Smart Cruise Control

Discussion in 'Hyundai Kona Electric' started by IslandGuy, Aug 4, 2021.

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  1. I was wondering if anyone else has experienced what I have experienced when using cruise control in my 2019 Hyundai Electric, and if they know why.

    So I am driving down a highway that also has stop lights. The speed limit is 80 and I'm doing 85. I'm using the smart cruise feature which causes the car to stay a certain distance behind the car in front of me and also comes to a stop when the car in front of me stops.

    However, if I am doing 85 km/hr and I'm coming to a stoplight where cars are sitting still waiting for the light to turn green my car does not slow down soon enough to stop safely so that I have to manually apply the brakes.

    Is this because the radar can't see far enough ahead to see the stopped car and slow down sooner?
     
    electriceddy likes this.
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  3. Sometimes it has trouble if it’s on a curve because the radar can’t see around the corner, but I’ve never had a problem. I usually cover the brakes and play chicken to see if the car will stop, and it always does just a lot harder than I would normally apply the brakes so there can be a bit of a pucker if you’re not ready for it. If you set the smart cruise distance to further away (4 bars vs 1 bar) it will usually catch it and start slowing down sooner so it doesn’t have to lock up the binders.


    Sent from my iPhone using Tapatalk
     
    navguy12 and Lars like this.
  4. My cruise distance setting is maxed out at 4 lengths. I wish they had 5 or 6 lengths but I'm wondering if the radar isn't strong enough to see that far.
    I think you made a good point about "playing chicken" with the car to see if it will stop in time. I can see that I'm going way to fast to stop in time to not collide with the stopped car at the light so I have stopped that game. It works fine 40-50 km/hr.
     
    Shawn Schinkel likes this.
  5. Same. It can be scary but it always does stop. The car is a bit more thrill-seeking than I am. And yes, a curve further reduces the perceived following distance and can can result in a real adrenalin rush!
     
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  6. Killer regen in that last 100 meters (140 kW depending on speed), pretty much double what the BMS allows at the best charging scenario.
    I tend to tap the brakes and let auto-regen take over, usually at most half that recharging rate and for a longer period (of course you still have to stop eventually). Better for overall range and reduced energy consumption.
    More worried about the traffic behind not adapting to the "quick stop" smart cruise control offers. Not much meat back there and a lower impact collision would probably write off the car.
     
    mho, MRP, navguy12 and 1 other person like this.
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  8. Good thoughts. I worry about my car stopping in time but it's true that I should probably be more worried about others behind me which are trying out the smart cruise and whether it will stop in time.
     
  9. You can see if the car "sees" the car in front of you. The auto Regen should be blue if it sees a car in front of you.

    However I've experienced the same and I'm also not going to let the car figure out if it's going to stop or not. The risk is too high, the breaking too hard and the insurance increase not worth it if it fails to detect the car.
     
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  10. Good points about the car behind not dealing with the quick stop and not wanting to deal with vehicle damage or insurance increases. For me, the main reason I'll use the brake pedal to start slowing earlier at those Island Highway lights is the same reason I don't drink and drive. I couldn't live with myself if I maimed or killed someone in the car in front (or even behind) just because I'm enjoying the thrill of having the car brake quickly. That, and I absolutely do not trust it to never fail. Oh, and it scares the bejeezus out of me when I leave it a bit late.

    It would be nice if the cruise could pick up the stopped cars earlier, and I assume it can't because of physics, but I don't see it as much different as having to brake when the light is turning and there's no car in front of me. I absolutely love the smart cruise on the highway and this feature doesn't take anything away from that.
     
    navguy12 likes this.
  11. Yes, the car with smart cruse ON follows aggressively to my taste also. Yes, it will stop the car but I would break earlier. Interestingly my 2016 Prius worked the same way. I think it is a good idea to be aware and have your foot hoovering above the break pedal when the traffic stopped completely ahead.
     
    navguy12 likes this.
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  13. Well, that's not the intentional use of SCC. That's how the emergency braking works. There is actually a video on YouTube that's showed how bad done of those work. Some drive right through the pedestrian, which is how they tested it.
     
  14. I want to permanently disable the Front Collision Assistant, and not have to turn it off every time the car is started. It creates too much of a risk driving in Seattle Traffick of rear collision by someone not prepared for my car to do a full brake ABS stop.

