2nd Most Awaited Q and A Answer?

[MrForbes]

I'd play it safe and have something that connects the two arms at the outer ends. It's a pain, but it'll save having to deal with the issue later when they finally come out and say that's what they meant all along.

edit: and a bonus, it's less likely to poke into other robots

[BX MARK]

So to be clear, you can or cannot have one solid piece, reaching out at two different points, as long as the distances don’t add up to more than 14”?

[jvriezen]

My totally unofficial, but unambiguous interpretation of the writings of the GDC.

An appendage is considered a single appendage if, during its normal extension for usage outside the frame perimeter, all appendage components which intersect the frame perimeter projection are contiguously connected entirely outside the frame perimeter projection.


This would allow a 'fork' like appendage to not break the rule when only the tines of the fork are intersecting the frame perimeter during its deployment, but the normal usage of the fork appendage would need to be such that the portion connecting the tines must also be out of the perimeter projection as it is used.

And I don't think it matters if one tine of the fork is used to manipulate balls, and the other tine is used for moving the bridge -- multipurpose appendages are fine.

[Bob Steele]

Originally Posted by jvriezen

My totally unofficial, but unambiguous interpretation of the writings of the GDC.

An appendage is considered a single appendage if, during its normal extension for usage outside the frame perimeter, all appendage components which intersect the frame perimeter projection are contiguously connected entirely outside the frame perimeter projection.

This would allow a 'fork' like appendage to not break the rule when only the tines of the fork are intersecting the frame perimeter during its deployment, but the normal usage of the fork appendage would need to be such that the portion connecting the tines must also be out of the perimeter projection as it is used.

And I don't think it matters if one tine of the fork is used to manipulate balls, and the other tine is used for moving the bridge -- multipurpose appendages are fine.

I would have to respectfully disagree with this line of reasoning. Other than the fact that it is redundant ("contiguously connected") a
contiguous assembly must mean that it is simply connected... the new answer does not say that it has to be contiguous OUTSIDE the frame perimeter. I quote directly from Q&A:

" To elaborate, an Appendage is a contiguous assembly that may extend beyond the Frame Perimeter per Rule [G21]."

I looked at the old wording "an appendage, when extended beyond the Frame Perimeter, is a contiguous assembly" and this simply doesn't make sense...you can't define a contiguous assembly as one that extends beyond the frame perimeter..you define it by the definition of contiguous (ie connected). They were simply cleaning up the answer.


If it looks like an appendage, quacks like an appendage and moves like an appendage...it is an appendage... contiguous means connected..connected could possibly mean moving all at once... but wouldn't have to ..


I think that Q and A is sufficiently clear on this topic. I also think it is unambiguous.

[jvriezen]

Originally Posted by Bob Steele

I would have to respectfully disagree with this line of reasoning. Other than the fact that it is redundant ("contiguously connected") a
contiguous assembly must mean that it is simply connected... the new answer does not say that it has to be contiguous OUTSIDE the frame perimeter. I quote directly from Q&A:

" To elaborate, an Appendage is a contiguous assembly that may extend beyond the Frame Perimeter per Rule [G21]."

I looked at the old wording "an appendage, when extended beyond the Frame Perimeter, is a contiguous assembly" and this simply doesn't make sense...you can't define a contiguous assembly as one that extends beyond the frame perimeter..you define it by the definition of contiguous (ie connected). They were simply cleaning up the answer.


If it looks like an appendage, quacks like an appendage and moves like an appendage...it is an appendage... contiguous means connected..connected could possibly mean moving all at once... but wouldn't have to ..


I think that Q and A is sufficiently clear on this topic. I also think it is unambiguous.

But how could you possibly EVER have two appendages exiting from the same edge then? If they can be connected inside the perimeter, then any thing you want to call two appendages on the same edge will be one by your definition --- unless one is totally disconnected from the bot, which of course violates a different rule. By your line of thinking, I can have any configuration whatsoever for appendage(s) as long as they all exit the perimeter along the same edge-- they are always connected to each other somehow via the bot parts.

[Jon Stratis]

Originally Posted by jvriezen

But how could you possibly EVER have two appendages exiting from the same edge then? If they can be connected inside the perimeter, then any thing you want to call two appendages on the same edge will be one by your definition --- unless one is totally disconnected from the bot, which of course violates a different rule. By your line of thinking, I can have any configuration whatsoever for appendage(s) as long as they all exit the perimeter along the same edge-- they are always connected to each other somehow via the bot parts.

