[msandford]

LIDAR gives you single sensor depth perception though without having to go through computationally expensive stereo vision mapping. There's definitely some benefit to that if it can improve your latency (or "framerate") such that you have extra time to swerve, slow down, etc.

[Symmetry]

Many stereo vision systems have an ASIC or FPGA that automatically calculate the depth information from the two images, like this guy:

http://carnegierobotics.com/multisense-s7

[msandford]

Yeah, and it's only 15 fps so that means at least 60ms between decisions. 80 mph is 117 fps so 60 ms represents 7 feet. If you ran at 30 fps then that's only 3.5 feet, at 60 fps it's 1.75 feet.

I'll grant you that saving 5.25 feet at 80 mph is definitely going to make a difference very rarely, but it will happen to some degree.

Also there's no pricing so I suspect it's super expensive, which is not at all what the parent was suggesting "but my money is on an array of super cheap cameras and better image recognition"

I suspect that LIDAR is also going to be fairly immune to glare where as vision systems are probably susceptible. Having a big depth hole open up in your mapping/planning system because of glare would likely bring the car to a screeching halt (literally) which isn't going to be good for the other cars around it.

[Symmetry]

If you only meant that the passive system described by the person you were responding too had too high a latency then I think we are in agreement.

However, regarding binocular versus LIDAR in general, I would say that while a greeter frequency is always better 15 Hz should be fine. And in fact the awesome $70,000 LIDAR used by Google's self driving car only runs at 15 Hz.

http://velodynelidar.com/lidar/products/brochure/HDL-64E%20D...

[zardo]

Lidar also, at least potentially, allows you to focus sampling on areas where you have less confidence in what you're seeing.

[msandford]

I think if I was going to ride in a self-driving car I'd want it designed like a hard realtime system where it is guaranteed to sample the road at X rate or whatever. Most of the time it won't matter at all and doing something adaptive would be fine.

But when the cameras go out completely (or get blinded or whatever) then you could end up with a really degenerate case where the software can't keep up with the car's motion and it freaks out and crashes (literally or figuratively).

Prior to suggesting that this couldn't happen, or would be extremely unlikely to happen, please remember the results of the Toyota "unintended acceleration" investigation: https://news.ycombinator.com/item?id=9643204

[Animats]

Stereo vision does little at long range, unless you have very wide camera spacing. Human stereo vision doesn't provide much depth info beyond 20m or so, and that's under good lighting conditions. LIDAR gives you equally accurate range data for anything it senses, regardless of lighting.