91 Fahrzeugkonstruktion
An eCall device has been mounted on some vehicles in France since 2003. It is an integrated car radio/GSM/GPS system that can be used with a SIM card. When an accident occurs, a call can be sent manually or automatically made to a telephone call centre. Knowing the geographic location, the vehicle identity and the possibility of a direct communication with the people involved enables the nearest emergency services to be called out. In this context, the LAB / CEESAR have set up a study aimed at evaluating the effectiveness of this system. The purpose of this paper is to detail the E-call system evaluation method of effectiveness used and give a global synthesis of the results.
The aim of this study was to evaluate the performance and accuracy of Event Data Recorders (EDRs). The analysis was based on J-NCAP crash tests from 2006"2007, with the corresponding EDR datasets. The pre-crash velocity, maximum delta-V and delta-V versus time history data recorded in the EDRs were compared with the reliable crash test data. The difference between the EDR pre-crash velocity and the laboratory test speed was less than 4 percent. In contrast, in several cases the maximum delta-V and delta-V versus time history data obtained from the EDRs showed uncertainty of measurement in comparisons with the reliable delta-V data. The difference in maximum delta-V in these comparisons was more than 5 percent in 10 of 14 tests and more than 10 percent in 4 of 14 tests. The EDRs underestimated the maximum delta-V in almost all tests. It was also concluded that the calculated acceleration from the EDR delta-V versus time history data showed good agreement with the instrumented accelerometer signal during the collision in almost all tests.
During the last 5 years, the number of cars fitted with side airbags has dramatically increased. They are now standard equipment, even on many smaller cars or less luxurious vehicles. While some side airbags offer thoracic protection alone, there are those that combine thoracic and head protection (of which most deploy from the seat). Other systems employ separate airbags for head and thorax protection, which are designed to be effective noticeably in a crash against a pole. This paper proposes an evaluation of the effectiveness of side airbags in preventing thoracic injuries to passenger car occupants involved in side crashes. First, the target population (who can take benefit of side airbag deployment and in what circumstances) is defined. Side airbags can be especially effective in cases of impacts on the door with intrusion at a certain impact speed. Then, an example case of a side impact with side airbag deployment is given were side airbag deployment is thought to have had a positive effect on injury outcome. A further case is presented where the impact configuration is likely to have reduced the effect of side airbag deployment on injury outcome. Finally, the estimation of side airbag effectiveness (in terms of additional occupant protection brought exclusively by the airbag) is proposed by comparing injury risk sustained by occupants in (more or less) similar cars (fitted or non fitted with airbags) because, during these years, car structure, and side airbag conception have considerably evolved. In-depth accident data from France, the UK and Germany has been collected. Out of 2,035 side impact accident cases available in the databases, we selected 435 occupants of passenger cars (built from 1998 onwards) involved in an injury accident between year 1998 and year 2004 for EES (Energy Equivalent Speed) values between 20km/h and 50km/h. The occupants, belted or not, were sat on the struck side, whatever the obstacle and type of accidents (intersection, loss of control, etc.). For multiple impact crashes, the side impact is assumed to be the more severe one. Passenger cars were fitted with (96) or without (339) side airbags. Most of the potential risk explanatory variables were correctly and reliably reported in the databases (velocity " impact zone " impact angle " occupant characteristics, etc.). The analysis compared injury risks for different levels of EES and different types of side airbags. A logistic regression model was also computed with injury variables (such as thoracic AIS 2+ or AIS 3+) as the dependant variable and other variables (including airbag type and EES) as explanatory injury risk factors. Results revealed statistically non-significant reductions in thoracic AIS 2+ and AIS 3+ injury risk in side airbag equipped cars in the impact violence range selected (odds ratio between 0.84 and 0.98 depending on types of airbags). The results are discussed. The non-significance is assumed to be due to a low number of cases. Statistical analysis for head injuries was not possible due to the low number of accident cases with passenger cars fitted with head airbags in the databases. Moreover, the discrepancies between the data coming from different countries (especially calculation of EES) might have introduced instability in the analysis.
This paper uses the national accident statistics of Great Britain to evaluate the effectiveness of Electronic Stability Control Systems (ESC) to reduce crash involvement rates. The crash experience of 8,951 cars is analysed and compared to a closely matching set of non-ESC cars using case-control methods. This is one of the largest ESC samples analysed to date. Overall the cars with ESC are involved in 3% fewer crashes although the effectiveness is substantially higher under conditions of adverse road friction. ESC equipped cars are involved in 15% fewer fatal crashes although this reduction represents the combined effect of ESC and passive safety improvements.
The second ESAR Conference took place at the Medical University Hannover. This year conference presents the current state of affairs of relevant research activities in the field of in-depth investigations. The first conference on ESAR (Expert Symposium on Accident Research) was established in 2004. It is planned to hold ESAR every two years. Hannover seems to be the right place for this conference concerning the fact that the first in-depth research team was found here in the year 1973 and comprehensive studies on accident analysis were spread out from here around the world continuously. This year conference topped all expectations in terms of the numbers of participants, in the variety of papers and the interdisciplinary of presenters from medical, psychological and engineering background. More than 100 delegates from all over the world, that means 13 different countries and from 4 different continents, came to Hannover, presented their results of accident investigation and discussed countermeasures for accident prevention and injury reduction. ESAR should be a platform for exchange of knowledge to find an optimized way for increase of traffic and vehicle safety by in-depth investigation and methodology. ESAR as international conference should be a platform for consideration of all nations round the world. This seems to be very important for the current situation, having high safety in the high industrial countries of Europe, US and Australia, but low safety and high injury risk in Asia and Africa.