Has anyone heard of a Tesla being rear ended because of phantom braking?

[Iron]

I'll just call it AEB and like the title said, I feel like I'm in a catch 22 using it.

I'm sure it will save lives, maybe even mine, someday. Problem is, a few times I've stopped short (nothing too serious) and it slams on the brakes as if I was going 50 into the back of a truck. It locks up the brakes completely and I've winced waiting for the hit from behind. Today a guy in a Toyota truck blew his horn angrily after having just avoided running into my bumper. Yeah, he'd have been following too closely on paper but the setting is really aggressive and doesn't leave the driver behind with much time to react. Thoughts?

 

[ATPMSD]

Trying turning it off and see if the car still brakes. In my MS it is:

Controls > Autopilot > Automatic Emergency Braking
Note it will reset each time the car is “started”.

And you can also turn off Obstacle-Aware Acceleration
Controls > Autopilot > Obstacle-Aware Acceleration

Then you can figure out where the problem lies. With that information you can schedule a service all with Tesla.

 

[andaconda]

I'll just call it AEB and like the title said, I feel like I'm in a catch 22 using it.

I'm sure it will save lives, maybe even mine, someday. Problem is, a few times I've stopped short (nothing too serious) and it slams on the brakes as if I was going 50 into the back of a truck. It locks up the brakes completely and I've winced waiting for the hit from behind. Today a guy in a Toyota truck blew his horn angrily after having just avoided running into my bumper. Yeah, he'd have been following too closely on paper but the setting is really aggressive and doesn't leave the driver behind with much time to react. Thoughts?

It's called "phantom braking" and we all seem to deal with it in one way or another. Many many threads on the subject.

 

[ATPMSD]

It's called "phantom braking" and we all seem to deal with it in one way or another. Many many threads on the subject.

Assuming this is in fact what he is talking about then he needs to learn to leave his foot on the accelerator and be ready to push on the pedal, just like the rest of us do.

 

[Iron]

I posted this as it's own thread and a mod moved it into this phantom braking thread. It is NOT phantom braking as I did stop short behind a car that did the same. It was excessive as it locked up the wheels in a situatation that didn't warrant it. I was fearful of getting rear ended. I know I can turn it off but I do wish I could use it and have it function sensibly.

 

[andaconda]

. . .I posted this as it's own thread and a mod moved it into this phantom braking thread. It is NOT phantom braking as I did stop short behind a car that did the same. It was excessive as it locked up the wheels in a situatation that didn't warrant it. I was fearful of getting rear ended. I know I can turn it off but I do wish I could use it and have it function sensibly.

Sorry, I misunderstood your post - apologies . . .
But I guess on a side note - you didn't rear end the car in front of you - so the car did do its job.
You know that you can also set the AEB for several different settings. I have mine set to 'early.'

 

[Iron]

Sorry, I misunderstood your post - apologies . . .
But I guess on a side note - you didn't rear end the car in front of you - so the car did do its job.
You know that you can also set the AEB for several different settings. I have mine set to 'early.'

No worries. If my post is in a thread with "phantom braking" in the title, I would have assumed the same. No, I didn't hit the car in front, but I also could have done that quite easily without locking up brakes. I came very near to being rear ended by a lifted pickup and was cussed out by the driver.

The AEB setting is either ON or OFF. There are no levels to chose from. I think you're talking about the forward collision warning, which I take it is just a warning.

 

[andaconda]

No worries. If my post is in a thread phantom braking in the title, I would have assumed the same. No, I didn't hit the car in front, but I also could have done that quite easily without locking up brakes. I came very near to being rear ended by a lifted pickup and was cussed out by the driver.

The AEB setting is either ON or OFF. There are no levels to chose from. I think you're talking about the forward collision warning, which I take it is just a warning.

Yes, you are correct. I see that 'early' is just for warning..

 

[israndy]

I have noticed that the car will stop unreasonably fast if a car in front of me is stopping quickly. The two add up and the car behind me REALLY has to stop fast. I have gotten honked at, but I look forward and see this big gap between me and the guy who stopped short. I wonder if the Tesla not only captures that extra real estate with the quick braking but also would use it if the car behind can't stop fast enough. It's trying to avoid an accident, it's already avoided the one in front is it looking at that car coming up quickly behind?

