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Viewing 1 to 30 of 784
2000-12-04
Technical Paper
2000-01-3460
Murat Okcuoglu
Trucks and sport utility class vehicles are established as choice of daily transportation in the US. A new breed of vehicles, commonly referred as “crossover vehicles”, based on passenger car derived platforms, are rapidly filling in the ranks between trucks and automobiles. Most of these vehicles are equipped with relatively sophisticated all wheel drive systems. This sophistication is necessary to fulfill the target mission of these vehicles, to provide an automatic and effortless all wheel drive capability while retaining refined on road comfort. Building on some of the existing systems and sensors, and integrating with other vehicle systems such as ABS, traction control and stability control systems, it is possible to enhance handling response by creating a moment along yaw axis. Pitch and roll movements can also be indirectly influenced. Further possibilities and enhancements will be feasible when drive by wire systems and active suspensions will become available.
2000-12-04
Technical Paper
2000-01-3464
Badih Jawad, Nabil Hachem, Sasa Cizmic, Janette Leese, William Bowerman
Traction control is an electronic means of reducing the wheel spin caused by the application of excessive power for the valuable grip. Wheel spin can result in loss control of the car, reduce acceleration and cause tire wear. In the front wheel tire the loss grip is experienced as underwater, where the front of the car ‘pushes’ forward, not turning as much as the driver has exposed by turning the tearing. In the rear wheels slip causing oversteer, where the rear of the car swings around, turning much sharper than the driver anticipated. The result of all these problems is that the driver starts loosing control of the vehicle, which is undesirable. With the new design of the Traction Control System, the amount of the wheel slippage is precisely controlled. In racing, this means corner can be taken constantly quicker, with system applying the maximum power possible while the driver remains in total control.
2000-12-04
Technical Paper
2000-01-3465
Ramanand R. Shetty, Lee B. Arnold, Alf Eriksen
The Gerodisc hydro-mechanical limited-slip differential has been successfully developed for a racing car application. This racing application requires that the differential's design be both torque and slip sensitive. This paper discusses the operation principle and general construction of the racing differential as well as the development of the limited-slip differential from the design phase to production. The limited-slip differential (LSD) operates within an existing 8.8″ axle housing. The LSD was designed to meet the high torque requirements of the application without sacrificing either durability or high speed tuning by using high thermal resistant friction material and a bimetal valve which thermally compensates for temperature variation.
2000-12-04
Technical Paper
2000-01-3467
Scott Kuan, Dean House, Tomaz Varela, Shan Shih
In recent years, several transit agencies have tested buses equipped with hybrid powertrain systems. It has been reported that hybrid powertrains have significant advantages over conventional diesel engine systems, in the area of emissions and fuel economy performance. Presented in this paper are engineering issues and suggestions from an auto component supplier point of view in the design of such a powertrain system. The particular system being considered consists of a downsized diesel engine, a generator, a battery package, two identical AC induction motors, and gearbox systems for the left and right driven wheels. The assembly is supported by an H-shaped suspension sub-structure uniquely designed to achieve the “ultra-low floor” configuration. Our discussion covers the system performance, as well as the durability issues. In particular, the presentation focuses on the durability and the design layout of the gearbox and suspension substructure.
2000-12-04
Technical Paper
2000-01-3469
Edward Bass, Joseph Johnson, Pat Wildemann
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.
2000-12-04
Technical Paper
2000-01-3470
William R. Cawthorne, Fereydoon Jamzadeh, Frank Sah
As regulations continue to require low and ultra-low vehicle emissions, Hybrid Electric Vehicles (HEV) are becoming an increasingly popular and attractive alternative to conventionally powered vehicles in the light, medium and heavy-duty markets. Computer modeling and simulations are used to develop HEV control algorithms and to investigate various system configurations. The use of simulations significantly reduces development time and expense. Additionally, the HEV designer is afforded a level of freedom to experiment with various algorithms and configurations without the expense of building prototypes for each new idea. This paper examines the modeling and simulation efforts currently being applied to hybrid electric vehicle development at Allison Transmission.
