Search Results

Injury Risk Curves are developed from cadaver data for sternal deflections produced by anterior, distributed chest loads for a 25, 45, 55, 65 and 75 year-old Small Female, Mid-Size Male and Large Male based on the variations of bone strengths with age. These curves show that the risk of AIS ≥ 3 thoracic injury increases with the age of the person. This observation is consistent with NASS data of frontal accidents which shows that older unbelted drivers have a higher risk of AIS ≥ 3 chest injury than younger drivers.

Injury risk curves for SID-IIs thorax and abdomen rib deflections proposed for future NCAP side impact evaluations were developed from tests conducted with the SID-IIs FRG. Since the floating rib guide is known to reduce the magnitude of the peak rib deflections, injury risk curves developed from SID-IIs FRG data are not appropriate for use with SID-IIs build level D. PMHS injury data from three series of sled tests and one series of whole-body drop tests are paired with thoracic rib deflections from equivalent tests with SID-IIs build level D. Where possible, the rib deflections of SID-IIs build level D were scaled to adjust for differences in impact velocity between the PMHS and SID-IIs tests. Injury risk curves developed by the Mertz-Weber modified median rank method are presented and compared to risk curves developed by other parametric and non-parametric methods.

In 1983, General Motors Corporation (GM) petitioned the National Highway Traffic Safety Administration (NHTSA) to allow the use of the biofidelic Hybrid III midsize adult male dummy as an alternate test device for FMVSS 208 compliance testing of frontal impact, passive restraint systems. To support their petition, GM made public to the international automotive community the limit values that they imposed on the Hybrid III measurements, which were called Injury Assessment Reference Values (IARVs). During the past 20 years, these IARVs have been updated based on relevant biomechanical studies that have been published and scaled to provide IARVs for the Hybrid III and CRABI families of frontal impact dummies. Limit values have also been developed for the biofidelic side impact dummies, BioSID, ES-2 and SID-IIs.

The development of the WorldSID 50th percentile male dummy was initiated in 1997 by the International Organization for Standardization (ISO/SC12/TC22/WG5) with the objective of developing a more biofidelic side impact dummy and supporting the adoption of a harmonized dummy into regulations. More than 45 organizations from all around the world have contributed to this effort including governmental agencies, research institutes, car manufacturers and dummy manufacturers. The first production version of the WorldSID 50th male dummy was released in March 2004 and demonstrated an improved biofidelity over existing side impact dummies. Full-scale vehicle tests covering a wide range of side impact test procedures were performed worldwide with the WorldSID dummy. However, the vehicle safety performance could not be assessed due to lack of injury risk curves for this dummy. The development of these curves was initiated in 2004 within the framework of ISO/SC12/TC22/WG6 (Injury criteria).

By adapting vehicle control systems to the skill level of the driver, the overall vehicle active safety provided to the driver can be further enhanced for the existing active vehicle controls, such as ABS, Traction Control, Vehicle Stability Enhancement Systems. As a follow-up to the feasibility study in [1], this paper provides some recent results on data-driven driving skill characterization. In particular, the paper presents an enhancement of discriminant features, the comparison of three different learning algorithms for recognizer design, and the performance enhancement with decision fusion. The paper concludes with the discussions of the experimental results and some of the future work.

A unified approach to collision warning due to in-lane and neighboring traffic is presented. It is based on the concept of velocity obstacles, and is designed to alert the driver of a potential front collision and against attempting a dangerous lane change maneuver. The velocity obstacle represents the set of the host velocities that would result in collision with the respective static or moving vehicle. Potential collisions are simply determined when the velocity vector of the host vehicle penetrates the velocity obstacle of a neighboring vehicle. The generality of the velocity obstacle and its simplicity make it an attractive alternative to competing warning algorithms, and a powerful tool for generating collision avoidance maneuvers. The velocity obstacle-based warning algorithm was successfully tested in simulations using real sensor data collected during the Automotive Collision Avoidance System Field Operational Test (ACAS FOT) [10].

