1-5 Event Data Recorder (EDR) System 45 Event Data Recorder System This vehicle is equipped with an event data recorder (EDR) system: The EDR mainly records data in the event of a crash or near-crash (for example, airbag deployment or hitting on a roadside obstacle) to help comprehend the vehicle system operation. 1 The EDR records data associated with vehicle dynamics and safety systems in a short time (generally within five seconds). Safety Depending on crash severity and type, data may not be recorded. Data details are as follows:
Data Element Meaning Purpose Delta-V, longitudinal Change in longitudinal vehicle velocity, which only represents the longitudinal component of the resultant delta-V To analyze the change in velocity in the direction of forward vehicle travel at the adjacent time points before and after the crash event Maximum delta-V, longitudinal Maximum value of the cumula- tive change in velocity, as recorded by the EDR, of the vehicle along the x axis, which should be used in combination with “time, maximum delta-V, longitudinal” To analyze the largest change in vehicle speed in the direc- tion of forward vehicle travel before versus after the crash event occurred Time, maximum delta- V, longitudinal Time from time zero to the point where the maximum value of the cumulative change in velocity is found, as recorded by the EDR, along the x axis.
to be used in combination with “maximum delta-V, longitudinal” To analyze the time of the largest change in vehicle speed in the direction of forward vehicle travel, at the time when the crash event occurred Service brake, on or off Used to detect whether the brake pedal was depressed To analyze whether the brake pedal was depressed at the time when the crash event occurred