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Why Tesla removed radar and ultrasonic sensors [video]

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Re: Why Tesla removed radar and ultrasonic sensors [video]

#101

Post by Veserv »

Nomentatus wrote: post #70
justapassenger wrote: post #68

Earlier quoted context omitted.

Andrej refused to answer the question about why, and instead gave whole speech about how change management and supply chain is hard. What else is there to expand on? And of course other companies encounter it. But this has very strong vibes of “no one knew health care can be so complicated”. And what should they do? Change management. Yeah, it’s hard, and costs money, but it’s a hard industry to be in. What they shou…

Andrej did answer, he said that the delta was tested and found wanting, then detailed a number of risks that came with keeping Lidar. Positive but small. Risks larger. That exactly answers "don't you want all the help you can get." (paraphrase, from memory.) Securing supply chains is hard period. Tesla and SpaceX have gone to heavy vertical integration because ensuring quality seemed to insist upon that. What specifi…

They said “change management” as in the management of changes not the replacement of the management team.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#102

Post by Nomentatus »

Veserv wrote: post #101
Nomentatus wrote: post #70

Earlier quoted context omitted.

Andrej did answer, he said that the delta was tested and found wanting, then detailed a number of risks that came with keeping Lidar. Positive but small. Risks larger. That exactly answers "don't you want all the help you can get." (paraphrase, from memory.) Securing supply chains is hard period. Tesla and SpaceX have gone to heavy vertical integration because ensuring quality seemed to insist upon that. What specifi…

They said “change management” as in the management of changes not the replacement of the management team.

I think they've actually said both at different times.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#103

Post by Nomentatus »

NBJack wrote: post #80
Nomentatus wrote: post #57

Earlier quoted context omitted.

No, he precisely said that the difference Lidar made was tested, and the delta (difference made) was quite small; not enough to outweigh the downsides. Elon has noted that humans do well, and that's relevant, but that observation was also tested, re lidar.

Basically everything he said as a justification (sourcing, firmware, etc.) applies to every sufficiently advanced part of the vehicle. By that logic, they should not be using touchscreens on the center console, etc.

If the safety delta was low after removing them, as 'tis with Lidar, absolutely.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#104

Post by fzeroracer »

ajross wrote: post #100
fzeroracer wrote: post #92

Earlier quoted context omitted.

> The LIDAR folks were wrong, basically. According to who? Tesla? Because Tesla has a vested interest in trying to prove that they're right even if they're obviously wrong. That's why they constantly try to downplay failures, software issues, device issues etc. I'm very confused by the attempts to discredit the usefulness of LIDAR. It's another tool you can use to improve the accuracy of your model. Sure, you can use…

The causality goes the other way. The LIDAR claim was that Tesla's vision approach couldn't work. It did.

Who made this claim? You keep making these grand statements but without linking to people or providing any proof.

Like there are going to be some environments where Tesla's vision is going to struggle, that's just a fact because you're relying on a more linear set of data. That's why you incorporate as many data points as possible for reasons other commentators have brought up. And I'm confused by how you qualify it as 'working', given we've seen multiple issues which are directly related to their vision approach.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#105

Post by fooblaster »

ajross wrote: post #100
fzeroracer wrote: post #92

Earlier quoted context omitted.

> The LIDAR folks were wrong, basically. According to who? Tesla? Because Tesla has a vested interest in trying to prove that they're right even if they're obviously wrong. That's why they constantly try to downplay failures, software issues, device issues etc. I'm very confused by the attempts to discredit the usefulness of LIDAR. It's another tool you can use to improve the accuracy of your model. Sure, you can use…

The causality goes the other way. The LIDAR claim was that Tesla's vision approach couldn't work. It did.

Tesla has not solved self driving, and by all accounts never will with their existing compute and sensor stack.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#106

Post by woeirua »

Andrej's argument about more sensors adding entropy strikes me as disingenuous considering that in the next question he then says that Tesla's biggest advantage over everyone else is "the fleet", which clearly introduces orders of magnitude more entropy into the system than anything else. Can you imagine the infrastructure required to gather video from "the fleet" anytime a car sees something unexpected? How about diagnosing what went wrong in that specific instance? How many thousands of these cases do they see everyday?

