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Technical Paper

HVE EDSMAC4 Trailer Model Simulation Comparison with Crash Test Data

2000-03-06
2000-01-0467
Engineering Dynamics Corporation (EDC) recently updated the Human, Vehicle, Environment (HVE) software program to enable modeling of passenger cars and light trucks towing trailers. This paper reports on a comparison between the HVE EDSMAC4 collision module of the 3-dimensional computer simulation program and instrumented crash tests, in which one vehicle in each test was a pickup truck pulling a trailer. Use of the EDSMAC4 trailer model was found to provide better correlation between the simulation and test damage profiles, rest positions, vehicle trajectories, velocities, and Delta-V. It was also determined that the NHTSA-derived stiffness coefficients are sensitive to the impact configuration and depending on the impact configuration, it may be necessary to refine the coefficients according to the configuration.
Technical Paper

Laser Welding of EGR Coolers - A New Process Technology for Heat Exchanger Manufacturing

2001-05-14
2001-01-1753
Laser welding is a joining process, which is comparatively new to industrial production and especially to heat exchanger manufacturing. Due to the high energy density of the laser beam, the process is characterized by faster welding speeds with deep penetration as compared to the conventional welding processes. Therefore laser welding technology is widely used in the automotive industry on a variety of different applications. This paper describes the application of laser welding as possible joining technology for exhaust gas heat exchangers made of stainless steel. The cooled exhaust gas recirculation (EGR) technology shows good potential for meeting the actual and future emission targets of diesel engines combined with acceptable fuel consumption. It will be shown that the selection of the base metal and the joining technology are extremely important for the durability of the product because of the severe operating environment the EGR cooler must endure.
Technical Paper

Electronic Braking System of EV And HEV---Integration of Regenerative Braking, Automatic Braking Force Control and ABS

2001-08-20
2001-01-2482
The desirable braking system of a land vehicle is that it can stop the vehicle or reduce the vehicle speed as quickly as possible, maintain the vehicle direction stable and recover kinetic energy of the vehicle as much as possible. In this paper, an electronically controlled braking system for EV and HEV has been proposed, which integrates regenerative braking, automatic control of the braking forces of front and rear wheels and wheels antilock function together. When failure occurs in the electric system, the braking system can function as a conventional man-actuated braking system. Control strategies for controlling the braking forces on front and rear wheels, regenerative braking and mechanical braking forces have been developed. The braking energy that can be potentially recovered in typical driving cycle has been calculated. The antilock performance of the braking system has been simulated.
Technical Paper

A Dual-Use Hybrid Electric Command and Control Vehicle

2001-11-12
2001-01-2775
Until recently, U.S. government efforts to dramatically reduce emissions, greenhouse gases and vehicle fuel consumption have primarily focused on passenger car applications. Similar aggressive reductions need to be extended to heavy vehicles such as delivery trucks, buses, and motorhomes. However, the wide range of torques, speeds, and powers that such vehicles must operate under makes it difficult for any current powertrain system to provide the desired improvements in emissions and fuel economy. Hybrid electric powertrains provide the most promising, near-term technology that can satisfy these requirements. This paper highlights the configuration and benefits of a hybrid electric powertrain capable of operating in either a parallel or series mode. It describes the hybrid electric components in the system, including the electric motors, power electronics and batteries.
Technical Paper

Effect of Heavy Vehicle Suspension Designs on Dynamic Road Loading – A Comparative Study

2001-11-12
2001-01-2766
In this paper road damage caused by heavy vehicles is studied. The effects of passive, semi-active and active suspension designs on dynamic road loading are compared. Attention is given to develop an accurate vehicle model with useful tandem suspension behavior. A nonlinear two-dimensional model of tractor-semitrailer is considered. The model includes nonlinear behavior of leaf spring and tandem suspension in the trailer axles. To obtain accurate results, a realistic road profile model is considered. The control scheme of the semi-active suspension system is based on the modified skyhook damper model. For the active suspension control system design, due to nonlinearity in the vehicle model, a linear quarter vehicle model is considered. Then linear quadratic optimal technique is employed to design the control law. Two road damage criteria were applied to assess the vehicle performance: The dynamic road stress factor and the 95th percentile dynamic loads.
Technical Paper

Development of a Multi-Body Dynamic Model of a Tractor-Semitrailer for Ride Quality Prediction

2001-11-12
2001-01-2764
Increasingly, manufacturers are looking to computer simulation methods to accurately assess ride quality potential of new vehicle designs as they are being developed. This requires detailed multi-body dynamic models to be developed with sufficient fidelity to replicate ride relevant phenomenon. These models must have the capability to: Represent the distributed mass and elasticity of the vehicle structures (e.g. frame ladder, cab, and trailer). Include the non-linear behavior of shock absorbers and elastomeric components. Reproduce the fundamental system dynamics that influence ride. Provide output of the acceleration, velocity, and displacement measures needed to compute ride quality. This paper discusses the development of an ADAMS multi-body dynamic model of a tractor semi-trailer for use as a predictive tool in evaluating ride quality design improvements.
Technical Paper

