Why Tesla removed radar and ultrasonic sensors [video] • Hacker News Board

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

#131

Post by taneq » Mon, Oct 31, 2022, 12:29 AM UTC

threeseed wrote: post #39

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…

It was an ominous answer. We really should be focusing on what is the best solution and trying to solve price issues through existing techniques e.g. economies of scale, competition, miniaturisation. Instead they are trying to build whatever solution they can that fits in a pre-defined cost window. Except this isn't a new phone or sneakers we are trying to take to market it's something that will directly impact peopl…

Whose money should “we” be spending on this grail quest?

This mindset is something I see a lot, that “best” means the technically optimal (or sometimes just personally most convenient) solution to the specific problem that they personally are working on. If they take a step back and look at the bigger picture, the technical merits are usually only a tiny part of the whole decision.

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

#132

Post by YZF » Mon, Oct 31, 2022, 12:30 AM UTC

FreakLegion wrote: post #62

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…

Taking his point to the extreme why use 8 cameras? just use 4? 1? One photo-diode?

Cameras can also fail at run-time there can (and is) be variability in how they're mounted, in the lenses, in the sensors. They can get blinded or not get enough light. Their cabling can fail random components can fail.

Tesla has claimed that vision outperforms vision+radar but anecdotal reports don't seem to support that conclusion. IMHO these technologies are not directly replaceable, but are complementary. It's like you can't replace your ears with your eyes (yeah, you can read lips, if they're visible).

But sure, there is a sweet spot. Is Tesla really optimizing for best performance at any cost or are they optimizing making more money and selling that to us as an improvement? That's really the question and I don't think we got a frank answer there.

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

#133

Post by throwawaylinux » Mon, Oct 31, 2022, 12:38 AM UTC

threeseed wrote: post #39

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…

It was an ominous answer. We really should be focusing on what is the best solution and trying to solve price issues through existing techniques e.g. economies of scale, competition, miniaturisation. Instead they are trying to build whatever solution they can that fits in a pre-defined cost window. Except this isn't a new phone or sneakers we are trying to take to market it's something that will directly impact peopl…

Everything in engineering has a cost tradeoff, and always has. And peoples lives are improved by things which they can afford There is no "best solution" you can talk seriously about without talking about cost.

Why not have a thousand sensors if more is better?

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

#134

Post by clouddrover » Mon, Oct 31, 2022, 12:38 AM UTC

ajross wrote: post #3

TheLoafOfBread wrote: post #2

This whole question about the vision boils down to "humans don't need it so cars should not need it too" the problem with this statement is that humans does not have wheels to move around, they have legs, but wheels are ridiculously simple compared to 4 legs tapping 160km/h on a highway. Same for birds - they also does not need jet engines to fly around, but imagine Airbus A380 flapping its wings and what kind of com…

But the question at hand is system control, not locomotion! You're not asking the automation to walk (well, I mean someday we will, but Teslas have wheels), nor the aircraft to flap. We want the automation to do what a human pilot would do. And that works with eyes. No, I think this argument is largely correct. And frankly settled: anyone who's driven recent FSD beta versions knows very well that the cars "see just f…

> You're not asking the automation to walk

Tesla should aim for parking first. Teslas do poorly at self parking:

https://www.youtube.com/watch?v=nsb2XBAIWyA

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

#135

Post by KVFinn » Mon, Oct 31, 2022, 12:43 AM UTC

TLDR: Tesla thinks LIDAR hardware is more expensive than the performance improvement it provides.

I didn't like his line of logic about how vision is necessary and sufficient, because that's how humans drive. Okay sure, but if some combinations of non-human sensors could drive better and/or cheaper than a vision only driving system, surely he would not argue for sticking with vision only? Maybe adding non-vision sensors lets you save hardware and software resources on the vision part of the system.

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

#136

Post by paulcole » Mon, Oct 31, 2022, 12:44 AM UTC

jandrese wrote: post #129

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…

> While it is true that humans do fine with only eyes We do not. Humans are terrible at driving. Traffic accidents are one of the leading causes of death in the developed world. Billions of dollars of property damage occur every year because humans are not up to the task. A self driving system that is as safe as an average human driver would be an absolute failure.

