[mitch57]

The several times that it has happened to me it's a very abrupt and out of thin air experience and is very short lived. It slams on the brakes out of no where and immediately recovers within less than a second. What's the most concerning is that if someone were tailgating me, which is a common occurrence where I live, they would most likely rear end me based on how hard it hits the brakes.

The issue is that even though I have both hands on the wheel and am paying attention it happens quicker than any human can recover from by steering or by hitting the gas pedal. Less than a second from slamming on the brakes to recovering from the false detection. By the time you realize it happened it's already released the brake. It's one of those "What the FU#K just happened?" moments.

It sounds to me like others are seeing a much longer false braking period where there is time to override it. Not so in my case.

Additionally, this safety feature is unacceptably slow to react to changes in the traffic around the vehicle. Both my BMW and my wife's 2022 Mazda CX5 react in the same delayed fashion. It sees a car ahead that's getting ready to make a turn and throws up the red car in the display and HUD as you get close and continues braking long after the car has already made it's turn.

Both of these vehicles have the reaction/response time of a 150 year old tortoise. I NEVER trust or rely on any of this accident prevention or autonomous driving technology.

[paul21]

Originally Posted by sigmabody

I don't think that's an inevitable problem, fwiw. Most "fuzzy" software systems (machine learning, heuristics, etc.) have an effective "certainty" factor in the output of their reasoning model (glossing over some details, but that's the idea), and vendors can tune this down to effectively eliminate false positives, even in the input cases which are not explicitly accounted for. In essence, you can write it like "if I'm not sure, don't so anything".

They don't, because they are making the trade-off to intervene, because they think that most drivers are bad/distracted, they want the systems to be more active, and they think that screwing it up in the corner cases is better than possibly not intervening in some cases. This may be correct/desirable for some drivers, but it doesn't remove the liability when their systems do bad things and cause accidents, and they will (and absolutely should) be sued for them. Then in an ideal world, they will adjust the algorithms to not act in the unsure cases, and the bad drivers will have a few more collisions, but the systems won't be as bad in the corner cases.

That's my thought and hope, anyway.

The problem is the decision making logic combined with the uncertainty in the state estimate. Even a low res 240x240 color camera has 240*240*(2^16) = 15B input values. Then combined with the radar sensor and vehicle speed info, it quickly becomes a gigantic space. So asking "what's the chance there is a car in front of me right now and closing distance" is very difficult. One pixel shifts, and the estimator could decide there's an unavoidable car. The vision and radar systems alone need extensive testing to get rid of edge cases.

What typically happens is a combo of real world driving and simulated driving, along with generated images based on both to prevent that one pixel shifts from having a large impact. It's not practical to cover it all, however, because there's too many inputs to simulate (death of the universe before it's calculated levels).

Then you have a system with uncertainty estimates and now you need a decision making logic to help. Fuzzy logic can work in some circumstances, but fuzzy rules become hard to tune. Suppose you find an edge case that failed. Now you have to go modify the rules, but that has a side effect on other cases. A better system in theory is a Markov decision process where there is isolation when decisions for single states are updated based on new information. The problem there becomes that the space is not well partitioned or easily tested because subtle changes in state can cause large differences in control outputs.


The bottom line is state estimation and decision making techniques are very old and well studied, but no one has come up with a way to prove that the system will work reliably in all circumstances.

[sigmabody]

Originally Posted by paul21

The problem is the decision making logic combined with the uncertainty in the state estimate. Even a low res 240x240 color camera has 240*240*(2^16) = 15B input values. Then combined with the radar sensor and vehicle speed info, it quickly becomes a gigantic space. So asking "what's the chance there is a car in front of me right now and closing distance" is very difficult. One pixel shifts, and the estimator could decide there's an unavoidable car. The vision and radar systems alone need extensive testing to get rid of edge cases.

To paraphrase Independence Day, "that's not entirely accurate".

Without getting into the weeds too much, there are many ways to do fuzzy logic on large input spaces without necessarily having a gigantic cross-product calculation space. As one example, that's mainly what deep learning networks are designed to achieve (ie: arrive at a pseudo-partitioned input space model which accurately captures the differentiating features of the input *******. There is also not generally a binary output from the models themselves (ie: the model doesn't say there is/isn't an obstacle, but rather there's a X% chance of an obstacle).

I'd agree that lots of testing is needed; I'm opining that I would prefer a system which was tuned to do nothing in the case of uncertainty, rather than the current model which seemingly reacts if it determines there is possibly an obstacle. I find that for my own driving, the system as currently tuned, which I cannot disable, makes my own usage of the vehicle less safe, and I think that's something which should (and ideally will) lead to some large liability settlements, and ultimately a course-correction in the system design.

Edit: I have no idea why the forum censors "space", but maybe it'll be visible in this edit?

[b.frank70]

Originally Posted by Scopes1936

This happened to me twice in two days with my 2023 X7. I was driving the car myself, no driver assistance and no cars or obstacles in front of me. I was on the highway going 70 MPH the car slammed on the brakes and for a few seconds it started to slow itself down. A message appeared that said “emergency stop. Vehicle is stopping… “image of a gas pedal and foot” then cont. driving. Completely different than the front end collision warning.

Has anyone figured out what triggers this?