Testing Control Systems of Trucks and Truck-Trailer-Combinations With Hardware In The Loop – Very Real Tests In a Virtual World

2001-11-12
2001-01-2768
This article presents state-of-the art of modern hardware-in-the-loop systems for testing electronic chassis control systems in trucks and in truck/trailer combinations. In the last few years, hardware-in-the-loop has proven to be a time and cost-saving testing method for passenger cars, ideally complementing real driving tests. Due to the increasing functionality and complexity of chassis control systems in trucks, HIL will certainly prove to be a key technology for testing control systems of trucks.
Technical Paper

Factors Affecting the Friction Coefficients Between Wooden Pallets and the Wooden Floor of a Van -Type Semi-Trailer

2001-11-12
2001-01-2753
This paper investigates the coefficients of static and kinetic friction between the hardwood flooring of a used semi-trailer and the bottom surfaces of both an old and a new hardwood pallet, with varying cargo weights, at varying locations in the trailer. A total of 22 tests were performed with the pallets moving parallel to the longitudinal axis of the trailer and perpendicular to this axis. The results show that the variations in load did not statistically affect the friction coefficients. The older pallet had statistically smaller static and kinetic friction coefficients (s=0.32, k=0.26) than that of the newer pallet (s=0.35, k=0.29). The static friction coefficients were statistically dependent upon whether the test took place at the front (0.36), middle (0.34) or rear (0.32) of the semi-trailer. Kinetic coefficients behaved similarly: front (0.29), middle (0.27) or rear (0.26).
Technical Paper

A Vehicle Electrical System Architecture Based on a Multiplexed Design For Operator Controls and Indicators

2001-11-12
2001-01-2740
Increased features content, with electrical effects, have produced tremendous complexity in the design and support of the electrical system for commercial vehicles. Using individual wires coupled with various electro-mechanical components, to implement electrical system features, is no longer a desirable solution. Adding more wires and connectors reduces reliability and makes diagnosing electrical failures rather cumbersome. Likewise, customizing a vehicle with a specific set of features, by using discrete wire designs, make the assembly process prone to error. This paper explores a new approach to a vehicle electrical architecture that uses multiplexed wiring methods coupled with a programmable central control module. The most novel feature of the system is that the main electrical system control module may be reprogrammed with a unique set of vehicle features as required by each customer order.
Technical Paper

A Two-Dimensional External Aerodynamics Tool (EAT) for Simulating Airflow around Tractor-Trailer Combinations

2001-11-12
2001-01-2743
Understanding external vehicle aerodynamics is an integral step in reducing overall vehicle fuel consumption. This is particularly true for long-haul commercial vehicles where an incremental decrease in drag can translate into significant fuel savings based on the number of miles traveled over the course of a truck's working life. The ability to critically analyze the air motion adjacent to commercial vehicles is a step toward understanding the overall affects of external aerodynamics on the entire vehicle. To achieve this understanding, the aerodynamics problem must be divided into manageable tasks that can each yield qualitative and quantitative results. A two-dimensional (2D) External Aerodynamics Tool (EAT) has been developed that enables computational fluid dynamics (CFD) simulations of commercial vehicles to be performed quickly and easily.
Technical Paper

Approach of Debugging Control Laws of ABS Combined with Hardware-in-the-Loop Simulation and Road Experiment

2001-11-12
2001-01-2729
Anti-lock Braking System (ABS) is an important control system that can improve the automotive performance, reliability and safety obviously. Hardware-in-the-loop Simulation (HILS) testing is a promising method to assistant design automotive electronics system. In the State Key Laboratory of Automotive Safety and Energy, a HILS system was established to assistant design ABS. The HILS system is composed of a hydraulic control unit of ABS, a normal brake system, a commercial personal computer, a data acquisition card, and several signal-conditioning modules. Powerful software was programmed to perform managing input and output signals, solving 7-freedom and 15-freedom vehicle models, and acquiring response signals of the brake system. Based on the simulations of HILS system, the road experiments with the same conditions of ABS are very necessary and important.
Technical Paper

Feasibility of Modifying an Existing Semi-Trailer Air Suspension Into an Anti-Rollover System

2001-11-12
2001-01-2733
This paper examines the feasibility of modifying an existing semi-trailer air suspension system to function as an anti-rollover system in addition to its normal suspension operation. The semi-trailer model used is a dynamic, two-dimensional system. The anti-rollover system controller is formulated using projective control theory. All other factors being equal, simulations show that use of the modified suspension system decreases the weight shift when the semi-trailer undergoes lateral acceleration. By decreasing weight shift, the modified suspension system decreases the possibility of rollover.
Technical Paper

Adapting the Off-Highway Truck Body Volumetric Process to Real World Conditions

2000-09-11
2000-01-2652
SAE Standard J-1363 Jan 85 reaffirmed Nov 95 has served the off-highway truck industry well. However as off-highway trucks have become larger, now approaching 400-ton capacity versus 170-ton or maybe 190-ton in the mid-1980's, and as mining operations have become more sophisticated, pennies are counting where dollars used to. And with parametric 3-D CAD design becoming the norm, the need and the possibility of more accurately defining the reality of what an off-highway truck body will carry and where that load will rest fore-to-aft on the truck chassis has become paramount. With a single tire on a 300 ton plus capacity off-highway truck costing in excess of $25,000 to $30,000, proper load placement and accurate truck loading are absolutely essential.
Technical Paper

