GPS

It really sort of goes without saying that in any sort of V2X scenario the location of objects is important.

The biggest problem however is that straight GPS is accurate to a five foot radius. For V2X to function that is way too large of a margin of error. A five foot radius of accuracy means that your car could be in any one of three lanes on a highway as an example.

That means that V2X must augment straight GPS significantly (and efforts such as GNSS are underway to assist in the effort). You see, for V2X to work, any object must have it’s location known to within at most one inch margin of error and really even that might be too large.

To start with, GPS accuracy can be improved through onboard sensors that know the exact locations of fixed items such as a house, lightpoles, traffic lights, etc. A vehicle can then use simple triangulation as it moves by a fixed object combined with GPS to help make its location significantly more precise, and continue to do so as it travels (basically, continually calibrating it’s location while it drives)

Further, and just as importantly, a robust V2X system should not automatically trust the broadcast location or speed data of any vehicle within range of its own onboard sensors.

We have seen proposals put forward by others to allow some arbitrary number of cars operating with 100% agreement to “fix” a car that is broadcasting “incorrect” data. On this point we disagree. Allowing other cars to effectively control location and speed data would make it far to easy for multiple people working in concert to cause incredible mayhem by “fixing” so-called “incorrect” data (that is in reality accurate) and in that way dangerously affecting another vehicle.

While we absolutely do believe that a robust V2X system should have “permission and cooperation first” as a default with regard to the movement of other vehicles around it, we believe that one vehicle should not exactly “trust” anything said by another vehicle that it can verify with its own sensors. Further, most roadways, with preciously few exceptions have more than enough well known fixed items by which to adjust and keep calibrated its own location and speed that it is not needed for adjustment and calibration to be “given” by other vehicles.

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