Is AEB sufficient, even with standard cruise control?

[GarrickS]

This discussion is bizarre.

 

[ninefiveone]

This is like asking if the front bumper and autopilot are redundant. Then faulting the front bumper for not being as good as AP.

 

[GarrickS]

This is like asking if the front bumper and autopilot are redundant. Then faulting the front bumper for not being as good as AP.

Tesla should really design that front bumper to be more like autopilot.

 

[gregincal]

Tesla could configure AEB to operate just like AP. Then you would be subject to phantom braking, even when AP was off. Or it might be like you're the student driver and AEB is your grandmother operating the second brake pedal any time your driving upsets her. That's why it's only for emergencies only at this time. There is always the collision warning system to give you a better chance at accident avoidance.

AEB may be improved once FSD advances far enough. FSD has to decide all on its own whether to brake hard or not. That will require a better false alarm rate than the current EAP. I expect it will still be pretty limited to avoid interfering with your driving, but that's what forward collision warning is for.

This is it exactly. TACC is not in any way "enhanced AEB". TACC is you deciding to let the car to take complete control of speed at all times, and if you don't like what it's doing, you turn it off. AEB lets you drive the car and only brakes in an emergency, but when it intervenes it takes control from you without your permission. The reason that every single car manufacturer implements emergency braking to only lessen but not completely avoid accidents is that the car is going is only going to involuntarily take control from the driver when it is absolutely certain there is going to be an accident, not just that it feels it knows better than you what a safe speed is.

 

[internalaudit]

You've got a point but I think it is more because of legal ramifications-- they have to say it will not avoid accidents but only lessen impact. My RAVH's AEB has turned on a few times and I wasn't going to rear end the car in front of me.

 

[ninefiveone]

Toyota uses the exact same type of wording for their system. There’s no publically available information on what triggers there system. The fact that it triggers when it shouldn’t should be a point of concern, not something to replicate.

 

[internalaudit]

Of course I'd rather it trigger than not trigger at all because the AEB does prime the brake for harder braking. If I get rear ended first, I am considered not at fault.

How can the AEB predict a collision so accurately when the car in front could start accelerating fast in the last second?

 

[BrettS]

Of course I'd rather it trigger than not trigger at all because the AEB does prime the brake for harder braking. If I get rear ended first, I am considered not at fault.

Even if you are not at fault, getting rear ended is going to be a huge inconvenience. Especially if it happens because your AEB had a false trigger and didn’t need to stop.

How can the AEB predict a collision so accurately when the car in front could start accelerating fast in the last second?

This is the crux of the problem... there are so many different possible situations that it is very difficult for the computer to know when to engage AEB and when not to engage AEB. Certainly in the situation you describe AEB would be engaged, and rightly so, as it would appear that your car is about to run into another car. If that car moves away at the last second, all the better.

 

[ItsNotAboutTheMoney]

You've got a point but I think it is more because of legal ramifications-- they have to say it will not avoid accidents but only lessen impact. My RAVH's AEB has turned on a few times and I wasn't going to rear end the car in front of me.

No, it's not about legal ramifications.

AEB is a safety system. Its job is to reduce severity of injuries.
Harder braking increases the chance of being rear-ended and the relative speed of collision.
False positives increase the chance of being rear-ended.
A low-speed collision results in fewer, less severe injuries.

Until we have perfect systems working with complete front and rear information, expect collisions.

 

[ElecFan]

I don't think it has anything to do with the (im)perfection of systems. The M3 manual reads:

When a frontal collision is considered unavoidable, Automatic Emergency Braking is designed to apply the brakes to reduce the severity of the impact.

So the AEB is *designed* to act only when the driver is (considered to be) unable to avoid a collision not because it's imperfect.

This seems logical to me, since otherwise the system could conflict with the drivers adequate reaction. Of course the system could in actual situations be able to avoid accidents, of which there are many Youtube videos.

 

[ItsNotAboutTheMoney]

I don't think it has anything to do with the (im)perfection of systems. The M3 manual reads:

So the AEB is *designed* to act only when the driver is (considered to be) unable to avoid a collision not because it's imperfect.

This seems logical to me, since otherwise the system could conflict with the drivers adequate reaction. Of course the system could in actual situations be able to avoid accidents, of which there are many Youtube videos.

It really does relate to imperfection: if it were perfect they'd be able to have it set to avoid collisions where possible. The system would be able to brake at the last possible moment, and only collide if it saw certain collision from the rear.

