Visualizing the 54in cylinder

FIRST General Forum
1

I made a quick graphic to help me visualize the 54in diameter circle, which is very restricting on climbing. Even more so now that the bumpers appear to count towards this restriction.*

I thought I would share this picture so other teams can take a rough cut at what mechanisms might work and which ones might not. You could even print and then cut out the extra perimeter circle and the robot profiles and move them around to help figure out how your robot can move around the pyramid.

http://i.imgur.com/8zx7c.png?1

*This may not always be true, please keep yourself apprised of team updates!

2

I really like this graphic. We spent some time working with the angles, since our plan was to tip our robot to climb. It still is an extremely tight fit even with a robot at 60 degrees.

3

The 54" rule is one of my big frustrations in this year’s set of rules. I think the 54" cylinder rule is a practically unenforceable rule that is a big lose-lose scenario.

For me personally, the 54" cylinder rule is reminiscent of the 2007 year (Rack ’n’ Roll) when there was a 72"x72" maximum “playing configuration” any time the robot was outside of the home zone. In order to come up with an arm solution that could lift tubes up to the top row of the rack, we implemented a triple-jointed arm (think of an arm like for a dentist’s office x-ray machine) that ended up being too unwieldy and extremely hard to control. We had considered many two-jointed solutions but couldn’t get one to work without occasionally exceeding the 72"x72" size limit.

Then, when we went to our regional, we saw many robots which used designs which we had discarded as illegal, as the mechanisms would pass through illegal-sized configurations. We even quietly measured about four of these when doing “pit scouting” and confirmed that our calculations were correct and that the robot would pass through an illegal configuration every time it raised a tube through horizontal. However, since the robots fit in the sizing box they passed inspection. A violation of the 72"x72" rule could only be called on the playing field by the referees when they observed a robot exceeding the volume. Well, it was practically impossible for a referee to make such a call without stopping the match and popping out onto the field with a 72" x 72" box! As such, we never saw any robots called for violation of the rule unless a tall robot fell over, at which point the violation would be called. It was extremely frustrating to have built an unsuccessful robot which satisfied the rules, when we saw many robots with much simpler designs that we could have made work, but which we had not built, as we knew they would violate the rules! My gripe was really not with the other teams, but was instead with the GDC making a rule like that which was practically unenforceable and thus penalized teams that went out of their way to follow the rules while implicitly rewarding teams that didn’t hold the same level of self-enforcement.

I think this year is even worse. The 54" cylinder is incredibly small, and I think most teams don’t even realize that fact. Last year’s regulation 38x28 robot with bumpers (approx 44x34) doesn’t even FIT in a 54" cylinder! (The diagonal would be approx 55.6").

Given past experience, I expect that there will be many robots which regularly violate the 54" cylinder, but without any penalty. In game play, the rule will be practically unenforceable, as it is nearly impossible to accurately determine if a tipping, rocking, climbing robot violated the 54" cylinder during a climb while watching the robot from the side of field!

Even worse, whether the 54" rule is properly enforced or not, many folks involved will be adversely affected by the rule!

If an attempt is made by inspectors and referees to require the rule to be satisfied, they will be the “bad guys” for many teams that didn’t fully understand the limitation and come to tournaments with robots that are illegal in some circumstances. Referees will have to make judgment calls that will be hard to substantiate either way. Many teams will have invested countless hours building robots that are regularly illegal.

Alternatively, if the rule isn’t really properly enforced (this is what I think will happen) then teams that ruled out design solutions that break the rule will have to deal with seeing other teams that implemented those solutions enjoy a major competitive advantage at tournaments.

From my perspective, the 54" cylinder rule is a practically unenforceable rule that is a big lose-lose scenario. Why the GDC would not learn from past mistakes and continue to make such unenforceable rules is a mystery to me. I’ve even mentioned rules such as this on previous end-of-season surveys…

Oh well, we’re attending the Week 1 Granite State Regional. I guess we’ll find out there what will end up happening with this rule – my speculation is that the rule will be poorly enforced, and well-intentioned teams that exercised great diligence to follow the rule will be the ones that lose.

