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by deelowe 3062 days ago
> the car in front of you has stopped or slowed.

This is different from what happened in the tesla case. What happened here is that the vehicle in front of the car was moving and in view of the tesla's radar sensor obstructing the view of the firetruck. That car then moved and now a stationary object was suddenly in front of the car. From the Tesl's view point, an object just magically appeared somewhere in front of the car.

I'm not familiar with radar systems, but I imagine in this scenario the system isn't precise enough to know that this stationary object that suddenly appeared isn't an overhead sign or some other similar object that pops into the field of view of the radar system. It probably has something to do with radar not being extremely directional, constantly having stationary things pop up due to reflections and various objects in the periphery, having a limited sampling rate, and needing to do a filtering or other sorts of magic to make sure there aren't constant false alarms etc. I can see how cruising along at 50mph, the system doesn't have enough time to figure all this out and stop (e.g. not enough samples or there being a noise floor on stationary object data). It appears the correct way to solve this is with 3d lidar systems combined with sort of of mapping technology, but those are still too expensive/difficult to put into every day vehicles.

1 comments

I said "the car in front of the car in front of you". That car is not visible either since the car in front of you is blocking it. Subaru has commercials indicating this scenario is addressed as far as I can tell.