# High Speed AEB Automatic Emergency Braking



## scottf200 (Sep 21, 2017)

The Model S and X have High Speed AEB (> 50 MPH & <= 90 MPH). It appears that the 3 only has Low Speed AEB at this point (<= 50 MPH).

Perhaps this has been discussed but has there been any news on Tesla doing testing and then adding High Speed AEB (note: hardware radar/camera are typically the issue but the 3 has them. On the Volt, for example, you only get the undocumented High Speed AEB if you also get the Driver Confidence Package II and ACC/Adaptive Cruise Control). 
(Aside: Volt and Bolt Low Speed AEB is <= 37 MPH; Gen II LEAF is Low Speed <= 50 MPH
; Volt's undocumented High Speed AEB supposedly comes with ACC -- can not find doc)

Model 3 manual:


> Automatic Emergency Braking operates only when driving between approximately 7 mph (10 km/h) and 50 mph (80 km/h).


Related story: https://insideevs.com/tesla-autopilot-2-5-activates-high-speed-aeb/


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## LucyferSam (Sep 13, 2017)

scottf200 said:


> The Model S and X have High Speed AEB (> 50 MPH & <= 90 MPH). It appears that the 3 only has Low Speed AEB at this point (<= 50 MPH).
> 
> Perhaps this has been discussed but has there been any news on Tesla doing testing and then adding High Speed AEB (note: hardware radar/camera are typically the issue but the 3 has them. On the Volt, for example, you only get the undocumented High Speed AEB if you also get the Driver Confidence Package II and ACC/Adaptive Cruise Control).
> 
> ...


High speed AEB should be activated by a software update fairly soon, my delivery specialist expected it to happen sometime in the next month or 2.


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## Guest (Jan 29, 2018)

High speed AEB requires radar. It can't work with cameras and ultrasonic sensors. Usually, adaptive cruise works only with radar and therefore high speed AEB is available only if radar is mounted. Radar is an expensive thing, compared to cameras. Some vehicles have radar but still don't have high speed AEB.


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## Dan Detweiler (Apr 8, 2016)

arnis said:


> High speed AEB requires radar. It can't work with cameras and ultrasonic sensors. Usually, adaptive cruise works only with radar and therefore high speed AEB is available only if radar is mounted. Radar is an expensive thing, compared to cameras. Some vehicles have radar but still don't have high speed AEB.


I thought auto pilot was currently running on the RADAR and one camera. Am I wrong on that?

Dan


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## Guest (Jan 30, 2018)

Dan Detweiler said:


> I thought auto pilot was currently running on the RADAR and one camera. Am I wrong on that?


AEB is no a subsystem of AP.

Tesla's AP is a mix of lane keep (one camera) and radar (following distance).


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## Dan Detweiler (Apr 8, 2016)

arnis said:


> AEB is no a subsystem of AP.
> 
> Tesla's AP is a mix of lane keep (one camera) and radar (following distance).


Which are both active...right?

Dan


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## Guest (Jan 30, 2018)

Yes. Except if you engage adaptive cruise and turn the wheel yourself.


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## Runt8 (May 26, 2017)

arnis said:


> High speed AEB requires radar. It can't work with cameras and ultrasonic sensors. Usually, adaptive cruise works only with radar and therefore high speed AEB is available only if radar is mounted. Radar is an expensive thing, compared to cameras. Some vehicles have radar but still don't have high speed AEB.


Not sure I understand this as it relates to the Model 3, which comes standard with radar.

An owner recently posted a list of "coming soon" features he received from Tesla, one of which was high speed AEB.


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## Mistersandman (Sep 23, 2017)

Has anyone ever tested AEB to see if it actually works? I had the collision avoidance warning activate on me this morning when a car in front of me was cut off and slammed on his brakes. Since I was paying attention I anticipated it and broke way early. It got me to thinking if AEB would have actually stopped or slowed for me had I not done anything.


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## Bokonon (Apr 13, 2017)

Mistersandman said:


> Has anyone ever tested AEB to see if it actually works? I had the collision avoidance warning activate on me this morning when a car in front of me was cut off and slammed on his brakes. Since I was paying attention I anticipated it and broke way early. It got me to thinking if AEB would have actually stopped or slowed for me had I not done anything.


