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Viewing 1 to 30 of 336
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Technical Paper
2011-01-0656
Jason A. Lustbader, John P. Rugh, Brianna R. Rister, Travis S. Venson
In the United States, intercity long-haul trucks idle approximately 1,800 hrs per year primarily for sleeper cab hotel loads, consuming 838 million gallons of diesel fuel [1]. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working on solutions to this challenge through the CoolCab project. The objective of the CoolCab project is to work closely with industry to design efficient thermal management systems for long-haul trucks that keep the cab comfortable with minimized engine idling. Truck engine idling is primarily done to heat or cool the cab/sleeper, keep the fuel warm in cold weather, and keep the engine warm for cold temperature startup. Reducing the thermal load on the cab/sleeper will decrease air conditioning system requirements, improve efficiency, and help reduce fuel use. To help assess and improve idle reduction solutions, the CoolCalc software tool was developed.
2011-04-12
Technical Paper
2011-01-0174
Lisa Larsson, Torbjörn Wiklund, Lennart Löfdahl
The aim of the study was to investigate the cooling performance of two cooling package positions for distribution vehicles by using Computational Fluid Dynamics. The first cooling package was positioned in the front of the vehicle, behind the grill and the second position was at the rear of the vehicle. Each case was evaluated by its cooling performance for a critical driving situation and its aerodynamic drag at 90 km/h, where the largest challenge of an alternative position is the cooling air availability. The geometry used was a semi-generic commercial vehicle, based on a medium size distribution truck with a heat rejection value set to a fixed typical level at maximum power for a 13 litre Euro 6 diesel engine. The heat exchangers included in the study were the air conditioning condenser, the charge air cooler and the radiator. It was found that the main problem with the rear mounted cooling installation was the combination of the fan and the geometry after the fan.
2011-04-12
Journal Article
2011-01-0162
Ming Jiang, Huaizhu Wu, Kebing Tang, Minsuk Kim, Sivapalan Senthooran, Heinz Friz, Yingzhe Zhang
The engineering process in the development of commercial vehicles is facing more and more stringent emission regulations while at the same time the market demands for better performance but with lower fuel consumption. The optimization of aerodynamic performance for reduced drag is a key element for achieving related performance targets. Closely related to aerodynamics are wind noise and cabin soiling and both of them are becoming more and more important as a quality criterion in many markets. This paper describes the aerodynamic and aero-acoustic performance evaluation of a Dongfeng heavy truck using digital simulation based on a LBM approach. It includes a study for improving drag within the design of a facelift of the truck. A soiling analysis is performed for each aerodynamic result by calculating the accumulation of particles emitted form the wheels on the cabin. One of the challenges in the development process of trucks is that different cabin types have to be designed.
2013-04-08
Technical Paper
2013-01-1343
Marco Mammetti, David Gallegos, Alex Freixas, Jordi Muñoz
The focus of the work is to carry out a study of the relative impact of the rolling resistance measurements on CO₂ emission and fuel consumption reduction for heavy-duty vehicles. For the purpose of the study, friction coefficients of the tires from tire test machine according to UN/ECE Regulation No 117 test procedure have been used. The rolling resistance coefficient has also been obtained from SAE J1263 and SAE J2263 procedure for coast-down determination on proving ground. The fuel consumption has been simulated and tested on the proving ground by following FIGE standard cycle and stabilized speed conditions. A simulation tool has been developed and validated by testing different rolling resistance coefficient tires, analyzing their effect on the fuel consumption. The analysis of the contribution of the tires to fuel consumption achieved on the test track has been correlated with the experimental results and those obtained from the simulation tool.