 

[Iron]

I have noticed that the car will stop unreasonably fast if a car in front of me is stopping quickly. The two add up and the car behind me REALLY has to stop fast. I have gotten honked at, but I look forward and see this big gap between me and the guy who stopped short. I wonder if the Tesla not only captures that extra real estate with the quick braking but also would use it if the car behind can't stop fast enough. It's trying to avoid an accident, it's already avoided the one in front is it looking at that car coming up quickly behind?

I don't think it cares about what's happening behind it. Would be nice if that was thrown into the equation. Thing is, it's stopping so fast, if a person is close behind, it's going to be very difficult for their reflexes to compete. Heck, the ABS is kicking in when mine slams on the brake.

 

[sandman1330]

I have noticed that the car will stop unreasonably fast if a car in front of me is stopping quickly. The two add up and the car behind me REALLY has to stop fast. I have gotten honked at, but I look forward and see this big gap between me and the guy who stopped short. I wonder if the Tesla not only captures that extra real estate with the quick braking but also would use it if the car behind can't stop fast enough. It's trying to avoid an accident, it's already avoided the one in front is it looking at that car coming up quickly behind?

I think it's a limitation of vision unfortunately. I don't think it has the fidelity necessary to truly judge closure. I've noticed this with TACC since it went from radar to vision - it plays the accordion game a lot more than it used to on following distance. I just don't think it's that good at judging closure rates, not as good as radar is/was anyway.

Vision sees the brake lights come on ahead, and because it can't judge closure, just initially slams on the brakes until it has enough data and processing time to judge the actual closure rate. I'm not sure this is ever going to be fixed with vision (at least on HW3).

 

[enemji]

Vision sees the brake lights come on ahead, and because it can't judge closure, just initially slams on the brakes until it has enough data and processing time to judge the actual closure rate. I'm not sure this is ever going to be fixed with vision (at least on HW3).

I am pretty sure the brake lights don’t play into this algorithm.

What if it was a huge wall or a large trailer that had jackknifed and laying across? These have no brake lights.

 

[sandman1330]

I am pretty sure the brake lights don’t play into this algorithm.

What if it was a huge wall or a large trailer that had jackknifed and laying across? These have no brake lights.

I disagree. My car brakes as soon as the brake lights of the car ahead of me come on, even if they aren't really slowing down, and the brake lights are even shown in the visualization.

Obviously it's not the only factor - vision needs to see that large trailer. But responding to brake lights doesn't mean it can't also respond to other obstacles. It isn't only one or the other...

 

[cdnev]

I think it's a limitation of vision unfortunately. I don't think it has the fidelity necessary to truly judge closure. I've noticed this with TACC since it went from radar to vision - it plays the accordion game a lot more than it used to on following distance. I just don't think it's that good at judging closure rates, not as good as radar is/was anyway.

Vision sees the brake lights come on ahead, and because it can't judge closure, just initially slams on the brakes until it has enough data and processing time to judge the actual closure rate. I'm not sure this is ever going to be fixed with vision (at least on HW3).

I'm inclined to agree that this issue may be somehow associated with the vision system, it becoming a bit confused and then overreacting. I've not done a lot of long distance in my 2020 MS up to this point, but have now begun a 2 month cross-Canada road trip from Vancouver to Newfoundland and back.

I began using a lot of TACC on the Trans-Canada through Alberta today and experienced too many of these weird braking incidents--enough that my spouse refuses to use TACC on the trip.

However, I did start to see a particular pattern appear when a braking event would occur and it got so I could predict when it would happen. The conditions were on very long straight stretches where any vehicles ahead were quite far in the distance. However, two factors were always present, some long undulating stretches of road and the water mirage effect with no other vehicles in the car's view ahead. If TACC was on and we could start to see the water mirage on the roadway as the road started to dip in the distance--boom we'd get a fairly hard braking and then steady slowdown.

The first one was a shock, but as others have said, being prepared to override the braking with the accelerator had the desired effect. After about four of these events with significant accelerator override, the braking response became less dramatic. I'm just guessing that the neural net was starting to learn that it's behaviour was inappropriate due to the override. It will be interesting to see if our Model S TACC eventually learns how to recognize this mirage effect and behave correctly as my trip progresses.

