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Technical Paper

Field Effectiveness Calculation of Integrated Safety Systems

The vehicle dynamics of all scenarios from the database will be simulated in PC-Crash, an accident-reconstruction software. Since the brake assist is obligatory from 2012 on, the system and its effect on each single accident scenario will be modeled.
Technical Paper

Methods of Occupant Kinematics Analysis in Automobile Crashes

Understanding occupant kinematics is an important part of accident reconstruction, particularly with respect to injury causation. Injuries are generally sustained as the occupant interacts with the vehicle interior surfaces and is rapidly accelerated to the struck component's post-impact velocity. This paper describes some methods for assessing occupant kinematics in a collision, and discusses their limitations. A useful technique is presented which is based on free-body analysis and can be used to establish an occupant's path of motion relative to the vehicle, locate the point of occupant contact, and determine the occupant's velocity relative to that contact location.
Technical Paper

RASSI: A Systematic Approach for On-site Crash Investigations and In-depth Accident Data Collection in India

India's growing trend of serious road accidents has created an urgent need to understand the primary factors involved in these crashes and in the resulting severe injuries and fatalities. In order to improve the safety of highways and automobiles for all road users, a consortium of safety researchers and vehicle manufacturers has come together to collect first-hand, detailed and consistent crash and injury data for traffic accidents on Indian roads. After three years of pilot studies, a methodology, called Road Accident Sampling System - India (RASSI), has been developed for conducting on-site crash investigations and collecting in-depth accident data on road accidents in India. The processes developed under RASSI to investigate onsite crashes and collect quality accident data suitable for detailed analysis are described. The program includes all types of traffic accidents with injury outcomes.
Technical Paper

Near and Far-Side Adult Front Passenger Kinematics in a Vehicle Rollover

In this study, U.S. accident data was analyzed to determine interior contacts and injuries for front-seated occupants in rollovers. The injury distribution for belted and unbelted, non-ejected drivers and right front passengers (RFP) was assessed for single-event accidents where the leading side of the vehicle rollover was either on the driver or passenger door. Drivers in a roll-left and RFP in roll-right rollovers were defined as near-side occupants, while drivers in roll-right and RFP in roll-left rollovers were defined as far-side occupants. Serious injuries (AIS 3+) were most common to the head and thorax for both the near and far-side occupants. However, serious spinal injuries were more frequent for the far-side occupants, where the source was most often coded as roof, windshield and interior.
Technical Paper

Mobility in mining: Issues for road safety improvement

The increase of mining activities in the northern regions of Chile has brought about a new environment in terms of mobility to those areas where this industry has moved forward. This change has not only affected road traffic accidents on public roads of the surrounding mines, but also the inner organization of the mining companies, which must fulfill strict regulations, achieving the highest levels of safety. Given this situation, the current road traffic accidentology with respect to the northern regions of Chile has been analyzed in this paper. The results of the analysis have shown the relevant weight of the human factor and the state of the infrastructure related to the number of road fatalities. Thus, this paper provides solutions to combine the existing driver-centered technologies together with GPS systems that can track the movement of several vehicles and the design of safety berms in mine haul roads to mitigate the number of fatalities associated with mining activity.
Technical Paper

Real-world car accident reconstruction methods for crash avoidance system research

Development of crash avoidance systems and active safety systems must not be only based on experimental knowledge. The goal is to provide an efficient answer to still unsolved severe real-world car crashes which occur despite enhanced passive safety devices. This requires to know precisely the pre-crash conditions during about 3 to 10 seconds before impact. The paper describes the multidisciplinary systemic approach leading to the comprehensive methodology used in accident reconstruction in order to determine the best scenario, and to assess initial car speeds, paths and events in the different phases of the accident. This has already been carried out for about 400 car crashes with car occupant injuries (including 6% fatal and 10% severely injured). The necessity of collecting data on the spot of the crash scene is highlighted. Three well-trained investigators are involved.
Technical Paper

