Vision can also get you 3D maps, either in active manner (IR floodlight or structured lighting) or not. I will reserve my judgement until see more from either side.
If anything, knowing when to reliably ignore a sensor modality is the kind of intuition more associated with general AI.
A similar paradox occurs when trying to fuse multispectral imagery. You'd think early fusion of RGB and IR would be better since it gives the higher-resolution filters access to more data, but it does worse than late fusion. My understanding is that late fusion forces the network to "work harder" to solve object detection using IR only, and then once you've wrung what you can out, then you fuse with RGB detections.
Since radar is "one pixel" there's essentially only one object detector possible: object or nothing. If yes-object, fusion tries really hard to make sense of the RGB filters to figure out what partial detection looks like an object, which is almost always a false positive.
Waymo has its own custom developed 4D imaging radar and I imagine most of the other SDC players have their own versions.
[1] https://blog.waymo.com/2020/03/introducing-5th-generation-wa...
[2] https://aurora.tech/technology/driver
[3] https://www.mobileye.com/blog/radar-lidar-next-generation-ac...
Given this post is about radar usage in self driving and how Tesla/Karpathy touts their capabilities, I compare them to other SDC players, not other car manufacturers who are not in the game. And their SDC competitors are running away because they have the newer 4D radars.
Only if you don’t consider Waymo, Cruise, Mobileye and others as Tesla competitors.
+1 to the other commenter (grandparent comment).
Radar has a range resolution and an angular resolution. Andrej completely omitted this fundamental aspect in his talk.
In my humble opinion, Andrej needs a real Radar engineer in his group before making such a statement in his talk.
Nobody can be smart for all topics, which makes all humble also.
This makes some important assumptions, namely that Tesla built a lidar and radar perception pipelines and sensor fusion of equivalent quality to their competitors, and then decided they were unnecessary.
Given that their competitors have shown substantially better perception than Tesla, and that Tesla has a significant economic incentive to deliver autonomous driving on a sensor suite that already shipped years ago, I find that difficult to believe. Did Tesla build good enough perception to dismiss lidar and radar purely on their merits. Unlikely I think. Did an intern build a student-quality lidar pipeline that "proved" Elon's camera-first approach is the right one? More likely.
That sounds like a problem with the network's architecture and not the data itself
I am actually on sensor-fusion side, and think a transformer can merge everything and generate a coherent world-view. But this is a hard problem and people side-step them after the evaluation shouldn't be dismissed blatantly.
For one:
> It gives you a more robust view of the world than using a single sensor modality.
How can we evaluate that correctly?
In effect, they solved the disagreement problem by sticking their head in the sand and pretending their sensors are never wrong.
This is actually my main criticism of Tesla's approach. They don't seem to have enough cameras to do the job well, and its showing in a lot of actual system limitations.
Take a look at how dense the point cloud from Waymo's 5th gen LIDAR is: https://www.youtube.com/watch?v=COgEQuqTAug&t=11599s. They just talked about this a few days ago.
I am actually on sensor-fusion side, but I don't think we should jump to the conclusion LIDAR is the best 3D mapping method.
For one example, a truck has a breaking distance of 600ft, either Velodyne or OS1 LIDAR has range less than that.
Even if you believe this goal is possible to achieve at some point in the future, I think the argument falls apart when you consider that it will take years, probably decades, for a pure vision approach to catch up to where Waymo is today in terms of safety. (They have cameras too.)
That Tesla can’t afford to fit expensive LiDAR sensors to all of the cars it sells is Tesla’s problem. Regulators won’t give a shit that pure vision is “better” in theory. They will simply compare Tesla’s crash rate in autonomous mode with that of Waymo and other AV operators, and act accordingly.
However, nowadays it starts to look that 100% reliable depth estimation from cameras might actually require a human-level AI to work and also solid-state LIDAR technology is becoming cheap enough and integrateable into normal cars, but Tesla can't really change their stance on this without admitting that FSD options they already sold would not actually become FSD within the lifetimes of these vehicles. I suspect this might also be the reason why Karpathy looks more and more nervous with each new talk
That's pretty much a given at this point but they will not admit it until a class-action lawsuit forces them to.
you don't need 100%, and even humans are far from 100% (500Mpx resolution of our eyes allows to basically sheer brute force through it in many cases). The stereo setup provides great and fast estimation with several megapixel resolution with good fps (way better than lidar) for majority of situations. It is some share of the [part of the] scenes, and you really know it right then and there, where you need AI and/or very sophisticated compute heavy algorithms. So instead of throwing AI and the compute power at those parts, you just pull the points from the lidar (and even radar if the things are that bad) covering that segment. And that way, given a couple more iterations of sensors (from current 20Mpx+ to the hundreds Mpx) and compute, it will be doing even better than humans. Anybody not doing sensor fusion would be a loser though - just like going into a fist fight with one hand intentionally disabled.
