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Is rear camera used for AP?

Discussion in 'Model S' started by whitex, Mar 8, 2016.

  1. whitex

    whitex Member

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    Since introduction of AP I noticed that on some roads the speed limit on the dashboard doesn't show up until a speed limit sign is encountered. Then recently I noticed that sometimes it shows up earlier. For a while I thought that maybe the nav system looks it up in some database, but then I noticed that the speed limit showed up as soon as I passed a sign for the opposite traffic, therefore only viewable in the rear view camera. Combine that with the fact that the car can parallel park in reverse, even sense parallel and perpendicular parking spaces in the read, makes think it may be connected to the MobileEye chip. Does that mean we may get rear car awareness on the IC at some point in the future (showing cars behind, not just in front of the Model S), or is that camera not usable for safety things because it has no wiper and therefore it may be dirty, so anyone relying on checking blinds spots on the IC could cause an accident because of it? Just a thought, if anyone actually knows and is willing to share, that would be interesting to know.
     
  2. Mark Z

    Mark Z Active Member

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    I have noticed that Model X does not change lanes as quickly now on busy freeways, compared with several weeks ago.

    IMHO, the rear camera might be looking if it is safe to change lanes. Just my opinion.
     
  3. garygid

    garygid Member

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    As far as we know, the rear view camera only provides a video feed for you to
    view on the 17" screen, and is not used by AutoSteering, Auto Parking, Summon,
    Lane Changing, or anything else ... as far as we know, for now.

    When the Gen 2 sensors arrive, to better enable higher levels of Auto Driving,
    it is likely that a lot more cameras will be used, giving both all-around far vision,
    and all-around near vision to see objects right near or even up against the car ... IMO.
     
  4. Max*

    Max* Autopilot != Autonomous

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    I believe wk057 stated that the rear camera is connected directly to the MCU and thus not used for AP.

    I could be wrong.
     
  5. ecarfan

    ecarfan Well-Known Member

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    There is no information stated by Tesla that indicates the rear camera is used for any AP functions. That does not mean they are not using it in some way that they have not disclosed,but given the poor quality of the image in adverse weather conditions, it seems unlikely.
     
  6. whitex

    whitex Member

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    So when the car does parallel, or perpendicular parking in reverse, that is purely based on ultrasonic sensors?

    Also, did anyone else notice whether the reverse traffic speed signs register if there are no forward direction speed limit signs available?
     
  7. mikeash

    mikeash Active Member

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    Parking seems to be ultrasonic sensors and dead reckoning using the information previously gathered from the front camera and radar. You can see on the screen that the car remains fully aware of the location and dimensions of the target parking space even as it maneuvers around, to much greater precision than the ultrasonics allow.

    I don't think it registers speed limit signs facing the other way. That wouldn't make any sense anyway. Speed limit signs denote the beginning of the limit. If you're picking them up from the rear, then you're reading them as you're going out of the zone! If it's just a reminder sign then sure, it'll be correct, but any time you transition between limits it'll get things wrong.

    The car sometimes knows speed limits with no sign. It may have some internal database of road speed limits, or it may be remembering from previous drives on the same road when it could see a sign. You're probably seeing it figure out the speed in this way, and it just happens to occur at a time when you're passing a sign facing the other way.
     
  8. whitex

    whitex Member

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    #8 whitex, Mar 8, 2016
    Last edited: Mar 8, 2016
    I think you missed something in your analysis here. If the speed zones are changing, there should be a sign on your side. If there is no sign, then the speed limit should be the same as the zone were just in (actually you are still in the same zone) so the sign you saw in reverse is a reminder not a zone change. The only time this fails if there are asymmetric speed zones (one direction has different speed limit than than the other).
     
  9. mikeash

    mikeash Active Member

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    It also fails if the sign on your side is covered by trees, is behind another vehicle, got knocked over, was stolen, etc.
     
  10. CHG-ON

    CHG-ON Still in love after all these miles

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    Several SW updates ago, the speed and distance at which my car recognized a change in limit by reading the signs changed. Unfortunately, I do not know which update changed it. When I bought my car, prior to V6.2, I noticed that it would register the new speed limit the very second the windscreen passed the speed limit sign every single time. I was very impressed. It was uncannily consistent. Clearly, the front right camera saw it and registered it immediately. Somewhere in the line of updates, the recognition slowed and did not make the change until I was perhaps 100 ft past the new limit sign. It has stayed consistent since I noticed the change. While not scientific, it feels that it is always about 100 ft beyond the sign every time. I wonder if they added a delay for some purpose. I am quite sure that the rear camera could not read the limit sign, as it is at the wrong angle, and if it could see the sign, it would only see the back of it.

    Regarding AutoPark, it uses only the ultrasonic sensors once it has passed the spot that qualifies. Pretty impressive when you think about it. I do not know if the front camera has anything to do with identifying the spot. I would personally doubt it because it would have to be one heck of a wide angle view to see and measure the space. Unless it simply sees a void and then lets the ultrasonics measure it. That would be pretty darn impressive too. net-net, I don't know how they do it. But every time I have used it, it has parked my car absolutely, positively perfectly: even spaces front to back, bang-on straight in the space and the tires are approx 8-10" inches from the curb. I always thought I was a really good parallel parker until my Miss put me completely to shame!
     
  11. wk057

    wk057 Senior Tinkerer

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    Correct. It's connected in a way that it has no way to really export the image to anything. It just can be put as an overlay on the 17" screen. The actual camera "app" displays black, and the chip that sits between the GPU and the screen just overlays the camera feed on to those black pixels. The car uses non-black pixels to draw the backup lines. It wasn't as powerful before, since it would literally just overlay where it was told with no exclusions, resulting in odd video artifacts in early firmware.
     
  12. whitex

    whitex Member

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    That would not be a failure of AP, that would still be proper interpretation of the rules of the road. If the sign is missing, it is not the failure of the driver (human or AP) for not following it. If you were going in a X mph zone which changed to Y mph zone but someone stole the sign, how would you know you should be driving Y but not X? Or do you think that "Your honor, I wasn't speeding, I just assumed someone just stole the 100mph sign from in front of that school." defense would work in court? ;-)

    - - - Updated - - -

    Thanks for an authoritative answer! Too bad, I was quietly hoping for 360 (or at least front120+rear120) awareness possibilities.
     

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