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False Automatic Emergency Braking Event

conman

Active Member
Aug 19, 2017
1,438
2,154
Melbourne, Australia
I had a false Automatic Emergency Braking event today - the full thing, not just phantom braking on AP. I was travelling at about 50km/h on a side street with a divider with lots of parked vehicles, some traffic cones for footpath works, and many confusing moving shadows from trees and the high winds. The vehicle slammed on the brakes as hard as possible with a big red horizontal truck on the cluster, and the message "Automatic emergency braking in progress," bringing me to a complete stop. Of course there was no truck in front of me - nor any vehicle at all in fact - but luckily there was no one behind me either, or they would have ploughed straight into my butt. Unlike phantom braking on AP where I can just hit the accelerator and override the phantom braking, the car refused to respond until I had come to a complete stop.

It seems my driving is evoking some funky behaviour from the autopilot computer. I didn't have my wits about me enough to file a bug report at the time. I'm still on 2019.32.12.7, and I can see the car uploaded 100MB more than usual today when I got home so hopefully it was video footage of the non-event and they can classify it as a false positive. Unlike phantom braking on AP, I suspect these are few and far between.
 
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Tam

Well-Known Member
Nov 25, 2012
9,715
8,865
Visalia, CA
...Unlike phantom braking on AP where I can just hit the accelerator and override the phantom braking, the car refused to respond until I had come to a complete stop...

To clarify, you meant you floored the accelerator and the car's automatic brake system continued braking until the car came to a complete stop?

That's contrary to the owner's manual.

Could it be that you were manually applied the brake pedal and thought it was the accelerator?

If there were no pedal confusion, Tesla needs to fix this your car so it can comply with the owner's manual.

Tesla can retrieve your data to see which pedal was pressed.
 

conman

Active Member
Aug 19, 2017
1,438
2,154
Melbourne, Australia
No I did not "floor it", I just had my foot on the accelerator since I was already driving and it was so abrupt that I worried I'd hit something and actually let go of the accelerator and looked down to see that message before attempting to accelerate again when it didn't respond until I had come almost to a stop. It wasn't quite a complete standstill before it took off again, it was just far more dramatic than a phantom braking event I've gotten from AP, and the accompanying message was something I'd never seen before. The workmen on the side of the road looked at me funny trying to figure out what I was doing.
 

Tam

Well-Known Member
Nov 25, 2012
9,715
8,865
Visalia, CA
No I did not "floor it", I just had my foot on the accelerator since I was already driving and it was so abrupt that I worried I'd hit something and actually let go of the accelerator and looked down to see that message before attempting to accelerate again when it didn't respond until I had come almost to a stop. It wasn't quite a complete standstill before it took off again, it was just far more dramatic than a phantom braking event I've gotten from AP, and the accompanying message was something I'd never seen before. The workmen on the side of the road looked at me funny trying to figure out what I was doing.


That sounds like the system worked as designed although AEB is imperfect and the incidence is not desireable and hopefully, there will be an improvement in the future.

A phantom brake can happen to TACC/Autopilot and also to AEB as well.

Phantom brakes in AEB can be quite much scarier.

But still, the design is the same: The Manual accelerator overrides Automatic brakes at all times.
 

conman

Active Member
Aug 19, 2017
1,438
2,154
Melbourne, Australia
That sounds like the system worked as designed although AEB is imperfect and the incidence is not desireable and hopefully, there will be an improvement in the future.

A phantom brake can happen to TACC/Autopilot and also to AEB as well.

Phantom brakes in AEB can be quite much scarier.

But still, the design is the same: The Manual accelerator overrides Automatic brakes at all times.
Sure thing, I understand the parallels, but I don't believe it will override unless you accelerate hard in AEB. Usually just a tap of the accelerator pedal in autopilot is enough to override the phantom braking, and it didn't help this time around. Either way I suspect all AEBs are logged given their nature and I described 100MB of extra upload.
 
Mar 1, 2018
120
154
San Marcos, CA
The Manual accelerator overrides Automatic brakes at all times.

