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A Short Introduction to Automotive Lidar Technology

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Re: A Short Introduction to Automotive Lidar Technology

#111

Post by ljlolel »

Animats wrote: post #93
aftbit wrote: post #19

Earlier quoted context omitted.

Have you ever seen the corners of a car that has been parked in a big East-coast city? They will sustain damage during the course of normal operation and storage, and many people will not stop and leave their insurance information, especially if the damage is perceived as minor and happens while the car is parked and the owner not present. Currently, the corners of a car are relatively non-critical to its function an…

Right. It seems to have been Waymo's decision to have zero blind spots around the vehicle perimeter, even if that means having the sensors stick out. Cruise had an accident where another vehicle knocked a pedestrian into a Cruise car, and the pedestrian was dragged. Cruise lost their California DMV autonomous license for that. So there's a good case for full perimeter coverage. Humans don't have that. The same week a…

They lost their license for not reporting it properly (as required under the license). Not for the accident.

Re: A Short Introduction to Automotive Lidar Technology

#112

Post by michaelt »

Animats wrote: post #8

That's a reasonable basic overview. I'm surprised that rotating scanners are still used. It's been twenty years since Velodyne built their first one. They work OK, but cost too much. I was expecting flash LIDAR or MEMS mirrors to take over. Continental, the auto parts company, bought the leading flash LIDAR company over a decade ago, but the volume market a big parts company needs never appeared. Waymo is still using…

> I'm surprised that rotating scanners are still used. It's been twenty years since Velodyne built their first one.

They're even older than that. SICK have been pointing laser range finders into spinning mirrors since about 1995 - albeit mostly for industrial safety systems which can be quite price-insensitive.

There's a few things to know about LIDAR to understand why spinning lasers make sense.

First of all, anything emitting a cone of light encounters "inverse square dropoff" - where moving twice as far away means you get a quarter of the light, per unit area. This is most visible with flash photography at night - but it also applies to LIDARs. And in an automotive application, ideally you want to be able to sense things 100m away. Illuminating a laser spot is much more practical than illuminating everything.

Secondly, whatever light source you use has to be eye-safe. And sure, IR has safety advantages over visible light here - but a light source bright enough to illuminate things at a 100m distance would be very hard to make safe, even with the advantages of IR. As a scanning laser never lingers in one point for long, it can safely be much more intense.

The third thing to know is whatever light source you're using, you're in competition with the sun. Sometimes the sun is low in the sky and directly dazzling your sensors. Other times it's illuminating the same things you want to illuminate. This means you can't make up for a weak light source and inverse-square dropoff with clever signal processing.

And finally, the makers of these cars envisage a future where every single vehicle on the road is using this technology. So there's also a risk of the reflected returns of two different vehicles interfering with one another. Even rotating LIDAR can be vulnerable to it, but flash LIDAR is particularly vulnerable.

Meanwhile, automotive companies aren't scared of moving parts. A car has loads of spinning parts already; they have mastered the art of making spinning things that can keep spinning for thousands of hours.

Re: A Short Introduction to Automotive Lidar Technology

#113

Post by KeplerBoy »

jaimex2 wrote: post #106
UltraSane wrote: post #81

Earlier quoted context omitted.

I find opinions like this to be almost as crazy as saying that the earth is flat because Waymo has a working, truly self-driving taxi service RIGHT FREAKING NOW while Musk is still promising to have one some day in the hazy future while NEVER making a single vehicle that can actually drive without someone in the car. Musk rejecting LIDAR means that he fundamentally doesn't understand the technological challenge of se…

It doesn't. It has a party trick that works in very specific conditions.

Do you expect a car with fewer sensors to fare any better soon?

Re: A Short Introduction to Automotive Lidar Technology

#114

Post by KeplerBoy »

tgaj wrote: post #24
quonn wrote: post #4

Earlier quoted context omitted.

It‘s not just Musk. Most automobile manufacturers have maintained that they need to find a way to do it with cheap and pretty sensors.

Theoretically if a human can drive a car using a pair of eyes connected to brain, it should be possible to do that using two cameras connected to some kind of image processing unit.

Sure, but why strive for that? We can have better than human perception by adding lidar and radar.

Re: A Short Introduction to Automotive Lidar Technology

#115

Post by UltraSane »

jaimex2 wrote: post #106
UltraSane wrote: post #81

Earlier quoted context omitted.

