Predicting proximity of driver head and thorax to the steering wheel (original) (raw)
Related papers
Annual proceedings / Association for the Advancement of Automotive Medicine. Association for the Advancement of Automotive Medicine, 2002
Recent laboratory investigations suggest that a deploying airbag may fracture the forearm. These studies positioned the arm in an overhand grasp placing the forearm over the airbag module. However, there is little published data on how drivers grip the steering wheel and the general proximity of the upper extremity to the airbag module. The objective of the current study was to identify 'real world' upper extremity positions and to correlate these with accident and experimental data. A survey of the National Automotive Sampling System (NASS) for the years 1995-99 revealed an increase in the number of forearm fractures due to driver-airbag interaction. As NASS does not provide the position of the forearm, common upper extremity positions were identified in a volunteer driving population. These positions were simulated using a specially instrumented 50(th) percentile male dummy to determine the relative injury risk for the different positions. Analysis showed that an under han...
2017
In an effort to improve crash protection for drivers seated in wheelchairs, a recent study by the University of Michigan Transportation Research Institute (UMTRI) conducted 48-km/h frontal sled tests and computer simulations for midsize-male and small female anthropomorphic test devices (ATDs), seated in wheelchairs in the driver position of a minivan. The tests and simulations used various seat belt configurations, including good and poor belt fit, and no belt restraints. The computer models that were validated using results from the sled tests were conducted with and without air bag deployment to investigate the potential benefits of steering wheel air bags for drivers seated in wheelchairs and the potential risks of being injured by deploying air bags. The results of the UMTRI sled tests and computer simulations showed that the deployment energy of advanced steering wheel air bags was not a concern with regard to causing serious injuries to drivers seated in wheelchairs. Rather, ...
OBSERVATIONAL STUDIES OF CAR OCCUPANTS' POSITIONS
The use of current seat belts has been shown to be effective in reducing deaths and serious injuries to restrained car occupants by 50% compared to unrestrained. Real world accident studies have identified limitations to the performance of set belts. This has led to the next major evolution in restraint design which is the development of the intelligent restraints. The options for intelligent retraints include making the system variable, to take account of occupant age and sex, occupant weight, occupant sitting position (relative to forward structures) and the severity of the collision which is occurring thus changing the characteristics of the seat belt. Data are presented on how a population of drivers and passengers actually sit in cars, and accident analyses will illustrate how injury outcome varies with age and sex for restrained occupants. The implications of the position of the hands on the steering wheel during normal driving and the rotational orientation of the steering wheel during an impact for airbag design are also included.
A DoE method in predicting injuries to out-of-position occupants from torso-only side-impact airbags
Airbag systems such as frontal and side-impact airbags are developed to reduce occupant injuries during vehicle collisions. Yet, such systems have caused serious injuries to outof-position occupants especially to smaller females and children. The primary objective of this study is to examine the different influential factors such as mass flow rate, fabric permeability ratio, fabric maximum inflated depth that contribute to OOP occupant injuries in airbag-related accidents. A mathematical model of Heidelberg stationary test, vehicle interior and seat mounted side-airbag is developed using the MADYMO code 7.4.2. The mathematical model of the airbag used in this study is a torso-only seat-mounted side-impact airbag (SAB). The airbag model is validated against similar study conducted by Hallman et al. and the results are found to be in good agreement. Once the airbag model is validated, the airbag and the anthropomorphic test dummy are positioned in a vehicle environment to better predict the occupant injuries in a static environment.
Accident Analysis & Prevention, 2012
The objective of this research is to elucidate the effect of side curtain airbag deployment on occupant injuries and safety when the occupant is either in-position or out-of-position (OOP). We used side impact vehicle collision simulations with a 1996 Dodge Neon model, which was further modified to include a side curtain airbag, a seatbelt, and a 50th percentile Hybrid III dummy. The airbag used in the study was inflated using both the uniform pressure (UP) and smooth particle hydrodynamics (SPH) methods. Inposition and OOP simulations were performed to assess and establish guidelines for airbag aggressivity thresholds and occupant position versus risk of injury. Three different OOP scenarios (OOP1, OOP2, OOP3) were initially setup following the work of Lund , then modified such that the dummy's head was closer to the airbag, increasing the chance of injury caused by the airbag. The resultant head acceleration as a function of time for in-position and OOP simulations shows that both UP and SPH methods produce similar peak accelerations in cases where the airbag is fully inflated prior to impact. In all cases, the head peak accelerations and the head injury criteria for simulations with an airbag were significantly lower when compared with the no airbag case, which would typically indicate that the use of an airbag results in improved occupant protection during side impact. However, in the case of OOP2 and OOP3, the neck flexion forces actually increase significantly when compared with the no airbag case. This finding indicates that the HIC and neck flexion forces criterion are in conflict and that there may be a tradeoff in terms of occupant injury/safety with a side curtain airbag that is strongly correlated to the occupant position. Consequently, this study shows that safety devices result in a significant effect on occupant injury/safety when the occupant is in OOP conditions. Moreover, in some cases, simulation results show that the side curtain airbag may not make the occupant safer. This study requires further investigation of the vehicle-specific airbag and its interaction with an occupant in various OOP conditions.
