on the proving ground. Turning and braking performance qualities were evaluated by computer simulation and by experimental tests. In turning performance the European combination had a 9 percent advantage in rollover threshold, compared to a generic U.S. vehicle with properties that were in the midrange of U.S. design practice. Higher suspension roll stiffness and higher chassis weight on the European tractor and semitrailer accounted for the higher threshold.
Technical Paper

A Comparison of Controller Designs for an Active, Electromagnetic, Offroad Vehicle Suspension System Traveling at High Speed

1998-02-23
980924
This paper discusses controller development for an active, off-road vehicle suspension system. A brief review of electronic filters and their characteristics is used to provide insight on the difficulties of designing a control algorithm for negotiating hilly and rough terrain at higher speeds. Two controller designs are presented. One was designed by pole placement and causes the suspension response to approximate a Type 1 Chebychev filter. The other was designed using constrained optimization. A comparison and discussion of simulation results leads to the conclusion that the suspension should be adaptively or predictively controlled for arbitrary terrain and velocity conditions.
Technical Paper

A Comparison of Crash Patterns in Heavy Trucks with and Without Collision Warning System Technology

2004-10-26
2004-01-2651
Collision warning systems (CWS) are a relatively new technology to reduce or mitigate motor vehicle rear-end and side impact collisions. This study compared available police-reported crash experiences of 6,143 CWS-equipped heavy trucks with the experiences of 383,058 heavy trucks without CWS. Data were from the Motor Carrier Management Information System (2000-2002). Results suggest that CWS-equipped trucks had a significantly lower proportion of crashes involving other moving vehicles and a significantly lower proportion of multiple vehicle crashes compared to trucks without CWS, (40% vs. 49%, p<0.0001; 62% vs. 67%, p<0.004 respectively). These changes are the first crash-data based evidence that supports the design effect of CWS. However, more studies are needed to determine the specific impacts of CWS on heavy truck crashes.
Technical Paper

A Comparison of Results Obtained With Different Analytical Techniques for Reconstruction of Highway Accidents

1975-02-01
750893
For several staged collisions, results obtained with closed form reconstruction calculations and with a computerized step-by-step procedure are compared with measured responses. A refined, closed-form reconstruction procedure is defined, derivations of the analytical relationships are outlined and detailed results of sample applications are presented. Closed form calculation procedures for estimating impact conditions became a topic of interest in relation to the development of an automatic starting routine for iterative applications of the Simulation Model of Automobile Collisions (SMAC) computer program. The accuracy of initial estimates of speeds determines the total number of iterative adjustments of SMAC that are required to achieve an acceptable overall match of the evidence. Since a high degree of success was achieved in the refinement of such calculation procedures, the end product, by itself, is considered to be a valuable aid to accident investigations.
Technical Paper

A Computer Graphics Interface Specification for Studying Humans, Vehicles and Their Environment

1993-03-01
930903
This paper describes a general purpose computer graphics interface for performing detailed two- and three-dimensional studies involving the dynamic response of humans and vehicles during the pre-crash, crash and post-crash phases of a motor vehicle accident. Specifications are provided for human, vehicle and environment models which can be constructed and analyzed using the interface. The requirements of analysis methods which may be incorporated into the interface are examined, and several examples are provided. Finally, the paper illustrates how the interface is used for creating high-level animations to view the resulting human and/or vehicle motion on various output devices such as computer displays, printers, plotters and video tape recorders.
Technical Paper

A Computer-Based Study of the Yaw/Roll Stability of Heavy Trucks Characterized by High Centers of Gravity

1982-02-01
821260
A class of heavy truck vehicles, characterized primarily by high centers of gravity, was studied using analysis and computer simulation to identify and understand the relationship between directional and roll stability of such vehicles during steady turning maneuvers. Findings of the computer-based study suggest: (1) directional instability (yaw divergence) is possible for such vehicles during steady turning while operating at elevated speeds on horizontal road surfaces, (2) yaw divergence will lead to rollover in the absence of corrective steering action and/or reduced speed, and (3) the primary mechanism responsible for precipitating yaw divergent behavior in such vehicles is the nonlinear sensitivity of truck tire cornering stiffness to vertical load acting in combination with typical heavy truck fore/aft roll stiffness distributions. In addition, the influences of roadway superelevation and driver steering control as contributors to vehicle stabilization are examined and discussed.
Technical Paper

