# Presentation: 912402

## May 5, 1999

**May 5, 1999**

*Recording Automotive Crash Event Data***Augustus “Chip” Chidester, National  Highway Traffic Safety Administration ****John Hinch, National  Highway Traffic Safety Administration****Thomas C. Mercer, General Motors Corporation ****Keith S. Schultz, General Motors Corporation**

- National Transportation Safety Board
- Symposium On Recorders

## Crash Scene

*Crash Scene*

## 1914 Car Crash in Scotland

- Source: http://www.sol.co.uk/s/scott.wilson/Old_Traffic_DundAcc1914.jpg

*1914 Car Crash in Scotland*

## Crash Scene

*Crash Scene*

## The Opportunities Are Vast

**18,000 Tow-away crashes per day**
**Equivalent to about $600 million worth of crash Tests per day (18,000 crashes * $35,000 / test)**
**Current total production of crash tests conducted for US vehicles is estimated around 5,000 / year**

## Background

**Need for real world crash data - crash pulses**
**Today - methodology based on observation of post crash vehicle deformation **
**Need for more detailed data to define crash conditions (pre-impact conditions, detailed deceleration data)**
**Recommendations from NTSB & JPL**

## NTSB

**NTSB public forum on air bags and**
**   ****child passenger safety (March 1997)**
**NHTSA (H-97-18)**
- “Develop and implement, in conjunction with the domestic and international manufacturers, a plan to gather better information on crash pulses and other crash parameters in actual crashes, utilizing current or augmented sensing and recording devices.”

## JPL

**Study feasibility of installing and obtaining crash data for safety analyses from crash recorders on vehicles**
**JPL findings**
- Crash recorders exist already on some vehicles with electronic air bag sensors, but data recorded are determined by the OEMs
- These recorders could be basis for an evolving data-recording capability that could be expanded to serve other purposes

*JPL*

## JPL (cont’d)

**Questions of data ownership and data protection would have to be resolved, however**
- Where data ownership concerns arise, consultation with experts in the aviation community regarding use of aircraft flight recorder data is recommended

*JPL (cont’d)*

## Potential Uses of Event Data

- Improve Vehicle Design/Highway
- Infrastructure

- Provide a Basis for Regulatory &
- Consumer Information Initiatives

- Provide Objective Data for
- Crash Reconstruction

- Develop an Objective Driver
- Behavior Database

- _vehicle systems_
- - airbag sensing system deployment criteria
- _highway systems_
- - roadside safety feature design standards

- - offset frontal impact severity
- - average/extreme vehicle decel pulses

- _alleged defects & litigation _
- - unintended vehicle acceleration
- - crash & airbag deployment sequence

