AEB Won’t Prevent an Accident

[Tam]

And this is exactly what TSB has now reopened its investigation on.

I'm beginning to suspicion that the CID is too slow to be reliable in this, whereas in older cars (MB) it's fine.

What's CID please?

I don't see why NTSB re-opens Autopilot case when they already knew what happened with the last Florida case: It's an assistive system that will continue crash over and over again if there's no competent human in control.

It's true that for self-driving goal that Tesla car should not plow into a stationary vehicle in front.

This issue has been worked on a long time ago but it might be safe to assume that the technology is still in its infancy and there's no third party test proving that it can reliably stop for stationary obstacles at 90 MPH.

An old Mercedes failed test clip since the good old time in 2010:

 

[Max*]

It wouldn't be good business for AEB to prevent collisions. Two reasons:

• collisions bring more publicity than avoiding collisions
• collisions bring more repeat business (body parts, new vehicles)

I completely disagree. It would be good business.

The problem is mixing detection performance (all accidents detected = 100%. Most accidents = 90%) with false positives/false alarms (all accidents detected = 1,000 false alarm. Most accidents detected = 10 false alarms).

[made up numbers to get the point across]

The problem is that if you prevent 100% of collisions, and have multiple false positives the person will hate AEB and try to disable it.


If AEB could have prevented 100% of collisions with a minuscule false alarm rate, they would have done it already. We're not there yet. Probably not toooo far off. Just not there yet.

 

[chillaban]

I completely disagree. It would be good business.

The problem is mixing detection performance (all accidents detected = 100%. Most accidents = 90%) with false positives/false alarms (all accidents detected = 1,000 false alarm. Most accidents detected = 10 false alarms).

[made up numbers to get the point across]

The problem is that if you prevent 100% of collisions, and have multiple false positives the person will hate AEB and try to disable it.


If AEB could have prevented 100% of collisions with a minuscule false alarm rate, they would have done it already. We're not there yet. Probably not toooo far off. Just not there yet.

On top of this:

AEB kicking in too proactively can lead to a situation where it is blamed for an accident, which is legally problematic for the vendor. For example, you could say "Well I was going to swerve away from the truck, but AEB kicked in and reduced my speed and there was no longer an opening in the adjacent lane. Had AEB not kicked in, I would've been able to avoid the accident".

Cars can't read your mind yet, which makes "driver assist" systems really problematic. It really is sensible that AEB only kicks in when it's sure you're doomed for a collision and there's no possible escape route. Otherwise, there's too much potential for interference.

 

[brkaus]

Think of the case where a car is running some sort of slalom course. Weaving in and out of obsticles quickly. It is very difficult to decide if/when to kick in AEB.

What if your driving recklessly and want to cut in a small gap on the freeway? The car slams on the brakes before you swing the steering wheel.

AEB needs to kick in when it decides there is no other way out, and not before. The target is close enough in distance and within some angle/cone from the current tragectory that it couldn’t otherwise be avoided.

Theoretically, heading for the side of a 100’ wide wall is very different from heading towards an 8’ wide Wall.

Of course, above argument is shot when using auto-steer. It should know where it is headed, the turn of the lane, etc.

 

[Shock-On-T]

It wouldn't be good business for AEB to prevent collisions. Two reasons:

• collisions bring more publicity than avoiding collisions
• collisions bring more repeat business (body parts, new vehicles)

The main reason is that false positives can cause collisions, so they give it very high specificity. The accident is certain before they deploy.

 

[FlatSix911]

One additional issue is that the FD has blocked 2 lanes per their policy and has created a serious hazard for anyone in the HOV lane.
This has always been a major issue in California when a single lane for emergency response worked well previously.
This policy needs serious reconsideration as the second accident was entirely preventable.

Thanks for the good Public Service Announcement so owners can understand what the manual says in theory. To apply to this case, we still need a car log in order to figure out how the accident happened and whether the AEB was activated or not. Did the owner swerve to the left and thus disable AEB?

How slow was the car traveling? Does the car log say 65 MPH? Look at all the air bags: Front, side curtains..., photo angle doesn't document evidence of deployment!

 

[Tam]

One additional issue is that the FD has blocked 2 lanes per their policy and has created a serious hazard for anyone in the HOV lane.
This has always been a major issue in California when a single lane for emergency response worked well previously.
This policy needs serious reconsideration as the second accident was entirely preventable.

First responders were killed in the past which makes this policy a life saving one. Fire truck is served as sacrificial obstacle to shield workers who work within the 2 lanes.

Any attentive human driver would be able to spot the fire truck and respond appropriately.

Hopefully Tesla's camera and radar will be just as good as any attentive human driver to avoid plowing into a stationary object.

But that day is certainly not now.

 

[FlatSix911]

First responders were killed in the past which makes this policy a life saving one. Fire truck is served as sacrificial obstacle to shield workers who work within the 2 lanes.

Any attentive human driver would be able to spot the fire truck and respond appropriately. Hopefully, Tesla's camera and radar will be just as good as any attentive human driver to avoid plowing into a stationary object. But that day is certainly not now.

