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Viewing 271 to 300 of 15869
2014-04-01
Journal Article
2014-01-0803
Tau Tyan, Jeff Vinton, Eric Beckhold, Xiangtong Zhang, Jeffrey Rupp, Nand Kochhar, Saeed Barbat
This paper presents the final phase of a study to develop the modeling methodology for an advanced steering assembly with a safety-enhanced steering wheel and an adaptive energy absorbing steering column. For passenger cars built before the 1960s, the steering column was designed to control vehicle direction with a simple rigid rod. In severe frontal crashes, this type of design would often be displaced rearward toward the driver due to front-end crush of the vehicle. Consequently, collapsible, detachable, and other energy absorbing steering columns emerged to address this type of kinematics. These safety-enhanced steering columns allow frontal impact energy to be absorbed by collapsing or breaking the steering columns, thus reducing the potential for rearward column movement in severe crashes.
2014-04-01
Technical Paper
2014-01-0810
Youmei Zhao
The Hybrid III 50th male dummy is widely used in front impact crash tests in the world to evaluate the vehicle safety performance. The chest impact calibration test should be conducted after certain amount of crash tests to ensure that the dummy has the right performance during the crash tests. The impact velocity in the current chest calibration tests is 6.71 m/s and the chest displacement corridor is 63.5 mm to 72.6 mm, which was based on the cadaver tests carried out in 1970s. After over forty years' development, the vehicle safety has been improved significantly with applications of seat belt and airbag technologies. In the European and China new car assessment program (ENCAP and CNCAP), the higher performance limit for the front impact dummy chest compression is 22mm and the lower performance limit is 50 mm, which is much lower than the dummy chest calibration corridor.
2014-04-01
Technical Paper
2014-01-0811
Horst Lanzerath, Niels Pasligh
Abstract Structural adhesives are widely used across the automotive industry for several reasons like scale-up of structural performance and enabling multi-material and lightweight designs. Development engineers know in general about the effects of adding adhesive to a spot-welded structure, but they want to quantify the benefit of adding adhesives on weight reduction or structural performance. A very efficient way is to do that by applying analytical tools. But, in most of the relevant non-linear load cases the classical lightweight theory can only help to get a basic understanding of the mechanics. For more complex load cases like full car crash simulations, the Finite Element Method (FEM) with explicit time integration is being applied to the vehicle development process. In order to understand the benefit of adding adhesives to a body structure upfront, new FEM simulation tools need to be established, which must be predictive and efficient.
2014-04-01
Technical Paper
2014-01-0300
Tao Zhang, Helder Antunes, Siddhartha Aggarwal
Abstract As vehicles become increasingly connected with the external world, they face a growing range of security vulnerabilities. Researchers, hobbyists, and hackers have compromised security keys used by vehicles' electronic control units (ECUs), modified ECU software, and hacked wireless transmissions from vehicle key fobs and tire monitoring sensors. Malware can infect vehicles through Internet connectivity, onboard diagnostic interfaces, devices tethered wirelessly or physically to the vehicle, malware-infected aftermarket devices or spare parts, and onboard Wi-Fi hotspot. Once vehicles are interconnected, compromised vehicles can also be used to attack the connected transportation system and other vehicles. Securing connected vehicles impose a range of unique new challenges. This paper describes some of these unique challenges and presents an end-to-end cloud-assisted connected vehicle security framework that can address these challenges.
2014-04-01
Journal Article
2014-01-0420
Mathias Poklitar, Lothar Seybold
As part of the launch of the refrigerant R-1234yf there were a number of studies done regarding the ignition behavior of this new refrigerant in passenger cars. These tests were conducted by a number of automobile manufacturers, component suppliers, and the refrigerant supplier under laboratory conditions at the component and vehicle level. In November 2009 the international automotive industry concluded that the R-1234yf can be used safely in automotive air conditioning systems. Further tests were conducted by different automobile manufacturers, suppliers, and the refrigerant supplier under various laboratory and vehicle operation conditions means hot surfaces in the engine compartment. A number of vehicle manufactures have conducted full vehicle crash tests.