A novel longitudinally sliding overhead video screen monitor was developed to address consumer needs for vehicles equipped with rear seat entertainment and long length sunroofs. Long length sunroof openings in vehicles are causing engineers to mount video screen monitors in locations other than the overhead. Typically, they are mounted on the floor console or on the back of front seat head restraints. Floor console mounted video screen monitors generally do not provide a comfortable viewing distance or angle for second and third row occupants. Head restraint mounted video monitors cause issues with seat shake and two monitors adds to the vehicle cost unnecessarily. The mountable sliding video monitor assembly comprises of a video display screen, brackets for mounting the monitor, a pair of tracks that are movable with respect to each other, a series of ball bearings, and a roof mounting bracket. The inner main track is adapted for mounting the pair of tracks to the vehicle.

The essential concepts for developing a moving deformable barrier that may serve as a vehicle surrogate in assessing vehicle compatibility are described in this paper. Although moving deformable barriers have been used for assessing other safety criteria, their purpose in those cases is to reproduce a limited set of responses in the struck vehicle. An MDB for vehicle compatibility however, needs to be able to reproduce the responses of both the vehicles. The present study describes the concept of developing such barriers by generating ‘response corridors’ for the significant variables by nonlinear finite element simulations and then selecting design parameters such that the MDB response is within this corridor. It is observed that the response of the equivalent MDB representing a light truck vehicle is reproducible when response corridors are utilized.

The concept of height of force has been suggested by some researchers as one possible parameter defining the structural interaction probability between vehicles of different sizes. This proposed parameter was defined as the vertical centroid of forces exerted on a flat barrier surface when a vehicle crashes into the barrier. It is therefore measured as a function of elapsed time since crash. In this paper, the height of force is obtained from theoretical calculations and also measured in crash tests at 56 km/h against barriers instrumented with an array of load cells. It is observed that the measured values of height of force have significant errors which are dependent on factors other than the crash conditions and the properties of the vehicle's structure and geometry. These factors need to be taken into account in future discussions of using the height of force or the average height of force as an indicator of vehicle compatibility.

In 1983, General Motors Corporation (GM) petitioned the National Highway Traffic Safety Administration (NHTSA) to allow the use of the biofidelic Hybrid III midsize adult male dummy as an alternate test device for FMVSS 208 compliance testing of frontal impact, passive restraint systems. To support their petition, GM made public to the international automotive community the limit values that they imposed on the Hybrid III measurements, which were called Injury Assessment Reference Values (IARVs). During the past 20 years, these IARVs have been updated based on relevant biomechanical studies that have been published and scaled to provide IARVs for the Hybrid III and CRABI families of frontal impact dummies. Limit values have also been developed for the biofidelic side impact dummies, BioSID, EuroSID2 and SID-IIs.

This paper examines the effect that test barriers currently used for frontal and side impact tests have had on collision compatibility between different-sized vehicles. The peak force levels generated by the vehicles’ front structures are one of the significant factors in determining vehicle compatibility. It is shown from principles of mechanics that the use of fixed barriers as a test device may lead to higher force levels for front ends of larger vehicles and thus increase the incompatibility between large and small vehicles. Review of data from various sources supports this conclusion that the peak force levels of vehicles’ front ends have increased in proportion to their test mass. Available crash data is also examined for a relationship between NCAP ratings of vehicles and the likelihood of serious and fatal injuries to occupants of those vehicles. These data do not show any relationship between the frontal NCAP ratings of vehicles and their rate of serious or fatal injuries.

Different countermeasure designs for reducing the HIC (d) and to comply with FMVSS201U have been evaluated in many component-level studies by suppliers and OEMs. This study presents guidelines to support future countermeasure and interior designs. FMVSS201U has changed the way OEMs design interiors of the vehicles today. Most recently, much more work is being done to find ways to design interiors of the vehicles that comply with FMVSS201U while keeping the interiors aesthetically pleasing, attaining driver comfort and meeting driver visibility requirements. Introduction of side-rail airbags has further affected countermeasure design and packaging. This study focuses on several countermeasure designs in the side-rail region as used in a mid-sized vehicle implemented to meet FMVSS201U requirements and their efficiency with respect to Head Injury Criterion (HIC) reduction given a fixed packaging space.

