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So by "normal", I meant the radar-based systems in normal cars, also known as AEB. They are usually mounted low on the front fenders or grille. Semi truck trail
by vsskanth 3y ago
So by "normal", I meant the radar-based systems in normal cars, also known as AEB. They are usually mounted low on the front fenders or grille. Semi truck trailers are tall, have a huge empty gap between them and the road, and just high enough to not be seen by the radar. From the radars POV it appears like the road is unobstructed.
Obviously this isn't hard to detect with full LIDAR systems in self driving cars because they are on the roof and you have full depth information. This is why I do not mention "self driving cars" in my parent comment.
- aaronbeekay 3y agoDo you have a source for this? There’s a gap between semi wheels, sure, but the deck height of a semi trailer in North America is about 48”. If automotive radars weren’t able to detect objects above this height, they would miss a lot of obstacles… One automotive radar I’m familiar with, the Bosch MRR [1], lists a vertical FOV of ±15 degrees, and a 300 m maximum detection range. Assuming the sensor is mounted perpendicular to the ground at 0.5 m high, it should be able to see the top of a 13’6” semi trailer from ~15m away all the way up to its full range. Teslas don’t have radar anyway, so of course this wouldn’t have helped, but an AEB radar that can’t see the top of a semi truck isn’t very useful. [1] https://www.bosch-mobility.com/en/solutions/sensors/front-radar-sensor/ https://www.bosch-mobility.com/en/solutions/sensors/front-ra...
- vsskanth 3y agoRadars are usually tuned to ignore them because they don't have the fidelity to differentiate between a trailer on it's side and a tunnel and it leads to phantom braking.
- aaronbeekay 3y agoSure, but that’s a lot different from not being able to see them at all.