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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]

#61

Post by Nomentatus »

krapht wrote: post #56
alsodumb wrote: post #37

Earlier quoted context omitted.

It's funny you use Radar as an example of 'good sensor' while it is well known that most or maybe almost all?) of the stationary vehicle accidents you're talking about happened because of Radars inability to detect a stationary obstacle. On the other hand, RGB data does have that information, we use it everyday to avoid obstacles, even under foggy and rainy conditions (I'm no LIDAR expert but I know it sucks in rainy…

You mean some radars inability to detect stationary obstacles. Clutter rejection has a lot of more sophisticated algorithms to apply with greater compute power to throw at the problem.

These were flat truck/ambulance surfaces encountered at an angle - exactly the conditions that the first stealth fighter, with its angular surfaces used to evade some of the best radar in the world, because from most angles, no radio waves would be reflected back to the radar sensing device. It's hard to get the job done with nothing.

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

#62

Post by FreakLegion »

CharlesW wrote: post #11

I thought it was telling that Andrej immediately "reframed" the question because Lex asked the "wrong question". This is a classic evasion technique one learns from experience and/or media training. Lex's comment immediately after was a clever and gentle dig at Andrej's response. It seemed like all the "full cost" negatives Andrej mentioned were related to Tesla's ability to execute, and not what would actually produ…

> In other words, the results are better, but not enough to make up for the fact that Telsa can't support additional sensors without incurring a prohibitive amount of additional risk to Tesla. Risk to passengers doesn't appear to be a consideration.

You may be right about the actual decision process Tesla went through, but Karpathy is right in principle. One of the first things he says is "there can be problems with [the sensors]", and a lot of what he mentions increases the risk of run-time failure, not just cost.

It's easy to cast this as an optimization problem where you're trading off asymptotically improved sensing for linearly or superlinearly increased failure rates. There's certainly a point where the complexity of more sensors or certain types of sensors outweighs any marginal benefit they provide.

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

#63

Post by [deleted] »

throwntoday wrote: post #8
eachro wrote: post #4

So the key question is how much of an improvement does radar/sensors/etc give you over just using computer vision?

If we're to trust what Elon and the team said during the last few AI day, none. They stated that the ultrasonic and radar sensors were actually performing worse than their pure vision stack.

[deleted]

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

#65

Post by Nomentatus »

justapassenger wrote: post #10

TL;DW. Tesla doesn’t know how to do change management.

Given Andrej's explanation this verges on mere gainsaying. Could you expand on what you think they should be doing? Other firms would also encounter "entropy", they always do; what's your way of reducing that severely?

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

#66

Post by Nasrudith »

diskzero wrote: post #34
mongol wrote: post #30

What is it that makes Lidar so expensive? Is it something intrinsic to the technology that prevents costs from coming down?

A LIDAR sensor is a complex device with spinning motors, mirrors, lasers and more. Costs are coming down and less-expensive and more capable devices are coming to market. Once the price-points come way down, I wouldn't be surprised to see Tesla reconsider their decision to exclude them from their sensor platform.

They are also fairly power-hungry from what I heard.

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

#67

Post by alsodumb »

threeseed wrote: post #44
alsodumb wrote: post #32

Earlier quoted context omitted.

I think one should distinguish between 'all necessary information is already in the pixel-space' vs 'we already know how to extract all the information needed from pixel-space' The fact that (most) humans manage to drive around safely and successfully in current roads proves that the information needed exists in the pixel-space (not just current image, but say current + history). We don't yet have stacks that can suc…

> The fact that (most) humans manage to drive around safely and successfully in current roads proves that the information needed exists in the pixel-space But that doesn't mean that it translates to a car. We constantly move our 576MP resolution eyes in multiple orientations in order to visualise a scene and focus on the most important areas. Cars have fixed, low-quality cameras. We then interpret this data using the…

You kind of want to make it seem like a 576 MP resolution (where did you even get this number from while people still argue about a fair comparison between human eye and a camera?) or having to move your head/eyes to visualize your surroundings rather than actually having multiple fixed cameras covering the entire surroundings all the time is a good thing? If the resolution mattered that much, every car would have ultra-high resolution cameras on it.

Humans certainty have a stronger and general prior to make sense out of the information, and that's exactly why I left it as a possibility. Cars don't * yet * have anything close to it, just like they didn't have a way to accurate detect objects a few years ago and just like they didn't have a way to capture RGB information a few decades ago.

I am an optimistic guy, and I certainly believe in the power of learning at scale.

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

#68

Post by justapassenger »

Nomentatus wrote: post #65
justapassenger wrote: post #10

TL;DW. Tesla doesn’t know how to do change management.

Given Andrej's explanation this verges on mere gainsaying. Could you expand on what you think they should be doing? Other firms would also encounter "entropy", they always do; what's your way of reducing that severely?

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 should not do? Cripple products they already sold (like disabling radar in existing cars), because they need to milk their profit margins.

Andrej is a great researcher. But safety critical systems are very different from research projects.

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

#69

Post by 01100011 »

snovv_crash wrote: post #25
01100011 wrote: post #19

I still suspect it's because they need to preserve compute resources for vision processing. Sensor fusion is likely eating up too much of their current HW and limiting their progress in other areas. I suspect Tesla will have to admit they need to upgrade the current HW before they ever 'solve' FSD.

The amount of compute that sensor fusion uses is miniscule compared to running a NN or computing stereo depth maps. Sensor fusion runs in the background of your phone the whole time to power things like [0] for example. 0. https://sensor-js.xyz/demo.html

You are confused my friend.

Reading sensor data is not the same as feeding that data to a neural network and asking it to form a worldview composed of possibly conflicting sensor data streams(i.e. lidar vs vision vs ultrasonic).

You are somewhat correct that it is quite trivial to read sensor data. For many sensors, there is some work which needs to be done to denoise or cleanup the input data. That's not where the story ends, however.

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

#70

Post by Nomentatus »

justapassenger wrote: post #68
Nomentatus wrote: post #65

Earlier quoted context omitted.

Given Andrej's explanation this verges on mere gainsaying. Could you expand on what you think they should be doing? Other firms would also encounter "entropy", they always do; what's your way of reducing that severely?

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 specifically would the new management team do that would secure supply chains trivially, etc? What's not being done?

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