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Technical Paper

Design of the Occupant Protection System for Critical Side Impact requirements

2009-12-13
2009-28-0055
This paper describes the critical side impact requirements of overall global side regulations and the sensitivity of various side injury parameters on NCAP rating assessment. The federal side impact regulation FMVSS 214 made very stringent by adding oblique pole impact in addition to moving deformable barrier (MDB) test. Though the vehicle velocity is less in oblique pole test, the dynamic intrusions are more which causes severe injury for 5th and 50th %le occupants than MDB test. It was observed that typical injury parameter in side impact requirements is the thorax compression than other injuries, because it is very sensitive than Pelvic, Abdomen regions. To meet these critical injury requirements in side impact, the optimal side restraint system is mandatory in order to develop a safer vehicle with high NCAP score. The side restraint system includes side airbags (thorax and curtain), Hip pusher block/foam padding, door trim arm rest, seat belts and seats.
Technical Paper

Research and Development on the Modular Dummy Model

2009-01-21
2009-26-0056
The modular dummy model is a new concept to represent a crash dummy in computer simulation. The modular dummy model could be a solution with combination of acceptable responses and quick run times. The approach of the modular dummy model is to take an existing standard model and create rigid modules of all major dummy components (Head, Thorax, Pelvis, Femurs, Tibias, Feet, etc.), which are fully interchangeable between deformable and rigid modules. The special run time efficient component models for the neck and lumbar spine are also developed for the modular dummy. Mass and inertial properties of each rigid module are derived from the corresponding deformable part. The joint and connection definitions are shared between the rigid and deformable modules. The users only need to decide and select which modules should be used in order to achieve the best compromise between CPU time and accuracy for the specific application.
Journal Article

Pressure Based Sensing Approach for Front Impacts

2011-04-12
2011-01-1443
This study demonstrates the use of pressure sensing technology to predict the crash severity of frontal impacts. It presents an investigation of the pressure change in the front structural elements (bumper, crush cans, rails) during crash events. A series of subsystem tests were conducted in the laboratory that represent a typical frontal crash development series and provided empirical data to support the analysis of the concept. The pressure signal energy at different sensor mounting locations was studied and design concepts were developed for amplifying the pressure signal. In addition, a pressure signal processing methodology was developed that relies on the analysis of the air flow behavior by normalizing and integrating the pressure changes. The processed signal from the pressure sensor is combined with the restraint control module (RCM) signals to define the crash severity, discriminate between the frontal crash modes and deploy the required restraint devices.
Journal Article

Study on Characteristics of Event Data Recorders in Japan; Analysis of J-NCAP and Thirteen Crash Tests

2011-04-12
2011-01-0810
Event Data Recorder (EDR) is a device to record vehicle and occupant information for a brief period of time before, during and after a crash event. EDR is one of the promising devices for accident reconstruction by recording important information e.g. vehicle speed, engine speed, brake switch, throttle and delta-V. However, in order to use EDR for an accident investigation, reliability and accuracy of those EDR data must be examined firstly. The aim of this study is to evaluate the characteristics of EDR and to understand the performance of EDR for the improvement of accident reconstruction with more reliable and accurate information on an accident in Japan. The analysis is based on J-NCAP crash tests from 2006 to 2009 with corresponding EDR datasets. Full-overlap frontal collision test and offset frontal collision test of fourteen car models were analyzed.
Technical Paper

Securing the Path for Camera Systems by Visual Loop Testing

2011-04-12
2011-01-0451
Advanced Driver Assistance Systems (ADAS) in modern cars contain actively reacting functionality, like autonomous steering or braking assistants. The demand for functional Hardware-in-the-Loop (HiL) testing of these systems contains the need to create realistic models of the car's surrounding. Generating high-resolution photorealistic 3D-graphics in real-time proved to be critical, but with modern graphics technology, “Visual Loop” test-systems can be built. Integrated into test processes and with automated test case generation, these testing tools can improve the performance and quality of functional verification and validation significantly.
Technical Paper

