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Dynamic cruise control

Discussion in 'Prime Main Forum (2017-2022)' started by skierrob, Apr 1, 2019.

  1. Curlyone

    Curlyone Member

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    Got to put the cruise to the test last weekend on a long trip that went thru Oklahoma city. Lousy timing on my part put me in Friday afternoon traffic, and adding to the fun was 10 or so miles of single lane because of road work. Set set the cruise to 80, following distance to 2, didn't have to touch a pedal the whole time. Speeds went all the way from 80+ to 5 and back constantly. Really helped reduce the stress levels, I'm very happy with the adaptive cruise.
     
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  2. pghyndman

    pghyndman Active Member

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    We're still learning the nuances of the Dynamic Cruise Control, but love it!
     
  3. SteveMucc

    SteveMucc Active Member

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    you should be able to detect based upon the return timing. if you see returns to quickly (or instantly) or of too great a magnitude you can probably assume you're blind. you'd have to have something covering you that was completely radar absorbent to be able to truly blind you without being able to detect that to be the case (and then you wouldn't see any returns so you could detect blindness based upon that).

    I haven't looked at the design of the car radars systems but I assume they utilize some sort of code spreading/processing gain to allow them to process in an environment with other similar emitters and use lower transmitter power.

    I would assume that if the radar was detected as blind by the pre-collision then the DRCC would be disabled.

    Did anyone try enabling it when the pre-collision was faulted?
     
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  4. jerrymildred

    jerrymildred Senior Member

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    Great point! I stand almost certainly corrected. :)
     
  5. m8547

    m8547 Senior Member

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    We had another snow storm yesterday. I had another failure of the radar cruise control with no warning that anything was wrong, it just couldn't "see" the car ahead of me despite great visibility and some slush covering the radar sensor. It seems like the camera should help validate the data from the radar, because it was pretty clear that I was closing in quickly on the vehicle ahead of me, closer than the typical "1 bar" following distance.

    At some point I switched the cruise control off and back on, and I immediately got a yellow warning triangle and a message that said "clean radar sensor". It didn't go away until after I parked, cleaned the sensor, and turned the cruise control off and back on. I left the car on to see how quickly it would notice that the sensor was clean. So it seems like it only checks for obstructions in front of the sensor when you first turn on the cruise control (actually enable/disable it with the clicky switch, not just set or cancel it), and rarely or never after that. That seems like poor design.

    By the time I parked there was about 1/4 inch of slush covering the sensor. Obviously I don't expect it to work under that condition, but it should handle the problem better. The radar emblem should be heated to melt snow and ice, or maybe have a washer fluid jet to clean it. The car should use the camera to validate what the radar is seeing. The camera could also help see stopped traffic ahead, before the radar can see it. And it should more proactively alert the driver when it is not working, even if it stops working while the cruise control is enabled.
     
  6. fuzzy1

    fuzzy1 Senior Member

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    ... all of these just highlighting that fact that we are still at a stage of advanced driver assists, but not yet to a stage of self-driving cars. More work must be done to reach and certify the upcoming self-driving functions. They are not actually here yet, so drivers must not allow their expectations to get ahead of current technical reality.
     
  7. m8547

    m8547 Senior Member

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    Yeah, I don't think I'd ever trust Tesla's autopilot in the near future. There are just too many uncommon scenarios that it probably can't handle. The simplest being what if there is some debris in the road?

    But at least Tesla does regular software updates. I'll be surprised if we ever get any kind of update to TSS-P, and if we do it will probably be the most minimal thing they can do to correct or band-aid a defect, not make actual improvements.
     
  8. breakfast

    breakfast Active Member

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    You're not supposed to use Radar Cruise in the snow per the manual... By the way, the "clean sensor" comes on while driving - happens to me often in snowy conditions. At that point, turn off lane keep assist too, and the "yellow triangle" warnings will go away until you have the ability to clean your sensor (and your windshield - that camera at the top center also needs to be clear).
     

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  9. m8547

    m8547 Senior Member

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    I know I'm not supposed to use it, but radar should have super-human ability to see through fog and snow, so it seems like it could be helpful in white-out conditions. I do avoid cruise control when the roads are slippery since it can be a little unpredictable, which is why I'm only testing it now in these spring snowstorms.
     
  10. fuzzy1

    fuzzy1 Senior Member

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    One mustn't trust that feature at this time, because it simply isn't yet up to the self-driving job. It is merely a driver assist, the driver still must remain fully engaged all the time. That is why the owner's manual has so many disclaimers. It isn't just legal CYA, it is also a reflection of current technical reality.

