Display:

Results

Viewing 1 to 30 of 3351
2017-03-28
Technical Paper
2017-01-1561
Anton A. Tkachev, Nong Zhang
Rollover prevention is one of the prominent priorities in vehicle safety and handling control. A promising alternative for roll angle cancellation is the active hydraulically interconnected suspension. This paper represents the analytical model of active hydraulically interconnected suspension system followed by the general simulation. Passive hydraulically interconnected suspension systems have been widely discussed and studied up to now. This work specifically focuses on the active hydraulically interconnected suspension system. Equations of motion of the system are formalised first. The entire system consists of two separate systems that can be modelled independently and further combined together for simulation. One of the two systems is 4 degrees of freedom half-car model which simulates vehicle lateral dynamics and vehicle roll angle response to lateral acceleration in particular.
2017-03-28
Technical Paper
2017-01-0059
Barbaros Serter, Christian Beul, Manuela Lang, Wiebke Schmidt
Today, highly automated driving is paving the road for full autonomy. From basic cruise control to complex automated systems, there is a wide range of technology on the road and more highly automated systems are being rigorously tested that are soon going to be available to consumers. Highly automated vehicles can monitor the environment and make decisions more accurately and faster than humans to create safer driving conditions while ultimately achieving full automation to relieve the driver completely from participating in driving. As much as this transition from advanced driving assistance systems to fully automated driving will create frontiers for re-designing the in-vehicle experience for customers, it will continue to pose significant challenges for the industry as it did in the past and does so today.
2017-03-28
Technical Paper
2017-01-0264
Venkatesh Babu, Ravi Thyagarajan, Jaisankar Ramalingam
In this paper, the capability of three methods of modelling detonation of high explosives (HE) buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) (2) Structured - Arbitrary Lagrangian-Eulerian (S-ALE), and (3) Arbitrary Lagrangian-Eulerian (ALE),are investigated. The ALE method of modeling the effects of buried charges in soil is well known and widely used in blast simulations today Due to high computational costs, inconsistent robustness and long run times, alternate modeling methods such as Smoothed Particle Hydrodynamics (SPH) and DEM are gaining more traction. In all these methods, accuracy of the analysis relies not only on the fidelity of the soil and high explosive models but also on the robustness of fluid-structure interaction. These high-fidelity models are also useful in generating fast running models (FRM) useful for rapid generation of blast simulation results of acceptable accuracy.
2017-03-28
Technical Paper
2017-01-1422
Toby Terpstra, Seth Miller, Alireza Hashemian
Photogrammetry and the accuracy of a photogrammetric solution is reliant on the quality of photographs and the accuracy of pixel location within the photographs. A photograph with lens distortion can create inaccuracies within a photogrammetric solution. Due to the curved nature of a camera’s lens(s), the light coming through the lens and onto the image sensor can have varying degrees of distortion. There are commercially available software titles that rely on a library of known cameras, lenses, and configurations for removing lens distortion. However, to use these software titles the camera manufacturer, model, lens and focal length must be known. This paper presents two methodologies for removing lens distortion when camera and lens specific information is not available. The first methodology uses linear objects within the photograph to determine the amount of lens distortion present. This method will be referred to as the straight-line method.
2017-03-28
Technical Paper
2017-01-1411
Gary A. Davis
For at least 15 years it has been recognized that pre-crash data captured by event data recorders (EDR) might help illuminate the actions taken by drivers prior to a crash. In left-turning crashes where pre-crash data are available from both vehicles it should be possible to estimate features such as the location and speed of the opposing vehicle at the time of turn initiation and the reaction time of the opposing driver. Difficulties arise however from measurement errors in pre-crash speed data and because the EDR data from the two vehicles are not synchronized; the resulting uncertainties should be accounted for. This paper describes a method for accomplishing this using Markov Chain Monte Carlo computation. First, planar impact methods are used to estimate the speeds at impact of the involved vehicles. Next, the impact speeds and pre-crash EDR data are used to reconstruct the vehicles’ trajectories during the approximately 5 seconds preceding the crash.