Rollover Crash Sensing and Safety Overview

This paper provides an overview of rollover crash safety, including field crash statistics, pre- and rollover dynamics, test procedures and dummy responses as well as a bibliography of pertinent literature. Based on the 2001 Traffic Safety Facts published by NHTSA, rollovers account for 10.5% of the first harmful events in fatal crashes; but, 19.5% of vehicles in fatal crashes had a rollover in the impact sequence. Based on an analysis of the 1993-2001 NASS for non-ejected occupants, 10.5% of occupants are exposed to rollovers, but these occupants experience a high proportion of AIS 3-6 injury (16.1% for belted and 23.9% for unbelted occupants). The head and thorax are the most seriously injured body regions in rollovers. This paper also describes a research program aimed at defining rollover sensing requirements to activate belt pretensioners, roof-rail airbags and convertible pop-up rollbars.
Technical Paper

Challenges in Simulation and Sensor Development for Occupant Protection in Rollover Accidents

Automotive occupant safety continues to evolve. At present this area has gathered a strong consumer interest which the vehicle manufacturers are tapping into with the introduction of many new safety technologies. Initially, individual passive devices and features such as seatbelts, knee- bolsters, structural crush zones, airbags etc., were developed for to help save lives and minimize injuries in accidents. Over the years, preventive measures such as improving visibility, headlights, windshield wipers, tire traction etc., were deployed to help reduce the probability of getting into an accident. With tremendous new research and improvements in electronics, we are at the stage of helping to actively avoid accidents in certain situations as well as providing increased protection to vehicle occupants and pedestrians.
Technical Paper

Modeling of Occupant Impacts During Rollover Collisions

This paper describes a modeling method whereby the occupant impacts during rollover collisions may be predicted with sufficient accuracy to predict their injury level. By using MADYMO to reconstruct the vehicle motions during a rollover collision and the subsequent vehicle accelerations, the model may also be used to calculate occupant impact accelerations if reasonable estimates of interior surface stiffnesses are used.
Journal Article

Vehicle and Occupant Responses in a Friction Trip Rollover Test

Objective: A friction rollover test was conducted as part of a rollover sensing project. This study evaluates vehicle and occupant responses in the test. Methods: A flat dolly carried a Saab 9-3 sedan laterally, passenger-side leading to a release point at 42 km/h (26 mph) onto a high-friction surface. The vehicle was equipped with roll, pitch and yaw gyros near the center of gravity. Accelerometers were placed at the vehicle center tunnel, A-pillar near the roof, B-pillar near the sill, suspension sub-frame and wheels. Five off-board and two on-board cameras recorded kinematics. Hybrid III dummies were instrumented for head and chest acceleration and upper neck force and moment. Belt loads were measured. Results: The vehicle release caused the tires and then wheel rims to skid on the high-friction surface. The trip involved roll angular velocities >300 deg/s at 0.5 s and a far-side impact on the driver’s side roof at 0.94 s. The driver was inverted in the far-side, ground impact.
Technical Paper

Evaluation of the Effectiveness of Volvo’s Pedestrian Detection System Based on Selected Real-Life Fatal Pedestrian Accidents

The objective of this work is to test the potential benefit of active pedestrian protection systems. The tests are based on real fatal accidents with passenger cars that were not equipped with active safety systems. Tests have been conducted in order to evaluate what the real benefit of the active safety system would be, and not to gain only a methodological prediction. The testing procedure was the first independent testing in the world which was based on real fatal pedestrian accidents. The aim of the tests is to evaluate the effectiveness of the Volvo pedestrian detection system. The in-depth accident database ZEDATU contains about 300 fatal pedestrian traffic accidents in urban areas. Eighteen cases of pedestrians hit by the front end of a passenger vehicle were extracted from this database. Cases covering an average traffic scenario have been reconstructed to obtain detailed model situations for testing.
Technical Paper