2014-04-01
Journal Article
2014-01-0419
Bryan Styles, Jeffrey Santrock, Curtis Vincent, Michael Leffert, Narasimha Putcha
An evaluation methodology has been developed for assessing the suitability of R-1234yf in vehicles. This relates primarily to evaluating the flammability of R-1234yf in the engine compartment during a frontal collision. This paper will discuss the process followed in the methodology, the technical rationale for this process, and the results of the analysis. The specific types of analysis included in the methodology are: exhaust-system thermal characterization, computer simulated crash tests, actual crash tests, teardown and examination of crashed parts, and releases of refrigerant onto hot exhaust manifolds. Each type of analysis was logically ordered and combined to produce a comprehensive evaluation methodology. This methodology has been applied and demonstrates that R-1234yf is difficult to ignite when factors that occur in frontal crashes are simultaneously considered.
2014-04-01
Journal Article
2014-01-0422
Lothar Seybold, Bryan Styles, Ioannis Lazaridis, Hans-Joerg Kneusels
The European Commission (EC) as well as the United States Environmental Protection Agency (EPA) published legislations to regulate or encourage the use of low Global Warming Potential (GWP) refrigerants applied to Mobile Air Conditioning (MAC) systems. Europe mandates a GWP less than 150 of MAC refrigerants for new vehicle types. The thermodynamic refrigerant properties of R-1234yf are slightly different from the properties of R-134a, currently used in MAC systems. Although the basic material data show that R-1234yf is flammable, ignition tests performed for an automotive engine under-hood environment reveal design and packaging influences of its ignition behavior. After extensive collaborative research in 2009, the Society of Automotive Engineers Cooperative Research Team (SAE CRP1234) concluded that R-1234yf is suitable for use in automotive applications. Further ignition risk assessment regarding R-1234yf usage in MAC systems was done by SAE CRP1234-4 in 2013.
2014-04-01
Technical Paper
2014-01-0423
Raúl Ochoterena, Maria Hjohlman, Michael Försth
Abstract Fires in the engine compartments of surface and underground non-rail heavy duty vehicles are still highly frequent. Statistics show that most of the reported fires commenced in the engine compartment and that these were not promptly detected by the drivers. Fires which were not detected rapidly, spread oftentimes beyond the firewall of the engine compartment having notorious economical and environmental repercussions; furthermore, endangering the safety of the occupants. Detecting fires in the engine compartments of heavy duty (HD) vehicles with inexpensive and simple automatic detection systems is in general challenging. High air flows and large amounts of suspended pollutants, together with the complicated geometry and wide range of surface temperatures typically occurring during the normal operation of the vehicle, complicate the reliable operation of almost all types of detectors.
2014-04-01
Technical Paper
2014-01-0426
Jeff D. Colwell
Abstract Results from a full-scale vehicle burn test involving a 1998 compact passenger car were used to evaluate vehicle fire dynamics and how burn patterns produced during the fire correlated with important characteristics of the fire, such as the area of origin. After the fire was initiated at the air filter in the engine compartment, the fire spread locally and, once the temperature near the origin reached about 750°C, the temperature at all but one location within the engine compartment began to increase. These temperatures continued to increase for the next 6 minutes and then a temperature gradient began to develop in the passenger compartment between the ceiling and the floor. About 5 minutes after the engine compartment became fully involved, the ceiling temperature reached about 590°C and flame spread within the passenger compartment increased. Over the next 4 minutes, the passenger compartment also became fully involved.
2014-04-01
Technical Paper
2014-01-0429
Guanyu Zheng, Indrek Wichman, Andre Benard, Hongyu Wang, Xiaohui Li, Jie Gao
Abstract Flame spread over a melting thermally thick composite polymer is investigated in a channel flow above a condensed fuel. The condensed fuel consists of an isotropic (melted layer of) liquid near the heated surface and an anisotropic (not-yet-melted) solid surrounding it. The influence of the solid anisotropy is evaluated by changing the solid conductivity (ksx or ksy) in one particular direction (x in horizontal flame spread direction or y in vertical direction, see schematics in Figure 1) while keeping the other properties fixed. Note that the liquid conductivity kl has no isotropic behavior. Numerically, it is found that the flame spread rate decreases with either increasing ksx or ksy. The decrease with respect to ksy is less than for a comparable case described by the de Ris formula for an isotropic pure solid. The flame spread rate is more accurately determined by an analytical formula derived for spread across a melting solid fuel.
