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Cruise Control improvements

Discussion in 'Model S: User Interface' started by Robert.Boston, Dec 14, 2012.

  1. Robert.Boston

    Robert.Boston Model S VIN P01536

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    This thread is not about the lack of Adaptive Cruise Control, which has been amply discussed. Instead, I'd like to focus on what changes Tesla could make in software to improve the existing cruise control.

    My biggest complaint with the current implementation is the transition from CC on to CC off:
    • In ICE vehicles, turning off the CC puts you into "coast," i.e. neither the brake nor gas is applied. I like this result; it gently slows the car, so I can match the speed of the car ahead of me if I'm gaining on it.
    • In the Model S, turning off the CC throws the car into full regen braking, with the brake lights on.
    I can see why Tesla did this; like in an ICE, it's just transferring the inputs from the computer to your feet. The difference is that, in an ICE, if your feet are off the pedals, you coast; in a Model S, you regen.

    To effect a smooth transition, you have to get your foot on the accelerator and find the "match point" where, when you flick off the CC, you'll have no change in speed. This is not easy, and it's not fast.

    My suggestion is that the regen should be limited shortly after you turn off the CC. For the first second, allow the car to coast (0% regen). Over the next few seconds, increase the regen limit, so that by, say, four seconds you have full regen again. This would give the driver time to gracefully transition over to manual control.
     
  2. sfriedrich

    sfriedrich Member

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    Several weeks with the car... I second this.
     
  3. Zextraterrestrial

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    Should be programmable. Sometimes I want to regen hard when I push CC off. Otherwise I just put my foot where it needs to be to hit CC off without any change in speed.
    It isn't that hard once you do it a few times. It is like speed matching gears when you downshift a manual. Funtimes
     
  4. Robert.Boston

    Robert.Boston Model S VIN P01536

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    Your note suggests an important modification to my idea: if you manually apply the mechanical brake, regen should kick in to 100% immediately.
     
  5. Doug_G

    Doug_G Lead Moderator

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    I dunno, I've found I can easily match the throttle setting in the Roadster. Just takes a little bit of time to learn how much to push the pedal. Once you learn that it becomes automatic.
     
  6. mnx

    mnx 2013 P85

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    In my current car I always put my foot on the accelerator before deactivating cruise control via the stalk. Does it really take that long to match or go slightly above your current speed? Even if you only put a little pressure on the accelerator you won't go into full regen...
     
  7. efusco

    efusco Moderator - Model S & X forums

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    I agree with your observations, but suspect they won't change the setting. I think you do have to just learn to apply the accelerator a bit before you turn off the CC. I've found that when I know I'm going to a slower area that I just tap down the speed 5mph at a time...not sure if that flashes the brakes or not, but it isn't as aggressive of a slow down. Since I'll mostly use CC on longer highway drives I plan to use the "low" setting for the regen braking to minimize that intentional regen on downhill areas and when turning off CC.
     
  8. Zextraterrestrial

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    regen should be on 100% before using mechanical brake
    I like the CC how it is. Set your regen lower of you want less pull when disengaging CC. But, I think someone might like to be able to set the regen / CC so it auto speed matches when you drop CC
     
  9. wycolo

    wycolo Active Member

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    > I've found I can easily match the throttle setting in the Roadster. Just takes a little bit of time to learn how much to push the pedal. Once you learn that it becomes automatic. [Doug_G]

    But does it pass the 'Complete Dufus Test', i.e. if I turn my Roadster key over to a complete dufus (and who wouldn't??) will said dufus be imperiled by EV systems beyond his/her control? I say in this case it does, simply because the Roadster CC is hidden away and it would take weeks for dufus to begin to figure it out. Whew, this one is safe from the dufus-testers.
    --
     
  10. DaveVa

    DaveVa Sig Perf #236 VIN #484

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    "I want my, I want my, I want my ACC" sung to the tune of Money for Nothing ...
     
  11. vfx

    vfx Well-Known Member

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    This is exactly like the Roadster. A jarring regen when you turn off the CC.