For example, cameras are sensitive to glare from reflections (sun near sunset or reflecting on metallic objects) and oncoming traffic at night. Lidars operate on a different narrower wavelength and are unlikely to be affected by that, although they might struggle with objects that have low reflectivity at a long distance.
The fact that these sensors are different means that the intersection where a dangerous situation would not be detected by either sensor is much smaller than any sensor individually.
In any case, once AVs are deployed at scale, if it becomes apparent that some sensors can be removed or replaced by something else, then they will be if there's a case for it.
On what set of metrics do you think Waymo is safer? IMO it's too early to compare and cherry-picked proofs both from Waymo and Tesla are not really representative.
There are issues with reading too much into disengagements, but there certainly seems to be a large difference here.
[1] https://thelastdriverlicenseholder.com/2021/02/09/2020-disen...
Tesla wimps out and won't test in California, because they'd have to report.
You can read their other safety whitepapers in https://waymo.com/safety
That doesn't work when they scale up to any other set of normal roads, especially as density and complexity increases.
They will always map roads to precision, whether it's Arizona or San Francisco. Why is that a problem? You should either look at their CA disengagement reports over the years or wait until they roll out a service in SF (where they've been testing heavily). That will show how safe they are in dense environments.
The video with the Waymo car getting stuck and taking off from the rescue team had an example of this.
I guess it makes perfect sense from a engineering perspective.
The lidar/no lidar discussion is a fun one because people have different ideas about how the world works. Personally I think LiDAR is the modern version of expert systems. It appeals to a logical/geometric intuition but the approach is brittle to real world contact, especially when paired with HD maps which are a great way to drive yourself into a local maximum.
Having training data beyond a certain point is overrated, and Tesla's advantage in gathering it is overstated. Other companies are capturing this data as well. Is there any indication that the data Tesla is collecting is of a higher value, or is it just more bytes?
The notion that Tesla's model HAS to keep improving simply because they will be able to pile on more (unlabeled!) data is laughably false. And, in fact, quite insulting to the intelligence of even the most casual ML engineers.
Exactly, casual ML engineers. The issue of plateauing tends to occur because there is no more novelty to be had in the data. What mega-experiments like GPT and similar have shown us is that actually you can keep adding novel data and keep improving the model. Kinda inelegant, yet effective. The problem is, most institutions can't add more novelty beyond a certain scale, since that usually means shoveling more money at data storage and compute, on top of the novelty collection.
Tesla merely has to open the money tap to get more of both compute and storage, and let the real-time data flow in.
And if you watch the other parts of the presentation, you'll see the bits about them buying clusters with 5k+ A100 GPUs. Presumably they intend to do something with those. Probably not streaming Fortnite concerts.
The point of the higher scale isn't just more data, it also makes it easier to solve the unbalanced data problem, because rarer and rarer scenarios will appear in large enough numbers to work with.
That the exact opposite of what they are doing.
It seems like you didn't watch the talk at all.
given the nature of that data you can get a lot of unsupervised mileage, so to speak, out of it.
A team with funds like Tesla, Google, FAIR is going to be using NAS and have a continuous testing pipeline. Tesla has arguably the best environment for continuous testing which is the most difficult part of improving a model. Andrej even said in his talk that their supercomputer is in the top 5 for FLOPs.
SOTA on ImageNet for the past few years has been driven by pre-training on massive datasets. Vision transformers are increasingly more common and are extremely data-hungry.
It may be valuable enough to require a few petaflops less computing power.
You can only go so far by dumping more data into it. Diminishing returns.
Tesla is also the only company to claim to target L5 autonomy. Everyone else, including Waymo, is strictly targeting L4 and say L5 autonomy is not possible or realistic. L5 is a pipe dream.
Right now their profit model is selling cars, not autonomy, so everything is optimized for that, including the decision to not use LIDAR.
At some point when LIDAR is cheap enough there is no reason for Elon Musk to not give in and use them. Right now he's constraining the problem to the cost of the car.
I think that's largely an issue with the early LIDAR devices today, but not necessarily what may be to come.
