View Full Version : <R12> 72" x 72" Size Restriction
Kingofl337
09-01-2007, 22:37
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?
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?
Im not exactly sure i believe it does include it, but i would e-mail first and as for sure, if you find out please share.
Kevin Sevcik
09-01-2007, 22:45
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"?
Does this also apply for the endgame?
Jeremiah Johnson
09-01-2007, 23:44
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.
Joobacca
10-01-2007, 01:17
Do you think 72" this includes temporary expansion like and arm?
You DO realize that 72 inches is equivalent to 6 feet. Does that answer your question?
:rolleyes:
You DO realize that 72 inches is equivalent to 6 feet. Does that answer your question?
:rolleyes:
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.
Wayne Doenges
10-01-2007, 07:07
Last year you could not extend higher than 5'. If you had a 4' 6" bot that had a door on top that was 1' long and it rotated past the 5' limit when opening you would be penalized.
This year I see a 72" L x 72" W x infinite high box and if you extend out of this box you will be penalized. Even if it's only for a moment.
Just my $.02 :) YMMV
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.
R12 is very clear. They define a "Box" 72"x72" of which the diagonal is more than 101"
But, if the arm swings out of the box, you risk being panelized. I don't know if this will be an inspection item this year. The sizing is already complicated with the different classes. The Refs may have a way of measuring on the field.
Try designing a round robot using omni wheels. It will be very hard to define the width and depth axis.
Kingofl337
10-01-2007, 09:36
I guess the big problem is with and arm while its lifting a ringer from the ground robot will normaly break that 72" plane for a brief amount of time and then return to within the 72" rule. To stay within the rule your arm would have to retract the arm back in towards the robot before extending out again. I think the intention of the rule is to stop huge robots roaming around the field and not to limit arm design. But, thats question I'm trying to find out. :)
Brandon Holley
10-01-2007, 09:54
I honestly cannot wait to see the refs out there with tape measures trying to see what the invisble 72" box is, and when a robot extends out of it. Honestly this seems quite difficult to enforce if what were talking about is the correct interpretation.
MrForbes
10-01-2007, 10:05
I guess the big problem is with and arm while its lifting a ringer from the ground robot will normaly break that 72" plane for a brief amount of time and then return to within the 72" rule.
If the arm is built so that it's pivoting mount is at one end of the robot, and the arm is less than 72" long fully extended, you'll be ok. Consider making the arm so that it only can pivot up and down, it cannot swing sideways (or not very far sideways). A 66" long (total extended length) arm/hand mounted on a 56" high mast at the "back" of a robot, would be able to reach the floor and also score high ringers, I think. Make some sketches, see how the geometry works. There seems to me to be no need to make the robot extend further than 72" in length/width to perform it's task.
Richard Wallace
10-01-2007, 10:12
I honestly cannot wait to see the refs out there with tape measures trying to see what the invisble 72" box is, and when a robot extends out of it. Honestly this seems quite difficult to enforce if what were talking about is the correct interpretation.I can seen Robot Inspectors doing exactly that, before your robot ever gets to the field. An extra long arm is a potential safety hazard to people near the field boundary, such as referees, emcees, announcers, field resetters, etc. To protect those people, the Lead Robot Inspector has discretion under <R112> to keep any robot off the field, even for practice, until it has been brought into compliance with the rules.
Brandon Holley
10-01-2007, 10:51
I can seen Robot Inspectors doing exactly that, before your robot ever gets to the field. An extra long arm is a potential safety hazard to people near the field boundary, such as referees, emcees, announcers, field resetters, etc. To protect those people, the Lead Robot Inspector has discretion under <R112> to keep any robot off the field, even for practice, until it has been brought into compliance with the rules.
I also can see this, but there are many different orientations of robots. This also severely limits the types of arms you can make, articulation will require some thorough calculations.