2000-12-04
Technical Paper
2000-01-3480
Darris L. White
A large percentage of on-highway tractors today have air suspensions. Air suspensions require some type of control system to adjust the ride height. This system is usually referred to as a Load Leveling System. These systems come in a variety of different configurations but all basically have the same functions. When designed correctly, the system can reduce driveline vibration, reduce air consumption (improving compressor life and fuel efficiency), provide an accurate 5th wheel height and improve the ride quality. This paper explores how the characteristics of the leveling system affect the roll stability. One and Two-valve systems are considered, as well as, the position of the valve, response times, valve deadband and the systems response to an off-center load. Notably not every conceivable condition has been considered.
2000-12-04
Technical Paper
2000-01-3478
E. Esmailzadeh, B. Tabarrok
The planar mathematical model for various design configurations of articulated log-hauling truck in the form of a tandem axle tractor and two separate semi-trailer units, commonly known as super B train truck, is developed. A thorough kinematics and dynamic analyses of the log-hauling combination trucks, incorporating up to three axles to be steerable for the tractor, are carried out and the governing differential equations for the lateral and yaw planar motions are derived. Using a computer simulation model, the directional performance and the lateral and yaw and stability of this articulated truck is fully investigated through transient and harmonic response analyses. Finally, a parameter sensitivity analysis was carried out for different variables involved in the simulation model, to study the sensitivity of the steady-state response to various parameters.
2000-12-04
Technical Paper
2000-01-3483
Michael Schuster
SAE Recommended Practice J1540 provides an indirect method of measuring transmission efficiency. The method involves measuring torque losses resulting from a dynamometer setup in which two test transmissions are mounted in a fashion that allows them to rotate about their input and output shafts. For a variety of reasons, an energy-in-energy-out measurement approach may be more practical for heavy-duty vehicle transmissions. With an appropriate test setup, the analysis simplifies to comparing the torque entering the transmission to the torque leaving it, factoring in the gear ratio.
2000-12-04
Technical Paper
2000-01-3484
Masanori Suda, Teruyoshi Umemura, Yasutsugu Ueda
This study aims to develop a device for melting road snow by dropping hot water using exhausted heat of a vehicle, so as to recover the driving force on frozen road, especially at crossings and slopes. In the laboratory experiments, torque of model tires driving on a mock road of snow-and-ice sheet were measured together with the melting rate of the snow-and-ice, varying tire speed and hot water dropping procedures, and heat balance of this experiment was calculated. As a result, 8ml of hot water of 80 degree Centigrade was required until the tire contacts with the road surface by removing the 10mm thick snow-and-ice sheet. In the actual case, 8ml for the model tire corresponds to 400ml of hot water dropping on a driving tire, and 10mm thickness of snow-and-ice corresponds to that frozen in the coldest night in Sapporo, Japan. Simulation studies of snow melting by hot water dropping were carried out for 3 representative cities in Japan for 23 winter seasons.
2000-12-04
Technical Paper
2000-01-3490
Richard Harris, Tony Petree
Sterling, a new brand name in the trucking industry, wanted to develop a competitive medium duty product. The Sterling cab is versatile and can be adapted to meet target market needs. However, the Sterling chassis is heavy and expensive for medium and light-heavy applications. Freightliner chassis components provide a more versatile platform. The Sterling cab and Freightliner chassis provided the starting point for development of a new product called ACTERRA. Sterling's need for this product required an aggressive development plan. Although timing was critical, other major project targets were desired, including low cab height, good visibility, maneuverability, low cost, product flexibility, and attractive appearance with strong ties to a Sterling family identity. The result is an attractive and competitive package delivered to the market in minimum time. This paper summarizes the product content and project approach taken to launch ACTERRA.
2000-12-04
Technical Paper
2000-01-3491
Beth Mooney, Craig Haehn
Field research has shown that reduced visibility plays a significant role in night time accidents putting both commercial vehicle operators and passenger vehicles at risk when driving after dark. Glare from on-coming headlights or dim lit roads can hide road hazards like construction detours, deer and other large animals, cars or pedestrians off to the side of the road, and up-coming curves. Our solution to this problem is to restore daytime like visibility to the driver and increase the reaction time a driver has to negotiate through a developing situation in front of the vehicle. To accomplish this, Bendix is offering an infrared thermal imaging system, XVision, that consists of a camera (which incorporates a ferro-electric sensor), and a compact head up display (HUD) co-developed with Raytheon Commercial Infrared especially for use in commercial vehicle applications.