Appling CAE to Understand the Causality of Dummy Neck Injury Readings

2011-04-12
2011-01-1069
The progress of computer technology and CAE methodology makes it possible to simulate dummy injury readings in vehicle crash simulations. Dummy neck injuries are generally more difficult to simulate than injuries to other regions such as the head or chest. Accordingly, improving the accuracy of dummy neck injury data is a major concern in frontal occupant safety simulations. This paper describes the use of an advanced airbag modeling methodology to improve the accuracy of dummy neck injury readings. First, the following items incorporated in the advanced airbag model are explained. (1) The Finite Point Method (FPM) is used to simulate the flow of gas. (2) A folding model is applied to simulate the folded condition. (3) The fabric material properties used in the simulation take into account anisotropy in the fiber directions and the nonlinear, hysteresis characteristics of stiffness.
Journal Article

A Component Test Methodology for Simulation of Full-Vehicle Side Impact Dummy Abdomen Responses for Door Trim Evaluation

2011-04-12
2011-01-1097
Described in this paper is a component test methodology to evaluate the door trim armrest performance in an Insurance Institute for Highway Safety (IIHS) side impact test and to predict the SID-IIs abdomen injury metrics (rib deflection, deflection rate and V*C). The test methodology consisted of a sub-assembly of two SID-IIs abdomen ribs with spine box, mounted on a linear bearing and allowed to translate in the direction of impact. The spine box with the assembly of two abdominal ribs was rigidly attached to the sliding test fixture, and is stationary at the start of the test. The door trim armrest was mounted on the impactor, which was prescribed the door velocity profile obtained from full-vehicle test. The location and orientation of the armrest relative to the dummy abdomen ribs was maintained the same as in the full-vehicle test.
Technical Paper

Load Transfer Through Hybrid III Shoulder and its Possible Effect on Chest Acceleration

2011-04-12
2011-01-1096
This paper illustrates that the shoulder complex of the Hybrid III allows a load transfer from the upper extremities that can be associated with an increase of the thoracic spine acceleration. The force transferred by the Hybrid III shoulder and clavicle joints is a result of both inertial forces and contact forces acting on upper extremities. Its possible effect on the 3ms chest injury parameter raises some concerns. First, the Hybrid III shoulder joint compliance has been questioned by other publications. Second, there appears to be no documentation in the literature that supports a relationship between shoulder joint load and chest injury risk in humans. Lastly, kinematics of the upper extremities can vary from test to test, especially between different test facilities, which could contribute to variation of chest response. In this paper, original experimental and simulation data are used to explore this topic.
Technical Paper

Rollover Crash Test Results: Steer-Induced Rollovers

2011-04-12
2011-01-1114
A series of rollover tests was conducted in a real-world environment in which a vehicle was driven or towed to highway speed then steered to induce a rollover. This research presents analysis of the rollover phase of five tests. In each test, the steering maneuver was initiated on-pavement, and the rollover was caused by tire-to-ground interaction. Tests included vehicles that tripped both on-pavement and on soil. Four tests ended with the vehicle at rest off-road, and one ended with the vehicle remaining on the pavement. A programmable remote control radio was used to steer the vehicles through a double-step steer maneuver to result in a rollover. The test vehicles were instrumented and data was collected during each test, including steering, suspension motion, rotational rates, and accelerations. A Global Positioning System (GPS) speed sensor (VBOX III manufactured by Racelogic) was used to monitor the vehicle speed. Data from all tests is presented in the Appendix .
Technical Paper

Rollover Testing of Recreational Off-Highway Vehicles (ROVs) for Accident Reconstruction

2011-04-12
2011-01-1117
This paper presents results of full-scale instrumented rollover testing on ROV type recreational vehicles. Five tests were conducted using two instrumented side-by-side ROVs at speeds between 20 and 32 mph on unpaved surfaces. Each test vehicle was brought to speed and released, allowing remote steering inputs to initiate turn sequences resulting in rollover. Accelerations were determined using x, y, and z axis accelerometers mounted at the vehicle CG and recorded using a robust data acquisition system. Roll rates were measured using a rotation rate sensor. Roll rates and key acceleration events are presented for each test. Mapping and measurement of the test site includes photography and digital survey of resulting tire marks, impact marks and gouging. Documentation and reconstruction of test roll sequences includes roll rates, vehicle positions and velocities, peak accelerations by impact, and scratch mark and damage examination. These are included in the appendix .
Journal Article