The rules are simple. Your robot may, during normal play, not exceed 72" X 72". Use your GP, stay within the confines of the rules, don't try to bend or break these rules and everything will be fine. Yes, some rules make the game hard - that's the point! With each limitation comes a new challenge, another opportunity to show off your team's ingenuity.
Personally, I would hope that refs would never have to whip out their 72-inch measuring sticks - if the robots are designed respectfully within the given boundaries, there won't be any problems.
AcesPease
10-01-2007, 11:00
The 72" rule is not an unreasonable restriction and may help you to a more stable arm design.
Kevin Sevcik
10-01-2007, 11:10
The rules are simple. Your robot may, during normal play, not exceed 72" X 72". Use your GP, stay within the confines of the rules, don't try to bend or break these rules and everything will be fine. Yes, some rules make the game hard - that's the point! With each limitation comes a new challenge, another opportunity to show off your team's ingenuity.
Personally, I would hope that refs would never have to whip out their 72-inch measuring sticks - if the robots are designed respectfully within the given boundaries, there won't be any problems.
Again, my only question is if it's a 72"x72" box you have to fit in, or if you paste something on your robot that says "72" this way, and 72" that way."
Richard Wallace
10-01-2007, 11:19
Again, my only question is if it's a 72"x72" box you have to fit in, or if you paste something on your robot that says "72" this way, and 72" that way."I expect the inpsection checklist will have a line item corresponding to <R12>. The test will probably be to place the arm or extension so that it is at its maximum reach, then verify that the robot still fits within the 72" wide x 72" deep limit. Of course, passing this test will not ensure that an arm is legal. Safety is always the paramount concern, and <R03> clearly says that an otherwise-legal device on a robot can be disallowed if, in the judgement of the inpsectors or referees, it poses a hazard.
Brandon Holley
10-01-2007, 11:30
i think this rule is good, arms could get out of control...but then again this is FIRST :-P
Kevin Sevcik
10-01-2007, 11:33
I expect the inpsection checklist will have a line item corresponding to <R12>. The test will probably be to place the arm or extension so that it is at its maximum reach, then verify that the robot still fits within the 72" wide x 72" deep limit. Of course, passing this test will not ensure that an arm is legal. Safety is always the paramount concern, and <R03> clearly says that an otherwise-legal device on a robot can be disallowed if, in the judgement of the inpsectors or referees, it poses a hazard.
I would surmise as much, but I'm going to ask the question anyways. I've seen enough official interpretations counter to my instincts that I feel safer just checking.
Richard Wallace
10-01-2007, 11:37
i think this rule is good, arms could get out of control...but then again this is FIRST :-PUhh, yeah. I was one of numerous volunteers to get inadvertently whacked by a tetra in 2005, while standing near the edge of the field. I recall seeing video somewhere of another volunteer actually getting capped, and something similar happened to a robot operator when an arm reached over the end wall and dropped one.
FIRST will continue searching for rules and procedures to keep us from hurting ourselves. However, none of this will substitute for judicious application of common sense.
Brandon Holley
10-01-2007, 11:40
FIRST will continue searching for rules and procedures to keep us from hurting ourselves. However, none of this will substitute for judicious application of common sense.
without a doubt
Pat Fairbank
10-01-2007, 11:52
The test will probably be to place the arm or extension so that it is at its maximum reach, then verify that the robot still fits within the 72" wide x 72" deep limit.I don't think this kind of test would work. The rule states that "a ROBOT may expand up to a maximum width of 72 inches and depth of 72 inches", not that the robot must fit within such a limit at maximum extension.
If a team were to design a robot with an arm that was mechanically capable of exceeding the limit, but either programatically limited the horizontal extension of the arm or trained their operators to always stay within the limit, it wouldn't appear to be a violation of <R12>.
I don't think this kind of test would work. The rule states that "a ROBOT may expand up to a maximum width of 72 inches and depth of 72 inches", not that the robot must fit within such a limit at maximum extension.