2000-12-04
Technical Paper
2000-01-3494
Chris Brune, Todd Rydman
Nearly every area of vehicle electronics is experiencing a design and implementation revolution. Drive-by-wire concepts, controller area networks, and “on-line” information systems are rapidly changing the way we view vehicle electronics. Advancements in technology enable improvements or even revolutionary changes in the way products are designed. Enhancements in semiconductor technology are enabling an evolutionary change in the design of products for all types of vehicles. Electrical systems are supporting the movement towards higher voltages, more features, and more power. Today, heavy duty signaling applications may have as many as 20 bulbs connected to the flasher, forcing designers to look towards higher reliability, solid state switching methods.
2000-12-04
Technical Paper
2000-01-3496
G. Allan Hagelthorn
This technical paper follows a series of four previous SAE Technical Papers dealing with progress of wheel bearing adjustment on tractor/trailer combination vehicles. Since 1995 there has been increased attention devoted to improvement of wheel retention due to the high incidence of highway accidents caused by “lost wheels”. This presentation will supplement the information provided in the earlier papers by discussing the efforts performed by various activities during the past several years. In addition, the attempt will be made to further stimulate highway safety by projecting the course of future activities.
2000-12-04
Technical Paper
2000-01-3497
Grigore Danciu, Cristian Andreescu
The paper presents a low-cost method of very fast diagnosis of general technical state of a bus fleet. The engine power is estimated from the no-load acceleration time. A low-cost PC and a very simple interface allow obtaining in a few minutes pertinent information if the vehicle can run or not. If not, more sophisticated tests are necessary.
2000-12-04
Technical Paper
2000-01-3499
Min-Ho Kim
The aerodynamic characteristics of large trucks have become more and more important in recent vehicle designs. Good Aerodynamics improve performance in high speed cruising and increase driving comfort. Hence, detailed knowledge of the flow field around corner vanes is essential to improved fuel efficiency and reduced dirt contamination on the vehicle body surface. In this study, three-dimensional flow characteristics around a corner vane attached to a truck cab were computed for steady, incompressible, and high-speed viscous flow, adopting a RNG k-ε turbulence model. In order to investigate the influence of corner vane configuration and structure, computations and actual driving tests were carried out for four different cases at a high Reynolds number, Re=4.1× 106(based on the cab height). The aerodynamic behavior of global flow around the corner vane was examined.
2000-12-04
Technical Paper
2000-01-3498
Andrew S. McLandress, Josef Loczi, Vladimir Griaznov
A Rapid Duct Development and Diagnostic airflow simulation Tool (R3DT) has been developed that allows computational fluid dynamics (CFD) airflow simulations to be performed on complex three-dimensional (3D) Heating, Ventilation and Air Conditioning (HVAC) ducts quickly, easily and cost effectively. R3DT is a very automated approach to performing grid generation and CFD. It draws upon the strengths of the tools of ICEM CFD Engineering to create a fully tetrahedral mesh for complicated air duct geometries based on the original CAD data. It also uses FLUENT™ as the tetrahedral CFD solver. R3DT enables designers to make informed design decisions based on the predicted performance of their duct designs early in the development process, with the data still in CAD format. The concepts behind R3DT, as well as its application to a series of three-dimensional ducts with varying levels of geometrical complexity will be presented.
