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Comment by taneq | Hacker News Reader

What does this say about the quality of the automatic emergency braking, if it can't detect a substantial metal object directly in front of the car?

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Autopilot has trouble with stationary objects.

https://www.wired.com/story/tesla-autopilot-why-crash-radar/

What would it take to get Tesla to admit the product is unsafe and should be disabled until they get it right? Or will they simply plow on until a regulator steps in?

> What would it take to get Tesla to admit the product is unsafe...

People should start to vote with their purse. In other words, stop buying these cars, or start selling their stocks.

This philosophy, though admirable in support of personal liberty, ignores that a commons exists.

How is that OK? O.o

So it can't drive for shit. Right? "Autopilot" my ass!

Depends on how close it is and what it is. Have to weigh the energy of the impact against the pitch introduced by braking. You need the bumper to take the hit, so that it and the crumple zones can do their job.

However, for a wall or highway barrier, it's probably almost always worthwhile to shed as much energy as possible. You're going to pitch yourself under the barrier where the bumper won't take the hit, like you might when colliding with another vehicle.

> Have to weigh the energy of the impact against the pitch introduced by braking. You need the bumper to take the hit, so that it and the crumple zones can do their job.

Eh? The vast majority of real frontal impacts will be under heavy braking. If a few degrees of dive under brakes is enough to compromise the crumple zones' effectiveness then your car is bad (and I don't believe any Teslas are bad in this way.)

I believe the parent is talking about small overlap crash?

Small Overlap tests: this is where only a small portion of the car's structure strikes an object such as a pole or a tree, or if a car were to clip another car. This is the most demanding test because it loads the most force onto the structure of the car at any given speed. These are usually conducted at 15-20% of the front vehicle structure.[1]

Modern cars are surprisingly good at small over crash tests, see this video someone linked on HN a few days ago https://www.youtube.com/watch?v=DHlj8-JcWa8

1. https://en.wikipedia.org/wiki/Crash_test

I mean, this advice is pretty firmly held for hitting things like animals. Albeit for other reasons -- it helps prevent them from going over the hood and towards the windshield.

Generally the pitch won't matter that much in vehicle-to-vehicle collisions. Only when the pitch would angle the front bumper completely under the other vehicle, which I admit isn't much of a concern. And not really a concern at all in vehicle-to-barrier collisions.

However, if we're talking about idealized automated driving systems, I hold by my original assertion. I would expect such a system to be able to correctly analyze when releasing the brake right before collision to reduce pitch would be beneficial.

Accelerating into an animal to increase car's pitch is something I had heard growing up in deer country, but it seems to be a myth: http://www.discovery.com/tv-shows/mythbusters/mythbusters-da...

That seems like a silly idea; the pitch change is not nearly as drastic as during braking. Cars decelerate faster than they accelerate. I don't know of any car that can go 0-60 in 100 feet, but there are plenty of cars that can go 60-0 in that distance:

http://www.motortrend.com/news/20-best-60-to-0-distances-rec...

Advice I've seen is to brake as hard as you can to shed energy, then release the brake to correct the pitch as close to collision as you can time it. No acceleration involved.

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