Like much public policy, I suspect that the well-intentioned goal has resulted in many more civilian traffic fatalities than FD/PD...

 

[sorka]

Yep, AEB doesn't prevent collisions.
It might, however, be the reason the driver wasn't injured.

Wouldn't it prevent collisions where the speed at detection was already 25 mph or less

 

[Rusty1]

Wouldn't it prevent collisions where the speed at detection was already 25 mph or less

I think the answer is maybe. It should come to a complete stop, but will it prevent a collision. I think that depends on road conditions and your brakes, etc. You might still hit the vehicle in front of you. It might be a minor collision but still a collision.

 

[The Duke]

Nicki has always given me an "Oh *sugar*" triple beep in plenty of time to stop. She beeps sometimes when she should not. But that's OK, I value her opinion. Even when I cannot see two cars in front, she beeps if I need to be on the brakes. I wonder if this feature was installed and turned on during this accident. If so it may be another case of the stationary object and radar.

 

[brkaus]

Tesla allegedly on Autopilot hits firetruck with 65mph • r/teslamotors

 

[chillaban]

Tesla allegedly on Autopilot hits firetruck with 65mph • r/teslamotors

I kind of feel for the driver. IME AP1 loves to smooth its input. It's really good at predicting the path that you will follow relative to the path of the lead car, but if the lead car moves away and reveals another (stationary) car, I've seen it take a second or two to admit that. At 65mph that's not a very good outcome.

 

[Shock-On-T]

Wouldn't it prevent collisions where the speed at detection was already 25 mph or less

Only if it had time to drop the 25mph.

 

[benfar]

Wouldn't it prevent collisions where the speed at detection was already 25 mph or less

See this from here 2017 Tesla Model S to see that the tested Model S traveling at 25 mph did in fact avoid a collision with a stopped vehicle. The vehicle in the accident should have had the same radar unit, but may have had different software than version 8.1 in the tested vehicle. Note that the accident report is that the initial speed was 65 mph, not 25 mph, but presumably AEB would have activated as soon as the radar detected the fire truck and the Tesla could respond.

 

[chillaban]

It's amusing, as an aside, that IIHS's "high speed" autobrake is defined as 25mph.

 

[benfar]

It's amusing, as an aside, that IIHS's "high speed" autobrake is defined as 25mph.

Yes, and in fact the European AEB tests with stopped vehicles call 30 mph (50 km/h) "slow speed" and have a second 48 mph (80 km/h) "high speed" test. See the table below from http://cdn.euroncap.com/media/1384/...13-0-a837f165-3a9c-4a94-aefb-1171fbf21213.pdf .

They haven't yet tested a Tesla with AEB, but here for example are their results for a 2017 Volvo S90, from http://cdn.euroncap.com/media/26358/euroncap-2017-volvo-s90-datasheet.pdf . Notice that the Interurban results for crash avoided up to 80 km/h (48 mph) involved a driver reacting, rather than the "autobrake function only" which was sufficient to prevent a crash at 25 mph. That implies that a forward collision warning was given earlier than automatic braking would have started, and the test's "human-driver-equivalent" test mechanism reacted. (They use that to standardize reactions to driver warnings for all test cases.) If it had not, then after some delay presumably automatic braking would have slowed the vehicle to reduce crash impact, but not prevent it. This is how forward collision warning is designed to work with automatic braking, before there's enough confidence to auto-brake.

 

[benfar]

Continuing from above, the European test approach here http://cdn.euroncap.com/media/26358/euroncap-2017-volvo-s90-datasheet.pdf shows examples of auto-braking from speeds too high to avoid a crash with a stationary vehicle, but those tests aren't being reported for current vehicles. Here is an example from that document for an earlier-year Volvo V40 with an optional pedestrian-detection safety package, which shows crash avoidance for initial speeds up to 35 km/h and speed reductions for tested initial speeds up to 50 km/h. In all cases that collision was not avoided, auto-braking did not start until about one second before impact. Presumably, greater confidence in the detection would allow auto-braking to begin earlier, while avoiding unwanted braking due to false stopped-vehicle/stationary-obstruction detections.

 

[benfar]

What's CID please?

I don't see why NTSB re-opens Autopilot case when they already knew what happened with the last Florida case: It's an assistive system that will continue crash over and over again if there's no competent human in control.

It's true that for self-driving goal that Tesla car should not plow into a stationary vehicle in front.

This issue has been worked on a long time ago but it might be safe to assume that the technology is still in its infancy and there's no third party test proving that it can reliably stop for stationary obstacles at 90 MPH.

An old Mercedes failed test clip since the good old time in 2010:

From news I saw, NTSB has not re-opened an investigation. They and NHTSA teams were sent to gather information. Based on that, each will decide what if anything else is warranted.

I believe the earlier post's "CID" was probably a typo, and actually meant "CIB" for crash imminent braking. This NHTSA website page Driver Assistance Technologies explains their definition and how it fits with other technologies to help avoid or mitigate potential crashes into vehicles or stationary obstructions.

 

[YauKwan]

I didnt read this thread. But AEB prevented me from running into the person in front of me in a three car accident.