FRC 1444 - 2016 Reveal

[catacon]

Originally Posted by Street_dreamZ

Looks great, love the shooter! It looks like it articulates to a fixed position, is that correct? How does that mechanism work? Also, it looks to me like your breaker isn't the most accessible, you might want to think of other places to put it in case the inspectors don't like it there.

I wish you the best of luck in building your climbing mechanism and the with the rest of the season!

Thanks!

The shooter does move to a fixed up position which can be adjusted between matches if necessary (I don't see us ever doing that, though). Basically, the shooter has two pieces that form a smooth, quarter-ring for the ball to roll on. The pivot motor for top of the shooter (with the wheels) is able to rotate 90 degrees in its mount. This rotation opens/closes the latch which allows the shooter to pivot up and down.

Here's a render of the mechanism: http://i.imgur.com/wV21jDP.jpg

Originally Posted by Jaci

That is some nice looking vision tracking. Care to give any insight about it?

We are using a PS3 Eye camera with a 12-RGBLED ring and running OpenCV on an ODROID. We do some thresholding to find green blobs and then look for corners. Since we know the dimensions of the target we can get the transform from the camera to the target using the eight corner points (highlighted in the video). We then find the angle (yaw) between a vector straight out of the shooter and a vector from the shooter center to the target center. The magnitude of the second vector is the distance to the target which also determines the shooter wheel speed.

The big tricks are setting the exposure correctly to minimize ambient light and finding the transform. Once you have the transform, you can do any sort of vector math you'd like to determine position on the field, etc.