I find opinions like this to be almost as crazy as saying that the earth is flat because Waymo has a working, truly self-driving taxi service RIGHT FREAKING NOW while Musk is still promising to have one some day in the hazy future while NEVER making a single vehicle that can actually drive without someone in the car. Musk rejecting LIDAR means that he fundamentally doesn't understand the technological challenge of se…

It doesn't. It has a party trick that works in very specific conditions.

But it works vastly better than anything Tesla has made so what does that say about Tesla?

Re: A Short Introduction to Automotive Lidar Technology

#116

Post by jeffreygoesto »

rightbyte wrote: post #101
0_____0 wrote: post #22

Earlier quoted context omitted.

IIRC the data coming out of the Conti radars was preprocessed to give bearing, distance, and size of an object in the FOV of the unit. I don't know if I ever saw the true raw data out of one of them, but I'm curious what it looks like.

Ye I have a hard time imaganing how a car radar image looks like. On boat radars it seems like the radar have really high resolution (can see much further than lidars) but have worse accuracy. I.e. things looks like blobs. A lidar image at 50+ meters is very sparse.

Roughly like in this paper https://www.semanticscholar.org/paper/RadarScenes:-A-Real-Wo...

Re: A Short Introduction to Automotive Lidar Technology

#117

Post by quonn »

Klaus23 wrote: post #44
quonn wrote: post #4

Earlier quoted context omitted.

It‘s not just Musk. Most automobile manufacturers have maintained that they need to find a way to do it with cheap and pretty sensors.

This is simply not true. Let's look at the best autonomous driving features available today, i.e. level 3: Mercedes Drive Pilot: Uses a lidar (and a dummy unit) up front. BMW Personal Pilot: Uses a lidar (and a dummy unit) up front Honda SENSING Elite: Uses 5! lidars They all use lidar, and some of the placement locations are downright hideous (Mercedes EQS). I think further development will require even more/better…

Maybe they changed their mind on it in the last 10 years. I had as the source a high-ranking BMW manager as well as an Audi one who each gave a public lecture at a university with such a statement.

Re: A Short Introduction to Automotive Lidar Technology

#118

Post by mavhc »

altacc wrote: post #104
UltraSane wrote: post #81

Earlier quoted context omitted.

I find opinions like this to be almost as crazy as saying that the earth is flat because Waymo has a working, truly self-driving taxi service RIGHT FREAKING NOW while Musk is still promising to have one some day in the hazy future while NEVER making a single vehicle that can actually drive without someone in the car. Musk rejecting LIDAR means that he fundamentally doesn't understand the technological challenge of se…

I think anyone who listens to Musk talking about something they themselves know a lot about quickly realises that Musk's skills are elsewhere. He can motivate and market the hell out of a business whilst snorting more ketamine than a herd of horses but he is not a technical genius by any means. He pays people well to agree with him and fires them when they don't, so I suspect that his companies that produce better an…

It's weird that what he does is so easy yet no one else is making EVs at scale in USA, or landing rockets, 10 years after SpaceX did it

Re: A Short Introduction to Automotive Lidar Technology

#119

Post by ProblemFactory »

tgaj wrote: post #24
quonn wrote: post #4

Earlier quoted context omitted.

It‘s not just Musk. Most automobile manufacturers have maintained that they need to find a way to do it with cheap and pretty sensors.

Theoretically if a human can drive a car using a pair of eyes connected to brain, it should be possible to do that using two cameras connected to some kind of image processing unit.

> Theoretically it should be possible to do that using two cameras connected to some kind of image processing unit

That "some kind of image processing unit" in humans has an awful lot of compute power and software.

If you remove $100k of sensors but have to add $200k of compute to run more advanced computer vision software, then it's a bad tradeoff to use only cameras, even if in theory that software is possible.

Re: A Short Introduction to Automotive Lidar Technology

#120

Post by tordrt »

UltraSane wrote: post #81
jaimex2 wrote: post #30

Earlier quoted context omitted.

They went deep down the wrong path and need to justify their mistake. Waymo will be killed off any day now.

I find opinions like this to be almost as crazy as saying that the earth is flat because Waymo has a working, truly self-driving taxi service RIGHT FREAKING NOW while Musk is still promising to have one some day in the hazy future while NEVER making a single vehicle that can actually drive without someone in the car. Musk rejecting LIDAR means that he fundamentally doesn't understand the technological challenge of se…

Karpathy said in some podcast that Tela uses LIDAR in training, and by doing this they can get a lot of the benefits. Not sure that all off the "worlds experts" agree with you that you HAVE to use LIDAR. Rate of progress for FSD has been very impressive lately. I personally think that its very plausible that Tesla might beat Waymo to large scale location independent autonomous driving.
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