Patterns of injury associated with automobile airbag use
Postgraduate Medical Journal, 1998
The wide use of automobile airbags has undoubtedly reduced the mortality and the incidence of serious injuries from motor vehicle accidents. However, automobile airbags appear to be associated with a variety of injuries including fatal injuries, ocular injuries, upper limb and chest injuries. Further improvements in airbag design together with education of the general public in their use should help reduce airbag-related injuries.
Effectiveness of airbag restraints in frontal crashes - what European field studies tell us
2000
UK and German field accident data show that European airbag systems provide a 32% and 55% reduction in Abbreviated Injury Scale (AIS) 2+ injury to the cranium and face when belted drivers sustain Maximum Abbreviated Injury Scale (MAIS) 2+ injury in frontal crashes. The greatest benefits of airbags were seen in crashes exceeding 30 km/h delta V (velocity change). Airbags do not appear to affect a reduction in chest injuries and they exert a neutral influence on the incidence of cervical spine strain. Drivers in airbag vehicles sustained proportionately more AIS 2+ upper limb injuries than those in vehicles without airbags. That difference was largely the result of a higher proportion of clavicle fractures. Overall, deployment thresholds correlate well to the onset of moderate/serious head injury but there appear to be some unnecessary deployments at low crash severities. (A) For the covering abstract of the conference see ITRD E206422.
Journal of Forensic Sciences, 2017
The Office of the Chief Coroner for Ontario database for 2011-2012 was used to compare fatal injury patterns in drivers whose third-generation airbags deployed compared to first-and second-generation airbag deployments and airbag nondeployments with and without seatbelt use. There were 110 frontal and offset frontal crashes analyzed. The small sample size meant that the odds of craniocerebral, cervical spinal, thoracic, and abdominal injuries were not statistically different for airbag generation, deployment status, and seatbelt use; however, the risk of fatal thoracic injuries in third-and second-generation cases was increased. Seatbelt usage in third-and second-generation deployment cases reduced the risk of all injuries except abdominal trauma. High severity impacts and occupant compartment intrusion were frequently observed. The analyses in this retrospective study were challenged by data that were not collated in a standardized way and were limited in details about scene, vehicle, and driver variables.
Probability of Frontal Airbag Deployment in Bumper-Bumper and Underride Collisions
SAE 2019-01-0620
Airbag deployment thresholds can be a useful metric of collision severity in accident reconstruction applications. The National Automotive Sampling System (NASS) has provided a publicly-available database of realworld motor vehicle collisions, including more than 10,000 event data recorder (EDR) reports retrieved from airbag control modules. These reports typically indicate the airbag deployment status and the corresponding Delta-V of each recorded event. A prior study analyzing crash data in the NASS database demonstrated the airbag deployment threshold varies between vehicle manufacturers and over time. However, the analysis was limited to Ford and GM vehicles due to insufficient data. This paper expands on the prior study of frontal airbag deployment thresholds by analyzing newer years of NASS EDR data (4,000 additional reports). We found that the Delta-V threshold for a 50% probability of deployment event is higher for Toyota than for GM and Ford vehicles. Moreover, SUVs and pickup trucks had higher deployment thresholds than sedans. An increase in Delta-V thresholds was observed for more recent vehicle model years. A higher Delta-V is required for frontal airbag deployment in underride collisions, in which a sedan contacted a vehicle with higher ground clearance (SUV, pickup truck, or van), compared to collisions with direct bumper-bumper engagement. Based on the findings, we developed a logistic regression model that predicts the probability of frontal airbag deployment with a known change in velocity (ΔV = 0 to 45 mph), vehicle manufacturer (GM, Toyota, Ford), vehicle type (sedan, SUV, pickup truck), model year (1994-2001, 2002-2016), and impact configuration (underride, bumper-bumper) with 82% accuracy. This study provides information about airbag deployment behavior beyond what is reported in owner’s manuals and National Highway Traffic Safety Administration (NHTSA) guidelines.