    Anyone know how this is done?
     
  15. Unfortunately impossible. It will turn on every time you start the car and you will have to turn it off every single time.
     
  16. hobbit

    hobbit Well-Known Member

    There are one or two things I do routinely at every startup/takeoff. Tap the regen back to 0,
    because we cannot default it to 0. If I'm heading out from home, there's a particular shallow
    downill I use to throw it in neutral for a quick rotor cleanoff, especially if it's been wet. You
    could easily just train youself to do a few control changes at startup to work around minor
    bugs and oversights that we will simply be unable to get Hyundai to fix, because they think
    their engineers/designers are smarter than all of us.

    However, the larger and much more horrifying picture is that you"re trying to rely on clearly
    faulty systems that threaten your safety and that of others, and rather than discarding that
    and using your own judgement and driving your own car, doing your own optimizations
    because you can be far more predictive than some crapped-up sensor in the bumper ...
    instead, you come here and gripe about all the surprises that garbage keeps handing you.
    When [not if] that fails you in a more catastrophic way, are you going to expect a lot of sympathy?

    If you were behind me letting a poor design run your life, you would definitely get communication
    that it needs to cease right now.

    _H*
     
  17. eastpole

    eastpole Active Member

    I might express it differently but I agree with Hobbit that you (IslandGuy) and Shawn are doing product testing on public roads. I hope it will not take you long to finish your testing and decide that you probably shouldn't do that.

    The Smart Cruise Control is not designed to do what you are asking it to do, and if it fails... That would be a terrible time to get a lecture from the design engineers (in a court room) about what it *was* actually designed to do. The marketing text reads:

    Smart Cruise Control (SCC) is not a collision avoidance or warning device. SCC is for highway use only and should not be used in poor weather, heavy or varying traffic, or on winding or slippery roads. Driver remains responsible to slow or stop the vehicle to avoid a collision. See Owner’s Manual for further details and limitations.
    This is poorly worded, at least for Canada. All roads are highways. SCC is intended for use limited access roads or freeways.

    I could be wrong about this -- if you have a reason to think so, let me know here.
     
    Lars, Esprit1st, navguy12 and 2 others like this.
  18. BenignShrug

    BenignShrug New Member

    So, if you are following a car and it slows down, you will slow down. It can see that the car is moving it brings you in line with it, great. However, if the car ahead of you was stopped, and wasn't actually being "followed" then ACC isn't controlling your vehicle. The emergency stop kicks in because it just thinks you are going to hit another object. It's not a function of range.

    Think if you were driving in a tunnel, and it starts to turn, do you want your car to drive along the tunnel ignoring the walls or do you want it to be slowing down because you are approaching a solid wall?

    It is likely that the ACC is designed to ignore non-moving objects. I.e objects whose delta v is exactly negative your forward velocity. That gets passed to the emergency braking system when range drops below a certain threshold.

    Thus when I am doing 100, and the vehicle in front of me slows down, I will slow down. The relative velocity is such that it knows it is moving and I want to follow. As I have ACC engaged... But if I am approaching a wall, or a parked car, or a stopped car that wasn't ever seen as a valid ACC target (never saw it decelerate in front of me), ACC does nothing, and the event triggers Emergency Collision Avoidance in a most uncomfortable way.
     
  19. Mike Althaus

    Mike Althaus New Member

    Thanks for posting, I was actually using SCC in the rain this week and wondering to myself if it was good enough to handle inclement conditions. Will be more cautious about using it in the future.
     
    Lars and navguy12 like this.
  20. Smart Cruise Control is not autopilot or self-driving, just like Lane Keeping Assist is not autopilot or self-driving.
     
    Mike Althaus and Esprit1st like this.
  21. ENirogus

    ENirogus Active Member

    All of the 'smart' cruise systems ignore non moving objects or they would go insane, braking for street signs and such.
    As mentioned the emergency collision avoidance is what kicks in
     
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  22. Aj123456

    Aj123456 New Member

    I can only guess that once the radar lost the car ahead the SCC accelerated back to the set point at the rate determined by the SCC response setting: slow, normal or fast. ("Slow" could be misinterpreted as coasting, perhaps?)
     
  23. Clint

    Clint New Member

    Thanks people.
    I learned a lot in this thread re SCC
    Clint
     

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