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Viewing 1 to 30 of 1405
2011-04-12
Technical Paper
2011-01-0109
Flavio Cimolin, Michele Rabito, Andrea Menotti
A complete methodology for the thermo-mechanical analysis of optical devices for the automotive industry is presented. The objective is to predict the thermal field all over the lamp, highlighting the zones with risk of melting, and the deformations and stresses associated with it. The proposed approach is based on a Computational Fluid-Dynamic (CFD) simulation capable of capturing all the heat transfer phenomena occurring inside and outside the lamp: conduction between different components of the device, natural convection associated with density changes in air (buoyancy effects), and radiation heat transfer. The latter requires a fairly complex modeling strategy in order to provide a satisfactory (and conservative) treatment for the source of power, i.e. the filament, which can be obtained by means of a proper inclusion of transparency.
2011-04-12
Technical Paper
2011-01-0111
John D. Bullough
Photometric performance specifications for vehicle headlamp specifications in North America are given in terms of luminous intensity values at various angular locations with the objective of providing sufficient illumination for forward visibility while controlling for glare toward oncoming and preceding vehicle drivers. Abundant evidence suggests that luminous intensity is an appropriate metric for characterizing the degree to which a headlamp can produce disability glare through veiling luminances under a wide range of viewing conditions. Notwithstanding that discomfort glare exhibits a differential spectral sensitivity from the photopic luminous efficiency function used to characterize light, luminous intensity does not always predict discomfort glare. For example, the luminance of the luminous element(s) can be more predictive of discomfort when headlamps are viewed from relative close distances.
2011-04-12
Technical Paper
2011-01-0110
John D. Bullough
Recent technological developments have begun to add a number of new configurations for vehicle forward lighting to the realm of possibility, including high-intensity discharge and light-emitting diode headlamps, and adaptive forward-lighting systems. These systems can offer substantial differences in performance and appearance from conventional filament-based headlamps that have been ubiquitous for many decades. These differences have not gone unnoticed by the U.S. driving public. A review of newspaper articles published during the past several years was conducted in order to assess public perceptions of vehicle headlamps in terms of their ability to support visibility and their impacts on headlamp glare.
2013-04-08
Journal Article
2013-01-1157
Matthew P. Reed, Sheila Ebert-Hamilton
Seat belt anchorage locations have a strong effect on occupant protection. Federal Motor Vehicle Safety Standard (FMVSS) 210 specifies requirements for the layout of the anchorages relative to the seating reference point and seat back angle established by the SAE J826 H-point manikin. Sled testing and computational simulation has established that belt anchorage locations have a strong effect on occupant kinematics, particularly for child occupants using the belt as their primary restraint. As part of a larger study of vehicle geometry, the locations of the anchorage points in the second-row, outboard seating positions of 83 passenger cars and light trucks with a median model year of 2005 were measured. The lower anchorage locations spanned the entire range of lap belt angles permissible under FMVSS 210 and the upper anchorages (D-ring locations) were distributed widely as well.
2013-09-08
Journal Article
2013-24-0177
Philipp Vögelin, Peter Obrecht, Konstantinos Boulouchos
Future engine emission legislation regulates soot from Diesel engines strictly and requires improvements in engine calibration, fast response sensor equipment and exhaust gas aftertreatment systems. The in-cylinder phenomena of soot formation and oxidation can be analysed using a pyrometer with optical access to the combustion chamber. The pyrometer collects the radiation of soot particles during diffusion combustion, and allows the calculation of soot temperature and a proportional value for the in-cylinder soot density (KL). A four-cylinder heavy-duty Diesel engine was equipped in all cylinders with prototype pyrometers and state of the art pressure transducers. The cylinder specific data was recorded crank angle-resolved for a set of steady-state and transient operating conditions, as well as exhaust gas recirculation (EGR) addition and over a wide range of soot emissions.
2013-09-24
Technical Paper
2013-01-2391
John Woodrooffe, Daniel Blower, Carol A. C. Flannagan, Scott E. Bogard, Paul A. Green, Shan Bao
This paper explores the potential safety performance of “Future Generation” automated speed control crash avoidance systems for Commercial Vehicles. The technologies discussed in this paper include Adaptive Cruise Control (ACC), second and third generation Forward Collision Avoidance and Mitigation Systems (F-CAM) comprised of Forward Collision Warning (FCW) with Collision Mitigation Braking (CMB) technology as applied to heavy trucks, including single unit and tractor semitrailers. The research [1[ discussed in this paper is from a study conducted by UMTRI which estimated the safety benefits of current and future F-CAM systems and the comparative efficacy of adaptive cruise control. The future generation systems which are the focus of this paper were evaluated at two separate levels of product refinement, “second generation” and “third generation” systems.
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.
