<R12> 72" x 72" Size Restriction

[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).

[Lil' Lavery]

Actually width and depth are clearly defined in most situations by <R07> (see chart on page 8 of Section 8). The width is your 28" dimension, and depth is your 38" dimension. Unless one of those dimensions is rotated in your starting configuration, I doubt it would be allowed to be rotated later.

[Coop]

i might be wrong, but that definition only is for the starting configuration of the robot. Look at this example. A robot expandes to the full 6x6 square. it has an arm that is in the bottom left corner and ends in the top right. how is that any different from making a square robot with that length arm and making it fit diagonally.
correct me if im wrong.
-coop, team 1717

[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.

[roboticshirt]

Originally Posted by Kingofl337

Outside the home zone the robot can expand to max of 72"l x 72"w and unlimited height. Do you think 72" this includes temporary expansion like and arm?

Where the arm might stick 4 or 5 feet outside the robot to place the top tube?

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"?

Originally Posted by BobC

But the question was "Where the arm might stick 4 or 5 feet outside the robot to place the top tube?"

38 inch robot plus 60 inch arm equals 98 inches which is more than 72 inches.

i really belive that the 72 in limit only applies to the footprint, that means that arms could extend farther.

[Coop]

Originally Posted by roboticshirt

i really belive that the 72 in limit only applies to the footprint, that means that arms could extend farther.

the arm cannot extend beyond the footprint. the footprint=a shadow of your robot straight below it.
-coop, team 1717

[Madison]

Originally Posted by Coop

the arm cannot extend beyond the footprint. the footprint=a shadow of your robot straight below it.
-coop, team 1717

...at noon, on the Equator.

Edit: On the solstice.

[Kevin Sevcik]

And the Q&A comes through. The answer is that the robot must fit inside a 72" x 72" x infinity virtual box at all times. So the diagonal trick works. I suppose still under question is whether it must be designed mechanically to never exceed the size, or whether it can be a driver/controls thing.

[Brandon Holley]

Originally Posted by Coop

the arm cannot extend beyond the footprint. the footprint=a shadow of your robot straight below it.
-coop, team 1717

Did I hear someone mention flux integrals ?! hehe

[Taylor]

Originally Posted by M. Krass

...at noon, on the Equator.

Edit: On the solstice.

We had to back out of the West Michigan Regional due to lack of $$ - now we're going to have to travel to the Equator?
FedEx ought to love that one.

[AdamHeard]

Originally Posted by Kevin Sevcik

And the Q&A comes through. The answer is that the robot must fit inside a 72" x 72" x infinity virtual box at all times. So the diagonal trick works. I suppose still under question is whether it must be designed mechanically to never exceed the size, or whether it can be a driver/controls thing.

Awesome.

They can't enforce a mechanical limit because of the home zone rule. Also, there are software limits. If the pots on an arm limit the movement to a legal range, it would be crazy for the inspectors to make the team fully expand it. If the inspectors ask my team that, i will state "Sir, we can't make our robot do that, it simply isn't possible with our software" or something along those lines.

[BobC]

Originally Posted by roboticshirt

i really belive that the 72 in limit only applies to the footprint, that means that arms could extend farther.

I think it means to make believe you are playing in a 72 x 72 square test tube. The test tube goes from the floor all the way to the ceiling of the arena.

[Stephen Kowski]

Originally Posted by GDC

The intent of Rule <R12> is that the robot must be able to fit within a 72" x 72" virtual box at all times. The orientation of the robot within the box is inconsequential.

I think we can put this thread to rest.

[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!!!