collision prevention assist
06-18-2012, 04:28 PM
#26
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Blind spot assist thinks you are turning into the car at your side, when really the car is turning too. If you get the system that brakes to try to correct the steering, you better be holding on tight! . . . but I have gotten this false positive many, many times - I guess our intersections are big enough that we are probably doing 30+mph in the turn.
And that's the way it should be.
06-18-2012, 04:45 PM
#27
My understanding is that the latest version (2012) has an option of adding actual assist to D+. For blind spot assist, for example, when drifting left out the lane it will apply the right front brake (I think) to pull the steering wheel back to the right. I just remembered, though, that it only does this when the left blinker is off. So the scenario I mentioned would be cured by properly using the blinkers in turns.
06-18-2012, 09:22 PM
#28
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e350
Sorry I should make a distinction here. Blind spot assist does not apply brakes. However, ACTIVE blind spot assist (part of the driver assistance package) will use the brakes.
06-19-2012, 02:51 AM
#29
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Great feedback. They should probably integrate Distronic with GPS navigation maps so the car has more situational awareness...
I have never experienced the bug problem, but there are times the system gets "fooled." One common one for me is when I am approaching a stop light and there is a dedicated left-turn lane directly in front of me - my lane curves around the left-turn lane. The car assumes I will be going straight and sees someone waiting to turn left. It thinks I do not see it, so it gives me a double beep. I know it's going to do this, so I am ready to override with the throttle. To have the car apply 100% brake here would be very dangerous indeed, and could produce an unnecessary accident.
The car will also double beep on residential streets if there is a car parked on a left-hand curve. I think for some reason the parked car prevents the system from seeing the curve, and so again it assumes you will be driving straight into the parked car. Again I would not want 100% braking here.
The car will also double beep on residential streets if there is a car parked on a left-hand curve. I think for some reason the parked car prevents the system from seeing the curve, and so again it assumes you will be driving straight into the parked car. Again I would not want 100% braking here.
06-19-2012, 03:21 AM
#30
MBWorld Fanatic!
I don't think the car needs to sense the tire angle necessarily. I think at some point, they'd need to have 360 degrees of radar coverage around the car with object tracking. You can tell a vehicle is turning based on where it has been compared to where it is now... You could likely use this and speed data to extrapolate where the car might be in the future as well... I also think the Active blind spot assist looks at lane markers so presumably the situation you describe below should not happen because each turning lane should be marked and each car should be on its own lane...
One of my pet peeves is when a driver is clueless above lane markings when taking an exit from a circle or on a turning with other drivers on multiple simultaneous turn lanes. So many times I've had to take evasive action or slow down abruptly because someone leaves their lanes and cuts into my lane while turning. This would be a very tricky situation for an active driver aid system to handle.
In general I like Mercedes' approach where they aid you and give the driver every benefit of doubt and preserves the driver's discretion to take action as desired.
One of my pet peeves is when a driver is clueless above lane markings when taking an exit from a circle or on a turning with other drivers on multiple simultaneous turn lanes. So many times I've had to take evasive action or slow down abruptly because someone leaves their lanes and cuts into my lane while turning. This would be a very tricky situation for an active driver aid system to handle.
In general I like Mercedes' approach where they aid you and give the driver every benefit of doubt and preserves the driver's discretion to take action as desired.
I think the system would need a huge jump in capability to handle these things. Maybe, but I doubt it. The thing is that you get used to the things that normally happen, and overriding the system becomes automatic.
Another tricky false positive for blind spot assist: turning left or right from the center when multiple lanes turn the same direction. Blind spot assist thinks you are turning into the car at your side, when really the car is turning too. If you get the system that brakes to try to correct the steering, you better be holding on tight! I have no idea how the engineers could correct for that unless the car could somehow read the tire angle of the car beside you. Yes, blind spot assist shuts off at low speeds, but I have gotten this false positive many, many times - I guess our intersections are big enough that we are probably doing 30+mph in the turn.
Another tricky false positive for blind spot assist: turning left or right from the center when multiple lanes turn the same direction. Blind spot assist thinks you are turning into the car at your side, when really the car is turning too. If you get the system that brakes to try to correct the steering, you better be holding on tight! I have no idea how the engineers could correct for that unless the car could somehow read the tire angle of the car beside you. Yes, blind spot assist shuts off at low speeds, but I have gotten this false positive many, many times - I guess our intersections are big enough that we are probably doing 30+mph in the turn.
