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Car icon not following the road on NAV

Discussion in 'Model S: User Interface' started by Merrill, Jun 30, 2016.

  1. Merrill

    Merrill Active Member

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    Does anyone have the problem of not having the car on the road you are driving on. Sometimes even with good 3G the navigation shows the car off the road, there have been a few times I'm in the middle of a field. At some point the car does get back on the road.
     
  2. Pluto

    Pluto Member

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  3. MichaelS

    MichaelS Member

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    Merrill, I wonder if you are having the same problem I am having. I notice that you also have a 2013 MS60.

    The problem in my car stems from the fact that when I drive in reverse, the car software does not know that I am going in reverse. As a result, the map car icon goes forward, right into water and fields. The further I drive in reverse, the worse the error is. I roughly calculated that if I drive one foot backwards, the error on the map is about 2.5 feet forward.
    Here is how to check for it.
    1. Find a spot to safely back up in like a parking lot.
    2. Zoom the Google map to maximum magnification.
    3. Put the car in reverse.
    4. Close the backup camera app.
    5. Drive in reverse and watch the car icon.

    If I drive too long in reverse, it screws up the positioning of the car so badly, that if you try to navigate somewhere, your highlighted route ends up on a street next to you with the navigation nagging you to turn to get on the street you already are.

    Eventually, the car does correct itself because besides having GPS, there is also dead reckoning where the car counts wheel revolutions. Dead reckoning keeps the navigation accurate when you go through tunnels where there is no GPS.

    I discovered this issue because of the almost useless auto close feature released not to long ago. It never worked properly, very intermittently.

    I have Visual Tesla trip maps that show me driving 300 feet into the field behind my house when I back down my 80 foot driveway to the street. Then driving through buildings for a couple miles before the car position is finally accurate again.

    I hope everyone tries this test and reports back on the results. Maybe more feedback will give me ammunition to go back to Tesla and light a fire under engineering. The service department just threw up their hands and said we know nothing.

    One final note: The last time I had my yearly service, I had a P85 that was about the same vintage as my car. When I did the above test, the car icon would go forward slightly then back up. Then when I drive forward again, the car icon would be where it should.
     
  4. WannabeOwner

    WannabeOwner Member

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    I don't think I have that problem. I wasn't concentrating yesterday and overshot a "Turn right now" instruction. I backed up a handful of yards and immediately the instruction was "Turn left now"! ...
     
  5. MichaelS

    MichaelS Member

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    It's the backing up that screws up the navigation.

     
  6. Merrill

    Merrill Active Member

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    It is interesting that I do back out of our driveway about 60 feet, but the Model X nav works perfectly but the Model S does not follow the road at all times, eventually get back on track.
     
  7. GaryREM

    GaryREM Member

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    Just to be clear, your title says "...NAV". I think you mean "...map" because I think you are talking about the center screen when there is no route input to the navigation system.

    The map and the navigation system rely on sensors for much of the positioning, i.e. speed, direction, steering, with the GPS fine tuning. The map data keeps your position constrained to roads when possible. That's why you can go for some time without GPS signal and still track your route.

    It sounds like your system is not sensing the fact you are in reverse. I just went out and based out of my drive. Unfortunately, that was limited to around 60' and I didn't see anything anomalous.

    I suspect you have a sensor bad.
     
  8. Merrill

    Merrill Active Member

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    Sorry, yes it is the map not navigating. Part of the problem could be that a portion of my road is not on the map for about 1/2 mile, so when we get to the part of the road that is on the map it gets confused and does not follow the road until 2 miles or so. Eventually the car does come back to the road.
     
  9. Boatguy

    Boatguy Member

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    Part of the problem is that the GPS is more accurate than the maps onto which your position is being plotted, especially in places like rural Sonoma county. So when the car is shown in a field near the road, it's most likely the map that is in error. The same problem exists in marine charts where some charts haven't been updated since a British or French survey in the 18th century and can be off as much as half a mile. Most auto navigation software tries to correct for this by assuming you're on a street, and not in a field. But if the road is not on the map at all, it just plots your GPS position.

    But there is no excuse for what @MichaelS describes. Even if Tesla was just using the speed and heading data from the GPS (or DR), ignoring the position, it should go in the right direction. Per above, being plotted on an adjacent street can be symptomatic of poor map accuracy, but I can't imagine what programming error shows the car going in the entirely wrong direction.
     
  10. Merrill

    Merrill Active Member

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    Yes I understand above, but my Model X works great but it has LTE and the S does not. Could this be the issue.
     
  11. Boatguy

    Boatguy Member

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    I don't think so. GPS has nothing to do with cellular signals.
     

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