There's something to be said about measuring actual data with solid physics vs. inferring distances with billions of operations on RGB data. If you were landing a commercial aircraft in fog, you most certainly don't rely on your eyes to do most of it, but it is in fact possible to do safely precisely because we do have good sensors on them.
I fully agree with leveraging the scale and maturity of RGB sensors for cars today, the talk is spot on about that, but that's (a) circling back to the fact that Tesla needs to sell cars now not next year and (b) not a good case against use of LIDAR in the future.
As mentioned in this talk Tesla is taking an iterative approach and trying to make things safer for people today, not in 5 yrs from now. Maybe in a few years Tesla will see that to go from 10 million miles to 20 million miles they need 4k cameras at 60 fps, but the work they had already done would still have had a big impact. You don’t need to do things in one shot and get to the finish line.
> You don’t need to do things in one shot and get to the finish line.
I think we agree on these things. I wasn't trying to dispute their approach, rather explain their rationale for their current method, which is focused at actually selling product now.
> But $20k on a $40k car is too much
Those sensors don't need to be 20K-40K, they just aren't mass produced yet. That's why I think Elon Musk will change his tune in some years when those sensors are 1/100 the cost and 10X more accurate than vision.
The criticism of autopilot is really about it getting tripped-up in response to statistically rare, unusual circumstances, i.e., edge cases. Karpathy et al are working on getting better at those, bringing the rate of situations that surprise autopilot closer and closer to 0%, even if it can never be achieved -- there will be always be surprises. Personally, I would rather take a tiny risk of crash on rare, once-in-a-million-miles events with autopilot driving than a ~1% risk of crash per 1000 to 2000 miles with everyday human driving.
Prediction: Tesla will be the first of all major automakers to get to level 4 and 5 autonomy.
Lies, damn lies, and statistics.
Tesla here, is, again, being funny with the numbers. They LOVE to cite autopilot ON death statistics as being "10x safer than normal driving". What they fail to note is that Autopilot can ONLY be on while driving on a limited access highway. Highways are much safer to drive on than a mix of ALL ROADS, which is where the baseline figure comes from.
Another confounding factor is the price of the vehicle. The average CONFIGURED Tesla with the FSD package today costs what? $65k? More? Those X's and S's are $100k+. Nobody is buying that base Model 3. The point is that Tesla drivers are 1) Older and 2) Wealthy. Wealthy, older people get in far fewer car crashes than the average driver. In fact, car crash fatalities are really driven by two groups: drunks (or pill addicts), and young (teenage) men. Not saying it's IMPOSSIBLE to have a substance abuse problem and own a Tesla, but the average Tesla owner is less likely to have these issues. It's also less likely to own a Tesla while young.
So, Tesla autopilot stats should be compared to other comparably priced vehicles while driving on the highway ONLY. That would actually be a fair, honest comparison. I believe a recent outgoing BMW 5 series chassis finished its entire life without a single fatality in the US. That's right -- 4-5 years of service in the US without a single death. Turns out, wealthy people who drive expensive family sedans don't get in a lot of fatal highway crashes.
Here's a Forbes article (sorry) doing some of the back-of-the-napkin math. They estimated that in Q3 2019, autopilot really wasn't any safer than manual driving.
https://www.forbes.com/sites/bradtempleton/2020/10/28/new-te...
I disagree. Autopilot driving on the highway should be compared to all human drivers driving on the highway. Otherwise you wouldn't be comparing against human performance per mile driven apples-to-apples.
The BMW F10 535i had ZERO FATALITIES over its entire life in the US. Zero. It had no "self-driving" capabilities. Just lane-departure warning, BLIS, and ACC.
Yes, all evidence I've seen indicates that cars partially driven by computers (adaptive cruise control, lane-departure warning, blind spot information, etc.) are safer than cars entirely driven by human beings. The BMW you mention is safer precisely because it is partially driven by machines. The more we automate driving, as machines get better and better at it, the safer we will all be on the road.
Emphasis on PARTIALLY. Anyone who has read recent takeover scenario studies is rightfully horrified at the notion of a completely “hands off” driving experience, where the driver is expected to remain alert and vigilant but they’re not inputting any steering, throttle, or braking. Unsurprisingly, it takes people about 2 seconds to re-engage as active drivers. 2 seconds is way too long, which is why it may be safer to NOT use a system that does steering input in addition to throttle and brake. You need to keep the drivers actively engaged. And no, “touch the steering wheel every 30 seconds” is not active engagement. And if a car has “self driving” but also active driver monitoring, what’s the point? The driver doesn’t get to relax at all. The stress of driving doesn’t come from the input unless you’re racing. The stress of driving comes from having to stay alert. If I have to stay alert, I’d rather just drive myself instead of trusting an experimental system that drives like an indecisive, half-blind grandmother.
