22-02-2012 01:36

jblay

Re: pic: Team 341 presents Miss Daisy XI

Looks like another awesome miss daisy machine. That intake system is really cool and I look forward to seeing it in action. From the videos I have seen of competition and the practice we have done, it is becoming clear how difficult picking up the balls is going to be and your intake system looks like it has more than solved that issue.

22-02-2012 04:52

rcmolloy

Re: pic: Team 341 presents Miss Daisy XI

This is definitely a Daisy machine. I'm sure that come Championships, Jared and the team should be seasoned in and ready to what they wanted to achieve last year to really happen. Really impressive and can't wait to see it in action soon. Good luck and see you at Champs!

22-02-2012 05:10

Hawiian Cadder

Re: pic: Team 341 presents Miss Daisy XI

Wow, that COG is impressive, This looks like an awesome robot, cant wait to see it in action.

22-02-2012 06:57

Andrew Schreiber

Re: pic: Team 341 presents Miss Daisy XI

Daisy makes extrusion look sexy. Can't wait to see Miss Daisy XI at MAR. It's been a pleasure to watch her come together, can't wait to watch her run.

Best of luck Daisy!

22-02-2012 07:10

Mr MOE

Re: pic: Team 341 presents Miss Daisy XI

Great-looking bot! Can't wait to see it in action at the MAR disctrict events. See you all at Chestnut Hill!

22-02-2012 07:22

nlknauss

Re: pic: Team 341 presents Miss Daisy XI

Great robot Team 341! I really love the intake system on the robot, very unique and cool. See you at Chestnut Hill!

22-02-2012 11:00

lynca

Re: pic: Team 341 presents Miss Daisy XI

This frame rate is very impressive.

1. What camera are you using ?

2. What are the specs of your laptop ?

3. How do you transfer information between a laptop and cRio?

4. Do you have a openCV backboard tracking example available?

22-02-2012 11:57

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

1. The Axis M1011 camera. This does limit us to 30 frames per second when operating on the robot (at 640x480 resolution), but the code itself has been shown to process upwards of 200 frames per second when streaming images from disk. In actuality, 30 frames per second is more than enough since we are actually using the gyro for doing our feedback control anyhow. At 30FPS we utilize about 15% of our CPU.

2. It's a Core i5 with 6GB of RAM.

3. Camera data goes robot -> laptop through the wireless link to the Driver Station. Computed outputs go back through the link to the cRIO using WPI Network Tables.

4. I'll post our full code after the competition season has begun. For achieving basic throughput between camera, laptop, and cRIO, you can use the example square tracker that comes with the SmartDashboard installer. Here is our basic algorithm:

1. Convert image to HSV color space
2. Perform thresholding in HSV (enforce minimum and maximum hue, minimum saturation, minimum value)
3. Find contours
4. Take convex hull of contours (this is the step that helps ensure that partial obscuration from the rim/basket doesn't kill us)
5. Perform polygon fitting to contours
6. Filter polygons based on (a) number of vertices, (b) aspect ratio, (c) angles of horizontal and vertical lines.
7. Select highest remaining polygon as the top target.
8. Compute angle from camera center to target center and add this to the current robot heading
9. Command the new heading to the robot (it uses gyro and encoders to achieve this heading)
10. Compute range based on trigonometry comparing center of camera axis to center of target height
11. Command shooter RPM setpoint based on linear interpolation of a lookup table

The code has been very carefully optimized to reduce the allocation/deallocation of dynamic memory between subsequent calls, which is what lets us operate at breakneck speed. This also involved a lot of debugging to hunt down latent memory leaks existing somewhere in the layering of OpenCV/JavaCV/WPIJavaCV APIs.

22-02-2012 12:26

JamesTerm

Re: pic: Team 341 presents Miss Daisy XI

How did you solve the potential networking issues and latency? Do you have some interpolation for delayed frames? Do you have timestamps on the frames to know how long they took to trasmit... when you computed your position, and transmit this back to the robot does it take into account the latency on this end. How did you work around or simulate the FMS locked stress, and did you test against a typical network traffic of a match.