2004-03-08
Technical Paper
2004-01-1222
Scott Kimbrough
Monte Carlo simulation is used to determine the likelihoods of competing scenarios offered by opposing parties involved in a motor vehicle accident. A case study is presented in which there is a dispute among the parties about who passed who first. It is shown that even though both scenarios are possible, one of the scenarios has a much greater likelihood. Besides demonstrating how Monte Carlo simulation provides probability information that can be used to weigh the likelihood of competing scenarios, the case study also provides another example of how Monte Carlo simulation can dig information out of the evidence surrounding an accident that cannot be obtained by other methods.
2004-03-08
Technical Paper
2004-01-1191
Marcus Hiemer, Sebastian Lehr, Uwe Kiencke, Takanori Matsunaga
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.
2004-03-08
Technical Paper
2004-01-1207
Terry D. Day
SIMON is a new 3-dimensional vehicle dynamic simulation model. The capabilities of the model include non-linear handling maneuvers and collision simulation for one or more vehicles. As a new model, SIMON must be validated by comparison against actual handling and collision experiments. This paper provided that comparison. Included in the validation were lane-change maneuvers, alternate ramp traversals, limit maneuvers with combined braking and steering, vehicle-to-vehicle crash tests and articulated vehicle handling tests. Comparison against other models were included. No metric was provided for handling test comparisons. However, statistical analysis of the collision test results revealed the average path range error was 6.2 to 14.8 percent. The average heading error was -4.7 to 0.7 percent. Delta-V error was -1.6 to 7.5 percent. VEHICLE SIMULATION has many uses in the vehicle design and safety industries.
2004-10-26
Technical Paper
2004-01-2717
Wei Liang, Jure Medanic, Roland Ruhl
Control system design is one of the most critical issues for implementation of intelligent vehicle systems. Wide ranged fundamental research has been undertaken in this area and the safety issues of the fully automated vehicles are clearly recognized. Study of vehicle performance constrains is essential for a good understanding of this problem. This paper discusses safety issues of heavy-duty vehicles under automatic steering control. It focuses on the analysis of the effect of tire force saturation. Vehicle handling characteristics are also analyzed to improve understanding of the truck dynamics and control tasks. A simple differential brake control is formulated to show its effect of on reducing trailer swing.
2004-10-26
Technical Paper
2004-01-2648
Christopher W. Ferrrone
Current regulations (49 CFR Part 396.11 and 396.13) mandate that a commercial driver inspect the vehicle at the conclusion of the duty shift. This inspection should note any defects which were noticed during use. This report must be in writing. Unfortunately, many drivers have chosen not to do the inspection, but falsely fill out the report form or simply do nothing at all. A 2002 study shows that as many as 23.7% of all commercial vehicles inspected (levels 1, 2, 5) were found to be defective1. A 2003 study showed that as many as 23.2% of large trucks and 10.3% of commercial buses were deemed out of service2. This poor behavior has a direct effect on safety. Specifically an increased number of accidents related to maintenance defects. In fact, as much as a 5% increase in fatal accidents can be attributed to mechanical defects3. A product has been developed which forces the driver to go to each of the legally prescribed areas of the inspection.
2013-01-09
Technical Paper
2013-26-0017
Marcin Rychter
A tachograph which belongs to the group of ORD devices is the oldest recorder (On Board Recording Devices), and the duty of taking it was led into the USA already in 1939. In order to solve all these problems, they led with Directive of Advice No. 2135/98 from 24 September 1998 of the August of 2004 from the beginning of in the area of the European Union, new type of registering setting up in the road transport - digital tachograph. In order to make it impossible to abuse, a complex system of keys was applied cryptological and of certificates, saved in grating and devices, letting for explicit determining entitlements of users and authenticities of data, cards and devices. In spite of using the most modern keys and securing systems, with respect to elements of the system of digital tachographs a lot of modus operandis were observed so that they registered wrong sizes.
2013-01-09
Technical Paper
2013-26-0038
S. R. Nigade, S. S. Dandge, R. S. Mahajan, H. V. Vankudre
Automotive Industry Standard (AIS)-031 specifies the requirement of strength of large passenger vehicles in case of rollover. In India the certificate is granted after the successful completion of rollover test of the vehicle as per AIS-031. Complete vehicle is used for rollover test in which the vehicle is tilted laterally in the ditch of 800 mm. Such tests with complete vehicle are costly and unaffordable to small bus body builders. So according to Annex 2 of AIS-031, manufacture can carryout rollover on body sections of the vehicle. This is an equivalent approval method which is less costly compared to rollover test on complete vehicle. It requires detailed study of superstructure and selection of weakest body sections from the given superstructure of bus, which in turn requires mass and energy calculation of body section. For doing rollover analysis using body section, bus is selected which has already passed a full-rollover test.