> Traffic accidents are one of the leading causes of death in the developed world.

Perhaps leading cause of premature death or leading cause of accidental death or leading cause in demographics who are otherwise unlikely to die, but they are nowhere close to the top of the overall list.

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

#137

Post by bumby » Mon, Oct 31, 2022, 12:45 AM UTC

paulryanrogers wrote: post #118

bumby wrote: post #91

Earlier quoted context omitted.

I disagree, but mainly because of the way humans perceive risk. From a public standpoint I don’t think it’s sufficient because there’s inherent trust lacking in an automated system. With ape-driven systems we have a certain amount of trust because we can more accurately intuit what the other ape is reasonably thinking. This is not the case with autonomous driving which leads to a wider amount of uncertainty. Not unli…

AI cars can also get a software update at any moment. Human drivers won't change behavior en masse overnight.

You’re right, but that still misses the point. More frequently updated software doesn’t make people intuitively trust it more. For some, it can do the opposite by making them question why it needs to be updated so much to begin with.

Humans don’t generally measure risks statistically. They do so emotionally and with lots of cognitive biases. You don’t alleviate that with more and more facts, unfortunately.

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

#138

Post by sfifs » Mon, Oct 31, 2022, 12:50 AM UTC

pmarreck wrote: post #114

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…

Two thoughts: 1) He's not touching on the software cost of integrating different sensor data into the same trained machine learning model; it is likely far simpler to just stick to stereoscopic vision data (the same thing the human genome decided!) 2) That said, it seems at least theoretically advantageous to have a sensory system that exceeds that which humans are limited to; things like LIDAR can work in complete d…

> likely far simpler to just stick to stereoscopic vision data (the same thing the human genome decided!)

Yeah and till we had reliable and powerful artificial lighting, it was highly unsafe to journey in low visibility/ darkness. We used to finish journeys when darkness fell.

Animals that do require precise movement in low visibility (bats, dolphins) conditions often evolved ultrasound solutions.

So should we license Tesla vehicles to only operate when visibility and weather forecast is good and not drive in the dark at all?

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

#139

Post by imglorp » Mon, Oct 31, 2022, 12:50 AM UTC

mensetmanusman wrote: post #116

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…

I have some experience with LiDAR, they fail easily if a water droplet is on the cover or if signs are too bright. It’s a whole different technology challenge.

Why is LiDAR still expensive enough for the cost to be a problem for anyone? Why have large numbers not driven these down to commodity devices at this point? Or maybe similar tech at another frequency like spread spectrum microwave with phased array semiconductor antennae?

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

#140

Post by Retric » Mon, Oct 31, 2022, 12:51 AM UTC

a1369209993 wrote: post #121

Retric wrote: post #88

Earlier quoted context omitted.

The video has a more reasonable answer. The sensors are unreliable and expensive in terms of R&D. Having marginal parts which takes money from a finite R&D budget can easily result in a worse product. “They contribute noise and entropy into everything.” … “you’re investing fully into that [vision] and you can make that extremely good. You only have a finite amount of spend of focus across different facets of the syst…

> Having marginal parts which takes money from a finite R&D budget can easily result in a worse product. "Less sensors can be more safe/effective if that allows us to focus on making effective use of the sensor information we do have, which is the result we're aiming for with this descision." would be a reasonable answer (if true), but that doesn't seem like a fair interpretation of what he actually said.

It’s fairly rambling but he touches on that exact point several times most specifically here at the 2 minute mark:

“Organizationally it can be very distracting. If all you want to get to work is vision resources are on it and you’re actually making forward progress. That is the sensor with the most bandwidth the most constraints and you’re investing fully into that and you can make that extremely good. You only have a finite amount of spend of focus across different facets of the system.”

Which was from this section: Q: “Is it more bloat in the data engine?”

“100%” (Q:“is it a distraction?”) “These sensors can change over time.” “Suddenly you need to worry about it. And they will have different distributions. They contribute noise and entropy into everything and they bloat stuff”.

Even earlier he says:

“These sensors aren’t free…” list of reasons including “you have to fuse them into the system in some way. So that like bloats the organization” “The cost is high and you’re not particularly seeing it if your just a computer vision engineer and I am just trying to improve my network.”