All of these questions scared me away from this kind of solution. I hope you have some good answers for them.

I guess you can always set still for a few seconds and that should solve that.

22-02-2012 12:48

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

The short answer is that if we discover network latency/dropout to be a significant problem, we will move our image processing application to an onboard laptop. Failing that, our next fallback is to reduce resolution and/or framerate. To be frank, we auto target just fine at 5 fps (because the gyro loop is closed at 200Hz); we do 30 because we can

However, I do not expect this to be a major concern. In past seasons, teams have streamed live camera data directly to their dashboards with few problems. The only difference is now we are cutting out the cRIO altogether. While we haven't run simulations against an "FRC network simulator" (but if you know of a tool that could be used for this purpose I would be interested in trying it), in theory there is PLENTY of bandwidth to go around. With reasonable compression settings these images are only on the order of 10-20 kilobytes a piece.

We don't timestamp the images, but we do transmit our heading synchronously with new camera images being available. That way, the results returned by the vision application do not go "out of date" if they are received late. Out of order packets would be a bigger problem (it's UDP under the hood). But absolute worst case - like you said - this would be a transient problem and would straighten itself out within a second or two.

EDIT: Forgot to add, we also do low pass filtering of both outputs from the vision system to help smoothness (and to reject momentary disturbances like when we occlude the vision target with a flying basketball ). This should help with occasional frame drops as well.

22-02-2012 13:02

team222badbrad

Re: pic: Team 341 presents Miss Daisy XI

Clean looking machine!

It's nice to see another robot with a wide pickup! :-)

See you at Chestnut Hill!

22-02-2012 14:21

waialua359

Re: pic: Team 341 presents Miss Daisy XI

Nice job there Jared and Al!

22-02-2012 14:40

Lil' Lavery

Re: pic: Team 341 presents Miss Daisy XI

Awesome. Can't wait to play with 341 at Hatboro-Horsham. I'd volunteer to use your opposite-loader, but I'm thinking we want to shoot our balls in auto.

22-02-2012 15:06

ebarker

Re: pic: Team 341 presents Miss Daisy XI

What part number did you use for the optical photosensor / tachometer ?

Ed

22-02-2012 15:08

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

It is the Allen Bradley 42EF-D1MNAK-A2 from last years' Kit of Parts.

22-02-2012 19:06

BJC

Re: pic: Team 341 presents Miss Daisy XI

I know why. Nice looking robot.

23-02-2012 08:15

lynca

Re: pic: Team 341 presents Miss Daisy XI

Thank you Jared and Team 341, do you have an upclose picture of your shooter and encoder setup ?

23-02-2012 08:27

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

Here is a closeup of the shooter.

The sensor is on the left side of the picture, and two retroreflectors are mounted 180 degrees apart on one of the shooter wheels.

23-02-2012 11:09

Daniel_LaFleur

Re: pic: Team 341 presents Miss Daisy XI

Wonderful bot.

A couple of questions:
1> when your manipulator flips out it looks like it breaks the front plane of the bot in more than 1 location. Are you concerned that it might be ruled 2 appendeges?
2> when your manipulator is deployed it appears to obscure your numbers. Is that just the angle of the picture?

Otherwise, the bot looks gorgeous.

23-02-2012 14:26

Joe Ross

Re: pic: Team 341 presents Miss Daisy XI

I'm not sure why that would be a problem

23-02-2012 14:33

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

The entire thing is articulated as a single assembly. It is difficult to see from the photo, but there is a reinforcement bar all the way across the width of the bot right at the point where we cross the frame perimeter (on top of the bumper). We momentarily break the plane in two separate places during the act of deployment, but that has been explicitly allowed via Q&A and Team Updates.