2013-01-09
Technical Paper
2013-26-0029
Sujit Mungale, Leo S
Driver safety is one of the key considerations in truck design and development. Virtual simulation offers opportunities to reduce development time and the number of physical prototypes consumed for design verification and validation for safety parameters. Thus, the application of virtual simulations of crash has become an integral part of the vehicle development process. The continuously emerging scenarios involving challenging test requirements can only be tested by means of virtual simulation techniques. This paper presents simulations that are performed to verify various safety aspects to ensure crashworthiness of the truck cabin. The cabin structure was evaluated for various national/international safety regulations. The FE model and simulation methodology was validated through physical testing and correlated for frontal impact test and roof strength test as per AIS 029/ECE R29. Analysis performed to ensure compliance to upcoming regulation ECE R29 Revision 03 is also discussed.
2013-01-09
Technical Paper
2013-26-0146
A. N. Palkar
Transport plays major a role in the economic growth of the Nation and social welfare of the community. Wrong practices followed by Transport Operators result in environmental degradation and damage to Transport Infrastructure. To improve productivity and Safety of commercial transport sector in India, it is necessary for all transportation users to calculate, analyze and control the internal and external expenses. Dynamic weight of the moving truck is one of the methods which help to improve environmental quality, increase life of roads and bridges, increase life of the vehicle, enhance productivity and ensures high amount of safety. This paper describes System involving sensing techniques, design and integration, operational and feasibility analysis towards making it affordable, accurate and adaptable. This includes a proposal for regulatory bodies to respond to the challenge of implementation of rules for the productivity and safety of commercial road transport.
2014-04-01
Technical Paper
2014-01-0961
Alan R. Wedgewood, Patrick Granowicz, Zhenyu Zhang
Abstract Materials used in automotive components play a key role in providing crash safety to passengers and pedestrians. DuPont's lightweight hybrid material technology, which combines injection molded fiber reinforced plastics with drape molded woven composite materials, provides safety engineers with stiff energy absorbing alternatives. In an effort to validate the hybrid material's crash performance while avoiding expensive crash testing, numerical tools and methodologies are applied in evaluation of a hybrid composite test beam. Multi-scale material models capturing nonlinear strain-rate dependency, anisotropic characteristics, and failure criteria, are calibrated on a fiber reinforced plastic and a woven fabric. The fiber orientation and warp/weft angles were extracted from injection and drape molding simulation.
2013-10-07
Technical Paper
2013-36-0228
Fernanda Meneses Kelly, Helaine Maria Braga Sbampato
On cab-over trucks to access the engine and others components it is necessary to tilt the cab. This is a regular procedure done several times during the vehicle life cycle. In order to make it easier and safer for mechanical tilting system, it was developed an articulated safety bar to sustain and maintain the cab on the open position. On the current bars available in the market, to close the cab it is necessary that the operator get under the cab to disengage the safety bar. This procedure puts the operator under risk because an accident can happen while the disengagement and the cab can close over him. Thinking on that and looking for a better ergonomic and safety situation, the objective of this work is to present a new articulated safety bar that the engagement and disengagement is done automatically with the natural tilting movement of the cab. This solution was developed at Iveco Latin America for adoption on the new Vertis HD and is under patent process.
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
2014-01-0442
James K. Sprague, Peggy Shibata, Jack L. Auflick
Abstract A complete analysis of any vehicular collision needs to consider certain aspects of human factors. However, this is especially true of nighttime collisions, in which a more specialized approach is required. Classical collision investigation (frequently referred to as accident reconstruction) is comprised of kinetic and kinematic considerations including skid analysis, momentum techniques and other methods. While analysis based on these concepts is typically unaffected by low visibility conditions, the opposite is true of the perceptual and cognitive aspects of a “humans-in-the-loop” analysis, which can be enormously impacted by low visibility. Only by applying appropriate human factors techniques can the analyst make a defensible determination of how and why a nighttime collision occurred.
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
2011-01-2294
Thomas Klena II, Daniel Blower PhD, Kurt Fischer P.E., John Woodrooffe
About 360,000 commercial trucks are involved in traffic accidents in the United States per year. Approximately 20,000 truck drivers are injured in those crashes. This study examines traffic crashes of the commercial truck fleet for model years 2000 to 2008 contained in the Trucks Involved in Fatal Accidents (TIFA) and General Estimates System (GES) databases. Specifically, driver injuries, using the KABCO scale (injury severity), were analyzed to determine the association with crash type as well as with the truck configuration. A crash typology was developed to identify crash types, including the type of other vehicle or object struck as well as the impact point on the truck, associated with the most serious injuries. This research focuses on the frequency of commercial vehicle accidents and driver injury levels rather than the cause of the vehicle crash. Based on these findings, example cases from LTCCS were selected. These examples typify the most frequent crashes and injuries.