 

[FlyingKiwi]

It is due to imperfect information.. The car can't know from camera or radar data how grippy the bit of road it is on is, so it has to make an assumption about the available deceleration rate which determines how late it can start braking. If the road is clean and grippy it'll stop short, if the road is slippery you get to visit the repair shop with a bent car.

 

[internalaudit]

No, it's not about legal ramifications.

AEB is a safety system. Its job is to reduce severity of injuries.
Harder braking increases the chance of being rear-ended and the relative speed of collision.
False positives increase the chance of being rear-ended.
A low-speed collision results in fewer, less severe injuries.

Until we have perfect systems working with complete front and rear information, expect collisions.

So how come with the Toyota's, it's possible to engage the AEB without getting into a collision? How does the car know when it's going to collide or not? When the car ahead brakes hard and then accelerates hard, are you suggesting the AEB will be so smart not to turn on?

You have a point about being rear-ended but a lot of cases, there may be no cars following when the driver may have gotten distracted or the car in front brakes hard all of a sudden.

In those cases, I'd still want the car to brake sooner rather that not. It's not like the AEB system has only one setting. If I recall correctly, it will prime the brake first to make it more effective and if the driver still doesn't brake, it will auto brake.

For speeds below 40 mph, I doubt there will be a huge risk of whiplash or soft tissue injuries.

 

[Jim R]

It would be nice to spell out what AEB stands for - in the FIRST post. I'm not the only one who doesn't memorize all these acronyms.

 

[internalaudit]

It would be nice to spell out what AEB stands for - in the FIRST post. I'm not the only one who doesn't memorize all these acronyms.

Have you heard of Google search?

 

[Jim R]

Have you heard of Google search?

I searched. Still would be nice to include it.

 

[internalaudit]

^ That's true. I'm not trying to be an a$$ for sure. I hope I didn't come across that way.

Unless its for some acronym that could mean anything (I've done that where an acronym for something in audit could mean dozens of things related to project management), most things relating to car can be found typing the acronym and maybe the word car or vehicle.

 

[gregincal]

So how come with the Toyota's, it's possible to engage the AEB without getting into a collision? How does the car know when it's going to collide or not? When the car ahead brakes hard and then accelerates hard, are you suggesting the AEB will be so smart not to turn on?

You have a point about being rear-ended but a lot of cases, there may be no cars following when the driver may have gotten distracted or the car in front brakes hard all of a sudden.

In those cases, I'd still want the car to brake sooner rather that not. It's not like the AEB system has only one setting. If I recall correctly, it will prime the brake first to make it more effective and if the driver still doesn't brake, it will auto brake.

For speeds below 40 mph, I doubt there will be a huge risk of whiplash or soft tissue injuries.

The Toyota will auto-brake, but you can still get in a collision just like with the Tesla. Here is Toyota's description of the system, which is pretty similar to Tesla's:

Using an integrated camera and laser or radar to help detect other vehicles in front of you, the Pre-Collision System (PCS) can prompt you to take action using audio and visual alerts if it determines a frontal collision is likely. If you notice the potential collision and apply the brakes, PCS may apply additional force using Brake Assist (BA). If you don’t brake in time, PCS may automatically apply the brakes for you, helping to minimize the likelihood of a frontal collision or reduce its severity.

 

[ninefiveone]

Exactly.

Let’s be clear:

-OP wants AEB to be a convenience system so they can drive without paying attention
- Tesla clearly states they consider AEB a safety system that minimizes the severity of collisions (like a bumper) and do not intend it to be an accident avoidance system. This shouldn’t need to be spelled out but they designed there system accordingly.
- Toyota has similar but not identical goals with their system. They’ve also designed accordingly.

There is no point in comparing the systems as if they are or were meant to be identical.

 

[internalaudit]

The Toyota will auto-brake, but you can still get in a collision just like with the Tesla. Here is Toyota's description of the system, which is pretty similar to Tesla's:

Using an integrated camera and laser or radar to help detect other vehicles in front of you, the Pre-Collision System (PCS) can prompt you to take action using audio and visual alerts if it determines a frontal collision is likely. If you notice the potential collision and apply the brakes, PCS may apply additional force using Brake Assist (BA). If you don’t brake in time, PCS may automatically apply the brakes for you, helping to minimize the likelihood of a frontal collision or reduce its severity.

Of course. There is no way for a system to guarantee that there will be no collision.

If the car in front were to brake extremely hard especially after just cutting you off, a collision would be difficult to prevent.

I was just defending my point, from experience on a RAV4H, that its AEB will not only be kicking in when there is a guaranteed collision. This isn't airbag deployment.

It just doesn't make sense to design it that way.