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Adaptive Cruise Control
- Thread starter Kevin Harney
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graham
Active Member
I think you are probably right (of course, they are shipping me a without a glove box, so who is to say...) :smile:
Count me in for the adaptive cruise control also. It is easily the #1 most important feature for me. I bought a Roadster and the lack of ACC is driving me nuts, I can't stand it. The radar unit has some depth to it and it might eat into the front trunk space of the Model S. Guess what? I don't care! Just do it! It should be super easy to do on an electric car because of how powerful the regen is, you wouldn't need to even tie into the car's braking system. Hopefully they *will* tie into the car's mechanical brakes though because I would really like for the ACC to be able to bring the car to a complete stop. Someone at Tesla seriously needs to borrow a brand new BMW for a day and experience how good it can really be. The latest version of BMW ACC is amazing, much better than my Acura.
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+1 I have a BMW and I LOVE the system. Not sure if mine is the newest as my car is a 2009 but It is good. Mine, unfortunately, does not bring the car to a complete stop. Any ideas on why some cars do this and others do not ? Volvo even has two systems one that will stop the car if you are going less than 20 mph or so and the other that will slow the car on the highway - but those two systems will not work together ?!?!?!?! what is that ? 
Products operations liability. Imagine a system failure causes a full stop at >60 mph on the highway. Imagine the fun you'll have. That's why Volvo only does a full stop at <20 something mph.
Personally, I couldn't care less about that option. Either I can drive a car and I'm fully attentive, or I shouldn't drive a car at all.
No offense intended.
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Products operations liability. Imagine a system failure causes a full stop at >60 mph on the highway. Imagine the fun you'll have. That's why Volvo only does a full stop at <20 something mph.
Personally, I couldn't care less about that option. Either I can drive a car and I'm fully attentive, or I shouldn't drive a car at all.
So all you are saying is that some manufacturers are will to take the risk of a law suit and others are not ? Seems kinda lame to me .... you may be right of course but that is a lame excuse.
What I don't understand about Volvo's system is that at Highway speeds it will take you down to about 20 mph before it turns off - same as my BMW - but Volvo also has a system that stops the car if you are traveling less than 20 mph. But the two do not work together !!! uuuuugh seems to me at 20 mph you should switch from one system to the other. If for some unknown reason the car needs to stop itself then it should be able to finish the job. Why slow the car to 20 mph and then have an accident when the car (and the accident) could have been avoided all together ?
I hope that I NEVER need the system but I am glad that I have it none the less !
At the <20 mph the time to stop is shorter or near your reaction time. So it makes kind of sense to let the system do a complete stop. Also, a failure wouldn't be so disastrous at that low speed. AFAIK Volvo is the only one with such a system. But I didn't pay much attention recently. Could be others have it too.
At highway speeds, they assume you will pay attention immediately if the car beeps, light on the dash go on and braking occurs. And then you'll be able to decide yourself if you need to floor the brake pedal. Anything other will incapacitate the driver and could be a sword against them for lurking lawyers esp. in the US, if the driver relies on it and / or it fails. I'm pretty much sure that was their reasoning when Daimler and BMW introduced their systems years back. It's not that is not technically possible. Drive be wire is pretty much possible to day as seen on many prototypes. But products operations liability holds them back (and costs of course).
You seem to be missing my point really. I can totally see your point at highway speeds. My point is that it has already done the highway speed reduction to 20 mph at that point you are only going 20 mph so why not allow the other system designed for less than 20 mph kick in ? There are now several cars that will stop the car from highway speeds if necessary including Mercedes and a few others. The highway braking that occurs automatically is NOT full hard on braking. I think they are limited by regulations to something like 40% of braking capacity or something like that.
Seems so.
Because it is another system? "Switching systems" on such a crucial thing as brakes would be a nightmake if I where in charge as engineer. How to ensure a full, complete and successful handover? And even if it could be done, I still fail to see why it should. In what case would a system brake the car driving 60mph at 40% rate to 20 mph and then do a full stop WITHOUT driver intervention? The Volvo system is an emergy stop system trying to eliminate your reaction time. At 20 mph your reaction time happends to be same or larger than your stopping time. At 60 mph it's not so they leave to driver to decide but still cut off of your reaction time quite a bit. It's just that simple. Sorry if I still do miss your point.
OK good point. AFAIK Volvo is the only one with 2 systems. All others seem to be doing it with 1 system. Mercedes will do a full stop without driver intervention from full speed. Not sure about others ....
Several cars will come to a complete stop. The 2010 models of Audi, BMW, Mercedes, and Infiniti are examples. The 2010 Hyundai Genesis will work down to 6mph. It has nothing to do with dual-systems working together or potential lawsuits.