A Decision Network Framework for Vehicle Systems Engineering

2005-11-01
2005-01-3623
A Decision Network is an explicit model of the Thinking Breakdown Structure of any complex scientific, engineering, or societal challenge. Each node in the Decision Network represents a fundamental question that must be answered, i.e. a choice that demands a solution. A Decision Network provides an integrated Decision Management framework for any Systems Engineering effort that links business, technology and design choices. Effective Decision Management is the key to Systems Engineering success. This paper will provide an overview of a decision-centric approach to Systems Engineering built around Decision Networks. Lessons learned through the use of Decision Networks in other industries will be extrapolated for use in vehicle Systems Engineering.
Standard

A Dictionary of Terms for the Dynamics and Handling of Single Track Vehicles (Motorcycles, Mopeds, and Bicycles)

2000-01-13
HISTORICAL
J1451_200001
This dictionary of terms was prepared for use by those with a need to describe and understand the dynamics and handling of two-wheeled, single track vehicles. It is intended to span the gap between vehicle dynamics specialists and those with a more general interest. This report is pertinent to such areas as vehicle design and development, the description of two-wheeler properties, rider training and education, and the preparation of standards and regulations. This report was prepared by the SAE Motorcycle Committee, which solicits suggestions for improvements and additions to be considered in future revisions. Comments should be directed to SAE Headquarters.
Technical Paper

A Field Evaluation of the S-1 Pedestrian Guard: Transit and Shuttle Bus Applications

1998-11-16
982775
The need to reduce the injury to pedestrians that are run over or pinned beneath a bus is an ongoing concern for transit authorities and other operators. Occasionally, a pedestrian will be run over by the right rear wheel while exiting the rear door. This accident occurs in various scenarios such as when people exit the bus and become entangled in the door grab bars, or when they fall between the curb and the bus while it approaches or departs. With all scenarios, the S-1 Gard acts similar to a cow catcher, pushing the fallen pedestrian out and away from the rear tire. This paper will: outline various incident scenarios, evaluate the S-1 Gard's performance in a city environment, review installation of the guard as well as its maintenance requirements. The purpose of this paper is to bring to the attention of transit authorities and shuttle operators the overall value of this device.
Technical Paper

A Fuzzy System to Determine the Vehicle Yaw Angle

2004-03-08
2004-01-1191
The reproduction of the vehicle motion is a crucial element of accident reconstruction. Apart from the position of the center of gravity in an inertial coordinate system, the vehicle heading plays an important role. The heading is the sum of the yaw angle and the vehicle body side slip angle. In standard vehicles, the yaw angle can be determined using the yaw rate sensor and the wheel speeds. However, the yaw rate sensor is often subject to temperature drift. The wheel speed signals are forged at low speeds or due to slip. These errors result in significant deviations of reconstructed and real vehicle heading. Therefore, an intelligent combination of these signals is required. This paper describes a fuzzy system which is capable to increase the accuracy of yaw angle calculation by means of fuzzy logic. Before the data is applied to the fuzzy system, it is preprocessed to ensure the accuracy of the fuzzy system inputs.
Technical Paper

A Game Model of Lane Changing for Bus Exiting in a Connected Environment

2020-12-30
2020-01-5153
The research on connected vehicles has attracted much interest of governments and research institutions in these days. As researchers who have been deeply intrigued, we are particularly interested in investigating the lane changing issues of connected buses when exiting bus stops. In order to examine the utilities of both the buses and social vehicles in a connected environment, we employ the game theory to analyze the interactions between them. A two-player, non-cooperative, non-zero-sum game model was built in this paper. We analyzed 5 different scenarios for bus exiting at bus bay stops and curbside bus stops. The payoffs considered in the game model were mainly from the perspective of safety and time. Besides the commonly studied safety issues caused by collisions, we supplement the existing literature by adding on non-collision injuries caused by improper driving behaviors (e.g. excessive acceleration).
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