Development and test of a motor vehicle event data recorder

Abstract

A type of event data recorder (EDR) has been developed that can detect a crash automatically. and also record the motion of the vehicle and driver's actions during a predefined time period before and after the accident. The EDR consists of crash detection and vehicle motion sensors, a steering sensor, several digital input ports for detecting the driver's actions, a non-volatile memory device for recording and a microprocessor for controlling the unit. For reliable detection of accident-related crashes, it is important to understand the characteristics of the crash signal, which are very different from those of normal driving. Therefore, analytical considerations were taken in designing prefiltering circuits and selecting the appropriate parameters for identifying a crash. It is also necessary to select a proper combination of motion sensors and to design proper prefiltering circuits in order adequately to describe the motion of the vehicle. Analysis algorithms have been developed and implemented in order reliably to detect a crash, simulate precrash trajectories, and calculate velocity change, DeltaV, and PDOF for reconstruction analysis of crash accidents. The developed EDR was installed on passenger cars and several types of tests were conducted in order to validate the accuracy of the recorded data and usefulness of the analysis tool for reconstruction.