Centimeter accuracy is for surveyors. When you're talking about a self-driving car traveling at even 35 miles per hour, the difference between
one foot and two feet isn't usually meaningful, much less centimeter accuracy.
- If something is far enough out to be able to act on it meaningfully, you just need to know the approximate distance within ± a few feet and whether it is flat enough to run over or not.
- If it isn't, it's already too late and you're going to hit it anyway, so the accuracy doesn't buy you anything.
Never in my entire driving career have I even once wondered whether something was 750 or 751 centimeters away. If you don't need to know that information, there's a good chance your car doesn't, either.
This misses what I consider a critical point: Computers are not brains and do not work like brains. Even so-called neural nets only attempt to mimic a brain. They still start and end with numbers, and manipulate those numbers in between. Computers are still, no matter what else, very very fast calculators. The millimeter accuracy of lidar will provide the computer with more accurate numbers going in, and this will provide better numbers coming out.
Elon has said that lidar is a crutch.
Elon is just being ridiculous here. When you break a leg you need a crutch. A crutch is not a bad thing, it's an aid. Calling lidar a crutch is a glib way of dismissing a useful tool. It's like saying that a hammer is a crutch because you can pound nails with a rock. A hammer is better than a rock, and lidar plus cameras is better than cameras alone.
Lidar essentially becomes the training wheels for accurate vision-based FSD.
I disagree. More information is always better, and lidar provides additional information that cameras do not.
Never in my entire driving career have I even once wondered whether something was 750 or 751 centimeters away. If you don't need to know that information, there's a good chance your car doesn't, either.
This gets back to the different way that computers and brains operate: When we see someone walking we understand that they are moving. Computers do not "understand" anything. Highly-accurate range data over time tells the system that something is moving. This is important information that can be obtained from lidar data because of its accuracy, but which a computer cannot infer from the kinds of clues a brain is capable of processing. Range data based on cameras will never be as good.
In short, more information is always better. Elon says lidar is a "crutch," but what he's really doing is crippling his system by refusing to use an available tool. Maybe because of hubris. Something like, "We are so good we can do it without." Or maybe just because he's already sold FSD with the promise that your car has all the necessary hardware, and it would be too difficult or too expensive to add lidar now to all those old cars. This could cost Tesla the lead, and in this race, getting to commercially-viable FSD first is worth billions, maybe hundreds of billions.
We have seen that Elon was wrong when he said our 2018 cars had all the needed hardware. We have seen that he was wrong when he thought Tesla was just a year or two away from robo-taxi-capable cars. And now we see that their code needs a rewrite. It's time to accept that lidar is a necessary tool to achieve this goal. It's time to bite the bullet, accept that the hardware in today's cars cannot reach FSD, deal with the consequences of having sold a pig in a poke, and move on toward the goal.