2013-09-24
Journal Article
2013-01-2474
Helmut Theissl, Alois Danninger, Thomas Sacher, Herwig Ofner, Erwin Schalk
This paper describes a method for optimization of engine settings in view of best total cost of operation fluids. Under specific legal NOX tailpipe emissions requirements the engine out NOX can be matched to the current achievable SCR NOX conversion efficiency. In view of a heavy duty long haul truck application various specific engine operation modes are defined. A heavy duty diesel engine was calibrated for all operation modes in an engine test cell. The characteristics of engine operation are demonstrated in different transient test cycles. Optimum engine operation mode (EOM) selection strategies between individual engine operation modes are discussed in view of legal test cycles and real world driving cycles which have been derived from on-road tests.
2013-09-24
Journal Article
2013-01-2421
Donald W. Stanton
With increasing energy prices and concerns about the environmental impact of greenhouse gas (GHG) emissions, a growing number of national governments are putting emphasis on improving the energy efficiency of the equipment employed throughout their transportation systems. Within the U.S. transportation sector, energy use in commercial vehicles has been increasing at a faster rate than that of automobiles. A 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected from 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double.
2013-09-24
Technical Paper
2013-01-2394
John Woodrooffe, Daniel Blower, Carol A. C. Flannagan, Scott E. Bogard, Shan Bao
This paper focuses on the safety performance of Commercial Vehicle Forward Collision Avoidance and Mitigation Systems (F-CAM) that include Forward Collision Warning (FCW) with Collision Mitigation Braking (CMB) technology as applied to heavy trucks, including single unit and tractor semitrailers. The study estimated the safety benefits of a commercially available F-CAM system considered to be representative of products currently in service. The functional characteristics were evaluated and its performance generically modeled to estimate safety benefits. This was accomplished through the following steps: (1) first characterize the actual performance of these systems in various pre-crash scenarios under controlled test track conditions, and then reverse engineering the algorithms that control warnings and automatic braking actions; (2) developing a comprehensive set of simulated crash events representative of actual truck striking rear-end crashes.
2013-09-24
Technical Paper
2013-01-2392
Daniel Blower, John Woodrooffe
Heavy truck rollover remains a primary factor in truck driver fatalities and injury. Roll stability control (RSC) and electronic stability control (ESC) are technologies that have been introduced to reduce the incidence of rollover in heavy truck crashes. This report provides an analysis of the real-world experience of a large for-hire company that introduced RSC into its fleet starting in 2004. The carrier provided a well-documented set of data on the operations of its truck-tractors, including both those equipped with RSC and those that did not have RSC installed. The purpose of the analysis is to determine the effect of RSC on the probability of rollover, as well as to identify other factors that either contribute to rollover or help reduce its incidence. This study presents results on the incidence of rollover both in terms of rollovers per 100 million miles traveled and the percentage of crashes that resulted in rollover.
2013-09-24
Technical Paper
2013-01-2354
Gediz Kulac, Berzah Ozan, Yahya Oz
Steering performance as a vehicle dynamics attribute of a heavy commercial vehicle is dependent on series of design and tunable steering system parameters. The driver steering input as angle and torque is transmitted through steering column to the steering box with a combined function created by the steering column angles and orientations. In case the angle and torque transmission from steering wheel to steering box through steering column cannot be linearized because of the design constraints, the steering column input and output torque, angle and angular speed relations should be optimized for a good vehicle dynamics performance and in compliance with the OEM brand DNA This paper represents series of CAE analyses, optimization studies, verification tests and subjective evaluations related to the tunable parameters of the steering column.
2013-01-09
Technical Paper
2013-26-0145
S. Narayanan, S. Mithun, T. Sahul Hameed
A lift axle suspension system in a heavy commercial vehicle enables raising and lowering of the lift axle depending on the vehicle load condition. The states (raising and lowering) of the axle will be in logical sequence which depends on the vehicle load, ignition state, gear state and traction requirement. To arrive this complicate logic, the Lift Axle Control valve is designed. This LACV is an intricate assembly of pneumatic 3/2 valve, 5/2 valve, relay valve and solenoid valves. To predict the performance of this valve under various vehicle conditions, the entire valve is modeled in one of the commercially available multi-domain physical modeling software employing bond graph technique and lumped system and the performance is predicted. This paper deals with the modeling of LACV, simulation of misbehavior of LACV under certain condition, and the design analysis carried out to arrive design solution.