2014-04-01
Technical Paper
2014-01-0397
Pit Schwanitz, Sebastian Werner, Johannes Zerbe, Dietmar Göhlich
Abstract A new methodology for crash sensitive vehicle structures has been developed to be used during the early stage of the Product Development Process (PDP). By frontloading significant and simplified CAE simulations and the use of stochastic optimization methods in conjunction with highly parametric CAD models, new concepts can be quickly identified and evaluated based on reliable product insight. Vehicle crashboxes have been chosen for verification of the methodology. An analysis of different but comparable vehicles showed a large variety of designs although they all absorb the energy of low speed crashes within a velocity of up to 15km/h. A powerful optimization model with a parametric geometry engine, a crash-solver and suitable optimization software, used within a batch process, has been established. The optimal results for one particular crashbox concept are presented to demonstrate the methodology and the benefit of the approach.
2014-04-01
Technical Paper
2014-01-0375
Sanjeev Kumar, Rahul Bettakote, Pinak Deb
Abstract Offset crash compliance of a compact car is severe due to the compact layout and stringent fuel economy, weight and cost targets. Scope of the current work is to improve the structural crash performance of a compact car through CAE, in order to meet the offset frontal crash requirements as per ECE R94 Regulation. The project has been classified in three main phases. First phase includes the evaluation of baseline vehicle in CAE. In order to ensure the accuracy of CAE prediction, a methodology for predicting Spotweld rupture was implemented. Using this methodology, it is possible to find out the location and time of spotweld rupture as well as propagation of spotweld rupture in CAE. CAE results of spotweld rupture prediction showed good agreement with the physical test. In second phase, design iterations were carried out in order to meet the performance targets of structural deformation.
2014-04-01
Technical Paper
2014-01-0351
Ellen L. Lee, Patrick J. Lee, Mark S. Erickson, Wilson C. Hayes
Abstract When vehicle-specific stiffness coefficients cannot be acquired, stiffness coefficient values that are representative of the desired vehicle type, class, wheelbase or weight are routinely used for accident reconstructions. Since the original compilation of representative vehicle stiffness data almost 20 years ago, changes in crash testing standards and other safety and technological improvements in vehicular design have affected vehicle stiffness. While generic frontal stiffness data have been recently updated to reflect these vehicular changes, rear and side stiffness data have not. Structural, geometric and inertial data for over 300 passenger cars and light trucks were collected. Among the vehicles targeted were the top-selling cars, SUVs, vans and pickups for model years 1990 to 2012. Results indicated that all vehicle types demonstrated increases in mean stiffness over the time period considered.
2014-04-01
Technical Paper
2014-01-0336
Payman Khani, Mehrdad S. Sharbaf
Abstract Vehicular Network is an emerging and developing technology to improve traffic management and safety issues, and enable a wide range of value-added services such as collision warning/avoidance. Many applications have been designed to provide safety and comfort for passengers. This technology is a prolific area for attackers who will attempt to challenge the network with their malicious or rational attacks. In this paper we elaborate what a vehicular network is, different kinds of communication in this field, main mechanism and related parts and how vehicular networks work then we introduce some of its applications. After primary familiarity with this system we investigate to different type of attacker, more important security issues, How to secure vehicular networks (security requirements and some tools and methods to achieve secure vehicular networks), difficulties and providing viable security solutions, and at the end briefly explanation of related standards.
2014-04-01
Technical Paper
2014-01-0340
Satoshi Otsuka, Tasuku Ishigooka, Yukihiko Oishi, Kazuyoshi Sasazawa
Abstract In-vehicle networks are generally used for computerized control and connecting information technology devices in cars. However, increasing connectivity also increases security risks. “Spoofing attacks”, in which an adversary infiltrates the controller area network (CAN) with malicious data and makes the car behave abnormally, have been reported. Therefore, countermeasures against this type of attack are needed. Modifying legacy electronic control units (ECUs) will affect development costs and reliability because in-vehicle networks have already been developed for most vehicles. Current countermeasures, such as authentication, require modification of legacy ECUs. On the other hand, anomaly detection methods may result in misdetection due to the difficulty in setting an appropriate threshold. Evaluating a reception cycle of data can be used to simply detect spoofing attacks. However, this may result in false detection due to fluctuation in the data reception cycle in the CAN.
