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Autopilot TACC - still a work in progress

Discussion in 'Model S: Driving Dynamics' started by krisg81, Mar 19, 2015.

  1. krisg81

    krisg81 Member

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    Just traded my P85 for my P85D. I am happy with everything, including the new awesome launch performance. Although Autopilot (at least its initial features) were not a major deciding factor of the trade up, I thought I would give TACC a try.

    My first impressions are this thing is simply not up to par. It feels like a beta test. I have used it for may 50 total miles, and there were at least 3 encounters that made me say "Holy sh*t"

    1st encounter:

    I was cruising along at 74 MPH, distance setting at 4. A guy in a big stake-bed truck decided to change lanes about 7-8 car lengths in front of me. Nothing abrupt, he put his signal on and slowly changed lanes. He was probably traveling at 70mph when entering my lane, and was not speeding up so I was slowly approaching him. As he was halfway in my lane, my P85D maintained 74MPH and kept closing in on him, even while he was halfway in my lane. I thought, ok - I will go ahead and let this thing brake for me as I kept my foot hovering above the brake pedal. Sure enough, as he finally completely entered my lane, it waited until literally 2 car lengths to beep the collision warning sound and then abruptly hit the brakes (I have collision warning on the early setting). I still had plenty of time to brake on my own. The problem I see is it doesn't react until the car is completely in your lane, and its not smooth- it creates an erratic driving situation that other drivers might find strange or even cause a problem.

    2nd encounter:

    Stop and go traffic, car in front of my slowly changes to lane to the right of me, and the car starts accelerating before the car completely changed lanes- getting me a bit close for comfort to the car. Very weird.

    3rd encounter:

    Car in front of me changes lanes to the left, and car wants to suddenly brake- I hurried and pressed the accelerator, but it was a strange thing that it wanted to brake.

    Other than that it seemed to do well, it just needs to brake smoother. I guess I can't expect much as it the sensors and computer doesn't possess common sense, like slowing as a car seems to be changing lanes.. just kinda of disappointed and it seems like I am a tester for the technology still.
     
  2. brad.md.us

    brad.md.us Member

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    Thanks for posting. I feel like TACC is a work in progress and will improve over time. Nonetheless you have a responsibility to be in control of your car and to drive it with great care and attention - even when using cruise control or TACC. I also think that drivers should allow 7 car lengths when cruising at 70+ mph. 4 lengths at 74 mph is especially not long enough when you are getting to know something like TACC.

    Also, you should turn TACC off as you are exiting a highway. I understand that it is only meant to be used today from on-ramp to off-ramp and not beyond. Think about your 74 mph setting kicking in as you enter a road that has cars stopped in the distance ahead at a traffic light. The car with the TACC setting on would accelerate until it gets close enough to sense the stopped cars ahead - when you should probably be slowing or even braking. Be aware. The car can't see brake lights ahead.

    Enjoy your P85D. I am definitely enjoying my S85D!
     
  3. BerTX

    BerTX Member

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    Every time I read someone's description of this late braking, I think "I have seen many, many aggressive drivers who do this" -- racing up behind the offending car and slamming on the brakes at the last second, I assume to make them think they almost caused an accident. I wonder if the programmer thinks this is "normal" behavior? It's certainly not unusual behavior.
     
  4. Stoneymonster

    Stoneymonster Active Member

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    I doubt there's just one "programmer" working on a feature like this. Unless they are morons over there, it's a team with algorithm developers, implementors, and QA. I sincerely doubt that anyone went out to the freeway one day, looked at a bunch of cars and said "ok, that's what we'll do". These guys know what's safe, I suspect there are a lot of corner cases that haven't been accounted for yet with the sensors.
     
  5. krisg81

    krisg81 Member

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    What is worse is if you are traveling with passengers they wonder why you are not slowing down until the last second. As the driver just getting used to this technology, its nerve racking because theres no progressive slowing down - just abrupt braking that reminds me of driving with my Grandma.. always a little anxiety because you don't fully trust her abilities lol
     
  6. Lump

    Lump Active Member

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    Here is another report of TACC not recognizing a flat bed truck\trailer #238
     
  7. Rockster

    Rockster Active Member

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    I've been using TACC for a few days now and I have a question: is the 1 through 7 setting intended to approximate car lengths? I've noticed that even though the distances changes in response to the settings, the numerical setting doesn't seem to approximate typical car lengths.
     
  8. ItsNotAboutTheMoney

    ItsNotAboutTheMoney Active Member

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    Please tell Tesla. They might be aware already, but you effectively have described test cases for them to work on.
     
  9. BerTX

    BerTX Member

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    Sorry, I'm having trouble with my keyboard and it's driving me crazy. I got frustrated and forgot to put :wink: at the end. I was being silly. It's tough to type on a website about esla when your capital "T" doesn't work. :wink:
     
  10. Stoneymonster

    Stoneymonster Active Member

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    Not your fault, I had too much coffee today. :scared:
     
  11. BerTX

    BerTX Member

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    Why isn't the following distance speed related -- a car length for every 10 MPH or whatever? Granted, the car can react much faster than a human, so reaction time is greatly reduced. It's almost like this is Automatic Emergency Braking rather than collision avoidance (I just learned the difference).
     