Effects of Safety Belt Pretensioning on ATD Motion in Rigid Fixture Rollover Testing

2011-04-12
2011-01-1118
General Motors conducted a series of subsystem rigid fixture sled rollover tests to evaluate the effects of various safety belt pyrotechnic pretensioners on Anthropomorphic Test Device (ATD) head motion. Twelve tests were conducted using a rigid fixture comprised of a modified compact sport utility vehicle (SUV) body encased in a rigid exoskeleton. The testing simulated the pre-trip/trip, free flight and first roof to ground impact phases of a field representative curb trip initiation rollover crash test with a roof to ground impact angle of approximately 180 degrees. Various combinations of safety belt lap anchor, buckle and retractor pretensioners were tested and film analysis was used to measure trailing side ATD head motion relative to the vehicle. Additionally, a new analysis technique of measuring the reduction of lap webbing length during the crash event was developed for evaluating the ability of a restraint system to reduce ATD head motion during the rollover tests.
Technical Paper

A Simulation-Based Calibration and Sensitivity Analysis of a Finite Element Model of THOR Head-Neck Complex

2011-04-12
2011-01-1123
The THOR-NT dummy has been developed and continuously improved by NHTSA to provide automotive manufacturers an advanced tool that can be used to assess the injury risk of vehicle occupants in crash tests. With the recent improvements of finite element (FE) technology and the increase of computational power, a validated FE model of THOR may provide an efficient tool for the design optimization of vehicles and their restraint systems. The main goal of this study was to improve biofidelity of a head-neck FE model of THOR-NT dummy. A three-dimensional FE model of the head and neck was developed in LS-Dyna based on the drawings of the THOR dummy. The material properties of deformable parts and the joints properties between rigid parts were assigned initially based on data found in the literature, and then calibrated using optimization techniques.
Technical Paper

Influence of Tinted Windshield Glass and its Orientation on Visual Performance of Driver During Night Time and its Effect on Road Safety

2013-01-09
2013-26-0033
Visibility through windscreen along with front lighting system is one of the most important elements of road safety. Windscreen also provides the good visibility to driver to drive safely during night time. As per the rule windscreen visual light transmission should be minimum 70%. Windshields are made-up of tinted glass which produces light transmission varying from 70% to 95%. Windscreen installation is various from vehicle to vehicle, the visual light transmittance at different installation angle and its effect to the visibility are not fully understood. Vehicle headlamps and front fog lamps are evaluated for the illumination without consideration of driver's visibility with the combination of wind screen and its installation angle. This paper describes the effect of different ranges of tinted wind shield glass on driver's visibility at various installation angle of windshield along with the headlamp illumination.
Technical Paper

An Alternate Methodology to Measure the A-Pillar Obstruction in Passenger Cars

2013-01-09
2013-26-0030
With ever increasing demand for vehicle safety and fuel efficiency, Body in White (BIW) designers are striving for vehicle's body mass optimization leading to the development of lean designs. Nevertheless, considerations like ergonomics also play a significant role while deciding the vehicle structure. As an example, A-pillar (front pillar) plays a major role in vehicle's passive safety. Increase in its cross section size, beyond a particular grade and gauge optimization is eminent to meet target requirements of rigidity and crash. However, the increased obstruction because of the wider section would not only lead to poor visibility and a claustrophobic feeling to the driver but also lead to a lesser response time for him or her to prevent a collision. Obstruction from A-pillar can be a subjective feeling of driver but it should also be quantified and measured to optimize the A-pillar structure. Numerous methodologies are being adopted globally to measure the A-pillar obstruction.
Technical Paper