2000-12-04
Technical Paper
2000-01-3426
David A. Sloss, Paul Green
This paper provides background and suggestions for safety research for the Army's 21st Century Truck program (21T). The goal of that program is to reduce large truck related fatalities by 50 percent by the year 2010. As background for the proposed research program, this paper contrasts military and civilian trucks and their drivers. Based on that information and considerations of new technology, human factors research needs are identified in the areas of: 1. driver workload measures and assessment 2. collision avoidance and warning systems 3. night vision 4. interface integration 5. baseline studies of driving 6. in-vehicle interfaces 7. alertness monitoring
2000-12-04
Technical Paper
2000-01-3425
David J. Gorsich, Elio DiVito
This paper will describe the Army's Vehicle Intelligence Program and discuss some of the VI technologies being considered for use within the Army's Tactical Wheeled Vehicle fleet. It will describe some initial modeling efforts that focus on the fuel efficiency impacts of selected VI technologies and will suggest the impacts of an integrated and networked fleet with regard to logistics. Lastly, it will identify several areas of AVIP research that are being considered in the near term. All of these programs impact directly on the 21st Century (21T) Truck program. [1]
2000-12-04
Technical Paper
2000-01-3429
Douglas Miller, Ray Schandelmeier, Ferdinand Zegel
Radian Inc, working in partnership with the U. S. Army National Automotive Center, has been designing and developing a Thermal Imaging Inspection Station (TIIS) for assessing and diagnosing the condition of truck tires and other components of vehicles in a real-time operational environment. Recently, multiple failures of M939 truck tires (14.00R20, Load Range J, manufactured by both Michelin and Goodyear) have been reported, and the U. S. Army Tank-Automotive and Armaments Command (TACOM) contracted with Radian to participate in a tire-testing program, using the TIIS at the TACOM tire-testing lab and in field tests, in hopes of determining the cause of these failures. Tires that failed on the tire dynamometer demonstrated similar problems to tires that failed in field operations. Thermal images recorded in the lab and in the field under similar conditions were highly comparable.
2000-12-04
Technical Paper
2000-01-3435
Bernd Rosmislowsky
Mannesmann VDO, Information Systems Commercial Vehicles, has developed a new driver's workplace for regular service buses. The modern design of the cockpit includes important innovations: a completely redesigned dashboard, which can be adjusted in relation to the steering wheel and so adapted to the driver's needs. Thus the working conditions of the driver are markedly improved. Since the vehicles on the regular German bus services were standardized at the end of the 60's, no further important alterations in the working environment of the driver have been made. However in the interim period, technology has made decisive progress. In a concept worked out in concert with professional associations, vehicle manufacturers, ergonomics experts, trade unions, interest groups and transport services, the criteria for a modern cockpit in a city bus have been established and were demonstrated in a study at the IAA in 1994.
2000-12-04
Technical Paper
2000-01-3433
Fujio Momiyama, Naohiro Yuhara, Jun Tajima
The toe-change of road-wheel, so-called compliance-steer(CS), caused by suspension compliance is proved to occur around a steady instantaneous center under steady run at constant speed. The adverse/proverse CS, that increases/decreases the side-slip angle versus the velocity vector of vehicle, is realized by locating the center rearward/forward of the axle. By designing the front/rear wheel CS as a proverse/adverse CS with nonlinear compliance that is large at on-center but small at off-center, vehicle characteristics to reduce lateral deviation caused by disturbance and to improve tracking performance are possible.
2000-12-04
Technical Paper
2000-01-3418
David R. Woerner, Raman Ranganathan, Alley C. Butler
A backpropagation through time algorithm was used to model and predict the rollover of a tank truck carrying varying liquid volumes, traveling at various speeds, and performing a number of steering maneuvers of up to 12 seconds duration. The training and testing data sets were built with data produced by simulations using first principle models. Because neural networks have trouble predicting behaviors beyond the boundaries of their training sets, the training set was weighted with 5 per cent of the input examples involving vehicle rollover due to sloshing. The network outputs under test data sets produced very strong correlations with first principle roll simulations in both rollover and non-extreme steering maneuvers.
2000-12-04
Technical Paper
2000-01-3417
Shan Shih, Rajesh Somnay, Robert Hannon, Joseph Kay
Effective linear and nonlinear drum brake system FEA (finite element analysis) models have been developed. Such models can help engineers understand many drum brake related issues, such as lining wear and mechanical and thermal instability. The pressure distribution at the drum and lining interface is an important piece of information in drum brake design. Besides the accurate prediction of the shoe factor, the models can be used to guide designs for improving brake efficiency, reducing component weight and enhancing durability. Progress is also being made in developing hybrid models that integrate FEA models with other analysis techniques. This approach offers engineers easy-to-use design tools. The integrated design and analysis approach will help product design and development by reducing cycle time, cost and improving product quality.