As for numbers: from a full frontal view, you can actually read them just fine when your intake is deployed. The intake is mostly air

23-02-2012 15:40

JesseK

Re: pic: Team 341 presents Miss Daisy XI

I do too. I wonder if penalties will factor in, because with such a wide intake you know they'll gain control of more than 3 balls if 4, 6, 8 (etc) balls exist at the ... errm, wrong ... spot. Of course, with the right timing that won't matter. There are other indirect fringe benefits to such a strategy too. (We might have the same issue...)

Can't wait to see this bot in action!

23-02-2012 17:00

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

The intake naturally self-limits to 3 (at a time) when gathering from a bridge.

08-05-2012 21:23

JeremyLansing

Re: pic: Team 341 presents Miss Daisy XI

Sorry for the thread resurrection, but I was wondering what the flat belting material you guys used for your intake and elevator was. It looked similar to the flat urethane belting here:

http://www.mcmaster.com/#urethane-flat-belts/=hg9xsd

We are looking to build an intake and elevator in the offseason, and we were curious what it was and how it worked for you. We used the round urethane belting from McMaster this year, but we had a lot of problems with it walking across the pulleys, it looks like you didn't have to use anything to keep the belt in place. Thanks!

08-05-2012 22:16

OZ_341

Re: pic: Team 341 presents Miss Daisy XI

McMaster #6075K15 is the belt we used.
It was awesome and reliable. Very little, if any stretching. No failures and tracking was simple. Just build up a crown of electrical tape under the belt and it naturally centers.
We did have to experiment with various ways of welding the belts. But that was also not too bad to figure out. This belting was just right for this application.

08-05-2012 23:31

Yankeefan181

Re: pic: Team 341 presents Miss Daisy XI

I just wanted to say, this robot should be an inspiration to teams everywhere. It was not built by professional engineers, and it wasn't machined to pieces. However, it was still one of (if not the) best robots in the country. Congratulations Miss Daisy, you are truly a role model team and very well-deserving of your Hall of Fame title.

08-05-2012 23:34

Andrew Schreiber

Re: pic: Team 341 presents Miss Daisy XI

To quote Jared, "every part of that bot was precision machined... to within 1/16th of an inch"

08-05-2012 23:40

dodar

Re: pic: Team 341 presents Miss Daisy XI

Machined? I thought Miss Daisy grew all their robots...

09-05-2012 08:49

Jared Russell

Re: pic: Team 341 presents Miss Daisy XI

There was definitely some precision work that went into this robot (the shooter side plates and guide rails were laser cut Delrin, as were the bearing retainers in the drive and a few motor mounting plates throughout the machine. The belly pan was waterjet by a sponsor). Our engineers (all four of us!) worked side by side with our students on every aspect of design and construction of the robot.

But for the most part, our robot is one that 90%+ of FRC teams could have built (though our heavy reliance on COTS parts such as gearboxes and wheels generally pushes our bot towards the upper end of the allowable total cost). Except for the parts I noted above, all of our machining and construction was conducted in our build space, which is pretty low tech (a small low cost mill and 3-in-1 lathe plus wood shop tools).

Our design approach this year was simple: Build the simplest possible machine that could execute our desired game strategy (3+ ball hybrid, effective key shooting in teleop, and triple balancing), add in some killer software, and never stop improving/iterating.

09-05-2012 10:06

Nick Lawrence

Re: pic: Team 341 presents Miss Daisy XI

Gee, I wonder where this came from Jared.

Congratulations on an amazing season. I can only dream of having such a dominating performance all season long.

It was cool to watch this robot evolve from the start.

-Nick

09-05-2012 16:41

JeremyLansing

Re: pic: Team 341 presents Miss Daisy XI

Awesome, well it sounds like we know what we will be using. We had quite a few issues this year with the round urethane belting rolling around and jamming our pickup and this sounds like exactly what we need, can't wait to get some to test.