Image Segmentation Technique for on Road Pedestrian Detection During Night Time

2013-01-09
2013-26-0025
On-road pedestrians are becoming vulnerable due to the increasing road traffic. They are more vulnerable during night time due to low visibility and increasing risk due to driver's fatigue while driving. This work is aimed at developing a segmentation algorithm based on the dual-level adaptive thresholding approach, referenced from the available literatures. However the normal approaches show certain shortfalls especially for a near distance pedestrian. The work presented here explains the modifications to the dual thresholding algorithm to enhance the segmentation. Instead of fully dependent on the intensity of object as suggested in the referenced literature, the color properties of the object and saturation intensity is also used during preprocessing and segmentation. Further, rather than using 1-D odd window, 1-D even window is used to calculate the different thresholding levels.
Technical Paper

Development of an Advanced Thorax / Shoulder Complex for the THOR Dummy

2013-01-09
2013-26-0019
Thoracic injuries are one of the main causes of fatalities and severe injuries in car crashes. The tools available today for studying these injuries are not up to par with the latest implementation of restraint systems and airbags. THORAX-FP7 is a collaborative medium scale project under the Seventh Framework. It focuses on the reduction and prevention of thoracic injuries through an improved understanding of the thoracic injury mechanisms and the implementation of this understanding in an updated design for the thorax-shoulder complex of the THOR dummy. The updated dummy should enable the design and evaluation of advanced restraint systems for a wide variety (gender, age and size) of car occupants.
Technical Paper

Self Adaptive Front Lighting Mechanism for the Fixed Headlamp Mounted Two Wheelers

2013-01-09
2013-26-0065
A sports segment two wheelers should never compromise in styling, performance and safety. One of the styling and performance improving feature is adding fairing to the vehicle with the headlamp fixed in it. The headlamp will not rotate with the steering system causing visibility issues to the rider during cornering. In order to correct these visibility issues, a self adaptive front lighting mechanism has been constructed to rotate the headlamp about its vertical and longitudinal axes during cornering based on the steering angle and the vehicle lean angle. Visibility area has been increased significantly towards the inner side of the corner. This system works mechanically to make it affordable in Indian market.
Technical Paper

A Study on Improvements in Side Impact Test vs CAE Structural Correlation

2013-01-09
2013-26-0034
Computer Aided Engineering (CAE) plays an important role in the product development. Now a days major decisions like concept selection and design sign off are taken based on CAE. All the Original Equipment Manufacturers (OEMs) are putting consistent efforts to improve accuracy of the CAE results. In recent years confidence on CAE prediction has been increased mainly because of good correlation of CAE predictions with the test results. Defining proper correlation criteria and using a systematic approach helps significantly in building the overall confidence level for predictions given by CAE simulations. Representation of manufacturing effects on material properties and material failure in the simulation is still a big challenge for achieving a good CAE correlation. This paper describes side impact test vs CAE correlation. The important parameters affecting the CAE correlation were discussed.
Technical Paper

Development of Lens Condition Diagnosis for Lane Departure Warning by Using Outside Camera

2014-04-01
2014-01-0167
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.
Technical Paper

Qualitative Analysis of Principal Stress on Free Boundary under Dynamic Load Based on Dynamic Photoelastic Method

2014-04-01
2014-01-0826
Abstract When an object was subjected an impact loading, stress wave was produced in the object. Studying the regularity of stress-wave propagation was significant to the study of objects subjected to impact loading. When stress wave travelled in the object, principal stress on free boundary was useful to theoretical analysis and calculation. In this article, a new kind of dynamic photoelastic apparatus was used. Isochromatic and isoclinic of the object subjected to impact loading could be obtained combining dynamic photoelastic experiment and related test equipment. By analyzing the isoclinic, there would be a conclusion that the angle between the isoclinic and the free boundary was not 0°or 90°. So the values of the two principal stress on the boundary were all not 0. The result obtained from the electrometric method came to the same conclusion. Analysis showed the result of dynamic photoelastic method was compatible with the result of electrometric method.
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