Earlier quoted context omitted.
Humans tend to move their heads, which is why one-eyed depth perception still works.
Humans can also drive RC cars, airplanes, quadcopters, etc using a single unmovable camera.
Also video games
How the LIDAR tech GM just bought probably works
51–60 of 72 posts
Re: How the LIDAR tech GM just bought probably works
#52Interesting. Frequency-modulated continuous-wave LIDAR is easy to do as a one-point device. Many such devices have been built. But they're usually short range, such as the discontinued Swiss Ranger, and don't reject ambient light as effectively as pulse systems. Being both eye-safe and sunlight-tolerant is hard. Eye-safe is easier if you can increase the diameter of the outgoing beam. Eye safety is measured based on…
You can get some pretty impressive dynamic range out of the new silicon photomultiplier detectors that companies like SensL, Hamamatsu, and Ketek have been putting out. Despite the name, they aren't related to old-school photomultipliers - they're basically large arrays of very tiny Geiger-mode avalanche photodiodes on a single chip. This solves the low dynamic range issues from traditional large-area avalanche photo…
Advanced Scientific Concepts built some actual photomultiplier LIDAR devices for DoD. Photomultipliers have very low latency - picoseconds. One photon in, one electron out. So they built an InGaAs sensor as the target of a photomultiplier tube. Sensitivity is very good, but the technology is expensive.
Re: How the LIDAR tech GM just bought probably works
#53OK I have a question, but dont shit on me if you think its stupid: Wouldnt any of these smart cars be able to know they physical volumes of many number of cars, including themselves, as well as communicate with eachother - and share their velocity, direction, volume, intentions so as to have a hive mind of the moving bodies? What if you also just had a beacon which reported this information to other cars in a short n…
(Assuming I'm understanding you correctly,) if the issue were only other vehicles, this might be feasible. However, the world includes much more than just the other vehicles on the road, and the road and its environs aren't static. I can imagine something similar to what you're proposing being a part of the overall system, I suspect there will always be the need for something vehicle-based that "sees" the environment…
Yeah I meant in addition to, not instead of.
And I was saying that these beacons should be just a part of the car and super cheap. The beacon just says "hey I'm a Prius and this is my speed direction and location"
But you'd have to make them completely anon - we already have too much activity tracking.
So the devices should cycle through random IDs that just spray out the specs of the vehicle, but they change frequently the ID so you can just say that a smart car would know that it just sees various cars - not that it knows that "Jim is just ahead on the left"
Re: How the LIDAR tech GM just bought probably works
#54I assume LIDAR is needed since the AI isn't advanced enough to do depth perception? If I can drive with two eye balls, then I'd think a circular camera array would be plenty. Maybe this is what Tesla plans on using (in combination with RADAR).
Forget about cars, this tech is applicable beyond cars. They could potentially scan colors by changing the frequency, discern materials and even use different resolutions, which could make scans much faster. I have no idea why nobody did it so long ago.
Re: How the LIDAR tech GM just bought probably works
#55I assume LIDAR is needed since the AI isn't advanced enough to do depth perception? If I can drive with two eye balls, then I'd think a circular camera array would be plenty. Maybe this is what Tesla plans on using (in combination with RADAR).
While LIDAR and stereo cameras (as well as RGBD depth cameras like Kinect) both effectively do the same thing, LIDAR typically has a much longer effective range while keeping high resolution. To give you an example, this[1] commercially available sensor head can give great resolution stereo depth at around 10m but the included LIDAR unit is good out to around 30m. LIDAR also has the advantage of operating on a differ…
This is also LIDAR.
Re: How the LIDAR tech GM just bought probably works
#56Re: How the LIDAR tech GM just bought probably works
#57One of the advantages for solid-state LIDAR has to be an increase in reliability. Nobody wants to buy a car which requires a new LIDAR to be installed after 100,000 miles for the sum of $7,000. Hopefully once production starts and yield rates increase the unit costs can shrink small enough to being becoming feasible for integration into lower-end products like cell phones or laptops. I think there are a lot of cool a…
>Nobody wants to buy a car which requires a new LIDAR to be installed after 100,000 miles for the sum of $7,000.
How much does a chauffeur cost for 100,000 miles?
Re: How the LIDAR tech GM just bought probably works
#58Wondering why no one has thought of using a Acousto-optic modulator? https://en.wikipedia.org/wiki/Acousto-optic_modulator It's solid state, has a very fast response time, super cheap to manufacture, and can steer a beam with high precision. And they are very efficient, achieving a >90% first-order diffraction efficiency. The AOM material can be solid and thermally insulating (such as glass), so you can get very high…
From the Wikipedia page:
> Consequently, the deflection is typically limited to tens of milliradians.
This is the big drawback with AOMs. They're very precise, but the angle through which they steer beams is small. You would need hundreds of scanners to scan a full circle under the best conditions.
AOMs are interesting though in that they provide a way to modulate the frequency of the light they deflect. This is how I've seen them used before: as a very precise way to introduce small frequency shifts into a laser beam for physics research.
Re: How the LIDAR tech GM just bought probably works
#59Interesting. Frequency-modulated continuous-wave LIDAR is easy to do as a one-point device. Many such devices have been built. But they're usually short range, such as the discontinued Swiss Ranger, and don't reject ambient light as effectively as pulse systems. Being both eye-safe and sunlight-tolerant is hard. Eye-safe is easier if you can increase the diameter of the outgoing beam. Eye safety is measured based on…
There's a promoted comment on the original post that addresses the question of interference between lidars from multiple cars on the same street (short version: coded pulses so each unit can recognise its own reflections). But your comment makes me wonder about another issue: what about eye safety in a street crowded with autonomous cars? Each car's lidar may be eye safe on its own, but how safe is a busy street that's being continually scanned by dozens of cars at once?
Re: How the LIDAR tech GM just bought probably works
#60OK I have a question, but dont shit on me if you think its stupid: Wouldnt any of these smart cars be able to know they physical volumes of many number of cars, including themselves, as well as communicate with eachother - and share their velocity, direction, volume, intentions so as to have a hive mind of the moving bodies? What if you also just had a beacon which reported this information to other cars in a short n…
Imagine you are potentially the first autonomous car maker to market. You need to build a car that assumes no other cars can talk to it. The idea you have is good, but is probably a solution that gets addressed much farther down the road.