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  • Crash recorders have been more and more frequently used in accident reconstruction and crash investigation. It has also been shown to be useful in linking dummy readings in laboratory crash tests with real-life injury outcome. In this lecture some different aspects of the usefulness crash recorders and some potential applications of detailed crash data are presented. Different types of crash recorders are listed and described. Some previous crash recorder initiatives are summarised and running projects in large fleets are presented. Finally some examples of results based on crash recorder information are presented.
  • There are many reasons why crash recorders are useful. They give an opportunity to look “inside” the crash event, as more detailed data are available. It removes one level of uncertainty in collision analysis. It is a possibility to record and analyse information previously not possible to obtain. Furthermore, the use of crash recorders means an increase of measurement accuracy. An example is measurements of crash severity. By measuring acceleration pulse in the crash phase and travel speed you get the possibility to use relevant impact severity parameters influencing injury outcome. Injury causes and mechanisms will by that be better understood.
  • This slide shows some potential applications of detailed crash data. Phrase 1 By recording pre-crash data evaluation of active safety systems may be conducted. Phrase 2 By recording crash data with higher quality evaluations of interior safety systems may be conducted more effectively. It is possible to calculate injury risk versus impact severity which is useful for this purpose. Phrase 3 Furthermore accident reconstruction of occupant kinematics may be done using advanced occupant simulation codes with real-life data, such as crash pulse and car characteristics, as input. It gives a possibility to link dummy readings in the laboratory with real-life injury outcome. By that you may calculate injury risk functions for various injury criteria. With such information it is possible to validate injury criteria in crash tests against real-life injury outcome.
  • Phrase 1 There may be different purposes of crash recorders. They may be used primarily as a research tool or as a source for information to be used for legal aspects. Often they are used for both purposes. Phrase 2 Crash recorders may record information in the pre crash, crash and post crash phases. Many existing crash recorders record information in all three phases while some only record information in the crash phase. Phrase 3 Several parameters can be recorded in the pre crash phase, such as speed before impact, acceleration before impact, if the brakes were used, angle of the steering wheel, belt use etc. In the crash phase the acceleration pulse and velocity may be recorded. Also the dynamic performance of the interior safety systems, such as airbags and seatbelt pretensioners, may be recorded. In the post crash phase velocity and acceleration after impact may be recorded. Phrase 4 There is a large variation in the way crash recorder is integrated in the car, from fully integrated in the electronics of the car to a self contained device with its own power cell.
  • There will be a large variation both in if and in how data is stored in the various existing crash recorder projects. The ability to have access to the various databases also varies. In the USA projects have started to deal with this issue on the US market. It is important that such data can be available for research purposes, especially for increased knowledge in the legislative process.
  • 13_Kullgren.ppt

    1. 1. Crash recorders – opening up the box <ul><li>Anders Kullgren </li></ul><ul><li>Head of road traffic safety research at Folksam </li></ul>
    2. 2. <ul><li>Why crash recorders? </li></ul><ul><li>Potential applications </li></ul><ul><li>Different types of recorders / running crash recorder projects </li></ul><ul><li>Examples of results </li></ul><ul><li>Summary </li></ul>Crash recorders - content
    3. 3. Benefits of using crash recorders <ul><li>Increased quality of accident data </li></ul><ul><ul><li>Increased accuracy of data </li></ul></ul><ul><ul><li>Possibility to use information previously not possible to obtain </li></ul></ul><ul><li>Better evaluation of new safety technology </li></ul><ul><li>Knowledge of injury thresholds for the design of a crashworthy road transport system </li></ul><ul><li>Better understanding of injury causes and injury mechanisms </li></ul><ul><li>Influence on accident involvement risk? </li></ul><ul><li>Useful from legal aspects (insurance) </li></ul><ul><li>Information used for ”e-Call”systems </li></ul>
    4. 4. Some applications <ul><li>Pre-crash data to investigate collision causation </li></ul><ul><ul><li>Evaluation of active safety systems </li></ul></ul><ul><li>Crash data to investigate crashworthiness </li></ul><ul><ul><li>Evaluation of interior safety systems </li></ul></ul><ul><ul><li>Calculate injury risk versus impact severity </li></ul></ul><ul><li>Accident reconstruction </li></ul>minor injuries AIS1+ (n=278) moderate injuries AIS2+ (n=72) serious injuries AIS3+ (n=18) 0 0,2 0,4 0,6 0,8 1 0 5 10 15 20 25 30 Risk Mean acceleration (g) N=452
    5. 5. Furhter applications <ul><li>Linking laboratory to real-life crashes </li></ul><ul><ul><li>Reconstruction of occupant kinematics using advanced occupant simulation codes with real-life data, such as crash pulse and car characteristics, as input </li></ul></ul><ul><ul><li>Calculate injury risk functions and injury tolerance levels </li></ul></ul><ul><ul><li>Validation of injury criteria </li></ul></ul>
    6. 6. Types of crash recorders <ul><li>Purpose of the recorder </li></ul><ul><ul><li>Research </li></ul></ul><ul><ul><li>Legal aspects and accident involvement </li></ul></ul><ul><li>Pre crash, crash and post crash data </li></ul><ul><li>Type of parameters recorded </li></ul><ul><ul><li>Performance of the car </li></ul></ul><ul><ul><li>Crash severity </li></ul></ul><ul><ul><li>Driver behaviour </li></ul></ul>
    7. 7. Examples of running “large fleet” projects <ul><li>Since 1990s - GM and Ford cars (more advanced in late 90s) </li></ul><ul><li>Since 1995 - Volvo DARR in Volvo cars – approx 500.000 cars fitted </li></ul><ul><li>Other manufacturers, Saab etc… </li></ul><ul><li>Since 1992 - Folksam CPR project - 220.000 cars fitted with Crash Pulse Recorders </li></ul><ul><li>Since 1995 - UDS in Austria, Switzerland and Germany… </li></ul>
    8. 8. Storage and availability of data <ul><li>Important that such data can be available for research purposes </li></ul><ul><li>Important for designers of both road infra-structure and cars </li></ul><ul><li>Who will have access to the data? </li></ul>
    9. 9. Some examples of results from the Folksam crash recorder database <ul><li>Example of crash </li></ul><ul><li>Exposure data </li></ul><ul><li>Injury risk </li></ul><ul><li>Evaluation of safety technology (airbag) </li></ul>
    10. 10. Toyota Yaris – Saab 900 (old) Minor injuries (clav. fracture) Driver + front seat pass. fatally injured
    11. 11. Number of crashes and injured - Delta-V
    12. 12. Injury risk - Delta-V
    13. 13. Influence of airbags on risk of whiplash injury in frontal impacts (1999 figures)
    14. 14. Summary <ul><li>Crash recorders are important </li></ul><ul><ul><li>for evaluation of new safety technology </li></ul></ul><ul><ul><li>to get knowledge of injury thresholds for the design of a crashworthy road transport system </li></ul></ul><ul><li>Important to encourage initiatives where data can be available for research institutes and governmental bodies </li></ul>
    15. 15. Wider use <ul><li>A wider use of crash recorders or event data recorders is desirable. A mandatory fitment of such devices would help but is not necessary. </li></ul><ul><li>It is important to ensure that data from recorders will be collected and stored in such a way that it is available to designers of both cars and road-side objects, and especially to the responsible bodies for the road transport system. </li></ul>