Cyclist’s Black Box

A road cyclist’s next problem after he is hit by a motorist  is that the motorist gets away scott-free when fault is theirs.  I’ve been stewing on this project for 3 years now, lacking the time and money to put it into reality. Sooner or later I think I will probably get swiped and I want court admissible evidence to back up my story. So now is the time.


I am looking for general interest to find out whether I am just a bit too serious about all this, or if there is a genuine need for such a device that I have to this point produced a concept prototype.

The functionality is as follows :

  1. High quality video and audio for 5 seconds before and 5 seconds after the impact. 25 frames per second progressive video provides for highly granular history.
  2. All movements 5 seconds BEFORE and 5 seconds AFTER  the impact are recorded in high detail (by accelerometer)  so that the direction the cyclist was hit from, the impact force, and the trajectory post impact are all available for analysis and re-creation.
  3. Impact detected by 3 axis accelerometer triggers the storing into memory of the previous 5 and next 5 seconds of video, audio and acceleration forces.
  4. GPS for location and time fix
  5. Encryption of evidence in flash to prevent data tampering.
  6. Minimal video compression to provide for high zoom without degradation of image.
  7. To be located underneath saddle between saddle rails- this is probably the most solid part of the bike and is also rigidly attached to the rest of the bike (important to transfer forces accurately)
  8. Size – about 2 x matchboxes (or less) and waterproof.
  9. Battery life : 12 hours. charge via non-contact charger .
  10. two tiny cameras with 180 deg lens take care of side and rear impacts
  11. forward looking 180deg FOV  camera  (1/2″ cube) must be located up front – no other way to get a good forward look.
  12. No on-off switch- movement activates system.
  13. Single ‘trigger’ button to take care of stationary altercations.
  14. Price sell for $250 or less ? I am not trying to make any more out of this, I would like though to see justice for riders that have been killed by motorists.

Recently,  devices with low enough power consumption have become available to make this a reality. In order to compress the video with virtually no compression artifacts (so that, for example a license plate can be zoomed in) , a large amount of memory must also be provided.  This memory is always storing the past 5 seconds of action, and is written to flash memory upon the trigger.  This memory requirement puts a base on cost and complexity. There are chips like Ambarella in the Go-Pro that can do the compression almost well enough but with too high a power consumption, and also there is a $250K pay-to-play up front fee for this sort of device. I choose a Xilinx FPGA which I can develop for a moderate cost .

I have considerable experience with all the electronic development aspects of this project, I possess all the expensive tools to make it go  but I lack skills in selling the concept, so I am all ears when it comes to suggestions partnering. I’ve built a basic prototype but to progress this I would like to see what interest there is.

What is important is the ability to present the data and it be beyond a reasonable doubt that it is accurate and untampered. I suspect a motorist, knowing that if an impact with a cyclist went to a court of law, if the evidence was to be so solid, they make a greater attempt to avoid the incident.

Maybe Garmin or someone will take it on, not sure, I’d be happy to talk to anyone who would like to bring this to fruition.


About glenenglish

electronics, bikes, mountains, propagation, RF systems, modems,
This entry was posted in Cycling. Bookmark the permalink.

6 Responses to Cyclist’s Black Box

  1. Sverre Holm says:

    Interesting. After my own bicycle accident where I hit a fence (so I couldn’t blame anyone), I was more inclined to get anti-lock brakes for my bike. I found several patents, but no practical products.

  2. Ross says:

    Lots of cyclists already use video cameras that record motorist vs cyclist incidents but often the authorities dismiss or downplay such evidence, not sure that this gadget would be any different.

    • glenenglish says:

      yeah… but they are NOT evidence grade from my conversations with the authorities . Hard to downplay tamper-proof evidence, together with the ballistics of the crash- IE direction and force cyclist was hit from. Courts cannot simply not dismiss evidence when it exists. Depends on the barrister I guess.

  3. Michael White says:

    Glen a great concept, keep me informed of your progress, I know a lot of the commuters I ride with in Sydney would be interested, particularly if it is small enough, the Go Pro is sensational, but too big and imposing on your head.

  4. Greg says:

    Have you thought about putting the idea on somewhere like kick starter? You might find the idea sells itself.

  5. Nader says:

    Dear Glen. This is definitely an excellent idea, and perfectly “kickstarterable” … You woulg get easily >300k$ out of this. The cycling community is huge all over the world, and this single concern is vastly shared amongst the community.

    I live in Paris. Some of my collegues riding a motorbike all make use of a gopro or alike afixed on their helmet. When I asked them why this, they all reply: to get evidence at court when I,ll be smashed away by a car.

    The problem is with the GoPro… No accelerometer, no crash data history. Only video.
    So your concept makes perfect sense (like the flight data recorder of a plane, per opposition to its voice recorder). I am sure your product would find its audience quite rapidly.

    On my side, i’m launching a product in january ( Once this one is on the shelf, I would be honored to contribute one way or the other to yours.

    Kind regards. Marc / Paris

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