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Comment by ricardobeat | Hacker News Reader

The detection zone is not vertical enough. Radar is tuned to mostly ignore overhead objects otherwise you’d have phantom emergency braking whenever entering a tunnel, parking garage or going through a pedestrian crossing. It wouldn’t normally have enough accuracy to distinguish between that, and the 1.5m high side of a semi truck.

Modern tech is changing that, but most collision prevention systems of today will not prevent this type of accident. Yet another reason to make guards mandatory. There are thousands of underride crashes and hundreds of deaths yearly, you only hear about the “automated driving” ones because it brings more clicks.

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I tried but found nothing to verify your claim most collision avoidance systems do not sense veritable enough, nor anything discussing them plus truck guards outside Tesla failing.

Can you please provide some sources for your claims?

That was just off the top of my head, but here are some links I found:

https://www.ti.com/lit/wp/spry312/spry312.pdf shows how 24ghz radar, the most common until recently, has resolution measured in half-meter increments

https://www.kiforte.com/fca_radar-656.html Kia manual showing how the radar cone only covers a height of 1.2 meters in front of the car

These radar sensors project a very wide beam, they can't see much right in front of the car. For example, there was a car reviewer on YouTube that recently put ultrasonic parking sensors against a camera-based Tesla, and they perform about the same, with the camera slightly better in some situations because it's looking from above - the bumper-mounted radar cannot see objects in the ground right beneath it. Honda also just added a camera in their latest generation collision avoidance system, to cover a wider range of situations.

A half meter is fine, more then enough to look for 2-3m of “thing” Infront of the car

And that is not specifying the cone/detection range of the radar? It is just the work area to keep clear while performing an alignment - otherwise the horizontal range of the sensor would be near useless

Ultra sonic is not radar, and using radar cars regularly will follow things 10s of meters away. Seeing a semi with them is not a problem.

Parking is not collision avoidance- and using cameras for it is dumb. They don’t work in fog snow or adverse conditions that radar will

None of what you’re saying contradicts my earlier points. How can radar tell the difference between a 1.5m high truck undercarriage, and a 2.1m high passage if resolution is .5m? If they could detect the truck, why aren’t cars constantly triggering emergency brakes when near an underpass? Why are 10000+ collisions and 100+ deaths like this happening every year when a majority of cars have these systems installed? Why did Honda add cameras if radar is good enough? The answers seems obvious, but you can do your own research.

Maybe because the bottom of a truck trailer is far below an overpass? Lol like multiple meters?

You are making up statistics now

And because camera’s improve safety in some situations when used in conjunction with radar?

That point is meaningless in a discussion about Tesla who removed radar entirely and the point being made here “cameras alone are not as good as radar” not “radar plus camera is better then radar”

> That point is meaningless in a discussion about Tesla who removed radar entirely

How so? You're trying to say that if they've kept radar this accident could not happen, and I'm showing you this is not necessarily true. Do you have any sources to back up the idea that radar-based collision-avoidance systems can prevent this type of crash? The data says otherwise.

Here is a very extensive article on the subject, and it gives a much higher estimate (400 deaths/year): https://www.pbs.org/wgbh/frontline/article/trucks-underride-...

That was the 'do your own research part', honestly there is a ton of data online about everything we discussed here. You cannot expect someone to provide sources for everything they say while all you're offering is opinions.

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