11 Event Data Recorders

Question 1

What is an EDR?

Answer 1

Definition: An Event Data Recorder (EDR) is a device installed in vehicles, similar to a flight data recorder in aircraft. It collects data during crashes or high-kinematic events triggered by factors like airbag deployment or accelerometer thresholds.

Key Features:

Stores crash-related data for later analysis.
Triggered by vehicle systems (e.g., airbags, crash sensors).
Focused on pre-crash and in-crash data.

Question 2

What data is collected?

Answer 2

First versions of EDR were focused on frontal crashes only
– Contained some pre-crash data and a segment of the crash data
– Sampled 5 seconds before event @ 1Hz
– Stored some vehicle information at event

• Vehicle Speed
• Engine RPM
• % Throttel
• Brake Switch

Question 3

EDR Applications

Answer 3

1. Vehicle Safety Development:
   * Used for designing and evaluating active and passive safety systems.
   * Provides insights into crash dynamics and driver behavior.
2. Crash Analysis:
   * Helps reconstruct crash events.
   * Useful for crash causation research.
3. Policy and Regulation:
   * Supports regulatory compliance (e.g., Part 563 requirements in the US).
4. Insurance and Legal Cases:
   * Assists in determining liability in crashes.
   * Used in pay-as-you-drive insurance models.

Question 4

Strengths and Limitations of EDR Data

Answer 4

Strengths:
* Provides objective, real-world crash data.
* Captures critical information for safety assessments.
* Complements other data sources like Naturalistic Driving Data (NDS).
Limitations:
* Lack of synchronization between pre-crash and in-crash phases.
* Limited sampling frequency (e.g., 2 Hz) can omit fine details.
* Data availability varies depending on crash type and severity.

Question 5

EDR synchronization issue

Answer 5

Problem:
* The exact timing of the crash event within the recorded pre-crash data is unclear.
* This affects the reconstruction of speed and acceleration profiles leading up to the crash.
Impact:
* Challenges in estimating vehicle dynamics and secondary crash risks.
* Limits the application of data in precise crash analysis.
Solutions:
* Increasing sampling frequency (e.g., 10 Hz).
* Enhancing synchronization mechanisms.

Question 6

Data Collected by EDRs

Answer 6

Pre-Crash Data:
* Vehicle speed.
* Engine RPM.
* Throttle position.
* Brake switch status.
In-Crash Data:
* Acceleration profiles.
* Airbag deployment details.
* Vehicle dynamics during impact.
Limitations:
* Sampling rates (e.g., 2 Hz for pre-crash data) may not capture detailed dynamics.
* Synchronization issues between pre-crash and in-crash data.