2017-03-28
Technical Paper
2017-01-1425
Brian Jones, Michael Calabro, Justin Brink, Scott Swinford
In minor inline rear-end accidents, vehicle damage is the primary tangible indicator of impact severity or vehicle change in velocity (V). Correspondingly, a technique for calculating change in velocity based on vehicle damage involves application of the Momentum Energy Restitution (MER) method. Offset inline rear-end testing, wherein minimal vehicle bumper or contact surface engagement occurs, has not been readily published to date. Thus, instrumented offset inline rear-end impacts were performed utilizing a 1997 Ford F-150 Pickup, 1996 Kia Sephia, and 1995 Chrysler LeBaron GTC. Vehicle engagement involved approximately 30.5 cm (12 in.) and 40.6 cm (16 in.) of lateral overlap with impact speeds ranging between 1.3 m/s (3 mph) to 4 m/s (9 mph). Test results indicated that a 30.5 cm (12 in.) or less lateral overlap between vehicle impacting surfaces promoted sideswipe impacts or an incomplete transfer of momentum relative to the bullet vehicle’s impact speed.
2017-03-28
Technical Paper
2017-01-1429
Sung Rae kim, Inju Lee, Hyung joo Kim
In motor-vehicle frontal crashes, occupants often suffer from the abdominal injuries when the lap belt excurses over the pelvic bone, commonly referred to as submarining. Especially, it is well known that the obese occupants frequently get injured caused by submarining due to out-of-position belt fittings. This paper aims to investigate the interaction between the pelvis and the lap belt during a frontal crash event. For this purpose, twelve sled tests on four obese female Post-Mortem Human Subjects (PMHS) and four sled tests on the Hybrid III 50th dummy were carried out. In each test, a 3D motion capture system was installed to track the movement of the pelvis and the lap belt. Moreover, the validated subject specific FE model scaled from the 50th percentile male GHBMC model to fit to obese female PMHS in prior study was also simulated.
2017-03-28
Technical Paper
2017-01-1437
William Bortles, Sean McDonough, Connor Smith, Michael Stogsdill
The data obtained from event data recorders found in airbag control modules, powertrain control modules and rollover sensors in passenger vehicles has been validated and used to reconstruct accidents for years. Recently, a system has been introduced that will allow crash investigators and reconstructionists to access, preserve and analyze data from infotainment and telematics systems found in passenger vehicles. The infotainment and telematics systems in select vehicles retain navigation data in the form of tracklogs that provide a time history of vehicle geolocation that may be useful in reconstructing a crash. This paper presents testing in which the GPS navigation data imaged from the vehicle is compared to independent GPS instrumentation to analyze the accuracy of the retrieved navigation data.
2017-03-28
Technical Paper
2017-01-1414
William Bortles, David Hessel, William Neale
When the steer axle of a vehicle with protruding wheel studs makes contact with another vehicle or object in a sideswipe configuration, the tires and wheel studs of the vehicle can deposit distinct geometrical patterns onto the surfaces it contacts. Prior research has demonstrated how relative speeds between the two vehicles and surfaces can be calculated through analysis of the distinct patterns. This paper presents a methodology for performing this analysis by visually modeling the interaction between wheel studs and various surfaces, and presents a method for automating the calculations of relative speed between vehicles. This methodology also augments prior research by demonstrating how the visual modeling and simulation of the wheel stud contact can extend to almost any surface interaction that may not have any previous prior published tests, or test methods that would be difficult to setup in real life.
2017-03-28
Technical Paper
2017-01-1430
Tony R. Laituri, Scott G. Henry
To consider injury trends and to establish bases for potential future risk analyses, we categorized head injuries in real-world frontal crashes as being "brain-related," "bone-related," and/or "otherwiserelated." Specifically, we studied adult drivers in towaway, 11-1 o'clock, full-engagement frontal crashes in the National Automotive Sampling System (NASS, 1995-2012 calendar years, 1985-2012 model-year light passenger vehicles). Those data were considered subject to three levels injury (AIS1+, AIS2+, AIS3+) , two levels of restraint (properly-belted, unbelted), and two eras of technology, based on driverairbag fitment (Older Vehicles, Newer Vehicles). For each injury level, 88 possible bins of data were formed to quantify injury rates for the various head-injury categories, eras, restraint levels, speed changes, and crash severities.
