Study on Characteristics of Event Data Recorders in Japan

To understand the performance of Event Data Recorder (EDR) for the improvement of accident reconstruction using reliable and accurate information, two types of crash test data are analyzed. The first type is the J-NCAP crash tests for understanding the EDR characteristics under fundamental crash conditions and the second type involves three crash tests reconstructing typical real-world accidents for grasping the EDR performance under more complex crash conditions than J-NCAP crash tests. Data obtained from EDRs are compared with data obtained from instrumented sensors and high-speed video cameras. The velocities determined from pre-crash data and the maximum change in velocity, delta-V, obtained from post-crash data are analyzed. EDR pre-crash data shows good accuracy. In J-NCAP testing, all differences between the EDR recording value and the laboratory test velocity were less than 4%. EDR post-crash data has more difference from instrumented sensor data. In J-NCAP testing some differences between maximum delta-V values were greater than 10%. The accuracy and reliability of the EDR data decreased under the complex crash conditions as compared to the results from J-NCAP crash tests.