I thought that the car not responding to the accelerator might be due to the "Obstacle-Aware Acceleration" feature, so I looked it up in the owner's manual. It doesn't sound like that's the case, but I did see this in the Automatic Emergency Braking section:

Automatic Emergency Braking does not apply the brakes, or stops applying the brakes, when:
  • You turn the steering wheel sharply.
  • You press and release the brake pedal while Automatic Emergency Braking is applying the brakes.
  • You accelerate hard [emphasis added] while Automatic Emergency Braking is applying the brakes.
  • The vehicle, motorcycle, bicycle, or pedestrian is no longer detected ahead.
So the accelerator doesn't always override the automatic braking. @conman probably accelerated, but not hard enough to disable it. I probably would have done the same thing.
 
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conman

Active Member
Aug 19, 2017
1,438
2,154
Melbourne, Australia
I thought that the car not responding to the accelerator might be due to the "Obstacle-Aware Acceleration" feature, so I looked it up in the owner's manual. It doesn't sound like that's the case, but I did see this in the Automatic Emergency Braking section:

Automatic Emergency Braking does not apply the brakes, or stops applying the brakes, when:
  • You turn the steering wheel sharply.
  • You press and release the brake pedal while Automatic Emergency Braking is applying the brakes.
  • You accelerate hard [emphasis added] while Automatic Emergency Braking is applying the brakes.
  • The vehicle, motorcycle, bicycle, or pedestrian is no longer detected ahead.
So the accelerator doesn't always override the automatic braking. @conman probably accelerated, but not hard enough to disable it. I probably would have done the same thing.
This is exactly what I said, I tapped the accelerator the way I normally would to override AP; I didn't mash it hard. I always have obstacle aware acceleration turned off because I get weird stalls when I least expect them under hard acceleration with it enabled (and there are no obvious obstacles.)
 

JTWIRE

Member
Nov 27, 2019
45
54
Manheim, Pa.
I have had a few occasions where the brakes applied automatically then they just go back to normal. A little disconcerting for a few seconds and don't know why it happens.
 

Battpower

Active Member
Supporting Member
Oct 10, 2019
2,131
2,202
Uk
This all sounds like 'situation normal' with my Raven S 10.2.1.

On narrow / reflective surface (wet) / dark & shadowy roads, especially with any activity near to the vehicle carriageway (pedestrians, parked vehicles, cyclists, reflective store windows) I have so many random and sudden intervention or sudden release of control by the car.

This made more dramatic by the car's complete disinterest in junctions immediately ahead, also when approaching much lower speed limit zone, where it accelerates into situations that it should be slowing down for.

The car seems completely happy to attempt to respond to what must be impossible interpretation of what it 'sees' like a traffic cone 'flickerring' on and off in the IC display or a cyclist suddenly 'jumping' off the sidewalk into the flow of traffic.
 

Silicon Desert

Active Member
Oct 1, 2018
3,675
3,789
Sparks, / GF1
I had a false Automatic Emergency Braking event today - the full thing, not just phantom braking on AP. I was travelling at about 50km/h on a side street with a divider with lots of parked vehicles, some traffic cones for footpath works, and many confusing moving shadows from trees and the high winds. The vehicle slammed on the brakes as hard as possible with a big red horizontal truck on the cluster, and the message "Automatic emergency braking in progress," bringing me to a complete stop. Of course there was no truck in front of me - nor any vehicle at all in fact - but luckily there was no one behind me either, or they would have ploughed straight into my butt. Unlike phantom braking on AP where I can just hit the accelerator and override the phantom braking, the car refused to respond until I had come to a complete stop.

It seems my driving is evoking some funky behaviour from the autopilot computer. I didn't have my wits about me enough to file a bug report at the time. I'm still on 2019.32.12.7, and I can see the car uploaded 100MB more than usual today when I got home so hopefully it was video footage of the non-event and they can classify it as a false positive. Unlike phantom braking on AP, I suspect these are few and far between.
yikes, scary. I see that this is an older thread. Did you ever figure out what happened? If the headlights start turning around in circles, I would call a priest to perform and exorcism :eek:
 

conman

Active Member
Aug 19, 2017
1,438
2,154
Melbourne, Australia
yikes, scary. I see that this is an older thread. Did you ever figure out what happened? If the headlights start turning around in circles, I would call a priest to perform and exorcism :eek:
Haha I figured what happened at the time anyway, based on the truck crossing in front of me according to the instrument cluster (that was completely imagined by my car.)
 
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