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Comment by spyder | Hacker News Reader

That's interesting because in some cases the radar can detect if the second car in front of you breaks but the one directly front of you doesn't:

https://www.youtube.com/watch?v=FadR7ETT_1k

I guess this was in ideal conditions or maybe the Tesla in the firetruck accident doesn't have this software update.

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That is nothing to do with any of this. There are two issues:

1. Autopilot didn't leave a big enough gap in front of the Tesla. Presumably because the radar has limited range, or maybe it was a big enough gap but the guy just wasn't paying enough attention.

2. Autopilot ignores stationary objects. This is a deliberate decision - apparently if you don't ignore stationary objects there are too many false positives from stationary objects you aren't driving into (signs, bridges, etc).

The root cause of 2. is that the radar doesn't have good enough angular resolution to say whether something is in your path or not - it can just detect things vaguely in front of you. The solution is probably LIDAR (which everyone except Tesla uses) or maybe some camera-radar data fusion, but obviously it doesn't do that at the moment.

The actual root cause of #2 is that, along with LiDAR, maps are also on Elon Musk’s “won’t do” list, so instead of comparing radar output to ground truth and detecting a stationary obstacle (which Waymo can do easily), Tesla tries to get by without any information about the world, and fails, badly and with sometimes fatal consequences.

There is no such thing as "ground truth". Maps are for navigation, not safety. IMHO the fact that companies keep using radar and lidar indicates that their vision systems are not as good as they should be.

So you have maps that record the location of stationary signs etc. and then have the car stop if it gets a radar return from a stationary object (e.g. fire truck) that's not on your map? Then when someone puts up a new sign you're slamming on the brakes until the map gets updated.

Not being able to tell if a stationary object is something you're going to hit or not (like LiDAR or stereo cameras might do) is more relevant to this case than maps.

The issue at hand is that the software filters out stationary objects. The case you describe only happens if the tesla is tracking the two cars in front of it and the further one breaks.

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