Re: We Want Pictures and Videos of Your Boulders
 

Here are our pictures (be warned there are a lot of them). Enjoy!
https://drive.google.com/open?id=0B6...DZmVVlrSWRUeWs

Re: We Want Pictures and Videos of Your Boulders
 

Best pictures yet!!!

Re: We Want Pictures and Videos of Your Boulders
 

We actually don't consider it "a lot" until you get into the 7 digits range ;) - but we do appreciate these and will check them out.

Re: We Want Pictures and Videos of Your Boulders
 

Guess we need to take some more then. Be right back.

Re: We Want Pictures and Videos of Your Boulders
 

I wanted to let you know that AndyMark might have sent you one of the rare invisible boulders. Our vision code seems to be pretty good at finding where these balls are hiding. See the one labelled "7" in the upper right corner of this image. You'll want to do your best not to lose it - I'm sure they'll be valuable some day.

Thanks again for the pics, they have honestly been quite helpful for testing.

Attachment 20019

Re: We Want Pictures and Videos of Your Boulders
 

Thank you we are extremely proud of that boulder, gives us a little more sensation during practice :cool:

Re: We Want Pictures and Videos of Your Boulders
 

Just in case anyone thought we were joking about this. It's finally been merged into our code and we are aiming to put this on a robot before too long:



The white paper should be coming soon too. :)

I'm super proud of my students who have been doing this research. They are some of the smartest people I know.

Re: We Want Pictures and Videos of Your Boulders
 

Can't wait to see it at the Rumble in the Roads.

Re: We Want Pictures and Videos of Your Boulders
 

We only have 2 of them- those things are expensive (though this is FRC we're talking about, so maybe not comparatively). One is pretty new and the other got caught up on a nail in a wooden prototype so it's all ripped. Oh, and also we played soccer outside with the ripped boulder.

Re: We Want Pictures and Videos of Your Boulders
 

Alright... it took us a year to get this working but it finally works:

https://youtu.be/OT5FHyLBjCg
https://youtu.be/eRMo1_hJNa0

That's a video of our robot from 2016 using a neural network based vision system to detect and pick up a game piece by itself (NO DRIVER INTERACTION) from the 2016 game FIRST Stronghold.

And contrary to what some teams are saying about the Nvidia TX1... we love it and we are using it and a Stereolabs ZED camera to detect the boulder and then send data back via ZeroMQ to a a National Instruments RoboRIO running LabVIEW along with a KauaiLabs NavX MXP IMU board to orient the robot, drive towards, and grab the ball.

So to all of you who thought we were joking when we were asking for pictures. We weren't. This is what we've done with them.

Also, check out this awesome custom case for our TX1:


Files for reproduction of the case are available here:
https://workbench.grabcad.com/workbe...vJsPGiurrAmGW7

EDIT: Code is available on our Github... it's been out there for a while though.

Re: We Want Pictures and Videos of Your Boulders
 

Wow! I'm looking forward to reading through the code. Is this something you would consider this season if the opportunity arises? How reliable is it? Can it follow moving game pieces (I noticed you waited for it to stop rolling in the video)? What are the benefits of this over using two infrared sensors, putting them on either side of the robot, and using the difference in distances to align the robot.*


*FRC272 used this method in 2010 to allign with the soccer balls. They wrote about their experience with this method in a powerpoint they used for a seminar last year here. The video isn't working, but I know this solution worked well for them.

Re: We Want Pictures and Videos of Your Boulders
 

Yes.

Ehh... not as much as we would like but it finally works on the robot and that's impressive.

Yes. https://www.youtube.com/watch?v=v9gof9Rafks

In theory, this has the ability to be more reliable and the ability to select different arbitrary targets. Unlike IR, it's not just looking for the presence of something... it's actually looking for the ball (the shape/color/ and whatever else the neural network has decided to focus on).

With all that said. If you're thinking about doing this yourself then understand that there is a ton of work that has gone into it and a ton more will go into it before it is reliable. This isn't something a potential championship winning team should be relying on to establish dominance for a match. It's untested, unreliable, and fragile.... it's still really frickin' cool though.

Re: We Want Pictures and Videos of Your Boulders
 

Cool! This is AFAIK the first working NN implemented on an FRC robot.

Have you tried comparing your NN approach to a more traditional model-based vision approach?

With a single camera I'd suggest trying the Hough circle transform on an intensity or edge image. If you assume that balls are sitting on the ground plane and your camera is at a fixed height and angle, you can constrain the range of radii that you need to consider.

With a stereo/depth camera rig you can do even better; estimate and remove points near the floor plane, and then look only at the points that remain and cluster into spheres (using a 3D template matching algorithm or Hough sphere transform, only now scale is entirely fixed).

(C)NNs are awesome technology and are quickly become ubiquitous in computer vision (and if only for this reason alone, they are a worthwhile learning exercise for your team!) They excel at solving hard detection and classification problems where humans don't have good intuition about how to specify useful visual features and the relationships between them. But for tracking a roughly monochromatic sphere on a level surface, I'd wager that human intuition is pretty good.

Re: We Want Pictures and Videos of Your Boulders
 

Another 900 mentor here (snow's coming so no one cares about work@work today).

For various definitions of working, but yeah we're really excited about it. Glad other people appreciate it.

A little bit, but this was one of those things where we thought it might be interesting to play with. The initial experiments worked way better than expected so we ran with it rather than prototyping a bunch of approaches.

Marshall - remember "robot maintains fixed height and angle throughout the match" for one of our design goals this time around. I know that takes all the fun out if it :)

More seriously, we do incorporate some of the scale-limiting ideas you mention to speed up our code. It is still CNNs doing the bulk of the work, though.

We kinda knew this was ambitious, potentially to the point of [hopefully spectacular] failure. Which kinda sums up what the team does every year.

I like to think the students who worked on the various parts got a lot out of it. Plus it works, so bonus.

We haven't spent a ton of time on comparable approaches. 2015 we had a cascade classifier working tracking recycling bins - but that's a similar amount of work as the CNN approach but with more drawbacks. Those LBP cascades were quicker at run time, though.

We spent a bit of time with meanshift and camshift and didn't have much luck.

Some of the non-intuitive things we found about the problem :

1. the balls are reflective, so they pick up the color of field lighting pretty easily. People can easily determine that they're gray despite this. Computers have a tougher time.
2. they are sorta monochromatic, except for the random white markings on them depending on the ball's rotation plus what I mentioned above. Plus shadows and whatever. Typical computer vision problems.
3. There's lots of gray stuff on the field in addition to the balls.

None of these are insurmountable. But we only had so many people to throw at the problem, which goes back to the point that the CNNs worked way better than expected pretty quickly.