4

In past years where we had maximum expansion rules (such as intakes last year) inspectors were asked to check if the robots could expand beyond that. If they COULD they would be noted and be watched closer. This isn’t optimal but it’s the best we mere mortals can do I guess (I hate volume limitations like this).

5

This rule was a little frustrating before today, but now with bumpers included for the first time since 2008, it is extremely frustrating!

Keep in mind that the cylinder dimensions remain relative to the floor at all times. That is the only silver lining so far.

6

2011 had an 84" cylindrical volume limit, which included bumpers.

7

Here is ‘half a robot in half a can’.

Note that it is slightly taller than 84in in this configuration relative to the ground.

8

In the grand scheme of “ways teams can knowingly cheat” designing a robot which goes outside the 54" cylinder isn’t even in the top 5. This rule, like many others, will primarily be enforced by the honor system.

148 will (of course) design our robot so that it doesn’t violate the rule. That goes without saying for us.

-John

9

Are inspectors going to extend a robot and tip it every which way to determine if any robot orientation is going to exceed the 54" cylinder? I’m pretty sure any robot over 48" tall will exceed the cylinder size if it tips over.

Relative to the floor is the whole problem here. If this was robot relative, then you could have a team extend mechanisms etc. and determine at inspection time in the pits whether they fit in the cylinder.

I’m with Ken that the biggest question here is how on earth this rule is going to be enforced. And what a team should do if the see another team that consistently violates this rule during matches but isn’t called for it.

10

The limit excluded bumpers in 2011, hence why I’m a bit frustrated with the inconsistency between years.

In the past inspectors have rigorously checked our robots to ensure compliance. At one point, inspectors wouldn’t allow us to compete with both an arm and a minibot ramp that together broke 84 inches, despite no intention of deploying both at the same time. This was cleared up before we played our first match and apparently the refs were notified of our single illegal playing configuration.

Your mileage may vary.

11

2011 was also robot relative, not floor relative. If you want to add to your list of inconsistencies.

12

I think the point of the above comments are that very few teams knowingly cheat but they just don’t do their due diligence or lack a complete understanding of a complex rule. I inspected several events last year and had to surprise a few teams about their extension beyond the frame. At least we have simple bumper rules this year.

13

Who knows. Usually it’s a non-issue. Last year we measured anything that extended out and that was that. Is it a perfect system? Heavens no. I was merely pointing out how similar situations had been handled.

14

[quote=““Hanlon’s Razor””]
Never attribute to malice that which is adequately explained by stupidity.
[/quote]

Sad but true, there are plenty of teams that just don’t read the rules all that well. I would be surprised if we didn’t see at least one 28"x38" robot come March. :frowning:

Rules like this put the impetus on the volunteers at the event to adequately enforce the rules that teams neglected to read. Based on other comments, it sounds like FIRST has made steps in that direction in subsequent years so hopefully it is a non-issue for teams that comply with the rules. And let’s be frank, if you are paying $6,000 to compete you better have a few spare hours to actually read the rule book.

15

@#@#@#@#. I hadn’t thought of that. What kind of remediation is going to be possible in order to get such a robot in compliance with the rules so the team can compete?

I suspect the most appropriate suggestion from the inspectors is going to be something like “Go build a smaller robot. We’ll help however we can.” I wonder how many teams can bring a spare KOP chassis box for just such an occasion.

16

Hopefully a few per regional, but with the PDV for the kit base this year, I suspect there will be many fewer available because veteran teams who usually build custom frames won’t have it just lying around…

17

The only good thing about this situation is that teams that didn’t know about the new size box are probably the same teams that didn’t know they could opt out of the Kitbot. Hopefully they at least wondered why it was so small for long enough to open the rules.

If not, the old Kit rail is somewhat adaptable. Cut it just short of the middle holes for an 8WD and you have an unevenly spaced, zero drop six wheel drive ready to go. It should turn…