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Tesla Live Stream – Autonomy Day [video]

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Re: Tesla Live Stream – Autonomy Day [video]

#151

Post by IshKebab »

tjoff wrote: post #139
sairahul82 wrote: post #114

Karpathy's presentation is really good. Watch it later if you get some time. The key points are - Telsa is using fleet for learning (Fleet learning). This has 3 components, a. Trigger infrasture that collects the kind of data telsa is looking for training. The rational here is we don't need massive amounts of same kind of data but needs right kind of data for training neural networks correctly. b. Data Engine which l…

Does anyone doing lidar not also do visual recognition?

Yeah I don't see how it is either/or. Autonomous driving is so hard surely you need all the sensors you can get! Maybe when it is working really well you can optimise the cost and only use cameras, but we are decades away from that.

I suppose if you want to use customers as guinea pigs you do have to have a low-cost solution first, which is why Telsa are advocating it. I'm sure if LIDAR were cheaper I'm sure they're be using it.

Re: Tesla Live Stream – Autonomy Day [video]

#152

Post by dragontamer »

Traster wrote: post #125

I'm sorry but I'm finding it really difficult to watch this and match up what the engineer is saying to what Elon Musk is saying. For example, the engineer says the custom ASIC does 144 TOps for 2 chips vs the NVidia drive Xavier - does 21 TOps. Okay, well yeah I expect your custom ASIC does have a nice performance advantage over the equivalent GPU. at 3.5x advantage probably seems reasonable. Cue Elon Musk: "At firs…

> For example, the engineer says the custom ASIC does 144 TOps for 2 chips vs the NVidia drive Xavier - does 21 TOps. Okay, well yeah I expect your custom ASIC does have a nice performance advantage over the equivalent GPU. at 3.5x advantage probably seems reasonable. Cue Elon Musk:

Here's my issue with that. The on-chip SRAM is only 32MB, and the RAM is LPDDR4 rated at only 68GB/s.

Assuming a dot-product (multiply + add) over INT8 data, that's a limitation of 2-operations per 68GB/s (that the RAM moves at). Or 136 GIOPS (Giga-integer8 operations per second). You're limited by RAM, based on what I've seen in the presentation.

Unless their neural net is 32MB and fits entirely in on-chip SRAM. That seems unlikely to me...

Re: Tesla Live Stream – Autonomy Day [video]

#153

Post by sytelus »

gonehome wrote: post #129
sytelus wrote: post #123

Earlier quoted context omitted.

> Lidar is an unnecessary mistake that competitors are making This is very controversial and rest of the industry thinks exact opposite, many even claiming that Tesla is being irresponsible and even delusional in trying to do autonomy without lidar. The main points I have heard in favor of lidar are that computer vision is very flaky not only in suboptimal weather but even in good weather. Cameras are simply no where…

They pair it with a forward facing radar which is inexpensive and good at depth perception. Elon predicts all competitors will eventually drop lidar. He mentions it's expensive, but also not as good in a lot of cases (and all roads/signs are designed for vision). He argues that getting vision to work is a prerequisite for getting self-driving to work and once you have it working, lidar is worthless (and unnecessary).

“In my view, it’s a crutch that will drive companies to a local maximum that they will find very hard to get out of,” Musk said. He added, “Perhaps I am wrong, and I will look like a fool. But I am quite certain that I am not.”

https://www.theverge.com/2018/2/7/16988628/elon-musk-lidar-s...

Re: Tesla Live Stream – Autonomy Day [video]

#154

Post by gambiting »

semi-extrinsic wrote: post #94
gambiting wrote: post #75

Earlier quoted context omitted.

And I don't want them to succeed because they are actively hostile towards 3rd party repairs and car modifications, plus their current model 3 microtransaction bullshit scares me as a customer, I'm dreading the moment other companies catch on with that. I'm specifically talking about the fact that the base model 3 ships with heated seats out of the factory but you can pay to have them unlocked with a software update.…

> I'm specifically talking about the fact that the base model 3 ships with heated seats out of the factory but you can pay to have them unlocked with a software update. If you think this is a new thing, you haven't followed the car industry much. Just as an example, my 2002 el cheapo Peugot was bought without the option to show instantaneous MPG/average MPG/range/etc. Spend two hours soldering/gluing on the missing $…

I can sort of understand the software differentiation - I have no issue with Windows Home and Pro editions having different price points even thought the code on the disc is identical for instance(maybe that's hypocritical of me?). But I do have an issue with paying for hardware(heated seats in this case) and that hardware being disabled until a payment is made. I don't know, it just feels different.

Re: Tesla Live Stream – Autonomy Day [video]

#155

Post by ehmish »

Traster wrote: post #125

I'm sorry but I'm finding it really difficult to watch this and match up what the engineer is saying to what Elon Musk is saying. For example, the engineer says the custom ASIC does 144 TOps for 2 chips vs the NVidia drive Xavier - does 21 TOps. Okay, well yeah I expect your custom ASIC does have a nice performance advantage over the equivalent GPU. at 3.5x advantage probably seems reasonable. Cue Elon Musk: "At firs…

This doesn't seem wildly inconsistent with my understanding of Elon musk, in that he has a higher level of confidence of his understanding of the world than others would, and in a "you don't know what you don't know " way it seems he didn't know about custom how custom ASICs are much more efficient at specific tasks than a general purpose computer. Doesn't make him a bad person, and in fact something like that is exactly who you want leading a company trying to change the rules of the industry they're in, it's the job of the boots on the ground to exercise due diligence here.