2017-03-28
Technical Paper
2017-01-1412
Christopher H. Goddard, David Price
Various mechanisms have been used to drive speedometers and other instrument gauges. This paper reviews the mechanisms used; in particular investigates the ability of stepper motors which have become the most common instrument motor in the last decade to freeze at the apparent reading prior to impact. Stepper motors require power to drive the needle to any indicated position, including having to return it to zero. Hence if power to the instrument is lost as a result of a collision, there is no power to move the needle and it should be left at the reading shown at the moment the power was lost. However, not all stepper motor instruments are the same and before accepting the reading, a number of criteria need to be considered to give a level of confidence in the result. As part of recent ITAI (Institute of Traffic Accident Investigators) crash test events in the UK, a number of instrument clusters were installed in vehicles to simulate both frontal and side impacts.
2017-03-28
Technical Paper
2017-01-1431
Ke Dong, Brian Putala, Kristen Ansel
Out-of-position (OOP) driver tests were designed to address concerns about airbag introduced injury in situations while the occupant is nearer to the airbag module than in a normal seated position. The 5th percentile female has instrumentation for measuring ATD sternum displacement (potentiometer) and acceleration (accelerometers) which can be used to compute compression rate. This paper documents a study investigating the capability of the chest accelerometers to accurately assess non-distributed loading of the chest during this test configuration. The study included ATD mechanical loading and instrumentation review. Finite element analysis was conducted using a Hybrid 3 - 5th percentile female ATD correlated to testing. The correlated restraint model was utilized with a Hybrid 3 – 50th percentile male ATD. A 50th percentile male Global Human Body Model was then applied for enhanced anatomical review.
2017-03-28
Technical Paper
2017-01-1410
Richard F Lambourn, James Manning
It occasionally happens, following a collision between a car and a pedestrian or in a deliberate assault with a motor vehicle, that the pedestrian comes to be caught or wedged beneath the car, and that the driver then travels on for a considerable distance, afterwards claiming to have been unaware of the presence of the person. In such incidents, investigators are often incredulous that the driver should not have been able to “feel” that there was something underneath his car, and that he did not stop at least to find out what the problem was. The only practical way of investigating the matter further is to carry out practical tests with a suitable car and dummy. This paper describes the tests performed by the authors following one such incident, and begins with accounts of two previous incidents investigated in a more subjective fashion.
2017-03-28
Technical Paper
2017-01-1427
Daniel Koch, Gray Beauchamp, David Pentecost
Tire disablement events can cause a drag force that slows a vehicle’s speed. In this study, the magnitude of the deceleration was measured in 29 high speed tread separation and air loss tests. The tires tested were circumferentially cut to create partial and full tread separations, or prepared to lose air rapidly. The deceleration rates were corrected for the slope of the road, aerodynamic drag and rolling resistance of each vehicle tested. These deceleration rates can assist in reconstructing the speed of a vehicle involved in an accident following a tire disablement.
2017-03-28
Technical Paper
2017-01-1299
Nagurbabu Noorbhasha, Brendan J. O'Toole
The objective of this research is to optimize the structure of a roll cage for an off-road vehicle that was used for SAE Baja competition by UNLV SAE Baja team. Baja SAE is an intercollegiate competition to design, fabricate, and race a small, single passenger, off-road vehicle powered by a 10 HP Briggs & Stratton 4-Stroke gasoline engine. Since the off-road vehicle is powered by a small capacity engine, the weight of the structure is very critical and must be optimized to improve the performance of the vehicle. In an effort to optimize the structure, a roll cage model was generated using CAD and a finite element (FE) analysis was performed on the structure. A grid independence study was carried out on the FE model to reduce the analysis computation time and space. The effects of stress and deformation of the structure were studied for a linear static frontal impact analysis on roll cage for various mesh sizes.