These adaptive cruise control systems work by using radar to measure the distance to the car in front of you. If there is no car there then guess what -- there is still radar energy being reflected back from surface irregularities on the empty road. How does it tell the difference? By taking a distance measurement, waiting a moment, then taking another distance measurement. It knows how far your car has travelled between those two readings, so if the "object" has grown closer by that same amount then it must be a stationary object (such as the road). Stationary objects are ignored. If the object appears to be moving then it will treat it as a car. As your own vehicle speed drops below about 20mph this calculation becomes much harder to do because your car isn't travelling far enough between samples to render an accurate calculation about the target object being in motion or not.
These ACC systems (even the fancy new ones) will let you plow right into a brick wall or parked car without ever even slowing down. The object has to be "moving" in order to be considered a car. On the fancy new systems, once your car "locks onto" a moving object, then if that moving object slows down to a complete stop then your car can maintain the "radar lock" on that object and also slow down to a complete stop. The fancy new systems just use more accurate radar sensors and faster CPUs and higher precision math libraries in order to work at the slower vehicle speeds.
The radar units are the best. The laser based systems (such as Infiniti and Lexus) don't work when driving directly into sunlight or when it is raining/snowing/heavy fog.
These adaptive cruise control systems work by using radar to measure the distance to the car in front of you. If there is no car there then guess what -- there is still radar energy being reflected back from surface irregularities on the empty road. How does it tell the difference? By taking a distance measurement, waiting a moment, then taking another distance measurement. It knows how far your car has travelled between those two readings, so if the "object" has grown closer by that same amount then it must be a stationary object (such as the road). Stationary objects are ignored. If the object appears to be moving then it will treat it as a car. As your own vehicle speed drops below about 20mph this calculation becomes much harder to do because your car isn't travelling far enough between samples to render an accurate calculation about the target object being in motion or not.
These ACC systems (even the fancy new ones) will let you plow right into a brick wall or parked car without ever even slowing down. The object has to be "moving" in order to be considered a car. On the fancy new systems, once your car "locks onto" a moving object, then if that moving object slows down to a complete stop then your car can maintain the "radar lock" on that object and also slow down to a complete stop. The fancy new systems just use more accurate radar sensors and faster CPUs and higher precision math libraries in order to work at the slower vehicle speeds.
The radar units are the best. The laser based systems (such as Infiniti and Lexus) don't work when driving directly into sunlight or when it is raining/snowing/heavy fog.
I know the slow Volvo system, the one that brakes you down to 0mph is intended for pedestrian safety. Thus it's possible that system is based on a IR camera instead of a radar to detect humans (and animals I suppose). Which might explain why the fast system only goes down to about 20mph and then has problems detecting the enviroment. I don't know of course but that would be my theory.
Cobos
Cobos
I did not know the new BMW system went down to 0 mph. I guess I bought 1 year too early
sigh..... isn't that always the case .... LOL
WhiteKnight
_____ P85 #549 _____ Sig Red / Sig White
Hey Tesla,
I really wanted Blind Spot Monitoring on the Model S. If you are considering it, I would gladly pay extra for it.
I really wanted Blind Spot Monitoring on the Model S. If you are considering it, I would gladly pay extra for it.
I'm not surprised that adaptive cruise is not available. I've watched how it works on my G37 and it's fairly sophisticated. It has to detect the car in front, but not the cars in adjacent lanes even while going around corners. It has to work in a wide variety of environmental conditions, and also automatically disengage when the conditions deteriorate; otherwise it might unexpectedly try to plow you into a car. If you were tired and had gotten too accustomed to it, and had it in "close follow" mode that could be dangerous (actually my G37 tried to do just that the other day - the car in front "disappeared" from the display, but I was paying attention and I only use distance settings 2 or 3). Also adaptive cruise operates both the accelerator and the brakes, which is more complex. Needs a bit more driver UI as well.
There might be "off-the-shelf" solutions available from suppliers, but they wouldn't understand regenerative braking, could be very expensive, and it would still require significant work to integrate with the car.
IMHO developing and validating adaptive cruise for the Model S would require a lot of real-world testing in a great variety of real-world conditions, including winter driving, storms, sunny days, etc. That will be both expensive and time-consuming. I suspect they simply don't have enough time in their schedule to do it.
There might be "off-the-shelf" solutions available from suppliers, but they wouldn't understand regenerative braking, could be very expensive, and it would still require significant work to integrate with the car.
IMHO developing and validating adaptive cruise for the Model S would require a lot of real-world testing in a great variety of real-world conditions, including winter driving, storms, sunny days, etc. That will be both expensive and time-consuming. I suspect they simply don't have enough time in their schedule to do it.
DrComputer
TeslaClubLA President
I agree it would take some work to get ACC or lane departure to work with the S, but it's not like those are "new" features to the automotive world. When building the S they could have easily purchased the technology from either of their two partners (Toyota or Daimler) and integrated during the design process.
efxjim
Member
Not quite a deal breaker but I place it on the top of my list of options wanted. LA traffic is not going to get better.
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