Given the progress of the FSD "beta" to date, and the fact that Andrej _left_ Tesla, I'd wager that he knows that this approach is a dead end, but he won't say that because he'd get himself in hot water with Elon.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#107

Post by petilon »

lostsock wrote: post #74
petilon wrote: post #33

I didn't find his answers particularly convincing. His answer focused on costs mainly, and how "the best part is no part". We have already seen multiple accidents caused by camera's limitations [1] which would not have happened if Tesla used Lidars. Cameras have poor dynamic range and can be easily blinded by bright surfaces. While it is true that humans do fine with only eyes, our eyes are significantly better than…

That video is from 2020, but Tesla didn't remove radar until 2021. Meaning that the crash occurred with radar still active, which I feel just backs up what Karpathy was saying.

Well, the car may have had radar hardware but there are questions as to whether the software was using it:

https://www.nytimes.com/2021/07/05/business/tesla-autopilot-...

Excerpt:

Mr. Rajkumar of Carnegie Mellon, who reviewed the video and data at the request of The Times, said Autopilot might have failed to brake for the Explorer because the Tesla’s cameras were facing the sun or were confused by the truck ahead of the Explorer. The Tesla was also equipped with a radar sensor, but it appears not to have helped.

“A radar would have detected the pickup truck, and it would have prevented the collision,” Mr. Rajkumar said in an email. “So the radar outputs were likely not being used.”

https://www.nytimes.com/2021/12/06/technology/tesla-autopilo...

Excerpt:

Tesla later said that during the crash, Autopilot’s camera could not distinguish between the white truck and the bright sky. Tesla has never publicly explained why the radar did not prevent the accident.

Re: Why Tesla removed radar and ultrasonic sensors [video]

#108

Post by petilon »

aeternum wrote: post #96
petilon wrote: post #33

I didn't find his answers particularly convincing. His answer focused on costs mainly, and how "the best part is no part". We have already seen multiple accidents caused by camera's limitations [1] which would not have happened if Tesla used Lidars. Cameras have poor dynamic range and can be easily blinded by bright surfaces. While it is true that humans do fine with only eyes, our eyes are significantly better than…

The dynamic range is the reason Tesla know counts photons rather than use traditional camera processing. They basically remove the concept of exposure entirely and simply pass the sensor photon counts to the neural net. This approach not only simpler as it removes photo processing/encoding but the result is that the NN can operate with a very high dynamic range similar to the human eye and in many cases can be sensit…

But it doesn't appear to be helping. Here's an example accident where depth data from Lidar would have helped:

"Tesla later said that during the crash, Autopilot’s camera could not distinguish between the white truck and the bright sky."

https://www.nytimes.com/2021/12/06/technology/tesla-autopilo...

Re: Why Tesla removed radar and ultrasonic sensors [video]

#109

Post by mensetmanusman »

jeffbee wrote: post #97
aeternum wrote: post #93

Earlier quoted context omitted.

Lack of focus is a major problem for companies and we all know that tech debt leads to increased bug counts. Team focus on vision which is by far the highest accuracy and bandwidth sensor allows for a faster rate of safety innovation given a constant team size.

Tesla engineers are currently doing post-commit review of Twitter source code. Focus is the last thing I would credit them with.

All of them?

Re: Why Tesla removed radar and ultrasonic sensors [video]

#110

Post by taf2 »

post_break wrote: post #73

I think this is the real reason: https://www.youtube.com/watch?v=LS3Vk0NPFDE Cost cutting.

Probably a benefit but also imagine the difference in software. You Boolean logic like radar says we are gonna hit , vision sensor says we have nothing there, sonar indicator says nothing there… so the idea of having just a really good single source of truth probably makes a lot of code a lot less complex… I have no way of knowing either way but from a less is less that can break point of view this seems kinda good… like many things only time can tell and at least we have different groups of people pushing on different potentially viable paths forward so that we can soon hopefully know if self driving is possible (wide scale) one way or the other
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