- - pre-crash driver braking/steering
- - belt use
- - vehicle speed

**Category**

**Potential Examples**

## The Haddon Matrix w/o EDR

*** *****Human**

***  *****Vehicle**

**Environment**

**Calculated Delta-V**

**Injury**

**Collision Damage**

**Environment****after****crash**

**Skid Marks**

## The Haddon Matrix w/ EDR

**Crash Pulse****Delta-V****Yaw****A/B Activation Time**

**Belt Use****Steering****Brake**

**Speed****ABS****Other Controls**

**Conditions**
** ****During Crash**

**Air Bag Data**
**Pre Tensioners**

**Location**

*** *****Human**

***  *****Vehicle**

**Environment**

**ACN (Automatic**
**Collision **
**Notification)**

*The Haddon Matrix w/ EDR*

**ACN**

**ACN**

## GM EDR Systems

*GM EDR Systems*

## GM Airbag SystemsData Stored

**State of Warning Indicator when event occurred (ON/OFF)**

**Length of time the warning lamp was illuminated**

**Crash-sensing activation times or sensing criteria met**

**Time from vehicle impact to deployment**

**Diagnostic Trouble Codes present at the time of the event**

**Ignition cycle count at event time**

**Maximum Delta-V for near-deployment event**

**Delta-V vs. time for frontal airbag deployment event**

**Time from vehicle impact to time of maximum Delta-V **

**State of driver’s seat belt switch**

**Time between near-deploy and deploy event (if within 5 seconds)**

**Passenger's airbag enabled or disabled state**

**Engine speed (5 sec before impact)**

**Vehicle speed (5 sec before impact)**

**Brake status (5 sec before impact)**

**Throttle position (5 sec before impact)**

**Parameter**

**1990**
**DERM**

**1994**
**SDM**

**1999**
**SDM**

## 1999 EDR Simplified Block Diagram

**Airbag Cutoff Sw.**
**And Indicator**

**Warning Indicator**

**Microcomputer Including EDR**
**  **RAM
-   32k ROM
-   640 EEPROM

*1999 EDR Simplified Block Diagram*

**Accelerometer**

**Low-pass Filter**

_**SDM**_

- Serial data bus

- Pre-impact data

**Airbags**

- Power

- Ignition Switch

## EDR Data 

**Time (msec)**

**Delta-V (mph)**

** ****0**

**Increasing**

** ****0**

**20**

**150**

**100**

**80**

**60**

**40**

**120**

## Pre-Impact Data1999 EDR 

**Crash Time (sec)**

**Engine Speed**

**Throttle Pos**

**Vehicle Speed**

**Brake OFF**

**Crash Occurs      **
**@ Time = 0**

**Brake ON**

## Accuracy and Resolution

**Parameter**

**Full Scale**

**Resolution**

**Accuracy**

**How Measured**

**When Updated**

**Delta V**

_**+**_** 55.9 mph**

**0.4 mph**

**~ **_**+**_** 10%**

**Integrated**
**acceleration**

**recorded every**
**.010s, calculated **
**every .00125s**

**Vehicle speed **

**158.4 mph**

**0.6 mph**

_**+**_** 4 %**

**Magnetic  pickup**

**vehicle speed **
**changes by **
_**>**_** 0.1 mph**

**Engine Speed**

**16383 RPM**

**1/4 RPM**

_**+**_** 1 RPM**

**Magnetic  pickup**

**RPM changes by **
_**>**_** 32 RPM.**

**Throttle**
**Position**

**100% Wide**
**open throttle**

**0.4 %**

_**+**_** 5%**

**Rotary**
**potentiometer**

**Throttle position**
**changes by **
_**>**_** 5%.**

**EDR Data**** **

## Validation

**0 **

**10 **

**20 **

**30 **

**40 **

**50 **

**Delta-V**

**0 **

**0.05 **

**0.1 **

**0.15 **

**0.2 **

**Time**

**Electronic data**

**EDR data**

## GM Tech 1 Retrieval Unit

## Vetronix EDR Retrieval Tool

## EDR Uses

*EDR Uses*

## SCIs InvolvingGMs’ EDRs

- 1998 Chevrolet Malibu

- 1995 Saturn SL

- 1996 Geo Metro

- 1995 Saturn

- 1996 Oldsmobile 98

- 1995 Chevrolet Lumina

- 1995 Geo Metro

- 1995 Geo Metro

- 1998 Pont. Grand Prix

**Y***

**Y**

**Y**

**Y**

**Y**

**Y**

**Y**

**Y**

**Y**

**N**

**N**

**N**

**N**

**N**

**N**

**N**

**N**

**N**

**23**

**13**

**19**

**NR**

**NR**

**12**

**14**

**NR**

**NR**

**50**

**16**

**20**

**11**

**17**

**24**

**9**

**11**

**2**

- Final seat belt determination was "not belted.
- Severe under-ride.

- Very minor damage

- *Physical evidence indicated shoulder portion
- of the belt under the driver's arm

- Driver stated belt used, no physical evidence

- Under-ride - visual of 14-18 mph

- Under-ride, 24 mph @ 150 msec

- The report writer specified the SDM Delta-V
- data as more representative of this crash

- Undercarriage impact.
- Visual estimate of  9-14 mph

- Inadvertent deployment

**MY - Make - Model**

**Driver Belted**

**Delta-V (mph)**

**Field**

**EDR**

**EDR**

**SMASH**

**Comments**

**NR = No Results**

## NHTSA SCI w/ EDR Involvement

- - Struck a heavy, parked truck in a severe bumper under-ride impact.
- - Such crashes typically generate long crash pulses.
- - WINSMASH estimated a Delta-V of 23 mph.
- - The investigator noted this Delta-V estimate appeared to be low.
- - Data from the on-board recorder indicated a Delta-V of approximately 50 mph.

_**Delta-V**_

_**Belt Use**_

- - Belt use status
-      unsure Investigator.
- - EDR was read.
- - EDR - “Belt Not Used.”
- - EDR was correct.

- Chevrolet Malibu

## Motor Vehicle Safety Research Advisory Committee

*Motor Vehicle Safety Research Advisory Committee*

## MVSRAC WorkingGroup Formed

**On April 29, 1998, NHTSA staff presented a briefing to the MVSRAC committee**
**Purpose was to recommend that a working group be formed**
**MVSRAC members indicated:**
- It would be several years before such devices would be wide spread enough to give researchers information on crashes
- Manufacturers were not far along in EDR technology
**Working group formed**
**MVSRAC Crashworthiness Subcommittee would organize EDR working group**

## MVSRAC WG Representatives

**AAAM**
**Blue Bird**
**CA DMV**
**Chrysler**
**FHWA **
**Ford**
**Navistar**
**GM**
**NASDPTS**

**Honda**
**NHTSA**
**NTSB **
**Private**
**Transport Canada**
**TRB**
**UVA**
**VW**
**Worcester**

## Objectives of MVSRAC W.G. 

**Define functional and performance requirements for on-board crash data recorders **
**Understand technology presently available to meet these requirements **
**Develop a set of data definitions **
**Discuss the various uses of the data**

## Objectives (cont’d)

**Discussions of legal and privacy issues**
**Historical overview of other agency’s actions related to data collection**

## Potential Outcomesof the MVSRAC WG

**Technical Report (by end of 2000)**
**Recommendations to Full MVSRAC for EDR actions**
- Establish National Data Base for EDR Data
- Encourage all manufacturers to develop EDR technology

## Conclusions

**Potential to Greatly Improve Highway Safety **
**Well-Coordinated Efforts will be Needed to Achieve the Results Envisioned by the NTSB**
**NHTSA’s MVSRAC Event Data Recorder Working Group will Establish Guidelines for Future On-Board Data Recording Capability**
**EDR Data is now being stored in NHTSA’s National Crash Data Bases **

## The End