2013-01-09
Technical Paper
2013-26-0150
Jeevan N. Patil, Sivakumar Palanivelu, Ajit Kumar Jindal
Air brake system is widely used in heavy duty trucks and buses due to its great performance and efficiency. Dual brake valve (DBV) is one the of major and crucial component of an air brake system as it is controlling the air flow from reservoir to brake chamber during braking operation. Currently, due to its own complexity, it is very difficult for designer to optimize different parameters. As experimentation is tedious and time consuming task, hence it is very important to have mathematical model of DBV during in early design stage. Differential equations have been formulated for individual component of DBV such as primary piston, primary valve, relay piston, and relay valve etc. system level mathematical model has been formulated and implemented in Matlab/Simulink to capture the dynamic pressure characteristic of DBV. At the same time mathematical model of DBV has been created in AMESim to check the validity of approach.
2013-01-09
Technical Paper
2013-26-0151
Arvind K. Jain, Sathish Madaswamy, Sudarsanam S, Venkat Srinivas
Demand for a refined Heavy Commercial Vehicle (HCV) is increasing due to rapid Indian economic growth, while the operating conditions and road infrastructures are still in a transition state of development. The same vehicle model will be operated in a range of operating road conditions like mining sites, construction sites, and highways with varying payloads and speeds by customers that are spread across the country. This variety of road inputs, payloads and speeds has made ride tuning as one of the major challenging process in the development process. This paper describes the attempt to assess ride comfort of HCV with fully suspended cab using numerical based simulation tools and its correlation with physical test results. The best suspension combination was finalized based on vertical and pitch acceleration at Center of Gravity (CG) of the cab. The trend of vertical acceleration obtained from the virtual model was correlated with the same obtained from physical test.
2013-10-07
Technical Paper
2013-36-0154
Rafael V. Carvalho, Ludmila C. A. Silva, Milton Amaro, Alessandro A. Ferreira, Aparecido M. da Rosa
Heating generation in rolling bearings is a critical point for development and application, specially for heavy trucks. Several problems can occur in the rolling bearing and in the system when the temperature increases. For example, at high temperature levels the rubber sealing can change its proprieties and volume, creating a high interference at the contact with the rings. The grease can also be affected and modify its viscosity, generating a possible leakage, which is not allowed during life. This papers aims to study the heat generation and evaluate, experimentally, the temperature stabilization in clutch release bearings for heavy duty application. With this purpose, several tests were performed and the results were analyzed to find the main factors that can be influenced.
2014-04-01
Technical Paper
2014-01-0491
Michael E. Zabala, Nicholas Yang, Stacy Imler, Ke Zhao, Rose Ray
Abstract Three years of data from the Large Truck Crash Causation Study (LTCCS) were analyzed to identify accidents involving heavy trucks (GVWR >10,000 lbs.). Risk of rollover and ejection was determined as well as belt usage rates. Risk of ejection was also analyzed based on rollover status and belt use. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants. These data were further analyzed to determine injury distribution based on factors such as crash type, ejection, and restraint system use. The maximum AIS score (MAIS) was analyzed and each body region (head, face, spine, thorax, abdomen, upper extremity, and lower extremity) was considered for an AIS score of three or greater (AIS 3+). The majority of heavy truck occupants in this study were belted (71%), only 2.5% of occupants were completely or partially ejected, and 28% experienced a rollover event.
2014-04-01
Technical Paper
2014-01-0435
Luciano Lukacs, Mahendra Dassanayake, Iuri Pepe
Abstract Nighttime driving behavior differs from that during the day because of unique scenarios presented in a driver's field of vision. At night drivers have to rely on their vehicle headlamps to illuminate the road to be able to see the environment and road conditions in front of him. In recent decades car illumination systems have undergone considerable technological advances such as the use of a Light Emitting Diode (LED) in Adaptive Front-lighting Systems (AFS), a breakthrough in lighting technology. This is rapidly becoming one of the most important innovative technologies around the world within the lighting community. This paper discusses driver's needs given the environment and road conditions using a survey applied to compare the needs of both truck and car drivers under different road conditions. The results show the potential and suitability of the methodology proposed for controlling truck-related lighting in any emergent market.