2011-09-13
Technical Paper
2011-01-2293
Darrell Bowman, William Schaudt
The mission of the Federal Motor Carrier Safety Administration (FMCSA) is to reduce crashes, injuries, and fatalities involving commercial vehicles [1]. According to the FMCSA, the development, evaluation, and deployment of advanced safety technology will be a key to realizing this goal. Currently, there are many safety systems in development that have the potential to significantly reduce crashes on our nation's roadways. For a variety of reasons, the potential benefits that these systems may provide in reducing crashes may never be realized. The Virginia Tech Transportation Institute (VTTI), in cooperation with FMCSA, has developed a program to evaluate promising safety technologies aimed at commercial vehicle operations (CVO). The objective of FMCSA's Advanced System Testing Utilizing a Data Acquisition System on the Highway (FAST DASH) program is to perform quick turnaround and independent evaluations of promising CVO safety technologies.
2011-09-13
Technical Paper
2011-01-2244
Peter Nordin, Par Degerman
Traditionally, an in-vehicle map consists of only one type of data, tailored for a single user function. For example, the navigation maps contain spatial information about the roads. On the other hand, a map built for adaptive cruise control use consists of the detected vehicles and their properties. In autonomous vehicle research, the maps are often built up as an occupancy grid where areas are classified as passable or impassable. Using these kinds of maps separately, however, is not enough to support the traffic safety enhancing and advanced driver assistance systems of today and tomorrow. Instead of using separate systems to handle individual safety or planning tasks, information could be stored in one shared map containing several correlated layers of information. Map information can be collected by any number of different sensor devices, and fusion algorithms can be used to enhance the quality of the information.
2011-08-30
Technical Paper
2011-01-1835
Harri Hillamo, Teemu Anttinen, Ulf Aronsson, Clément Chartier, Oivind Andersson, Bengt Johansson
Combination of flow field measurements, shown in this paper, give new information on the effect of engine run parameters to formation of different flow fields inside piston bowl. The measurements were carried out with particle image velocimetry (PIV) technique in optical engine. Good set of results was achieved even though the feasibility of this technique in diesel engines is sometimes questioned. Main challenge in diesel engines is background radiation from soot particles which is strong enough to conceal the PIV signal. Window staining in diesel engine is also a problem, since very high particle image quality is needed for velocity analysis. All measurements were made in an optical heavy-duty diesel engine. Optical design of engine was Bowditch type [1]. The engine was charged and equipped with exhaust gas recirculation (EGR). The exhaust gas level was monitored by oxygen concentration and the level was matched to former soot concentration measurements.
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.
2000-03-06
Technical Paper
2000-01-0844
Terry D. Day, Allen R. York
A new three-dimensional collision simulation algorithm, called DyMESH (Dynamic MEchanical SHell) was recently introduced.[1]* This paper presents a validation of DyMESH for vehicle vs. barrier collisions. The derivation of the three-dimensional force vs. crush relationship was described previously.[1] Here the application of three-dimensional force vs. crush curves using the outlined methodology is shown to be effective. Nonlinear force versus crush relationships are introduced for use in DyMESH. Included are numerous DyMESH collision simulations of several types of vehicles (e.g., light and heavy passenger car and sport utility) compared directly with experimental collision test results from various types of barrier tests (e.g., full frontal, angled frontal, and offset frontal). The focus here is not on the vehicle’s change in velocity, but on the acceleration vs. time history.
2000-03-06
Technical Paper
2000-01-0461
Denis Wood
An idealization of the elastic compression of the car on the basis of representing the car-body as a cylindrical shell with elastic wrinkles shows that three main factors govern the rebound velocity and hence the coefficient of restitution. These are the 3/2 power of acceleration at maximum dynamic crush, the square of the ratio of car-body mass to overall car mass and the half power of the position of the plastic/elastic crush interface. The model is applied to predict mean rebound characteristics for the car population. A comparison with published experimental data of the coefficient of restitution of the car population in frontal impacts with rigid barriers at impact speeds up to 100 km/h was made. The model predicted values of e similar in magnitude to those of the car population and also predicted a similar reduction in e with increasing impact speed.
2000-03-06
Technical Paper
2000-01-0462
Timothy J. Long
The determination of delta-V from the Barrier Equivalent Velocity (BEV) using energy analysis techniques such as CRASH3 is common in the field of accident reconstruction. This paper introduces a new methodology for determining delta-V in the field of accident reconstruction. Specifically it will introduce a linear analysis technique which utilizes the time to common velocity associated with two vehicles involved in an impact. This method employs all the assumptions used in the derivation of the CRASH3 damage based solution but rather than using an energy based solution a linear Barrier Equivalent Time (BET) method will be employed. This method requires the BEV, and thus the BET, of one of the vehicles involved in a collision and either the stiffness or the crush of the other vehicle. Instead of calculating the energies involved in the collision, the BET is used in conjunction with the time to common velocity in the impact.
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