Keep in mind that the primary purpose of AEB is to *mitigate* the impact of a crash once one is *likely* to occur, rather than *avoid* a crash entirely. As such, it's not really something that you'd *want* to test. 

Sounds like the forward-collision warning was effective, though!


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## Runt8 (May 26, 2017)

Bokonon said:


> Keep in mind that the primary purpose of AEB is to *mitigate* the impact of a crash once one is *likely* to occur, rather than *avoid* a crash entirely. As such, it's not really something that you'd *want* to test.
> 
> Sounds like the forward-collision warning was effective, though!


This.

All the professional testing I've seen use a flimsy structure covered with a radar opaque cloth to simulate a vehicle, often towed behind a truck. This allows AEB to be tested without damaging the vehicle.






I've also seen videos of people trying to test it themselves using cardboard boxes but that generally doesn't work (and then they are convinced that AEB doesn't work either...).


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## Mistersandman (Sep 23, 2017)

Bokonon said:


> Keep in mind that the primary purpose of AEB is to *mitigate* the impact of a crash once one is *likely* to occur, rather than *avoid* a crash entirely. As such, it's not really something that you'd *want* to test.
> 
> Sounds like the forward-collision warning was effective, though!


Yes. Of course I don't want anyone to try running into a brick wall. I was thinking of a simulation. Like a large piece of fabric or a big section of cardboard or a large piece of styrofoam. I tried searching for a video but I couldn't find anything specific to a Tesla that was successful. Also, I know what the manual says. Just interested in real-world data.


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## Guest (May 11, 2018)

Bokonon said:


> Keep in mind that the primary purpose of AEB is to *mitigate* the impact of a crash once one is *likely* to occur, rather than *avoid* a crash entirely.


No. Tests show that most city AEB systems avoid collision and mitigate in case of high speed.
Some avoid in both scenarios. There are no modern AEB systems that do not avoid entirely.


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## Mistersandman (Sep 23, 2017)

First Tesla Model 3 safety test results released, IIHS says 'superior rating for front crash prevention' - Electrek https://apple.news/Azg8cfKN4TgOsN5yYYPaUzw

Curious to see a video of it in action.


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## Spiffywerks (Jul 30, 2017)

How close does the car let you get before it brakes on it’s own? Today coming to a stop and let the car continue to roll slowly ahead, ~5mph, and came within 18” and it didn’t engage brakes. Does it only work when you go faster?


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## garsh (Apr 4, 2016)

Spiffywerks said:


> How close does the car let you get before it brakes on it's own? Today coming to a stop and let the car continue to roll slowly ahead, ~5mph, and came within 18" and it didn't engage brakes. Does it only work when you go faster?


I think many AEB systems only work reliably if the car you're about to hit is also moving.

https://www.leftlanenews.com/aaa-te...-of-some-emergency-braking-systems-92651.html


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## ahagge (May 6, 2017)

I'm still very curious to know why the AEB apparently didn't function in this case of rear-ending of a stopped vehicle:

https://www.washingtonpost.com/busi...ory.html?noredirect=on&utm_term=.9af1e3f780c0

I would have thought that there would have been _some_ deceleration, even if not enough to completely avoid the collision. It seems like AEB didn't function at all in this case...


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## DR61 (Apr 10, 2016)

ahagge said:


> I'm still very curious to know why the AEB apparently didn't function in this case of rear-ending of a stopped vehicle:
> 
> https://www.washingtonpost.com/busi...ory.html?noredirect=on&utm_term=.9af1e3f780c0
> 
> I would have thought that there would have been _some_ deceleration, even if not enough to completely avoid the collision. It seems like AEB didn't function at all in this case...


Radar detection will ignore stopped vehicles IF it did not detect them moving initially. So if a detected moving vehicle blocks radar detection of a stopped vehicle, then moves out of the lane, the radar will ignore the stopped vehicle. Too many false positives otherwise. This is true of most other makes with AEB as far as I know.