2011-04-12
Technical Paper
2011-01-1337
Talus Park, Ho Teng, Gary L. Hunter, Bryan van der Velde, Jeffrey Klaver
A Rankine cycle system with ethanol as the working fluid was developed to investigate the fuel economy benefit of recovering waste heat from a 10.8-liter heavy-duty (HD) truck diesel engine. Recovering rejected heat from a primary engine with a secondary bottoming cycle is a proven concept for improving the overall efficiency of the thermodynamic process. However, the application of waste heat recovery (WHR) technology to the HD diesel engine has proven to be challenging due to cost, complexity, packaging and control during transient operation. This paper discusses the methods and technical innovations required to achieve reliable high performance operation of the WHR system. The control techniques for maintaining optimum energy recovery while protecting the system components and working fluid are described. The experimental results are presented and demonstrate that 3-5% fuel saving is achievable by utilizing this technology.
2011-08-30
Journal Article
2011-01-1961
Takashi Hara, Naoki Shimazaki, Naoki Yanagisawa, Takeshi Seto, Shigehisa Takase, Takeshi Tokumaru, Takurou Mita, Takeshi Okamoto, Yoshio Sato
Study of DME diesel engines was conducted to improve fuel consumption and emissions of its. Additionally, DME trucks were built for the promotion and the road tests of these trucks were executed on EFV21 project. In this paper, results of diesel engine tests and DME truck driving tests are presented. As for DME diesel engines, the performance of a DME turbocharged diesel engine with LPL-EGR was evaluated and the influence of the compression ratio was also explored. As for DME trucks, a 100,000km road test was conducted on a DME light duty truck. After the road test, the engine was disassembled for investigation. Furthermore, two DME medium duty trucks have been developed and are now the undergoing practical road testing in each area of two transportation companies in Japan.
2011-09-13
Technical Paper
2011-01-2295
Keith Friedman, John Hutchinson, Dennis Mihora, Sri Kumar, Daniel Strickland
More than 900,000 long-haul sleeper cabs are projected to be on the road by 2030. About half of heavy truck occupant fatalities occur in rollovers. This paper discusses the current status of rollover protection systems for occupants in sleeper cabs and describes the outcomes from example crashes with sleeper cab occupants. A virtual testing methodology for evaluation of current designs under rollover conditions and restraint tests utilizing dummies and humans also are described. The paper includes discussion of finite element models used and their validation. Examples of results associated with various restraint system configurations are presented. The results show that incorporating effective lateral restraint is important in providing protection to sleeper cab occupants under rollover conditions.
2011-09-13
Technical Paper
2011-01-2292
Tianlei Zheng, Yuefu Jin, Zhao Wang, Michael Wang, Freda Fung, Fatumata Kamakate, Huiming Gong
To restrain the environmental and energy problems caused by oil consumption and improve fuel economy of heavy-duty commercial vehicles, China started developing relevant standards from 2008. This paper introduces the background and development of China's national standard “Fuel consumption test methods for heavy-duty commercial vehicles”, and mainly describes the test method schemes, driving cycle and weighting factors for calculating average fuel consumption of various vehicle categories. The standard applies to heavy-duty vehicles with the maximum design gross mass greater than 3500 kg, including semi-trailer tractors, common trucks, dump trucks, city buses and common buses. The standard adopts the C-WTVC driving cycle which is adjusted on the basis of the World Transient Vehicle Cycle[1, 2] and specifies weighting factors of urban, rural and motorway segments for different vehicle categories.