The BMW was safe PRIMARILY because it’s a well-designed, modern car, driven by an older and wealthy (safe) demographic. The assistance systems are probably secondary. They weren’t even standard on all vehicles and they were very primitive in that first generation.
If you actually read the Forbes article above, the back of the napkin math actually DOESN’T indicate that Teslas in autopilot are safer than normal driving. That’s the entire contention. I do not think these full-takeover systems are safer at the present time than active human drivers in comparable vehicles with safety assist systems. Tesla is very clearly fudging the numbers to make it appear as if autopilot is safer, but the claim doesn’t stand up to some really basic analysis.
This isn’t true anymore
Still not close to good enough for people to accept:
"Participants from both countries required Self Driving Vehicles to be 4-5 times as safe as Human Driven Vehicles" [0]
https://www.tesla.com/VehicleSafetyReport
> In the 1st quarter, we registered one accident for every 4.19 million miles driven in which drivers had Autopilot engaged. For those driving without Autopilot but with our active safety features, we registered one accident for every 2.05 million miles driven. For those driving without Autopilot and without our active safety features, we registered one accident for every 978 thousand miles driven. By comparison, NHTSA’s most recent data shows that in the United States there is an automobile crash every 484,000 miles.
It is not from your data alone. It maybe, but the data is not from a controlled experiment.
Because:
1. Autopilot disengages in dangerous/ambiguous situations. 2. The set of users with autopilot is different from those without.
I have to give it to Elon that he was able to keep his fans believing a big lie of their FSD system to achieve Level 4 / 5 autonomy last year, when this year it was admittedly Level 2 [2].
The fans will continue to believe his lies and keep on saying "It's coming soon, you'll see..." when they have just been sold a Fools Self Driving System™.
[0] https://twitter.com/Model3Owners/status/1406002366923612163
[1] https://twitter.com/comma_ai/status/1406304017400012800
[2] https://www.news18.com/news/auto/teslas-full-self-driving-cl...
It is also pretty easy to see that Tesla doesn't have to hit L5 to have won autonomy. It just has to successfully monetize L3/L4.
Now it’s an indefensible position on safety or economic grounds.
Obviously, pure vision is a viable system, as it's what we as humans use. The question remains as to whether or not it will be comparable to more precise LiDAR based systems in the near future.
Previous generations of LIDAR were not great at classifying small objects and road debris but it works great for detecting cars, pedestrians, etc.
https://paperswithcode.com/task/3d-object-detection
Next-gen LIDAR has great density, and I bet it would do a decent job differentiating between a plastic bag or a rock in the middle of the road. In addition to depth LIDAR also returns intensity and several other metrics, which can be used as input to an ML model. It's why you can read the lettering on the side of the semi truck in this video of Waymo's next-gen LIDAR.
That doesn't mean much considering no company is getting to L5 autonomy likely in our lifetime and possibly beyond.
How can you make such a strong statement when you simply don't know how to achieve full autonomy? This reminds of the teapot orbiting the Sun argument [0]. You and people defending Lidar by their teeth don't sound too different from religious zealots who've "seen the light".
If Tesla was developing their system with trained safety drivers or on closed courses, I think they would have higher moral ground to gamble here. But placing the untrained public behind the wheel of alpha quality software is unethical IMHO. There ways to develop autonomous software that are significantly less risky, and the only reason Tesla is doing it this way is for marketing/PR purposes as far as I can tell.
That is likely close to true with lidar as well. See also some of Waymo's recent struggles in unexpected construction zones.
Maybe lidar helps in getting there, but I'm afraid they all hit a pretty tough ceiling without this.
That example has nothing to do with lidar, but with planning. The car was able to detect the construction zone just fine.
If the only way it becomes practical to achieve L5 is to use LIDAR, Tesla can obviously add it. But if they waited until LIDAR was cheap and practical, they still wouldn’t be shipping any hardware doing autonomy today, and not collecting the data needed to train their models and delivering value today.
Also, with vision based systems, it operates in somewhat an intuitive fashion given we have eyes too.
Prediction: Tesla will be the last of all major auto manufacturers to get to L5 autonomy. Time interval between when Tesla L5 FSD is finally available and when humanity is destroyed by the general AI it runs on will be very awesome and also very short