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by merkaloid 2607 days ago
they do have that, but as you might imagine, the emergency brakes are only there to mitigate damage in case of a crash, not to prevent them
1 comments

Yes but in this case it didn't trigger.
These AEB features almost universally do not trigger on stationary objects when the car is moving more than 20 or 30mph.
https://youtu.be/kuxundRB1zM

good aeb trigger at speed. they might not avoid the crash entirely, but try to mitigate it.

Tesla is quite behind the state of the art here.

Teslas and other manufacturers will trigger at speed against a stationary vehicle detected by the adaptive cruise control system.

Teslas are beginning to trigger more at speed on perceived non-vehicle obstacles (added in a recent OTA update) but that is not without false positives which some have deemed the Tesla Brake Check.

I’ve experienced the errant braking, typically when a lane is partially obstructed but you are moving to avoid the obstruction, that is when it will trigger. I’m not a fan of this behavior. You can override it with a quick tap on the accelerator, but it jostles you.

Here is the Tesla's Model S video as well: https://www.youtube.com/watch?v=_5aFZJxuJGQ
yeah I don't understand why there are so many posts in this thread that claim AEB can't do this kind of things with so much video evidence going around.

but here's the point, vision system detects objects it knows how to detect, lidar systems detects obstacles; as such doesn't surprise me a bit tesla is trained to recognize car from that aspect only to plow into 90deg rotated trucks, as when for example they cross an intersection.

If you bothered to click on the Car And Driver link, you would have seen that these systems (particularly Tesla's system) work at least up to 50mph with stationary objects.
In the video, that’s 50kph (30 mph). The most advanced Volvo system decelerated but still crashes pretty hard at 80kph (50mph) when approaching a stationary vehicle decoy.

Note well, if the target was an inflatable rock or an inflatable jersey barrier parallel with the direction of travel, the results would be much, much worse.

In those other cars the ACC is picking up a car-like object on the sensors. A non-car-like object is designed to be ignored.

Again, you have failed to understand what I said. The CAR AND DRIVER link is this one: https://www.caranddriver.com/features/a24511826/safety-featu...

And it shows a Tesla's performance among other cars, not a Volvo's.

And anyways, that Volvo video does show AES invoking at 80km/h and 130 km/h, reducing the speed of the collision but not avoiding it.

Maybe you're right about the car vs rock distinction but so far your track record is pretty spotty. Provide a source for your claims.

I read the C&D article when it came out last year. Pretty sure it was linked from HN actually. They ran some tests with a few cars driving into inflatable vehicle decoys. As I recall they found the systems would fail as often as not.

I was speaking in terms of this crash, which was not a primary collision with another vehicle, when I said that AEB will not activate for stationary objects at speed.

The ACC will activate for a stationary vehicle at speed, but will not save you entirely at even modest speed. At 70mph even ACC can drive right into a stationary vehicle.

These systems often work by sharing the ACC sensors and lock onto and track vehicles. This is why C&D discusses specifically the case of a lead vehicle swerving to reveal a stopped vehicle, and how some systems fail to acquire the stopped vehicle in time to provide any brake input at all;

> Volvo's owner's manuals outline a target-switching problem for adaptive cruise control (ACC), the convenience feature that relies on the same sensors as AEB.

(C&D did not test drive a Volvo for that test, but they did review the Volvo system and comment on it)

It would not be fair to take the C&D testing with inflatable vehicle decoys, and use that to claim Tesla is behind by not activating AEB into a narrow profile partial forward obstruction (parallel jersey barrier).

Partial forward obstruction of a non-car object is the absolute worst case for false positives, because this roughly translates into “any signal at all on the forward sensor”.

I’ll try to find sample images of what the sensor data looks like under normal operating conditions and when looking at narrow profile forward obstructions.

This is a very tricky edge case. A bird can fly in front of you. Water can splash up from the car in front of you. An empty trash bag floating up in the air after being run over by a car in front of you.

I did not mean to imply ACC or even AEB will not slow down a car heading for a rear end collision with another stopped car. I was speaking about this event specifically. I apologize for not being more clear in my 1 sentence original reply.