06-22-2012, 10:27 PM
#31
MBWorld Fanatic!
Might have been answered, did not read the whole thread but thats option 233 Distronic Plus w/ PRE-SAFE Brake, we have it on my wifes E
06-22-2012, 10:30 PM
#32
MBWorld Fanatic!
option 237 Active Blind Spot Assist
option 238 Active Lane Keeping Assist
12-03-2012, 11:13 AM
#33
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e350
Ok I got a real world story to share from Saturday. I get off a highway to an inclined off ramp. I am driving to fast and not slowing down fast enough. I look away for a second. When I look back I need to press my brake harder than usual to not rear-end someone. I feel the ABS pumping and I stop rather easily (considering how fast I was going. The e350 really gets to a fast speed so smoothly it is sick. I call it a smooth criminal) with about 6 feet to spare. However, it would be nice if I got the double beep forward collision warning when I looked away. I have the driver assistance package.
What gives? The computer didn't think there was a problem?
What gives? The computer didn't think there was a problem?
12-03-2012, 05:14 PM
#34
The car does not know that you looked away. It is unclear to me in your post the exact sequence of events, but I am assuming that you had already reacted to the slowing cars in front before you looked away.
In my experience, the car does not advise you whether you are not slowing enough (until the very last instant before when the car deems an accident virtually unavoidable).
Instead, the car tells you when you have not reacted to an event in front of you - a car suddenly slowing, etc. If you have already reacted by lifting off the accelerator or braking (even too lightly) it does not provide a warning except for the one an instant before an imminent collision. Had you not previously reacted, you would likely have gotten a warning.
In my experience, the car does not advise you whether you are not slowing enough (until the very last instant before when the car deems an accident virtually unavoidable).
Instead, the car tells you when you have not reacted to an event in front of you - a car suddenly slowing, etc. If you have already reacted by lifting off the accelerator or braking (even too lightly) it does not provide a warning except for the one an instant before an imminent collision. Had you not previously reacted, you would likely have gotten a warning.
12-04-2012, 03:18 PM
#35
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The car does not know that you looked away. It is unclear to me in your post the exact sequence of events, but I am assuming that you had already reacted to the slowing cars in front before you looked away.
In my experience, the car does not advise you whether you are not slowing enough (until the very last instant before when the car deems an accident virtually unavoidable).
Instead, the car tells you when you have not reacted to an event in front of you - a car suddenly slowing, etc. If you have already reacted by lifting off the accelerator or braking (even too lightly) it does not provide a warning except for the one an instant before an imminent collision. Had you not previously reacted, you would likely have gotten a warning.
In my experience, the car does not advise you whether you are not slowing enough (until the very last instant before when the car deems an accident virtually unavoidable).
Instead, the car tells you when you have not reacted to an event in front of you - a car suddenly slowing, etc. If you have already reacted by lifting off the accelerator or braking (even too lightly) it does not provide a warning except for the one an instant before an imminent collision. Had you not previously reacted, you would likely have gotten a warning.
12-04-2012, 03:37 PM
#36
Besides, you do get a warning. I believe it is approximately 1.6 seconds before you are likely to run into something.
I've actually had the brakes trigger when going around a car turning left. It's a pretty good punch when you're not expecting it.
12-04-2012, 05:04 PM
#37
Super Member
OOOOOH! I CAN SEE IT NOW . . .
OOOOOH! I CAN SEE IT NOW . . .
Wait until the lawyers get ahold of this:
"My client's car did not warn him in time, and he plowed into a truck that was stopping in front of him. His Mercedes should have warned him much earlier! And then it should have stopped before hitting the truck!"
$1,000,000 for the client's pain and suffering, and . . .
$2,000,000 for pain and suffering of the 13 sheep in the truck he hit, and . . .
$500 for the broken iphone, on which the client was texting just before the accident.
Wait until the lawyers get ahold of this:
"My client's car did not warn him in time, and he plowed into a truck that was stopping in front of him. His Mercedes should have warned him much earlier! And then it should have stopped before hitting the truck!"
$1,000,000 for the client's pain and suffering, and . . .
$2,000,000 for pain and suffering of the 13 sheep in the truck he hit, and . . .
$500 for the broken iphone, on which the client was texting just before the accident.