2000-12-04
Technical Paper
2000-01-3411
Jared A. Powell, Steven S. Wreggit, Chris L. Kirn, Elizabeth Hayes
Communication is vital to the successful delivery of freight. A product that uses the latest communications technology, and makes that technology easily accessible to a driver would be a great benefit to the trucking industry. This paper focuses on the iterative design process of such a product called the Truck Productivity Computer™ (TruckPC). The TruckPC is a combination of an audio system, which includes radio, CD and weather, and an open platform communications and computing system. This paper discusses the driver-centered design process that was used in the development of both software and hardware interfaces. Topics discussed include the human factors guidelines that provided a basis for early design values and testing that concerned the design of the user input modes (buttons, knobs, speech recognition) and output modes (display, division of information on the display, text-to-speech synthesis).
2000-12-04
Technical Paper
2000-01-3403
Kevin Quaid
This paper presents the results of achieving compliance with established and proposed Occupational Safety and Health Administration (OSHA) rulemaking, reducing musculoskeletal disorders (MSDs), and improving efficiency for rail and bus transportation providers by implementing an organizational-wide ergonomics program. Specifically, potential hazards affecting bus mechanics are identified, and methods to reduce exposure are detailed.
2000-12-04
Technical Paper
2000-01-3401
Mats Johansson
Modularization does not only give economic and manufacturing advantages, it also provides a basis for development of a first class ergonomic driver environment. Scania Commercial Vehicle AB has a long tradition in producing highly modularized products and throughout the years Scania has gained a reputation of having a well-planned and flexible driver interface. The key to this has been a structured system, which has adaptation capabilities, and to use the strong points of modularization to gain functionality. By using versatile and functionally unique modules, a palette of functionality is formed. This palette provides the possibility to meet different drivers needs and preferences with good ergonomic solutions.
2000-12-04
Technical Paper
2000-01-3420
Dennis Wend, Paul F. Skalny, David J. Gorsich
The 21st Century Truck Initiative represents the premier partnership between government (Departments of Defense, Army, Energy, Transportation and the Environmental Protection Agency) and the U.S. trucking and supporting industries in seeking to develop and demonstrate commercially viable advanced technologies for trucks in the 21st century. At the request of senior leadership within the U.S. Departments of Defense and the Army, the Tank-automotive and Armaments Command's (TACOM) National Automotive Center (NAC), located at TACOM's Tank-Automotive Research, Development & Engineering Center (TARDEC), spearheaded the creation of this government-industry partnership to pursue the necessary leap-ahead technologies. By teaming the research and development efforts of government and industry, the partnership will improve fuel efficiency, increase safety, reduce owning and operating costs, and reduce emissions, while maintaining or enhancing the performance of military and commercial trucks.
2000-12-04
Technical Paper
2000-01-3434
Yongping Hou, Yujin Hu, Diqing Hu, Chenggang Li
In the paper, the kinematics model and a mathematical optimization model for the multi-axle steering system of heavy-duty vehicle are established based on the mechanism kinematics analysis. A new weight function is designed considering the probability of steering angle. Takes 10×8 heavy-duty vehicle as an example, the parameters of multi-axle steering system are optimized. The result shows that the result with weight function has better effect than other conditions. We also develop mechanism kinematics analysis and simulation software. The work in the paper will help to guide the design of steering system of multi-axle steering heavy-duty vehicle.
2000-12-04
Technical Paper
2000-01-3444
Derek Y. Kamemoto, Peder L. Hamberg, Gary P. Hansen
A patent pending microprocessor controller, detection algorithm and low cost sensor have been developed to accurately detect a refrigerant low charge state in mobile air conditioning systems. The device is intended to prevent damage to the air conditioning system compressor and was designed primarily for truck and bus applications although the principles may also be applied to automotive, agricultural, construction, mining equipment and stationary HVAC applications. The system uses a single, thermistor based refrigerant charge sensor, an optional high pressure transducer and a microprocessor controlled electronics module coupled with standard air conditioning system components to detect the presence or lack of refrigerant in the A/C circuit.
Viewing 1 to 30 of 784

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