If a team were to design a robot with an arm that was mechanically capable of exceeding the limit, but either programatically limited the horizontal extension of the arm or trained their operators to always stay within the limit, it wouldn't appear to be a violation of <R12>.
This sort of litmus test cannot work this season, as the rules explicitly state that robots are permitted to extended beyond this limit while in their home zone. It's entirely likely that many robots will have mechanisms that extend beyond 72", possibly even serving multiple functions, and that there's no comprehensive or accurate way of determining -- on or off the field -- whether this rule has been violated.
jdejoannis
10-01-2007, 15:19
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.
I've been doing a little trig, and a little Paint.
http://img19.imageshack.us/img19/7293/geogo6.gif
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?
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!)
That whole line was super confusing . As far as I understand we can only transform in width and length in the home zone but when we're out on the field we can go as high as we want within the restriction of the cieling. Is that what everyone else got?
Lil' Lavery
10-01-2007, 16:38
That whole line was super confusing . As far as I understand we can only transform in width and length in the home zone but when we're out on the field we can go as high as we want within the restriction of the cieling. Is that what everyone else got?
When in the home zone, you are allowed to expand as large as you want (provided you are still entirely in the home zone). When outside of your home zone, you may expand to a maximum of 72" "width" x 72" "depth".
Kevin Sevcik
10-01-2007, 16:51
I'm leaning toward jgannon's interpretation. I've already posted the question to the Q&A, so we'll see what the official word is.
I'm for jgannon's interpretation because BillP's reading means that the front and back of the robot is arbitrarily defined by someone other than the team. In that case specifically to the team's disadvantage. At the very least, the team should be able to decide which way is what. Saying that it would be okay on a round robot is just semantics and silliness. What if I have slightly bowed out plexi on all sides of my robot? There's no flat surface to attach the axes to there either.
Tristan Lall
10-01-2007, 16:56
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
10-01-2007, 16:57
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.
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
10-01-2007, 19:43
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
10-01-2007, 19:54
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?
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"?
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.
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
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. :p
Kevin Sevcik
12-01-2007, 13:43
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
12-01-2007, 13:58
:yikes: :yikes: 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
...at noon, on the Equator. ;)
Edit: On the solstice. :p
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
12-01-2007, 15:13
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.
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
14-01-2007, 18:04
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
14-01-2007, 22:06
I've been doing a little trig, and a little Paint.
http://img19.imageshack.us/img19/7293/geogo6.gif
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
16-01-2007, 23:29
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
19-01-2007, 00:32
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
19-01-2007, 07:08
FYI...this includes bumpers too...
http://forums.usfirst.org/showthread.php?t=1476
[QUOTE=Pat Fairbank;553092]I don't think this kind of test would work. The rule states that "a ROBOT may expand up to a maximum width of 72 inches and depth of 72 inches", not that the robot must fit within such a limit at maximum extension./QUOTE]
I think that Pat has shown that turning the robot on an angle is not a way around the rule. You will note that width and depth are described and definitions are in the rules on what these are.
Question is : if your robot goes straight up to 10' and falls over what then?
Penalty for exceeding as per the Q&A:
---------------------------------------------------------------------------------------------------------------------
FRC176
Default <R12>72 x 72 foot print
72 x 72
I have question on this subject. If your robot flips and while to upright yourself using an arm (if you have one) the robot exceeds the 72 x 72 foot print what is the penalty?
GDC
Senior Member
Default Re: <R12>72 x 72 foot print
Rule <R12> specifies that while outside of the Home Zone, the robot may not exceed 72 inches (width) by 72 inches (length). There is no exception for overturned robots.
In all cases involving a violation of this rule, the ROBOT may be disabled and/or disqualified.
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.
can you provide the link to where this question was answered?
- Bochek
EDIT: found it... http://forums.usfirst.org/showthread.php?t=1121 I agree that this is then possible, and man does it save my @$$
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