2017-03-28
Technical Paper
2017-01-1424
Mark Fabbroni, Jennifer Rovt, Mark Paquette
Collision reconstruction often involves calculations and computer simulations, which require an estimation of the weights of the involved vehicles. Although weight data is readily available for automobiles and light trucks, there is limited data for heavy vehicles, such as tractor-semitrailers, straight trucks, and the wide variety of trailers and combinations that may be encountered on North American roads. Although manufacturers always provide the gross vehicle weight ratings (GVWR) for these vehicles, tare weights are often more difficult to find, and in-service loading levels are often unknown. The resulting large uncertainty in the weight of a given truck can often affect reconstruction results. In Canada, the Ministry of Transportation of Ontario conducted a Commercial Vehicle Survey in 2012 that consisted of weight sampling over 45,000 heavy vehicles of various configurations.
2017-03-28
Technical Paper
2017-01-1433
Enrique Bonugli, Joseph Cormier, Matthew Reilly, Lars Reinhart
The purpose of this study was to determine the frictional properties between the exterior surface of a motorcycle helmet and ‘typical’ roadway surfaces. These values were compared to abrasive papers currently recommended by government helmet safety standards and widely used by researchers in the field of oblique motorcycle helmet impacts. A guided freefall test fixture was utilized to obtain nominal impact velocities of 5, 7 and 9 m/s. The impacting surfaces were mounted to an angled anvil to simulate off-centered oblique collision. Head accelerations and impact forces were measured for each test. Analysis of the normal and tangential forces imparted to the contact surface indicated that the frictional properties of abrasive papers differ from asphalt and cement in magnitude, duration and onset. Reduction in head acceleration, both linear and angular, were observed when asphalt and cement were used as the impacting surface.
2017-03-28
Technical Paper
2017-01-1456
Shailesh Pawar, Sandeep Sharma, Manoj Sharma
The heavy and light commercial vehicles are equipped with protection devices to enhance the safety of occupants in small vehicles in the event of under run and to reduce the degree of intrusions. These protection devices are SUPD (side under run protection devices), RUPD (rear under run protection devices), FUPD (front under run protection devices). Any passenger vehicles can impact with the heavy vehicles either from rear, front or side and meet the sever accident. During these types of impacts, there is a possibility that the passenger vehicle will go under the front, rear or side part of the truck and bus and cause serious injuries to the occupants. Side underrun protection device is one of the important system implemented in Vehicles as a regulatory requirement (as per IS 14682: 1999) for passive safety of N2 and N3 category vehicles.
2017-03-28
Technical Paper
2017-01-1462
Haiyan Li, Xin Jin, Hongfei Zhao, Shihai Cui, Binghui Jiang, King H. Yang
Computational human body models, especially detailed finite element models are suitable for investigation of human body kinetic responds and injury mechanisim. A real-world lateral vehicle-tree impact accident was reconstructed by using finite element method according to the accident description in the CIREN database. At first, a baseline vehicle FE model was modified and validated according to the NCAP lateral impact test. The interaction between the car and the tree in the accident was simulated using LS-Dyna software. Patameters that affect the simulation results, such as the initial pre-crash speed, impact direction, and the initial impact location on the vehicle, was analyzed. The parameters were determined by matching the simulated vehicle body deformations and kinematics to the accident reports.
2017-03-28
Technical Paper
2017-01-1446
Allen Charles Bosio, Paul Marable, Marcus Ward, Bradley Staines
With the introduction of the new USNCAP protocols, which incorporated assessment of a 5th percentile occupant in the passenger seat, a variety of solutions were introduced to achieve 5 star accreditation using additional restraint solutions such as, but not exclusively, knee airbags, dual pretensioning and adaptive venting . The engineering challenge was to understand and design a passenger airbag system that recognized and adapted itself to the smaller, belted, 5th percentile female, while adequately restraining the larger, unbelted, 50th percentile male. In this paper we describe the development of an airbag restraint which achieves 5 star performance levels, where the design focus from the outset was to achieve minimal head, neck & chest injury risk. This was achieved without the need for active adaptive features. The CAE tools Madymo and Radioss were critical to the design of a new patented airbag which repeatedly demonstrated USNCAP RRS <=0.66.
