Vehicle camera system that can detect a single brick at 150 meters

>Talk to anyone who lost an eye.

My mom has amblyopia and is old enough that it didn’t get treated. She can drive just fine, but she can’t grab the clothes line between her fingers. She has to sort of paw at it and catch it with her palm.

And I’d say visual processing is a lot more complex then we give it credit for. We don’t understand what’s really all going on yet. We still are trying to understand microsaccades for example. Ocular processing is extremely fascinating.

My eyes didn’t work together until I got prism glasses. I was utterly shocked to experience depth perception. Didn’t know it was missing.

Not to mention object recognition. If I see something that resembles a car, I know roughly what size I expect a car to be so based on the size it appears, I can reasonably estimate its distance from me. Of course this breaks down when objects don't meet our expectation in terms of size and can be the source of some interesting optical illusions.

Ego.

Lidars are expensive, fairly large, power hungry and depending on what your using them for, noisy.

Musk doesn't like them because they are expensive. Not because they don't work. He's spent billions trying to polish the turd that is their monocular depth estimation + radar system. Sure its impressive, but its nowhere near good enough for safe autonomy. (I am sceptical that they ever will with that sensor layout. Thats neatly avoiding the issue that there is no redundancy)

If you want ground truth data from a moving vehicle, then there is no real alternative to lidar[1]. Anyone who tells you otherwise is either:

1) an idiot

2) a musk fan

3) trying to sell you something.

Now, sure for "autopilot" (cruise control) where there isn't that much to do, radar and basic object detection is good enough. But any sign of danger and it backs off, leaving you no time to unfuck the situation.

[1] I work for a mapping company, There are other ways to get to <50cm accuracy point clouds, but its not fast and requires a boat load of GPU (in the order of thousands of hours per km driven)

The article briefly mentions (but does not do justice) to the fact that identifying small objects at extreme range is something that LIDAR is _also_ really bad at, due to extremely low effective resolutions by camera standards. High-end LIDAR units cap out at ~100 channels (roughly equivalent to vertical pixel size), usually over >100deg vertical field of view, for less than one "pixel" per degree. That's not nearly enough to detect a brick at 100m, and pales in comparison to the angular resultions an HD camera with a decent lens can achieve.

In general, it's not yet clear to me whether LIDAR is all that useful for the hard parts of the self-driving car problem. We know it's extremely useful for the easy parts (not hitting curbs, other vehicles, or walls), but it's not clear whether LIDAR helps that much with small objects, vehicle behavior prediction, or object classification (paper bag vs. dog)

I've worked with a researchers who use LIDAR heavily. Amazing technology, but aside from cost/weight/size/expense there's one big disadvantage. LIDAR doesn't work like eyes.

So in certain conditions LIDAR can see better than human eyes, like say complete darkness. This could lead to a car behaving differently than a human driver which might well cause an accident.

In other conditions LIDAR can see much worse than a human. Depending on the fog, snow, rain, dust, tumbleweeds etc can look more solid to a lidar than a human eye. Which can also cause accidents. A human might recognize a whisp of fog, whose outline and volume look like a fallen tree, but a camera would have a better chance.

So even with a magic LIDAR that costs $100, has good range, solid state, etc. it's not clear what LIDAR offers over a pair of cameras, or other cheap sensors like cameras, mm band (60 GHz) radar, and ultrasound.

Additionally LIDAR systems need cameras anyways. Is that a ambulance or UPS truck? Schoolbus or city bus? Police car or Camry? Does the police car have it's lights on? Did someone flash their high beams at you? Delivery truck or post office truck? Color is hugely important in predicting what's going to happen. Sure you can add cameras to LIDAR, but then why? Doubly is you have two cameras for distance.

So I'd love to be wrong, and indisputably LIDAR is getting better, but seems like pairs of cameras might well be the best fit for driving like a human. Doesn't seem like it could ever be LIDAR, but LIDAR + cameras could compete, but what does LIDAR give you over a pair of cameras?

Yes you could think of an analogous statement being: why do we need lenses? A raw exposed imager is just fine, we can use machine learning to extrapolate what the lens would be providing. And yes that's true but why in the hell would you want to spend time doing that? Self driving is hard enough already.

I think this article touches on some of it:

https://techcrunch.com/2019/04/22/anyone-relying-on-lidar-is...

I think it might be like ray tracing. It's the holy grail of graphics, which makes engineers very positive about it. Yet it is slow and expensive and most problems do perfectly fine if not better with "conventional graphics".

> When folks argue that lidar should not be used

This is a strawman. Nobody argues that it should not be used, only that driving is demonstrably possible without it.

From discussions with engineers that work at car manufacturers on technology for self-driving cars, the biggy is really the weather. All these technologies work fine in sunny weather, but it's really adverse weather conditions where things go south.

One of the friends told me that is belief is that proper self-driving is still a long time away, because of this.

> "If you flag..."

https://news.ycombinator.com/newsguidelines.html

One advantage of keeping it behind the windshield (aside from having a higher point of view), is that they get automatic camera cleaning from the windshield wipers (plus defrosting). If they put it lower behind the grill, then they need a completely separate cleaning/defrosting system.

My car's lower bumper mounted radar antenna stops working any time I drive in the snow because it quickly gets coated with a layer of snow.