The close-fitting cockpit of the modern Indy car single seat race car has the potential to provide a high level of head and neck impact protection in rear and side impacts. Crash investigation has shown that a wide variety of materials have been used as the padding for these cockpits and, as a result, produced varying outcomes in crashes. Additionally, these pads have not always been positioned for optimal performance. The purpose of this study was to investigate the head impact performance of a variety of energy-absorbing padding materials under impact conditions typical of Indy car rear impacts and to identify superior materials and methods of improving their performance as race car head pads. An extensive series of tests with the helmeted Hybrid III test dummy head and neck on an impact mini-sled was conducted to explore head padding concepts.

Forward collision warning (FCW) systems are intended to provide drivers with crash alerts to help them avoid or mitigate rear-end crashes. To facilitate successful deployment of FCW systems, the Ford-GM Crash Avoidance Metrics Partnership (CAMP) developed preliminary minimum functional requirements for FCW systems implemented on light vehicles (passenger cars, light trucks, and vans). This paper summarizes one aspect of the CAMP results: minimum requirements and recommendations for when to present rear-end crash alerts to the driver. These requirements are valid over a set of kinematic conditions that are described, and assume successful tracking and identification of a legitimate crash threat. The results are based on extensive closed-course human factors testing that studied drivers' last-second braking preferences and capabilities. The paper reviews the human factors testing, modeling of results, and the computation of FCW crash alert timing requirements and recommendations.

Crash-test-data on local longitudinal and shear stiffness of the vehicle front is needed to estimate impact severity from car deformation in offset or pole impacts, and to predict vehicle acceleration and compartment intrusion in car-to-car crashes. Repeated full frontal crash-tests were carried out with a load-cell barrier to determine the local longitudinal stiffness with increasing crush. Repeated off-set tests were run to determine shear stiffness. Two single high-speed tests (full frontal and offset) were carried out and compared to the repeated tests to determine the rate sensitivity of the front structure. Four repetitions at 33.4 km/h provided equivalent energy absorption to a single 66.7 km/h test, when rebound was considered. Power-train inertial effects were estimated from highspeed tests with and without power-train. Speed effects averaged 2% per [m/s] for crush up to power-train impact, and post-crash measurements were a reasonable estimate of front-structure stiffness.

This paper discusses a study conducted by GM to better understand the factors that influence injury potential in vehicle-to-vehicle side impacts. A number of other studies have been done which focus primarily on frontal vehicle-to-vehicle compatibility. GM focused on side impact compatibility in this study due to the risk of harm generally associated with this type of crash. Real world field performance was studied through an extensive six-state field analysis of recent model year (‘94+) vehicles. Of particular interest in this study was an efficacy analysis of the MVSS 214 dynamic side impact standard, which was phased-in starting with some 1994 model year passenger cars. Physical side impact crash testing of a 1997 passenger car was used to investigate the relationship of impacting mass, speed, geometric profile and stiffness on side impact intrusion and occupant injury.

Eight lateral dolly rollover tests were conducted on 1983 Chevrolet Malibusata nominal speed of 51.5 km/h (32 mi/h). Four of the vehicles had rollcages, and four had standard production roofs. Unrestrained outboard front GM Hybrid ill dummies with head and neck transducers were used. Numerous cameras documented the vehicle and dummy movements. Detailed vehicle kinematics data allowed quantitative analysis of the conditions for head and neck loads. For both roof structures, the dummies moved upward and outward from their seats due to rotation and acceleration of the vehicle. High head/neck loads were measured when the head contacted a part of the car experiencing a large change in velocity, often that part of the car which struck the ground. The results of this work indicate that roof strength is not an important factor in the mechanics of head/neck injuries in rollover collisions for unrestrained occupants.