Maybe this is being a bit too generous to the AI, but it almost seems like the long straight stretches with no vehicles to keep track of ahead are making the AI "drowsy" and that the mirage effect causes it to suddenly "wake up" and overreact--maybe it "believed" the road was turning into a cliff, who knows?

Cheers, Gary

 

[TS.42]

I'm inclined to agree that this issue may be somehow associated with the vision system, it becoming a bit confused and then overreacting. I've not done a lot of long distance in my 2020 MS up to this point, but have now begun a 2 month cross-Canada road trip from Vancouver to Newfoundland and back.

I began using a lot of TACC on the Trans-Canada through Alberta today and experienced too many of these weird braking incidents--enough that my spouse refuses to use TACC on the trip.

However, I did start to see a particular pattern appear when a braking event would occur and it got so I could predict when it would happen. The conditions were on very long straight stretches where any vehicles ahead were quite far in the distance. However, two factors were always present, some long undulating stretches of road and the water mirage effect with no other vehicles in the car's view ahead. If TACC was on and we could start to see the water mirage on the roadway as the road started to dip in the distance--boom we'd get a fairly hard braking and then steady slowdown.

The first one was a shock, but as others have said, being prepared to override the braking with the accelerator had the desired effect. After about four of these events with significant accelerator override, the braking response became less dramatic. I'm just guessing that the neural net was starting to learn that it's behaviour was inappropriate due to the override. It will be interesting to see if our Model S TACC eventually learns how to recognize this mirage effect and behave correctly as my trip progresses.

Maybe this is being a bit too generous to the AI, but it almost seems like the long straight stretches with no vehicles to keep track of ahead are making the AI "drowsy" and that the mirage effect causes it to suddenly "wake up" and overreact--maybe it "believed" the road was turning into a cliff, who knows?

Cheers, Gary

I agree with your assessments as the same thing happened to me on every build.

 

[zoomer0056]

I began using a lot of TACC on the Trans-Canada through Alberta today and experienced too many of these weird braking incidents--enough that my spouse refuses to use TACC on the trip.

I quit using TACC in the first week of having my Feb 2023 MSLR. The braking was not phantom but was due to the system braking for cars and bicycles safely off to the side of the road. I enjoy driving myself and don't want to be driven. So, I don't miss TACC at all, even on long drives.

 

[pipestem]

I would find if shocking there have been no accidents due to phantom braking no matter what the cause. i find that whenever I gain confidence it shocks me again. Only a few times s year but the result could be terrible. For my driving it is as most always a darkly shaded overpass, and then sometime the speed limit change, but I can believe others have seen other triggers. This is really my #1 gripe, it just seems like no real effort has been made or if so it’s sort of worse.

 

[Frank Langella]

Tesla's TACC is absolute garbage. I can't believe they're allowed to sell cars with it. In Nevada the heat mirages cause it to slam on the brakes OVER and OVER and OVER. Ended up driving from Vegas to Reno and back nearly completely manually. $60,000 car that doesn't have functional cruise control. Since they can't fix it they should at least give the option to have regular stupid cruise control to just maintain a constant speed at least.

 

[enemji]

Tesla's TACC is absolute garbage. I can't believe they're allowed to sell cars with it. In Nevada the heat mirages cause it to slam on the brakes OVER and OVER and OVER. Ended up driving from Vegas to Reno and back nearly completely manually. $60,000 car that doesn't have functional cruise control. Since they can't fix it they should at least give the option to have regular stupid cruise control to just maintain a constant speed at least.

That is not good.

that said, I always wonder where does one keep his/her right foot when cruise control is running? I find it more hard to keep my foot just hovering over the gas pedal. I'd rather keep it ON the gas pedal.

 

[Frank Langella]

When I'm on an essentially deserted highway why would I have my foot on the gas, hovering or otherwise. Is that really how most people use cruise control? Foot on the gas pedal in case you need 450 horsepower in an emergency?

Like, yeah, I do keep my foot on the gas but it's because the TACC is garbage, I don't know why someone would otherwise. If it worked properly I'd just keep my foot on the floor.