  12. mrElbe

    mrElbe Member

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    The TACC radar beam must be quite narrow or otherwise it would recognize the opposing lane. So, a vehicle half lane in front of you could was not registered by the beam causing the situations you described.
    I was using TACC last week on the highway set at 90 km/h and it followed traffic in front of me perfectly even through a town with low speed limit and a traffic light stop.
     
  13. krisg81

    krisg81 Member

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    Have you ever been in a situation cruising along at a decent speed and a vehicle moving slower than you changes lanes in front of you? How soon did the car decide to slow down to match his speed, while he is merging in the lane or did it wait until he was fully in the lane?
     
  14. Stoneymonster

    Stoneymonster Active Member

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    That sounds plausible. I'm willing to bet that further advancements on this sensor platform are going to come mostly from new image processing algorithms on the front camera, followed by a few changes to how radar is processed, and much further down, small tuning on the ultrasonics.
     
  15. mikeash

    mikeash Active Member

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    Word from my DS was that it doesn't mean anything beyond 2 is more than 1, 3 is more than 2, etc. It's not seconds, or car lengths, or anything like that. It's just, if you think you're too close, bump the number up. If you think you're too far, bump it down.

    Personally, I find 7 to be just about right. I tried 1 today and boy was that ever exciting in heavy traffic. The computer did a good job of aggressively tailgating the guy in front despite some big speed changes, but it's not really what I'm after.
     
  16. Todd Burch

    Todd Burch Electron Pilot

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    OP: Definitely report these situations to Tesla (although with their forum monitoring--particularly of safety-related issues like this--they probably have already seen it by now).

    Your first case sounds similar to another case reported, where a thin (in height) trailer was not recognized soon enough by the radar.

    Your second case is actually contrary to what I've seen--I'd agree very weird. Typically, a car changes to a lane next to me and my car will continue tracking it for about 2 seconds before it speeds up.

    Your third case is what I describe above...usually the car changes to an adjacent lane and slows to turn or something, and the S will continue tracking it and brake accordingly for about 2 seconds. For now I anticipate this and give some accelerator input.

    On the bright side, I have already seen some improvements in TACC even in a minor update. 2 examples of improvements in the minor revisions that have come out since TACC was released:

    1. When oncoming cars turn left and cross in front of me about 100 feet in front of my car, the S used to brake somewhat aggressively. I haven't encountered that much (if at all) since a recent minor update.

    2. For me, TACC doesn't disable as quickly when driving through a tunnel. Used to cut off within seconds of entering a tunnel...now it cuts out after a minute or so (presumably from bouncing radar reflections confusing the sensor?)

    So the takeaway and bright side is--these things should be worked out with future software updates.
     
  17. anxman

    anxman Member

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    I'm experiencing all of the situations described in this thread, and I had raised some of these in earlier threads about TACC.

    Specifically, when someone merges into my lane, the car does not react quickly enough to be fully safe. I have taken control of the Tesla on at least a few occasions when it accelerating into a car that was merging into my lane.
     
  18. martinwinlow

    martinwinlow Member

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    "Nonetheless you have a responsibility to be in control of your car and to drive it with great care and attention..." Good!
    "I also think that drivers should allow 7 car lengths when cruising at 70+ mph." WHAT!!!? That's only about 120 feet! Any sensible driving instructor will tell you this is barely half a 'safe' gap to leave at 70mph.

    Just stick to the '2 second rule' i.e. leave a gap that takes to seconds to cover at whatever speed you are doing and you will have adequate *thinking* time should something untoward happen. How do you judge that? Pick a bit of road-side furniture - a sign, a bridge - when the vehicle in front passes it (it helps if the object casts a shadow over the carriageway) start your 2 second count. If you get to the same object before 2 seconds is up, you are too close!

    120 feet is barely enough time for you to react (eye > brain > muscles) let alone do anything useful to avoid a bad day. MW
     
  19. benjiejr

    benjiejr Technogeekextraordinaire

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    OP, I've had similar situations and did as you did and hovered over the brake just to see how TACC would handle it. Later FW releases seem to have improved in my experience. What FW are you on? I'm on .179 now. Also, I typically use 4 as the distance and it does well in most cases for me, but when a car merges in front of me it still waits too long to respond IMO and I noticed that 7 leaves a better cushion in this scenario and is more subtle with responsiveness. The problem with 7 for me is that it leaves too much space, in general, and other drivers tend to enter that gap. It's funny how there's an art to following distance and I think the programming here will improve. I stick with 4 for now and just stay on alert.

    Most of the time I'm very happy with how TACC responds and sure does make highway driving so much more relaxing!
     
  20. Jaff

    Jaff Active Member

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    I used the TACC extensively a few days ago on an 1,100 km trip to Ottawa & back.

    I travelled through Toronto on the 401 in light to medium traffic...the TACC worked surprisingly well...no real issues nor close calls.

    A question for the OP...I had my setting at 7 whilst travelling at an average speed of 105 kph...did you try operating the TACC higher than 4 (considering your travelling speed of 74 mph?)

     

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