    What I want is as long as you are holding in the off button it is in coast mode. When you release, it stays at the new speed. This would be perfect.
     
  12. Lloyd

    Lloyd Active Member

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    Toyota required that the Regen be in the low setting when operating the curise control. (D not B) This prevents the uncomfortable decelation when turning off the cruise.
     
  13. mrcool1122

    mrcool1122 Member

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    An ICE car does not "coast" when you turn off cruise control. You're in the highest gear, usually, and you will get engine braking. In some cars, this will be very dramatic ... this is not a unique-to-Tesla phenomenon.
     
  14. Discoducky

    Discoducky Active Member

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    I had this same complaint driving the Civic Hybrid, but I do what Robert does and ease the transition with the throttle. Would be nice if the regen could be less jarring (NOTE: I've only had experience in test drives and put cruise on just once)
     
  15. strider

    strider Active Member

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    I use CC all the time in my Roadster and it quickly becomes second nature to match the speed w/ the pedal as you're canceling. In fact I do this in ICE cars too - if I have the CC set and come upon a car in the left lane going a few mph slower, if I disengage CC the car will start engine braking so I'll push in the gas pedal a bit and then disengage to ease the car down. I know, someone will chime in that I just need ACC but I've never had it and am perfectly happy w/o it.

    I want the car to do what I tell it to and not make decisions for me. I rarely ned to use the brakes while driving so if I see brake lights ahead of me I time the CC disengage to when I would go into full regen anyway. This reminds me of the no regen in cold weather thing - differences in the car's behavior freaks people out.

    You'll get used to it in no time.
     
  16. cinergi

    cinergi Active Member

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    The Model S is actually better than the Roadster in this respect. Model S regen isn't on/off in this situation (though it is a very steep curve) and it's not as strong.
    I personally am able to quickly find the "close enough" spot on the throttle and quickly compensate after shutting it off if I got it wrong.
    However, my faith in the general public being able to do that is low. Any other method (e.g. slowly turning it back on) also has serious problems (e.g. what to do if 0 regen and you step on the brake pedal?) ... tough problem for which I've see no suggestions that personally make sense to me based on having driven the Roadster and Model S over the last 2+ years.
     
  17. GSP

    GSP Member

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    The best solution is to have D and L on the shifter, and only apply regen in L (like the Volt). I like having cruise available in both, in L it will maintain speed going downhill. Toyota's D and B positions are similar.

    This would not only help cruise canceling, but having a quick regen on/off control is great for coasting to extend your EV range.

    GSP
     
  18. Norbert

    Norbert TSLA will win

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    Canceling CC means you want back manual control. So you need to put your foot on the pedal to the point corresponding to what you want the car to do. And then the car needs to do that. I don't see any other principle which would have general usefulness, although one might want the car to help transition gradually. But that might be un-wanted in important situations, so it might require a second button or method.

    The only reason to have the foot completely off the pedal, when you cancel CC, would be if you want full regen, so that's what you get. Or? Of course, with a new car, you need to re-learn where the points are on the pedal, so you can anticipate where to take over from the CC for a smooth transition, if you want one. What I usually do is push down the pedal slowly until I feel it accelerates the car above the level of CC, and then cancel CC, which is completely smooth since at the point manual control has taken over already. Of course, it is only possible where enough space is available.

    If you are asking the car to be in a special 'cruise-instead-of-regen' mode after canceling CC, then how would you get the normal behavior back, when you want/need it? That would seem to make the car more unpredictable, and so come at a cost, due to being more complicated, as then the car has three modes of operation: CC, non-CC, and something in between.
     
  19. mknox

    mknox Well-Known Member

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    Wouldn't setting the re-gen to low on the touch screen accomplish the same thing?
     
  20. GSP

    GSP Member

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    Yes, but then you wouldn't have regen when you want to slow down. You would be forced to use the brakes instead.

    Regen on/off (or low, med, high) needs to be on a primary control, just like the brake or accelerator or turn signal. The shifter works great. I use it more often than I use the brake pedal.

    I have tried to hold the Model S accelerator in the right spot to coast with zero kW on the dash. It is not easy.

    GSP
     

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