Google's self-driving car gathers almost 1 GB/sec • Hacker News Board

Re: Google's self-driving car gathers almost 1 GB/sec

#71

Post by Schwolop » Wed, May 01, 2013, 12:41 AM UTC

steve19 wrote: post #56

Game_Ender wrote: post #40

Earlier quoted context omitted.

That was an upper bound to show the absurdity of his non sourced "fact". The reality is much lower because the main sensor is the Velodyne, and it only produces 5-6MB/s. The primary focus of his picture is the Velodyne point cloud. Which he says is "1 GB per second" which is 100 times larger than it really is. I have worked on several fully autonomous vehicle projects based on Velodynes and their processing and loggi…

how well does the Velodyne work in heavy rain or snow?

It's also not officially water proof. That said, we used ours in light rain a few times and nothing bad happened to it. The data was pretty much useless however (although determining that was a large part of the point of the experiment).

Re: Google's self-driving car gathers almost 1 GB/sec

#72

Post by Schwolop » Wed, May 01, 2013, 12:44 AM UTC

grinich wrote: post #62

Game_Ender wrote: post #46

Earlier quoted context omitted.

As far as I know the "google maps" data is used for things like road locations, stop signs, and other traffic marker information. Their primary mapping data source is based on Velodyne data itself. You also have to think storage needs, would it really have 4-6TB storage array for just a few hour drive? I saw the tech lead of the project talk about 1.5 years ago. He said the primary sensor was the Velodyne, followed b…

Just because they're capturing it doesn't mean they're processing all of it immediately. This kind of data is great to keep around for simulations when you return home. Having ~10TB onboard storage isn't crazy.

From what I gather, they are capturing the velodyne data and turning it into a thinned point cloud of the areas of the USA in which they drive. Within this point cloud they can then do effectively a least-squares fit of the real-time view into the historical view and get another data source for localisation. Of course, there's GPS/IMU fusion too, but this sort of SLAM approach is fairly robust under GPS loss so combining them all in a filter is pretty standard practice. The scale of Google's data dwarfs most research projects, however.

Re: Google's self-driving car gathers almost 1 GB/sec

#73

Post by Samuel_Michon » Wed, May 01, 2013, 1:04 AM UTC

kyrra wrote: post #68

iharris wrote: post #3

There's a great presentation about Google's self-driving car here (check the second half for video of the real-time telemetry that it gathers): http://youtu.be/YXylqtEQ0tk One of the things that I found really interesting is how the car inches forward at a stop sign in order to show the "driver's" intent to other drivers. Lots of actions that seem to be second-nature for human drivers have to be carefully emulated he…

Thanks you for the link. It looks like the picture here is almost the same as what is shown in that video (from 1.5 years ago).

It is exactly the same. The picture on Twitter was the frame shown on 9:07 in the video. Given that the image is from a 1.5 year old promo video, which probably has been circulating all over, that puts the rest of the information in a new perspective as well.

Here’s a comparison I just put together: http://imgur.com/IfxYZL2

Re: Google's self-driving car gathers almost 1 GB/sec

#74

Post by Samuel_Michon » Wed, May 01, 2013, 1:37 AM UTC

Game_Ender wrote: post #23

He is off by an order of magnitude. The Velodyne 64 on that car only has a 100 Mbit connection [1]. Each of the 5-10 radars on that vehicle is connected over a 1MBit CAN bus [2]. The front facing is almost definitely a Gigi-E or Firewire camera so it's at most 1000MBit. Doing the math: 100 + 10*1 + 1000 = 1100MBit != 8192Mbit (1 GB) 1. http://velodynelidar.com/lidar/products/brochure/HDL-64E%20S... 2. http://www.kvas…

The picture Gross shared is a frame from a 1.5 year old promo[1], so he may also have misheard 1Gb for 1GB.

[1] http://imgur.com/IfxYZL2 – the bottom image is from this presentation: http://youtu.be/YXylqtEQ0tk

Re: Google's self-driving car gathers almost 1 GB/sec

#75

Post by dsl » Wed, May 01, 2013, 4:06 AM UTC

Game_Ender wrote: post #48

dsl wrote: post #26

Earlier quoted context omitted.

Having developed autonomous vehicles in a previous career, I can tell you that raw sensor data is far less useful than you think. By the time you are starting to hand over controls to the system itself you are pretty damn confident that your pipeline up to the control logic is all very solid. Also, i'm not entirely sure what you think the costs involved in a test are? We purchased about 20 acres of land for a test tr…

The true data rates (see my other posts) are most likely around 5-10 MB/s. Which is so low the benefits out weigh the costs. After all, what if their is an issue with the software? How are you going to reproduce without the logs, especially on a R&D system like Google has (yes it's still R&D, they can't even drive in the rain).

Your "true data rate" is completely wrong. You have no idea at what frequency they are converting analog to digital signals. You don't know for sure they are using off the shelf sensors. Your ignoring data sources in your calculations like OBD from the ECU or even GPS and AGPS data. etc etc.

Re: Google's self-driving car gathers almost 1 GB/sec

#76

Post by georgecmu » Wed, May 01, 2013, 4:19 AM UTC

Game_Ender wrote: post #23

He is off by an order of magnitude. The Velodyne 64 on that car only has a 100 Mbit connection [1]. Each of the 5-10 radars on that vehicle is connected over a 1MBit CAN bus [2]. The front facing is almost definitely a Gigi-E or Firewire camera so it's at most 1000MBit. Doing the math: 100 + 10*1 + 1000 = 1100MBit != 8192Mbit (1 GB) 1. http://velodynelidar.com/lidar/products/brochure/HDL-64E%20S... 2. http://www.kvas…

You are making an unwarranted assumption that they are logging the raw Velodyne data. Most likely that is not the case. Pointcloud data computed from raw Velodyne data can easily require an order of magnitude more space.

That said, this guy may be more than an order of magnitude off (confused MB and GB?). If 1GB/sec figure is correct, then they'd fill up a 10TB NAS in 3 hours. Forget about network throughput, how much storage do they carry in the back of that vehicle?

Re: Google's self-driving car gathers almost 1 GB/sec

#77

Post by netrus » Wed, May 01, 2013, 6:29 AM UTC

steve19 wrote: post #56

Game_Ender wrote: post #40

Earlier quoted context omitted.

That was an upper bound to show the absurdity of his non sourced "fact". The reality is much lower because the main sensor is the Velodyne, and it only produces 5-6MB/s. The primary focus of his picture is the Velodyne point cloud. Which he says is "1 GB per second" which is 100 times larger than it really is. I have worked on several fully autonomous vehicle projects based on Velodynes and their processing and loggi…

how well does the Velodyne work in heavy rain or snow?

Wow, never thought about that in the Google Car context. To be fair, I dislike driving in heavy rain myself, and most people drive much slower in such conditions. Still, that might be more of an issue in rainy Hamburg compared to the Bay Area ...