2008 CDR users conference

Mar 1, 2008 by

Allow me to pose a hypothetical construct. You were driving your car at night on the way home after a long day. Traffic was light in the 30mph zone and you waited in the left turn lane for the light to change. You saw a break in the traffic and accelerated. Suddenly you were broadsided by an oncoming car. The police find you at fault for an unsafe turn. Your only defense is that you thought you had time and the other guy must have been speeding. The other driver, a teenager driving his dad’s new Impala, admits he was in a hurry to get home, but says he wasn’t speeding when you pulled out in front of him. An accident reconstruction puts his speed between 28 and 33 mph at impact. Are you out of luck? The answer may lie in the CDR.

Last month I attended the 2008 CDR Users Conference in Houston, Texas. The 2007 conference had about 150 attendees, this conference had 270 from all over the US and Canada. CDR stands for Crash Data Retrieval, (or Recorder) which narrowly is applied to any vehicle with an air bag, and more broadly is applied to vehicles with electronic recording capability for their various powertrain control systems (such as delivery trucks and 18 wheelers). EDR (Event Data Recorder) is another commonly used term.

Here is a brief overview. Auto manufacturers (Original Equipment Manufacturers or OEMs) installed air bags to make vehicle crashes more survivable-to save lives. One of the first things that the engineers knew they had to do was monitor air bag effectiveness. Did the devices either fail to deploy when they should, or did they deploy unnecessarily? To track this, they installed system recorders that documented speeds and impact forces.

General Motors (GM) was the pioneer. Early devices provided a fairly elementary snapshot of what happened a few milliseconds before, during, and after a crash that involved an air bag deployment. As technology improved, the recording devices and sensors became more sophisticated. Some Fords provide 6 minutes of precrash data. GM looked at the various diagnostic electronic devices that they bought from their suppliers, and realized that they could more effectively contract with a single vendor to provide the diagnostic equipment, instead of multiple competing vendors or doing it in-house. They then signed an exclusive license agreement with a company called Vetronix to develop the software and hardware required to extract the data from the EDRs. A few years later, Ford made a similar decision and also signed up with Vetronix.

By now the word was out, and new stakeholders became involved in the CDR industry. Police began to recognize that CDR information could be used as additional evidence in prosecuting vehicular crimes.Accident Reconstructionists also sought to be able to use this information for their clients. What used to be the sole province of the OEMs now was opened up to a much larger community as Accident Reconstructionists, insurance companies and police departments began to buy the Vetronix equipment . For more than a decade, only GM and Ford vehicles could be interrogated by the Vetronix equipment.

All other OEMs considered their information proprietary. Safety is a primary sales feature and most OEMs were very reluctant to possibly share any information with their competition. Aside from GM and Ford, a subpoena or court order were generally required to force a manufacturer to share CDR information. The federal government has now stepped in and dictated that all OEMs make their information public by 2012 (by NHTSA Part 563).

A new issue was raised, relating to privacy, “Is the driver testifying against himself – or who owns the information?” The answer depends on the jurisdiction. I once listened to an hour presentation just on the legal differences between states. Privacy advocates have had limited success in their assertion that the CDR information is protected from police searches by the self incrimination rule.

Some jurisdictions say that the driver of the car at the time of the crash owns the information. Some states extend computer privacy legislation to cover CDRs. Some states bar CDR information from transferring to the new owner of a salvaged vehicle. Most states consider the owner of the car to be the owner of the CDR information. This will probably hit the Supreme Court in the next decade-until then, the rules vary. German law, by the way, is extremely privacy oriented (think Porsche/BMW/autobahn).

So what kind of information is available? There is no standard list –every model is different, depending on year manufactured and options ordered but here are 5 data elements commonly recorded from 5 seconds before the crash through a second after:

  • Vehicle speed
  • Throttle opening percentage
  • Engine rpm
  • Seat belt buckled or not
  • Brake light circuit activated or not

The federal 2012 rule requires 18 distinct data elements. The ‘08 Impala currently provides 105 elements, and most cars number in the dozens of distinct data elements, so it’s not like the OEMs are dragging their feet.

A couple years ago, Bosch bought out Vetronix’s CDR business, and they are beginning to relabel it as they release new equipment. At the conference, they addressed various technical topics related to CDR equipment and development. There currently are under 10,000 active users of the Bosch/Vetronix CDR equipment. The equipment connects the vehicle (or CDR) to the user’s laptop computer and runs the Bosch software to translate the raw data into useful information. Currently GEI has 22 different cables and adapters to fit the various different models. The software is constantly updating as OEMs release additional options and models, as well as modifying earlier settings. Users are trained and certified by Bosch approved courses.

Downloading a CDR is NOT plug and play-it is a very technical process. You have to know what you are doing and be current on the latest technical procedural changes and software updates.

Vehicles are becoming increasingly sophisticated, depending upon the manufacturer and the options. Side air curtains and roll over protection change the dynamics from a simple frontal deceleration (on the x axis) to 3 dimensional controls (adding the y and z axis of the car). Roll Over Sensors record lateral and vertical acceleration, roll rate history, active faults and some models even record steering angles that tells you where the wheels were pointed when it crashed (did they try to drive around the obstacle?).

The big news in the industry is that Chrysler has now also contracted with Bosch for CDR downloads, starting with the 2004 model year for selected model SUVs, trucks and crossover vehicles. Compliance with Part 563 is not an easy task as, while NHTSA attempted to standardize reporting requirements, each manufacturer has different design criteria and uses different EEPROMs, resistors, capacitors, diodes, accelerometers, switches, and air bags from a multitude of vendors. As an example, between GM, Ford, and Chrysler some record data each 8/10ths of a second, some each 2/10ths of a second, and some each 1/10th of a second.

Let us return to your hypothetical crash. If your CDR technician downloads the EDR, what will he find? Perhaps the Impala’s speed was a steady 32 mph with seatbelts buckled and brake activation at 1 second before impact. On the other hand, perhaps at 10 seconds before impact the throttle was wide open at 100% and at 5 seconds before impact the teenager’s speed was 92 mph. If the later was the case, even though he slowed down to the speed limit at the time of impact, he clearly was the cause of the accident, and you are off the hook.

CDR downloads can be a very useful tool to use “When You Need To Know What Really Happened”.

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