2017-03-28
Technical Paper
2017-01-1423
Alan F. Asay, Christopher D. Armstrong, Bradley Higgins, John Steiner
Traditional accident reconstruction analysis methodologies include the study of the crush-energy relationship of vehicles. The process of estimating crush-energy and delta-v in real world collisions is primarily based upon a comparison of structural crush between a vehicle involved in a real world collision with that of a test vehicle. This process is well known and documented in the scientific literature. However, this process is limited to both the availability of the crash test data and the proximity of the structure engaged on the vehicle in the test. The largest source of publically available crash tests is the National Highway Traffic Safety Administration (NHTSA) crash tests database. NHTSA has conducted numerous Federal Motor Safety Vehicle Standard (FMVSS) compliance and New Car Assessment Program (NCAP) crash tests of many passenger cars and pickup trucks sold in the United States.
2017-03-28
Technical Paper
2017-01-1439
John C. Steiner, Christopher Armstrong, Tyler Kress
The use of the United States’ Global Positioning System (GPS) to assist with the management of large commercial fleets of vehicles is quickly becoming commonplace. The GPS system can be used to track fleet vehicles resulting in more efficient and safe operations by refining and streamlining routing and operations. GPS-based fleet telematics data is also valuable for reducing unnecessary engine idle times and minimizing fuel consumption. Driver performance and policy adherence can also be monitored, for example by transmitting data regarding seatbelt usage when there is vehicle movement. Despite its advantages for fleet management, there are performance limitations that affect the utility of the system for analysis and reconstruction of accidents. The U.S. Air Force, responsible for maintaining and operating the GPS space and control segments, publishes information about these limitations.
2017-03-28
Technical Paper
2017-01-0435
Koundinya Narasimha Kota, Bharath Sivanandham
Abstract Active roll control system offers better solution in improving the vehicle comfort and handling. There are various ways of active roll control system actuation like electrical, hydraulic and electro-hydraulic combination systems etc. For the current work, dual hydraulic actuator based active roll control mechanism is used. In this paper we have used integrated Model-In-Loop (MIL) based simulation approach to validate the active roll control system. Dual linear hydraulic actuators models and control logic for improving the roll dynamics of the vehicle is built using Matlab/Simulink. The desired car characteristics maneuver and road profiles are modeled in IPG Car maker(a Model in Loop based tool). Simulink model is integrated with Car Maker model for validating the performance in extreme cornering maneuvers, such as double steer step, slalom 18m, fishhook.
2017-03-28
Technical Paper
2017-01-0080
Qilu Wang, Bo Yang, Gangfeng Tan, Shengguang Xiong, XiaoXiao Zhou
Mountain road winding and bumpy,traffic accidents caused by speeding frequently happened, mainly concentrated on curves. The present Curve warning system research are based on CCD, but the existing obstacles, weather , driving at night and road conditions directly affect the accuracy and applicability. The research is of predictability based on the geographic information and can told the driver road information and safety speed ahead of the road to reduce the incidence of accidents. In this paper, the main research contents include: to estimate forward bend curvature through the node classification method based on the digital map. Braking based on vehicle dynamics before entering the curve is used to identify the road. The critical safety speed which do not occur side-slip is calculated with the radius of curvature , side friction factor and so on using the vehicle lateral dynamics.
2017-03-28
Technical Paper
2017-01-1468
Do Hoi KIm
Previous studies have dealt with the relationship between the injury criteria of dummies and vehicle drop during high-speed head on collisions. Ultimately, vehicle drops are found to worsen the injury criteria of dummies when exceeding 60mm during high-speed crashes. Also, vehicle drops affected the front side member of the vehicle body the most. The present study dealt with methods of improving vehicle drops by enhancing the connective structure of the front side member, the short gun, and the A pillar. Analyses on various vehicles confirm that arch-shaped front side members are an extremely important factor. Furthermore, if the short gun and A pillar are properly connected at the top of the arch shape on the front side member during crashes, the deformation energy of the vehicle could be converted to energy for lifting the A pillar lower. With a so-called body lift structure, BLS has been applied to the B/C segment vehicles of Hyundai and KIA.