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## MelindaV (Apr 2, 2016)

ahagge said:


> I'm still very curious to know why the AEB apparently didn't function in this case of rear-ending of a stopped vehicle:
> 
> https://www.washingtonpost.com/busi...ory.html?noredirect=on&utm_term=.9af1e3f780c0
> 
> I would have thought that there would have been _some_ deceleration, even if not enough to completely avoid the collision. It seems like AEB didn't function at all in this case...


how do you know it didn't function? do you know the car was within the speeds AEB can function in?
Also, Tesla states there are specific cases it can not recognize obstacles, such as when the vehicle it is following suddenly changes lanes and there is something immediately blocking the lane.


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## garsh (Apr 4, 2016)

ahagge said:


> I'm still very curious to know why the AEB apparently didn't function in this case of rear-ending of a stopped vehicle:


As I posted right before that:


garsh said:


> I think many AEB systems only work reliably if the car you're about to hit is also moving.


In particular, radar has a hard time determining the size of things. Elon described how radar sees a coke-can as being huge. And you don't want your car slamming on the brakes for every coke can it sees on the road. So a simple way to avoid those false-positives is to consider only things that are moving WRT the background.

Here's a coke can reference:
https://www.tesla.com/blog/upgrading-autopilot-seeing-world-radar

_A discarded soda can on the road, with its concave bottom facing towards you can appear to be a large and dangerous obstacle, but you would definitely not want to slam on the brakes to avoid it._​


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## garsh (Apr 4, 2016)

Note that most of the high-speed AEB testing involves towing a dummy vehicle instead of leaving it sit still on the road.


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## Dogwhistle (Jul 2, 2017)

I wonder why AEB didn’t mitigate the recent crash of the Model S into the back of that stopped fire truck. It would seem that would be a perfect situation that AEB is designed to avoid. Perhaps the shape of the truck confused the system? Or perhaps it did engage, and that was the best it could do? 60-0 is a big speed differential, perhaps just too much for the system? I would like to see them release videos of what the car is supposed to do in situations like this, and others.


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## garsh (Apr 4, 2016)

Dogwhistle said:


> I wonder why AEB didn't mitigate the recent crash of the Model S into the back of that stopped fire truck.


It's _because_ it was stopped.
If it had been moving, AEB would have kicked in.

See the previous posts in this thread by myself and @DR61.


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## Guest (May 17, 2018)

Lately AEB city test is at 50km/h into stationary vehicle. Most vehicles pass that easily.
It's true that AEB often doesn't mitigate completely above that speed, but it does brake hard.


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## Dangermouse (Apr 27, 2016)

I was thinking about this a lot on my drive this morning. There are a lot of things that the radar will see, but will have to disregard just to get you through an intersection (stopped cars in a lane next to you, concrete barriers, etc.). This was especially true when going around curves...that's when the stopped objects that you will be passing will appear directly in front of you. Lots of opportunities for false positives.

When Autopilot auto-braked for me once on the highway when nothing was there, I did worry about who was behind me and how close. False positives could really do more harm than good overall.

That said, a little more clarity on how and when it will and won't work would really be nice.


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## Guest (May 17, 2018)

AEB with pedestrian detection (many vehicles since 2017) work on camera image recognition, not radar. Something Tesla had to be "superiest".


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## John Rea (Jun 19, 2017)

In my experience it works kind of wonky. If a car turns across the road in front of me, my M3 will suddenly slam the brakes when you are about 75 feet away and the car has already cleared out of the path. Kind of unsettling. Like it is responding late. That is when TACC is engaged so I'm not sure if that is EAB or TACC.


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## Feathermerchant (Sep 17, 2018)

My collision warning has gone off several times when coming around a curve with cars parked in the street. AEB has only gone off once. I was approaching a line of cars I could not see as I topped an overpass. They may have been moving or stopped I could not tell which. I started braking pretty hard. Enough to get stopped at the rear car's bumper leaving the maximum room behind me for others to get stopped. AEB intervened and braked to ABS which did get me stopped but also lead to much skidding of tires behind me (Porsche 911 to the shoulder). It was very exciting but there was no contact.


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