A Study on Head Injury Risk in Car-to-Pedestrian Collisions Using FE-Model

Head injury is quite frequently occurred in car-to-pedestrian collisions, which often places an enormous burden to victims and society. To address head protection and understand the head injury mechanisms, in-depth accident investigation and accident reconstructions were conducted. A total of 6 passenger-cars to adult-pedestrian accidents were sampled from the in-depth accident investigation in Changsha China. Accidents were firstly reconstructed by using Multi-bodies (MBS) pedestrian and car models. The head impact conditions such as head impact velocity; position and orientation were calculated from MBS reconstructions, which were then employed to set the initial conditions in the simulation of a head model striking a windshield using Finite Element (FE) head and windshield models. The intracranial pressure and stress distribution of the FE head model were calculated and correlated with the injury outcomes.
Technical Paper

Modeling the Effects of Seat Belt Pretensioners on Occupant Kinematics During Rollover

The results of a number of previous studies have demonstrated that seat-belted occupants can undergo significant upward and outward excursion during the airborne phase of vehicular rollover, which may place the occupant at risk for injury during subsequent ground contacts. Furthermore, testing using human volunteers, ATDs, and cadavers has shown that increasing tension in the restraint system prior to a rollover event may be of value for reducing occupant displacement. On this basis, it may be argued that pretensioning the restraint system, utilizing technology developed and installed primarily for improving injury outcome in frontal impacts, may modify restrained occupant injury potential during rollover accidents. However, the capacity of current pretensioner designs to positively impact the motion of a restrained occupant during rollover remains unclear.
Technical Paper

A Pilot Study at National Highway-8 for On-Site Crash Data Collection and In-Depth Investigation in India

The importance of on-site, in-depth accident research studies has been recognized internationally especially in developed countries. In order to address problems related to road safety, it is important to understand the epidemiology and causation of crashes. For this an in-depth investigation of the crash site, vehicles involved and injury details is required. Detailed crash information helps in analysing the events leading to crash and developing safety measures and/or intervention to reduce crashes. In order to pilot such an activity in India, an in-depth accident data collection activity had been carried out on national highway connecting Delhi to Jaipur (NH-8) for a duration of over a year by a joint team of IIT-Delhi and NATRiP. A total of 1220 road traffic accidents (RTA) notifications were received by the team, of which 186 cases were attended and detailed data was collected in a pre-decided format.
Technical Paper

Reconstruction of Pediatric Occupant Kinematic Responses Using Finite Element Method in a Real-World Lateral Impact

Computational human body models, especially detailed finite element models are suitable for investigation of human body kinematic responses and injury mechanism. 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. Parameters that affect the simulation results, such as the initial pre-crash speed, impact direction, and the initial impact location on the vehicle, were analyzed. The parameters were determined by matching the simulated vehicle body deformations and kinematics to the accident reports.
Technical Paper

Design and Evaluation of an Affordable Seatbelt Retrofit for Motor Coach Occupant Safety

Prevention of passenger ejection from motor coach seats in the case of rollover and frontal crashes is critical for minimizing fatalities and injuries. This paper proposes a novel concept of affordably retrofitting 3-point seatbelts to protect passengers during these significant crash scenarios. Currently, the available options involve replacement of either the entire fleet, which takes time to avoid extremely high costs, or all seats with new seats that have seatbelts which is still expensive. Alternatively, this paper presents the development of an innovative product that can be installed in seat belt-ready bus structures at a fraction of the cost. The efficacy of the design is studied using finite element analysis (FEA) to meet Federal Motor Vehicle Safety Standards (FMVSS) 210 standards for conditions involved in frontal and side impacts.
Technical Paper

Analysis of Finite Element Models for Head Injury Investigation: Reconstruction of Four Real-World Impacts

Previous studies have shown that both excessive linear and rotational accelerations are the cause of head injuries. Although the head injury criterion has been beneficial as an indicator of head injury risk, it only considers linear acceleration, so there is a need to consider both types of motion in future safety standards. Advanced models of the head/brain complex have recently been developed to gain a better understanding of head injury biomechanics. While these models have been verified against laboratory experimental data, there is a lack of suitable real-world data available for validation. Hence, using two computer models of the head/brain, the objective of the current study was to reconstruct four real-world crashes with known head injury outcomes in a full-vehicle crash laboratory, simulate head/brain responses using kinematics obtained during these reconstructions, and to compare the results predicted by the models against the actual injuries sustained by the occupant.