<R12> 72" x 72" Size Restriction

[Kevin Sevcik]

It almost certainly means anything for any amount of time. What should really get you thinking is if it only means you should be able to fit your robot inside a 72" x 72" area at all times, or if there are some sort of defined x-y axes on your robot that fix the orientation of the square.

That is to say, if you only have a pole sticking out the front of your robot, can you assume the pole is extended along a diagonal of that square and is limited to something like 90"? Or do the edges of the square have to be parallel to the sides of your robot and you're limited to 72"?

[Gboehm]

Does this also apply for the endgame?

[Jeremiah Johnson]

Originally Posted by Gboehm

Does this also apply for the endgame?

It doesn't apply if you're in the home zone. You can have a length as wide as the playing feild as long as you stay inside the playing feild.

[jdejoannis]

Originally Posted by Kevin Sevcik

It almost certainly means anything for any amount of time. What should really get you thinking is if it only means you should be able to fit your robot inside a 72" x 72" area at all times, or if there are some sort of defined x-y axes on your robot that fix the orientation of the square.

That is to say, if you only have a pole sticking out the front of your robot, can you assume the pole is extended along a diagonal of that square and is limited to something like 90"? Or do the edges of the square have to be parallel to the sides of your robot and you're limited to 72"?

The first one is likely to be the correct reading of the rule. Imagine a referee checking the robot with a 6x6 foot frame - orienting it as needed to fit everything in. The words "length" and "width" would simply refer to arbitrarily oriented Cartesian coord axes.

[jgannon]

I've been doing a little trig, and a little Paint.

The square is the bounding box, the rectangle is the robot. The diagonal of the box is 72√2, the length of the robot is 38, and the wasted part of the diagonal in the lower left is 14. As such, I calculate that an object of negligible width can protrude (72√2)-38-14 = 49.8 inches from the front of a standard size robot. Is this consistent with our current interpretation? Does this make sense in the spirit of the rule?

[BillP]

Originally Posted by jgannon

As such, I calculate that an object of negligible width can protrude (72√2)-38-14 = 49.8 inches from the front of a standard size robot. Is this consistent with our current interpretation? Does this make sense in the spirit of the rule?

No, this is NOT within the spirit of the rule as I understand it. The robot in your drawing clearly has a length (front to back) in excess of 72 inches. However, with the current wording of the rule, it would be OK if your robot was round because the "front" of the robot would be poorly defined.

It will be interesting to see how this is handled in the updates and the Q&A. It won't be officially answered anywhere else.

(PS, Good to see ya again Joey!)

[Tristan Lall]

Originally Posted by BillP

No, this is NOT within the spirit of the rule as I understand it. The robot in your drawing clearly has a length (front to back) in excess of 72 inches. However, with the current wording of the rule, it would be OK if your robot was round because the "front" of the robot would be poorly defined.

I don't think that we can define the length of a robot in any manner other than the bounding box approach above. Though many robots do have a preferred direction of travel (which might be assumed to be the length axis, with the width axis perpendicular to it), there are numerous robots where no one axis is inarguably the length—the omnidirectional drivetrains, for example. Similarly, the bounding box model is what's used to check the robot footprint at inspection. A robot can do what it pleases within the box, but it has to fit.

While we're on the subject, front and back are not especially meaningful, except that to comply with the rules, teams will arbitrarily designate them (e.g. to place the diagnostic light).

[MrForbes]

Originally Posted by jgannon

The square is the bounding box, the rectangle is the robot. The diagonal of the box is 72√2, the length of the robot is 38, and the wasted part of the diagonal in the lower left is 14. As such, I calculate that an object of negligible width can protrude (72√2)-38-14 = 49.8 inches from the front of a standard size robot. Is this consistent with our current interpretation? Does this make sense in the spirit of the rule?

that reminds me of the joke about the boy with the fishing pole trying to get on the bus. The bus driver said his five foot fishing pole was too long, you can only have something four feet long on the bus. So, the boy visited the garbage cans behind some stores and found a 3 foot by 4 foot box and put the fishing pole in it, and was let on the bus.

[Guy Davidson]

Originally Posted by jgannon

I've been doing a little trig, and a little Paint.

The square is the bounding box, the rectangle is the robot. The diagonal of the box is 72√2, the length of the robot is 38, and the wasted part of the diagonal in the lower left is 14. As such, I calculate that an object of negligible width can protrude (72√2)-38-14 = 49.8 inches from the front of a standard size robot. Is this consistent with our current interpretation? Does this make sense in the spirit of the rule?

I checked your math and you got it right. Then I considered the second case, in which the long side of the robot is perpendicular, rather than parallel, to the diagonal we're considering the arm to come out on. I did the math for that, and it seems that if your arm is coming out of the center of the wider side, its maximum length is actually 54.82", a gain of about 5". Maybe this helps someone.

-Guy

[Scott358]

I think the max arm length will be based upon those who have a turret and can position the robot in a corner of the 72" square, and extend the arm to the opposite diagnal corner.

The issue then becomes interesting when the turret rotates, but that will be for our programmer to figure out!!!

[Cyberguy34000]

oooh crap....


There goes our arm design! I feel really bad because it's my job to be up to date on the rules and I assumed that this rule didn't apply to arm extensions. oooooh. We were finishing the CAD and making parts too. It's going to be a looong weekend as we rethink the arm design.

crap crap crap crap crap

-Chris

[Don Wright]

FYI...this includes bumpers too...

http://forums.usfirst.org/showthread.php?t=1476