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[TERM]EDR:Event Data Recorderイベント・データ・レコーダ(2)SRS:AirBag:CDR:
The Automotive Event Data Recorder (EDR)
Written By: PIE Staff Engineer
9-1-2006
Categorized in: Forensic Services
Most people are familiar with “black box” technology in modern aircraft as a means to record information in the few minutes before a crash. However, most individuals are not aware that this very same technology might be present under the passenger’s seat of their personal vehicle. It is referred to as an automotive Event Data Recorder (EDR), and it has tremendous implications for any accident reconstructionist.
The EDR in most vehicles is located in the airbag control module. The purpose for the module is to monitor crash scenarios and deploy the airbags as needed. To complete this task, the module contains several accelerometers that record vehicle accelerations. When a large acceleration (or deceleration) is detected, the module recognizes this as an “event.” The EDR records only after the airbag module has completed its evaluation of an event.
The EDR will record approximately five seconds of pre-crash data, depending on the type of vehicle. This data includes:
1. Vehicle speed
2. Brake application
3. Accelerator application
4. Engine speed
The EDR will also record the crash phase, evaluating the various parameters every five milliseconds before the impact. This data can thus be analyzed to calculate the delta-V and duration of the impact. From this information and the pre-crash data, an impact velocity can be calculated.
In order to evaluate the contents of the EDR, it is necessary to have an interface that is capable of downloading the EDR data into a workable format. The Crash Data Retrieval system, or “CDR,” was developed by the Vetronix Corporation for this very purpose. Their relationship with General Motors began in 1984 when GM first started research and development on EDR technology.
Subsequently, Vetronix developed the first data retrieval system for GM in 1990. This system became available to the public in 2000. Several other automakers have since expressed an interest in the technology. In 2003, Ford contracted with Vetronix, and the system has subsequently been updated to download data from a variety of Ford vehicles.
The Vetronix CDR downloads pre-crash and crash data from the vehicle’s EDR module to any computer, and the Windows-based software presents this data in easy-to-read graphs and tables. The EDR data can be downloaded either from the vehicle diagnostic link (usually beneath the dash), or directly from the air bag module.
The CDR system will download information from over 90 percent of all GM vehicles newer than 1994, and from most Ford vehicles newer than 2001. This means that over 40 million vehicles on the road are covered by the Vetronix CDR system. More auto manufacturers are looking to come online with the system in the near future. Both Toyota and Daimler-Chrysler have EDR technology in a limited number of vehicles.
There are many useful applications for this technology. While the data is considered by many to be unsupported on its own, it can be used to support other forms of collision analysis such as crush energy calculations, delta-V, force, and momentum. The system has been used successfully by law enforcement in criminal trials, and the data has been admitted into court. Insurance adjustors can use the data to support or disprove their clients’ automotive claims. It is also a valuable tool to aid fleet managers in monitoring their drivers’ actions. The National Highway Traffic Safety Administration (NHTSA) and vehicle manufacturers alike have utilized this data in vehicle crash tests and safety studies.
There is a growing future for the use of this system. The next generation’s systems will not only record delta-V’s in the forward direction, but will also record lateral events. A new rule issued by the NHTSA on August 21, 2006, requires that new car buyers be notified if an EDR has been installed. The new rule will take effect starting with model year 2011 passenger cars and light trucks. The rule also requires automakers to each collect the same data.
At Professional Investigative Engineers, we are equipped to conduct airbag module examinations and EDR downloads using Vetronix CDR. In September 2006, we will be conducting a staged crash test in order to further evaluate the capability of the system. We will analyze the crash using momentum, crush energy, and force analysis, and will compare these results to the EDR data. Keep looking for a future article on the results of this test. F
For more information, please contact Matt Blackmer or Derek Pumphrey at 1.866.552.5246.
Attachments
AR_Sept06.pdf (720.75 KB)
SRS:AirBag:
CDR:Crash Data Retrieval
http://www.aacinvestigations.com/cdr.htm
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http://www.callpie.com/articles/articles/the-automotive-event-data-recorder-(edr).html
2010/3/9(火) 午前 4:17[ ogw*og*3 ]
SRS
AirBag
EDR
http://www.takatafound.or.jp/library/files/00144.pdf
2016/12/26(月) 午後 5:14[ ogw*og*3 ]