2014-04-01
Technical Paper
2014-01-0794
Yuanyuan Zhang, Shen Wu, Yuliang Shi, Jingang Tu, Jingguo Hu
Abstract The design of front rail is very important to vehicle safety performance. The test and CAE analysis are commonly used methods for design on the component level. Based on experience of impact test designed to simulate the performance of rail in vehicle rigid wall frontal impact, an inclined test is designed to simulate the performance of rail in vehicle offset deformable barrier impact. Two LS-DYNA computer simulation models are established including the effects of plastic strain rate, spot-weld failure, and stamping hardening. The deformation and mechanical properties are studied. The simulation results are correlated to the component tests very well in both cases. The usual impact test and inclined impact test for component rail can represent the main features of the rail performances in the vehicle frontal impact and offset impact respectively. Both of the simulation method and the component test method can support the early stage design for vehicle crash safety.
2014-04-01
Journal Article
2014-01-0802
Tau Tyan, Jeff Vinton, Eric Beckhold, Xiangtong Zhang, Jeffrey Rupp, Nand Kochhar, Saeed Barbat
The objective of this paper focused on the modeling of an adaptive energy absorbing steering column which is the first phase of a study to develop a modeling methodology for an advanced steering wheel and column assembly. Early steering column designs often consisted of a simple long steel rod connecting the steering wheel to the steering gear box. In frontal collisions, a single-piece design steering column would often be displaced toward the driver as a result of front-end crush. Over time, engineers recognized the need to reduce the chance that a steering column would be displaced toward the driver in a frontal crash. As a result, collapsible, detachable, and other energy absorbing steering columns emerged as safer steering column designs. The safety-enhanced construction of the steering columns, whether collapsible, detachable, or other types, absorb rather than transfer frontal impact energy.
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.
2014-04-01
Technical Paper
2014-01-0237
Prasad Rao Yerraguntla, Shashi Kulkarni, Deepak Asthana
Abstract Automotive Audio Signaling system is very vital and is controlled by local regulatory requirements. In India, usage of horn is very frequent due to highly congested traffic conditions, and is in the order of 10 to 12 times per kilometer. This results in the deterioration of the “contact”, which enables the functioning of the device. Hence the device requires premature replacement or frequent tuning, which are time consuming and results an increase in warranty costs and cost of service as well. Thus, to overcome this problem a unique and novel approach is proposed in this paper which enhances the life of the automobile horn, by implementing an additional pair of Contacts on circuit breakers, providing a parallel path for the power supply. This effort ensures that the life of the horn is increased by 5 times than the existing design.
2014-04-01
Technical Paper
2014-01-0198
Gauri Ranadive, Anindya Deb, Bisheshwar Haorongbam
Abstract Load cells and accelerometers are commonly used sensors for capturing impact responses. The basic objective of the present study is to assess the accuracy of responses recorded by the said transducers when these are mounted on a moving impactor. In the present work, evaluation of the responses obtained from a drop-weight impact testing set-up for an axially loaded specimen has been carried out with the aid of an equivalent lumped parameter model (LPM) of the set-up. In this idealization, a test component such as a steel double hat section subjected to axial impact load is represented with a nonlinear spring. Both the load cell and the accelerometer are represented with linear springs, while the impactor comprising a hammer and a main body with the load cell in between are modelled as rigid masses. An experimentally obtained force-displacement response is assumed to be a true behavior of a specimen.