2011-09-13
Technical Paper
2011-01-2284
Helena Martini, Björn Bergqvist, Linus Hjelm, Lennart Löfdahl
Today there are a large variety of drag-reducing devices for heavy trucks that are commonly used, for example, roof deflectors, cab side extenders and chassis fairings. These devices are often proven to be efficient, reducing the total aerodynamic resistance for the vehicle. However, the drag-reducing devices are usually identical for a specific pulling vehicle, independent of the layout of the vehicle combination. In this study, three vehicle combinations were analyzed. The total length of the vehicles varied between 10.10 m and 25.25 m. The combinations consisted of a rigid truck in combination with one or two cargo units. The size of the gap between the cargo units differed between the vehicle combinations. There were also three configurations of each vehicle combination with different combinations of roof deflector and cab side extenders, yielding a total number of nine configurations.
2011-09-13
Technical Paper
2011-01-2285
Lisa Larsson, Lennart Löfdahl, Erik Dahl, Torbjörn Wiklund
This investigation is a continuing analysis of the cooling performance and aerodynamic properties of a rear-mounted cooling module on a semi-generic commercial vehicle, which was carried out by Larsson, Löfdahl and Wiklund. In the previous study two designs of the cooling package installation were positioned behind the rear wheelhouse and the results were compared to a front-mounted cooling module. The investigation was mainly focused on a critical cooling situation occurring at lower vehicle speeds for a local distribution vehicle. The conclusion from the study was that the cooling performance for one of the rear-mounted installation was favorable compared to the front-mounted cooling package. This was mainly due to the low vehicle speed, the high fan speed and to fewer obstacles around the cooling module resulting in a lower system restriction within the installation.
2011-09-13
Technical Paper
2011-01-2263
Thomas Bardelang
Driver assistance systems (e.g. the emergency brake assist Active Brake Assist2, or ABA2 for short, in the Mercedes-Benz Actros) are becoming increasingly common in heavy-duty commercial vehicles. Due to the close interconnection with drivetrain and suspension control systems, the integration and validation of the functions make the most exacting demands on processes and tools involved in mechatronics development. In addition to a multi-stage test process focusing on the functions of the driver assistance systems (software), the “electrical” aspects (hardware) also form part of holistic maturity level validation. The test process is supported by state-of-the-art, high-performance tools (e.g. automatable component test benches and overall vehicle HiL systems) which, in particular, allow quick and accurate configuration in line with different vehicle variants.
2011-09-13
Technical Paper
2011-01-2241
Shuming Chen, Dengfeng Wang, Jiqiang Song, Gangping Tan, Bingwu Lu
The basic theory of statistical energy analysis (SEA) is introduced, a commercial heavy duty truck cab is divided into 35 subsystems applying SEA method, and a three dimensional SEA model of the commercial heavy duty truck cab is created. Three basic parameters including modal density, damping loss factor and coupling loss factor are calculated with analytical and experimental methods. The modal density of the regular wall plate of the cab is calculated with traditional formula. The damping loss factors of the regular and complicated plates are obtained using analytical method and steady energy stream method. Meanwhile, the coupling loss factors of structure-structure, structure-sound cavity, and cavity-cavity are also calculated. Four kinds of excitations are in the SEA model, including sound radiation excitation of engine, engine mount vibration excitation, road excitation and wind excitation.
2011-09-13
Technical Paper
2011-01-2182
Peter Gullberg, Lennart Lofdahl, Peter Nilsson
Today CFD is an important tool for engineers in the automotive industry who model and simulate fluid flow. For the complex field of Underhood Thermal Management, CFD has become a very important tool to engineer the cooling airflow process in the engine bay of vehicles. To model the cooling airflow process accurately in CFD, it is of utmost importance to model all components in the cooling airflow path accurately. These components are the heat exchangers, fan and engine bay blockage effect. This paper presents CFD simulations together with correlating measurements of a cooling airflow system placed in a test rig. The system contains a heavy duty truck louvered fin radiator core, fan shroud, fan ring and fan. Behind the cooling module and fan, a 1D engine silhouette is placed to mimic the blockage done by a truck engine. Furthermore, a simple hood is mounted over the module to mimic the guiding of air done by the hood shape in an engine bay.