Had car diagnosed at bmw. The problem with mine is the DXC control module not communicating properly. $1,600 fix. Just waiting on parts.

[b.frank70]

Originally Posted by b.frank70

Had car diagnosed at bmw. The problem with mine is the DXC control module not communicating properly. $1,600 fix. Just waiting on parts.

Update: parts changed out and working good.

[iTomH]

I had one of those "out of thin air" EMERGENCY STOP issue today with my new 2024 X5 50e. I was not using any of the Driving Assist technology. Just driving down a 2 lane road with no other cars within 1/4 mile of me. I've been trying to read everything I can find which brought me to this thread. My question is: Does the on board computer indicate WHY the Emergency Stop sequence was initiated? I would think somewhere in their software it would indicated what triggered the event.

[mosen7]

That must have been terrifying.
I have maintained a healthy level of awareness and suspicion even over the Drive Assist features in my X5. While I do enjoy the adaptive cruise control with distance control, lane keep etc and the view on the digital gauge etc. I have turned off all steering intervention features. The sudden and 99% mostly unnecessary corrections it has tried on me have not been subtle; sometimes pulling me into the next lane without need so I turned it off.
I have not experienced a full or near auto-full stop or a dramatic speed reduction such as the one you’ve described but reading this confirms my suspicions about what could happen. I was not an “auto-pilot” advocate before and definitely am not now.

I highly recommend you stay engaged throughout your driving experience. I recommend making an appointment and spending time talking to BMW Service, their Genius’ and have them run a complete inspection of your systems… think you will be okay but just to have some clarity and peace of mind going forward

[Xeno]

Originally Posted by Spencergnyc

Hi everyone. Over the course of my ownership with this car, about 7 months, I’ve had a few instances where the little red car would pop up on my dash alerting me of a possible collision, but nothing would ever happen. Today though, I was on the highway doing about 80 in the leftmost lane with no shoulder, and the emergency braking randomly kicked in. The car in-front of me was maybe 15 car lengths away and it was night time. My car took me from 80MPH to about 20MPH in a matter of seconds at 11pm in the fast lane. I couldn’t do anything. I nearly got rear ended by a truck while desperately trying to accelerate, but of course the car thinks it knows better than me and limited my acceleration as it thought I was about to crash. I’m now deathly afraid to drive my $74,000 car, which is my only car.

I was driving today in daylight with no vehicles less than 10 car lengths ahead. Suddenly without warning the red vehicle alert came up as the car hit the brakes. Fortunately no one was on my bumper as this would not have ended well for me.

The only new thing of late is that new-to-me Chattanooga, TN BMW did a firmware update a few days ago to 7/2023.23. It is also the case that my a/c is today not working properly even after I confirmed the correct settings.

In any event, if the a/c remains a problem I will have to give CHA BMW another try at getting things right.

[tksamtec]

Originally Posted by sigmabody

I can offer a slightly more humorous anecdote re the crappy emergency braking software, as a lighter side of the deadly serious issue that it is:

I've had my BMW for ~6 month now, and a couple months in I almost got stuck in my garage. The rear obstruction sensor had a false positive software issue, and slammed on the brakes, just as I was pulling out. Slow speed, but it (of course) wouldn't disengage either, because it was convinced something was there, even though there was nothing. I ended up having to restart the vehicle just to pull out of my garage.

Glad the OP is okay; hope I won't be the person who dies from this crappy software.

I have had this IDENTICAL scenario happen to me once as well. The 80mph to 20mph in the left lane issue here, would probably get me run over.... so I hope I never have to deal with that.

[COKen]

I have not had this happen to me on the highway, but it is my understanding that you should be able to override the auto braking by pushing on the gas pedal. Does anyone know if this is true or not?

Edit: Just found this in the manual

Brake intervention

The warning prompts the driver to intervene.
When the brake pedal is depressed quickly and
hard, the maximum braking force of the vehicle
is used.

The system may also assist with brake intervention
if there is a risk of collision.

When the vehicle is traveling at a low speed,
the vehicle may come to a complete stop.

City brake function: the brake intervention occurs
to up to approx. 50 mph/80 km/h.
With radar sensor: the brake intervention occurs
to up to approx. 155 mph/250 km/h.
At speeds above approx. 130 mph/210 km/h,
the brake intervention occurs as a brief activation
of the braking system. No automatic delay
occurs.

The braking intervention can be interrupted by
stepping on the accelerator pedal with sufficient
force or by actively moving the steering
wheel.

[TurtleBoy]

Originally Posted by COKen

I have not had this happen to me on the highway, but it is my understanding that you should be able to override the auto braking by pushing on the gas pedal. Does anyone know if this is true or not?

Yes, the automatic braking stops as soon as you hit the accelerator.

[TechCTU]

Originally Posted by TurtleBoy

Yes, the automatic braking stops as soon as you hit the accelerator.

Good tip to keep in mind!

[ikjm6779]

Woww

[Jrtampa]

I have had my car for 6 weeks. Never had a BMW before, but my husband has and he talked me into getting one. This just happened to me 2 days ago going about 40 with nothing in front or behind me (thank goodness). I called BMW and the service manager said they could “check for a malfunction” but obviously this has been an issue for a while. Has anyone had a resolution for this?