    No consumer-market systems are there yet. That is why several Telsa drivers who wrong-headedly tried to trust it, are dead.
     
    #30 fuzzy1, Apr 30, 2019
    Last edited: Apr 30, 2019
  11. jerrymildred

    jerrymildred Senior Member

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    I rarely use the DRCC even here in sunny FL. I for sure wouldn't use it in the snow. Also, radar is radio and just like over the air television, it has trouble penetrating rain and snow. That's why it's so useful for weather forecasters. The DRCC could theoretically penetrate the snow and slush like weather radar, but that would require radiating at dangerous levels.

    For those who don't already know, it's easy to bypass the radar function. Just long press the "clicky button" for about three seconds or so and it will be a regular cruise control.
     
  12. breakfast

    breakfast Active Member

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    I love the DRCC - it's fantastic. I use DRCC whenever the conditions are good enough and I'm on rural roads or highways - the level of added safety and decreased fatigue is a huge benefit on the many long drives that I need to take..especially ones with significant traffic. It's truly another pair of eyes... but it is, as we are all saying, a driver *assist* that requires constant oversight.

    As Jerry says - it's nice that regular cruise control can be activated at any time.
     
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  13. jerrymildred

    jerrymildred Senior Member

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    Totally agree. It's nice at times. I'm sure I'll make good use of it on our vacation trip. There's just too much herkey-jerkey, floor it & slam on the brakes going on for most of my local driving. I can anticipate better with the regular cruise in our conditions. If not surrounded by crazy people, I'd probably use it more.
     
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  14. m8547

    m8547 Senior Member

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    I didn't know about the regular cruise control option. I don't know when I'd ever use it, but it's good to know it's there. Thanks

    I use DRCC a lot, and I like it most of the time. But it is best for light traffic or stop-and-go traffic. It's not great for heavy traffic with crazy drivers, which is probably most of the time in Florida.
     
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  15. fuzzy1

    fuzzy1 Senior Member

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    That is the key. It is meant to be another pair of eyes. A secondary set. Drivers get into trouble when they wrongly elevate it to their primary or even only set of eyes.
     
    #35 fuzzy1, Apr 30, 2019
    Last edited: Apr 30, 2019
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  16. jb in NE

    jb in NE Senior Member

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    Even if the device could see through snow, the traction available would probably mean that it could not stop the car in time to avoid a collision with any object it detects. I only drive as fast as my eyes can see - it the visibility is reduced, slow down because you don't know what's ahead of you and you need time to react to whatever pops up.
     
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  17. ed4271

    ed4271 Member

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    This is what I do what I'm using Dynamic cruise control. You have three settings three car lengths two car lengths in one car length. What I'm in heavy traffic I usually use it on 3 car lengths sometimes because it keeps me from running into the back of a car when they suddenly stop. when I'm driving and the car in front of me is going slower than my cruise control and I go over to the next Lane to speed up I put it on one car length. The reason for that is because the car will speed up. But when you're driving and traffic starts to slow down you have to be careful I take mine off of one and put it on three which gives me enough time for the car to slow down without speeding up and then coming to a severe stop. I know you're not supposed to do to the rain but what I'm driving on the highway I use it because it's really helpful keeping me the distance from the vehicle in front of me especially when I cannot see it and the radar can.

    Posted via the PriusChat mobile app.
     
  18. bruceha_2000

    bruceha_2000 Senior Member

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    I bet that is in the manual somewhere. I didn't know about it. Now WHICH clicky button, the one on the steering wheel (far right) or the "master" on the CC stalk?

    I agree with @breakfast, I love the dynamic CC most of the time.
     
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  19. jb in NE

    jb in NE Senior Member

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    I have my doubts about dynamic CC. I was on the local interstate in moderate traffic, coming up on the car ahead of me. I went to pull out to pass and at that moment the CC shut the throttle and I almost got nailed by the truck coming in the left lane. That caught me by surprise and I had to hammer the throttle to get going again and not get run over.

    I found on my first trip home from California that I preferred static cruise control. I'll try dynamic again on this upcoming trip and see if it agrees with me.
     
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  20. Prius from Dad

    Prius from Dad Senior Member

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    That has happened to me on occasion, especially when the car in front of me is getting ready to exit and they slow down but don't fully leave the lane. I think it is because the car in front of you is still in the radar's "sight" when you are pulling out. I'm used to it now and disengage the DRCC when I see it happening.