2011-04-12
Journal Article
2011-01-0962
Noor-u-Zaman Laghari
This paper presents a simulation based analysis of the effect of various non-linearities on vehicle handling of rigid and articulated vehicles. First a description of a non-linear vehicle model is presented and non-linearities, including tires, suspension elasto-kinematics, springing and damping are discussed. Later sections present the simulations results for the effects of each non-linearity. Simulation analyses are carried out for the case of step steering maneuvers, which permit to deduce the overall vehicle model response variation in steady-state and dynamic conditions.
2011-04-12
Technical Paper
2011-01-0983
Md Manjurul Islam, Yuping He
An optimal preview controller is designed for active trailer steering (ATS) systems to improve high-speed stability of articulated heavy vehicles (AHVs). AHVs' unstable motion modes, including jack-knifing and rollover, are the leading course of highway accidents. To prevent these unstable motion modes, the optimal controller, namely the compound lateral position deviation preview (CLPDP) controller, is proposed to control the steering of the front and rear axle wheels of the trailing unit of a truck/full-trailer combination. The corrective steering angle of the trailer front axle wheels is determined using the preview information of the lateral position deviation of the trajectory of the axle center from that of the truck front axle center. In turn, the steering angle of the trailer rear axle wheels is calculated considering the lateral position deviation of the trajectory of the axle center from that of the trailer front axle.
2011-04-12
Technical Paper
2011-01-0979
Hocine Imine, Omar Khemoudj
The aim of the presented work is to estimate the vertical forces of heavy vehicle and identify the unknown dynamic parameters using sliding mode observers approach. This observation needs a good knowledge of some dynamic parameters such as damping coefficient, spring stiffness…etc. We propose in this paper, to identify some of these parameters which are, in practice very difficult to obtain and to measure. This identification will improve the quality of vertical forces estimation. Some experimental results are presented in order to show the quality of the estimation and identification. These estimation results are then compared to the measures coming from an instrumented tractor.
2011-04-12
Technical Paper
2011-01-0311
Ho Teng, Jeffrey Klaver, Talus Park, Gary L. Hunter, Bryan van der Velde
Waste heat recovery (WHR) has been recognized as a promising technology to achieve the fuel economy and green house gas reduction goals for future heavy-duty (HD) truck diesel engines. A Rankine cycle system with ethanol as the working fluid was developed at AVL Powertrain Engineering, Inc. to investigate the fuel economy benefit from recovering waste heat from a 10.8L HD truck diesel engine. Thermodynamic analysis on this WHR system demonstrated that 5% fuel saving could be achievable. The fuel economy benefit can be further improved by optimizing the design of the WHR system components and through better utilization of the available engine waste heat. Although the WHR system was designed for a stand-alone system for the laboratory testing, all the heat exchangers were sized such that their heat transfer areas are equivalent to compact heat exchangers suitable for installation on a HD truck diesel engine.
2010-11-03
Technical Paper
2010-22-0007
Matthew L. Brumbelow, Laura Blanar
Current requirements for rear underride guards on large trucks are set by the National Highway Traffic Safety Administration in Federal Motor Vehicle Safety Standards (FMVSS) 223 and 224. The standards have been in place since 1998, but their adequacy has not been evaluated apart from two series of controlled crash tests. The current study used detailed reviews of real-world crashes from the Large Truck Crash Causation Study to assess the ability of guards that comply with certain aspects of the regulation to mitigate passenger vehicle underride. It also evaluated the dangers posed by underride of large trucks that are exempt from guard requirements. For the 115 cases meeting the inclusion criteria, coded data, case narratives, photographs, and measurements were used to examine the interaction between study vehicles. The presence and type of underride guard was determined, and its performance in mitigating underride was categorized.
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