2014-04-01
Technical Paper
2014-01-0172
Edgar Yoshio Morales Teraoka, Shin Tanaka, Tsutomu Mochida
Abstract We develop a simulation tool which reproduces lane departure crashes for the purpose of estimating potential benefits of Lane Departure Warning (LDW) systems in the American traffic environment. Tools that allow a fast evaluation of active safety systems are useful to make better systems, more effective in the real world; however accuracy of the results is always an issue. Our proposed approach is based on developing a simulation tool that reproduces lane departure crashes, then adding the effect of the LDW to compare the cases with and without the safety system, and finally comparing the results of different settings of the safety system. Here, the accurate reproduction of the relevant crashes determines the reliability of the results. In this paper, we present the reproduction of the lane departure crashes occurred in American roads in one year, by using data distributions obtained from retrospective crash databases.
2014-04-01
Technical Paper
2014-01-0167
Masayuki Takemura, Masato Imai, Masahiro Kiyohara, Kota Irie, Masao Sakata, Shoji Muramatsu
Abstract Driver safety continues to be improved by advances in active safety technologies. One important example is Lane Departure Warning (LDW). European regulators soon will require LDW in big cars to reduce traffic accidents and New Car Assessment Programs in various countries will include LDW in a few years. Our focus is on rear cameras as sensing devices to recognize lane markers. Rear cameras are the most prevalent cameras for outside monitoring, and new Kids and Cars legislation will make them obligatory in the United States from 2014. As an affordable sensing system, we envision a rear camera which will function both as a rear-view monitoring device for drivers and as an LDW sensing device. However, there is a great difficulty involved in using the rear camera: water-droplets and dirt are directly attached to the lens surface, creating bad lens condition.
2014-04-01
Technical Paper
2014-01-0149
Chi-Chun Yao, Jin-Yan Hsu, Yu-Sheng Liao, Ming Hung Li
Abstract Vehicle Rollover Prevention/Warning Systems have recently been an important topic in Advanced Driver Assistance Systems (ADAS) of automotive electronics field. This paper will propose a rollover-prevention system implementation with vehicle dynamic model, video-detection technique and rollover index to help the driver avoid accidents as driving into a curve. Due to the reason that vehicle rollover motion analysis needs complicated computation and accurate parameters of vehicle stability in real time, in the first stage a vehicle dynamic model based on Extended Kalman Filter (EKF) algorithm is built, which can estimate vehicle roll/yaw motion in the curve by vehicle sensors. And then the image-based technique will be employed in detecting the front road curvature, and combined in the system to predict vehicle steering status. The final stage is to apply the vehicle rollover index with estimated vehicle motion to predict the dangerous level to drivers for warning.
2014-04-01
Journal Article
2014-01-0157
Mengmeng Yu, Guanglin Ma
In this paper, we present a real-time 360 degree surround system with parking aid feature, which is a very convenient parking and blind spot aid system. In the proposed system, there are four fisheye cameras mounted around a vehicle to cover the whole surrounding area. After correcting the distortion of four fisheye images and registering all images on a planar surface, a flexible stitching method was developed to smooth the seam of adjacent images away to generate a high-quality result. In the post-process step, a unique brightness balance algorithm was proposed to compensate the exposure difference as the images are not captured with the same exposure condition. In addition, a unique parking guidance feature is applied on the surround view scene by utilizing steering wheel angle information as well as vehicle speed information.
2014-04-01
Technical Paper
2014-01-0160
Louis Tijerina, James Sayer
Abstract The objectives of this study were a) to determine how expert judges categorized valid Integrated Vehicle-Based Safety Systems (IVBSS) Forward Collision Warning (FCW) events from review of naturalistic driving data; and b) to determine how consistent these categorizations were across the judges working in pairs. FCW event data were gathered from 108 drivers who drove instrumented vehicles for 6 weeks each. The data included video of the driver and road scene ahead, beside, and behind the vehicle; audio of the FCW alert onset; and engineering data such as speed and braking applications. Six automotive safety experts examined 197 ‘valid’ (i.e., conditions met design intent) FCW events and categorized each according to a taxonomy of primary contributing factors. Results indicated that of these valid FCW events, between 55% and 73% could be considered ‘nuisance alerts’ by the driver.