Re: Tesla Live Stream – Autonomy Day [video]

#156

Post by cr0sh »

isoprophlex wrote: post #36
mattrp wrote: post #30

Earlier quoted context omitted.

If you’ve listened to their earnings calls this is par for the course. Say what you will about his tweets, but I find these discussions fantastically informative and transparent.

absolutely glorious, they're taking questions. first question: can you use anything else besides ReLU activations in your neural net engine? this is wonderful

I'm not a NN expert, but based on what I have found, the point of using RELU instead of other activation functions is what is called the problem of "vanishing gradients".

Basically (IIRC), during backprop the error difference gets ever smaller the further back in layers you go, ultimately getting "lost in the noise", making learning in the earlier layers more difficult to impossible.

I'm not saying RELU is the only option to make this work, or that it's the only activation function that provides a "fix" for the issue; I'm sure there are other ways to deal with vanishing gradients that I don't know about.

I also lack the mathematical knowledge as to why RELU helps in this manner, but I suspect something having to do with the lack of "asymptotic structure" approaching the extremes (I don't know what the proper term would be). Or maybe it allows for some form of "forgetting", in the prevention of multiplying very small numbers (such values just go to zero ultimately)?

Maybe someone else here with the knowledge can explain it better, and we can both learn...?

Re: Tesla Live Stream – Autonomy Day [video]

#157

Post by gambiting »

kitsunesoba wrote: post #106
gambiting wrote: post #75

Earlier quoted context omitted.

And I don't want them to succeed because they are actively hostile towards 3rd party repairs and car modifications, plus their current model 3 microtransaction bullshit scares me as a customer, I'm dreading the moment other companies catch on with that. I'm specifically talking about the fact that the base model 3 ships with heated seats out of the factory but you can pay to have them unlocked with a software update.…

Personally speaking I would not want to share a road with an autonomous car that had been tinkered on by some random Joe. Autonomous farm vehicles or something, sure, but public roads are way too risky. This is not the desktop environment of your Linux laptop, it’s monstrously complex software controlling thousands of pounds of metal and batteries.

See, I don't agree at all. Just like all cars have to pass a pretty strict annual inspection to be on the road, I imagine autonomous cars will have to go through regular assessment too.

More specifically, I'm bothered by the fact that if you get into a crash in a Tesla, Tesla can disable your car and stop it from activating unless you do repairs at their approved dealership. You can't just buy parts from a scrapyard and get it running again, Tesla is the gatekeeper and they don't let anyone else hold the keys(they don't even release service manuals unless absolutely required by law). In contrast I could buy a brand new Mercedes CLS with its very respectable smart cruise control and Mercedes can't do anything to stop me from replacing the engine, the head unit, or fixing the whole thing if it's totalled - they just can't. It's not a freedom I'm willing to lose by buying a Tesla.

Re: Tesla Live Stream – Autonomy Day [video]

#158

Post by sangnoir »

gonehome wrote: post #129
sytelus wrote: post #123

Earlier quoted context omitted.

> Lidar is an unnecessary mistake that competitors are making This is very controversial and rest of the industry thinks exact opposite, many even claiming that Tesla is being irresponsible and even delusional in trying to do autonomy without lidar. The main points I have heard in favor of lidar are that computer vision is very flaky not only in suboptimal weather but even in good weather. Cameras are simply no where…

They pair it with a forward facing radar which is inexpensive and good at depth perception. Elon predicts all competitors will eventually drop lidar. He mentions it's expensive, but also not as good in a lot of cases (and all roads/signs are designed for vision). He argues that getting vision to work is a prerequisite for getting self-driving to work and once you have it working, lidar is worthless (and unnecessary).

Their forward facing radar has failed to avoid crashes into big, stationary objects (at least 2 semi trailers, a fire truck, and more). The explanation I got was that radar is rather noisy, so it's handy to filter-out stationary objects (like road signs, broken down vehicles on the shoulder, and fatally, any any semi trailer crossing your lane)

Re: Tesla Live Stream – Autonomy Day [video]

#159

Post by [deleted] »

danhak wrote: post #71
nikofeyn wrote: post #32

Earlier quoted context omitted.

how can you claim that? more than waymo? that would be extremely doubtful. google has been driving around cars with sensors and cameras for over a decade.

They have a fleet of hundreds of thousands of cars driving real-world miles all over the developed world.

[deleted]

Re: Tesla Live Stream – Autonomy Day [video]

#160

Post by toomuchtodo »

torpfactory wrote: post #150
sairahul82 wrote: post #114

Karpathy's presentation is really good. Watch it later if you get some time. The key points are - Telsa is using fleet for learning (Fleet learning). This has 3 components, a. Trigger infrasture that collects the kind of data telsa is looking for training. The rational here is we don't need massive amounts of same kind of data but needs right kind of data for training neural networks correctly. b. Data Engine which l…

Does anyone know how Lidar would work in the future when many other vehicles are also using lidar? From working with some different types of photo sensors (CCD, avalanche photodiodes, photomultiplier tubes), you might imagine that incident light from another car's emitter would be much brighter than the reflected light the lidar sensors are reading and cause saturation.

Phase lock or introducing jitter to laser timings. Check out Animats' comments on this topic, it's where I've learned from regarding this.
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