9000T Series John Deere Track Tractors

2000-09-11
2000-01-2634
The 9000T track-type agricultural tractors mark John Deere's entry into the high-horsepower, track tractor market. The 360-HP 9300T and the 425-HP 9400T tractors were designed with input from customers to meet customers' needs. Through customer input, on-farm research, and common sense, these tractors have been designed to work light in the spring, heavy in the fall, handle steep hillsides, turn under load and pull like a locomotive. Incorporating many of the already-market-dominating features of the 9000 wheel tractors plus innovative track vehicle features such as the wide stance, long wheel base, controllability, power, and versatility, these machines are truly amazing.
Technical Paper

Class 8 Trucks Operating On Ultra-Low Sulfur Diesel With Particulate Filter Systems: Regulated Emissions

2000-10-16
2000-01-2815
Emissions from heavy-duty vehicles may be reduced through the introduction of clean diesel formulations, and through the use of catalyzed particulate matter filters that can enjoy increased longevity and performance if ultra-low sulfur diesel is used. Twenty over-the-road tractors with Detroit Diesel Series 60 engines were selected for this study. Five trucks were operated on California (CA) specification diesel (CARB), five were operated on ARCO (now BP Amoco) EC diesel (ECD), five were operated on ARCO ECD with a Johnson-Matthey Continuously Regenerating Technology (CRT) filter and five were operated on ARCO ECD with an Engelhard Diesel Particulate Filter (DPX). The truck emissions were characterized using a transportable chassis dynamometer, full-scale dilution tunnel, research grade gas analyzers and filters for particulate matter (PM) mass collection. Two test schedules, the 5 mile route and the city-suburban (heavy vehicle) route (CSR), were employed.
Technical Paper

Development of an Air Intake System Using Vibro-Acoustics Numerical Modeling

2001-04-30
2001-01-1519
This paper describes the use of Vibro-Acoustics numerical modeling for prediction of an Air Intake System noise level for a commercial vehicle. The use of numerical methods to predict vehicle interior noise levels as well as sound radiated from components is gaining acceptance in the automotive industry [1]. The products of most industries can benefit from improved acoustic design. On the other hand, sound emission regulation has become more and more rigorous and customers expect quieter products. The aim of this work it is to assess the Vibro-Acoustics behavior of Air Intake System and influence of it in the sound pressure level of the vehicle.
Technical Paper

Factors Affecting Truck Driver's Perceived Comfort

2001-04-30
2001-01-1571
Truck driver's perception of ride quality/comfort is influenced by many factors relating to the driver, the vehicle and road surface roughness. A subjective rating survey was undertaken to identify the range of roughness wavelengths in the longitudinal road surface profile that affect the perceived ride of heavy articulated vehicles. They were found to range between 4.8 and 19.5 meters. Accordingly, a new roughness index called Profile Index (PI) was established. During the survey, data was collected on factors such as driver's age, years of driving experience, weight, vehicle's age, loading condition, cab location, type of driving axle suspension, weather condition and time of the rating. The effects of these factors were studied at different PI levels to test the viability of the PI as a measure of the perceived heavy vehicle ride and to establish if any of the above factors influenced the drivers' judgments during the survey.
Technical Paper

The DOE/NREL Environmental Science Program

2001-05-14
2001-01-2069
This paper summarizes the several of the studies in the Environmental Science Program being sponsored by DOE's Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The goal of the Environmental Science Program is to understand atmospheric impacts and potential health effects that may be caused by the use of petroleum-based fuels and alternative transportation fuels from mobile sources. The Program is regulatory-driven, and focuses on ozone, airborne particles, visibility and regional haze, air toxics, and health effects of air pollutants. Each project in the Program is designed to address policy-relevant objectives. Current projects in the Environmental Science Program have four areas of focus: improving technology for emissions measurements; vehicle emissions measurements; emission inventory development/improvement; ambient impacts, including health effects.
Technical Paper

Advanced Aerodynamic Devices to Improve the Performance, Economics, Handling and Safety of Heavy Vehicles

2001-05-14
2001-01-2077
Research is being conducted at the Georgia Tech Research Institute (GTRI) to develop advanced aerodynamic devices to improve the performance, economics, stability, handling and safety of operation of Heavy Vehicles by using previously-developed and flight-tested pneumatic (blown) aircraft technology. Recent wind-tunnel investigations of a generic Heavy Vehicle model with blowing slots on both the leading and trailing edges of the trailer have been conducted under contract to the DOE Office of Heavy Vehicle Technologies. These experimental results show overall aerodynamic drag reductions on the Pneumatic Heavy Vehicle of 50% using only 1 psig blowing pressure in the plenums, and over 80% drag reductions if additional blowing air were available. Additionally, an increase in drag force for braking was confirmed by blowing different slots.
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