2014-04-01
Journal Article
2014-01-0158
David LeBlanc, Mark Gilbert, Stephen Stachowski, Rini Sherony
Pre-collision systems (PCS) use forward-looking sensors to detect the location and motion of vehicles ahead and provide a sequence of actions to help the driver either avoid striking the rear-end of another vehicle or mitigate the severity of the crash. The actions include driver alerts, amplification of driver braking as distance decreases (dynamic brake support, DBS), and automatic braking if the driver has not acted or has not acted sufficiently (crash imminent braking, CIB). Recent efforts by various organizations have sought to define PCS objective test procedures and test equipment in support of consumer information programs and potential certification. This paper presents results and insights from conducting DBS and CIB tests on two production vehicles sold in the US. Eleven scenarios are used to assess the systems' performance. The two systems' performance shows that commercial systems can be quite different.
2014-04-01
Technical Paper
2014-01-0163
Stanley Chien, Qiang Yi, David Good, Ali Gholamjafari, Yaobin Chen, Rini Sherony
Abstract While the number of traffic fatalities as a whole continues to decline steadily over time, the number of pedestrian fatalities continues to rise (up 8% since 2009) and comprises a larger fraction of these fatalities. In 2011 there were 4,432 pedestrians killed and an estimated 69,000 pedestrian injuries [1]. A new generation of Pedestrian Pre-Collision Systems (PCS) is being introduced by car manufactures to mitigate pedestrian injuries and fatalities. In order to evaluate the performance of pedestrian PCS, The Transportation Active Safety Institute (TASI) at Indiana University-Purdue University Indianapolis is developing a set of test scenarios and procedures for evaluating the performance of pedestrian PCS with the support of the Collaborative Safety Research Center of Toyota. Pedestrian crashes are complex in that there are many aspects about location, driver behavior, and pedestrian behaviors that may have implications for the performance of the PCS.
2014-04-01
Technical Paper
2014-01-0164
Cheng-Lung Lee, Hongyi Zhang, Hong Nguyen, Yu-Ting Wu, Christopher Smalley, Utayba Mohammad, Mark J. Paulik
Abstract A novel multi-modal scene segmentation algorithm for obstacle identification and masking is presented in this work. A co-registered data set is generated from monocular camera and light detection and ranging (LIDAR) sensors. This calibrated data enables 3D scene information to be mapped to time-synchronized 2D camera images, where discontinuities in the ranging data indicate the increased likelihood of obstacle edges. Applications include Advanced Driver Assistance Systems (ADAS) which address lane-departure, pedestrian protection and collision avoidance and require both high-quality image segmentation and computational efficiency. Simulated and experimental results that demonstrate system performance are presented.
2014-04-01
Technical Paper
2014-01-0688
Kambiz Jahani, Sajjad Beigmoradi
Abstract Adequate visibility through the automobile windscreen is a critical aspect of driving, most often at very low temperatures when ice tends to be formed on the windscreen. The geometry of the existing defroster system needs to be improved in the vehicles, with the main aim of substantial increase in air mass flow reaching the windscreen through defroster nozzles and appropriate velocity distribution over the windscreen, while respecting all packaging constraints. The reason of this study is to investigate the windscreen deicing behavior of a vehicle by means of Computational Fluid Dynamics (CFD) with the main concern of improving deicing process by design an appropriate defroster. Two different defrosters with completely different geometry are considered for this purpose. A detailed full interior model of an existing vehicle is created via CAE tools.
2014-04-01
Technical Paper
2014-01-0478
Wade D. Bartlett, Duane Meyers
Abstract The evasive capabilities of motorcycles and riders are often an important consideration when analyzing a motorcycle crash. Specifically, the longitudinal distance or time required for a motorcycle to move laterally some distance can be of critical interest. Previous publications on this topic have not all measured the same thing and have often included limited test data so their results can be difficult to compare or apply. In addition to reviewing some of the literature on the topic, this paper will present the results of a series of tests conducted with four riders on four motorcycles swerving 2 m (6.5 ft) to their left after passing through a gate at speeds of 40 to 88 km/h (25 to 55 mi/h). The most recent testing involved relatively skilled riders who had faster transitions and greater willingness to lean than the “average” rider generally described in the literature.
Viewing 271 to 300 of 15869

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