2017-03-28
Technical Paper
2017-01-1301
Deepak A. Patil, Hrishikesh Buddhe
Frontal collisions account for the majority of car accidents. This paper presents the energy absorption properties of hexagonal honeycomb structures of varying cellular geometries under frontal impact simulations. Honeycomb cellular meta-material structures offer many distinct advantages over homogenous materials because their effective material properties depend on both their constituent material properties and their geometric cell configuration. The effective static mechanical properties, such as the modulus of elasticity and rigidity and Poisson’s ratio, of honeycomb cellular meso-structures are control by variations of their cellular geometry. While the crushing responses in terms of energy absorption with different cellular shape observe a difference in the generalization of honeycombs with and varying geometric parameters. Unit assembly model technique is used to evaluate the performance vehicle in frontal load cases.
2017-03-28
Journal Article
2017-01-0112
Mingming Zhao, Hongyan Wang, Junyi Chen, Xiao Xu, Yutong He
Rear-end accident is one of the most important collision modes in China, which often leads to severe accident consequences due to the high collision velocity. Autonomous Emergency Braking (AEB) system could perform emergency brake automatically in dangerous situation and mitigate the consequence. This study focused on the analysis of the rear-end accidents in China in order to discuss about the parameters of Time–to-Collision (TTC) and the comprehensive evaluation of typical AEB. A sample of 84 accidents was in-depth investigated and reconstructed, providing a comprehensive set of data describing the pre-crash matrix. Each accident in this sample is modeled numerically by the simulation tool PC-Crash. In parallel, a model representing the function of an AEB system has been established. This AEB system applies partial braking when the TTC ≤ TTC1 and full braking when the TTC ≤ TTC2.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
Abstract This paper reports on seventy additional tests conducted using a mechanical device described by Bonugli et al. [4]. The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined in order to define the system stiffness of the combined vehicle components. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The compression phase of a low speed collision can be modeled as a spring that is defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values [1,5].
2017-03-28
Technical Paper
2017-01-1413
Nathan A. Rose, Neal Carter, David Pentecost, Alireza Hashemian
Abstract This paper investigates the dynamics of four motorcycle crashes that occurred on or near a curve (Edwards Corner) on a section of the Mulholland Highway called “The Snake.” This section of highway is located in the Santa Monica Mountains of California. All four accidents were captured on video and they each involved a high-side fall of the motorcycle and rider. This article reports a technical description and analysis of these videos in which the motion of the motorcycles and riders is quantified. To aid in the analysis, the authors mapped Edwards Corner using both a Sokkia total station and a Faro laser scanner. This mapping data enabled analysis of the videos to determine the initial speed of the motorcycles, to identify where in the curve particular rider actions occurred, to quantify the motion of the motorcycles and riders, and to characterize the roadway radius and superelevation throughout the curve.
2017-03-28
Technical Paper
2017-01-1420
Kirsten White, Raymond Merala
Abstract This study presents a method to characterize the accuracy and precision of video-acceleration-position (VAP) devices, and presents results from testing of one such vehicle camera (“dashcam”) with global positioning system (GPS) used by taxi companies nationwide. Tests were performed in which vehicle kinematic data were recorded in a variety of real world conditions simultaneously by the VAP device, accelerometers, and a proven GPS-based speed sensing and data acquisition system. Data from the VAP device was compared to data collected by the reference instruments to assess timing, precision, and accuracy of reported parameters. Still images from the VAP video recording were compared with three dimensional laser scan data in order to analyze field of view. Several case studies are discussed, and some guidelines and cautions are provided for use of VAP data in accident reconstruction applications.
Viewing 1 to 30 of 3351

Filter