I'm just guessing here, but the big difference is how it's actuated. If a single motor drives two rods out the same side of the frame perimeter, those rods are one appendage. If you have two separate motors driving those two rods out, then they are separate appendages - they can be actuated together, and they can be actuated independently.

[nssheepster]

Originally Posted by Jon Stratis

I'm just guessing here, but the big difference is how it's actuated. If a single motor drives two rods out the same side of the frame perimeter, those rods are one appendage. If you have two separate motors driving those two rods out, then they are separate appendages - they can be actuated together, and they can be actuated independently.

Agreed. Even if they are wired together, it can be separate, so it would count as two. Still, might be best to play it safe, though.

[LinuxArchitect]

Originally Posted by MikeReilly

They are probably just waiting on wording. Look at the simulator, they have the type of appendage you're talking about. The intent of the rule is not to spread out multiple sides like wings, etc., is my guess.

I asked several of these questions and similar others. Some were rejected as being questions of if a certain design breaks a rule. They don't answer that. They answer questions about the rule itself.

I asked the question about wings, width etc.

My current interpretation is that they probably made a mistake in the rules and are trying to figure a way out. But the width is constrained within the perimeter frame until the appendage crosses one edge. Once outside the edge it can not go "beyond" that edge by more than 14 inches but beyond implies (in my mind) the direction in which the appendage is moving as it crosses the edge. Once out there, I see nothing to prohibit wings from extending out parallel to the edge that was crossed. These wings won't be crossing a second perimeter edge; perimeter edges surround the robot frame "like a piece of string", they do not extend virtually to the edges of the playing field.

What do YOU think?

[Siri]

Originally Posted by Bob Steele

contiguous assembly must mean that it is simply connected... the new answer does not say that it has to be contiguous OUTSIDE the frame perimeter.

Can I ask where you distinguish your interpretation versus last week's "fork" answer? I understand the search for clarity in newer answers*, but I can't find the necessary lack of clarity in it to support additional interpretations of this.

Q: If an extension forks outside of the frame perimeter, does it count as a single extension? For example, if 7" away from the frame, the appendage splits into two separate bars.
A. Only one appendage may extend beyond the Frame Perimeter. There are no rules prohibiting appendages that fork once outside the Frame Perimeter.

To me this would seem very strongly (i.e. barring [edit]finagling?[/edit]) to ban appendages that fork within the Frame Perimeter. Have I mistaken that?


*Under the precedent that the GDC will announce if they directly change their interpretation: e.g. "We have recently published conflicting responses in the Q&A...have revised the responses in question and added clarification in the Blue Box" - Team Update 2012-01-20.

[Squillo]

I see that a new question has been asked, and not yet answered by the GDC (thanks 1619). Hopefully they will know of our confusion and resolve it, one way or another.

I am wondering about this: an "H" shaped construction that has two pieces extending past the perimeter, joined by a bar that crosses between them (and is outside the perimeter when the 'appendage' is extended, but crosses from inside to outside during the course of extension), and then two more pieces that continue past the cross bar. Or for that matter, two pieces that cross the perimeter and are simply joined into a "u" with a crossbar outside the perimeter.

Any difference between those two? Either legal/illegal? Thoughts?

BTW, I just have to get this out there. I know it is the GDC's language, and I should take it up with them, but as a lawyer (and mentor/'rulesmeister') I really resent the negative connotation that has been placed on the term "lawyering". It just so happens that a large part of proper legal reasoning, argument and decision-making is focused on discerning the INTENT behind the rule, statute, or contract, and explaining how/why our interpretation is in accord with that INTENT - NOT, as some believe, looking for 'technical loopholes' that are contrary to the intent of the legislature/court/contract drafter. You engineers are MUCH better at that than we lawyers. Maybe we should call it "engineering" the rules...

BTW and FYI, the January 2012 issue of the magazine GPSolo, put out by the general practice, solo and small firm division of the American Bar Association, which is focused on volunteering and community service, contains an article entitled "Mentoring a High School Robotics Team" by yours truly, which details why I do this and plugs robotics in a big way. As soon as the online link is available, I'll post it. Would anyone care to suggest a forum or sub-forum that would be appropriate for that?

[RRLedford]

As I see it the uncertainty that needs clarification is the spatial location within which the 'contiguous" test will be applied. If the contiguous test is applied ONLY to what protrudes beyond the robot, then a forked appendage would be in immediate violation at the moment the two or more "tines" crossed the edge perimeter plane, since at that moment they are not contiguous within the space outside the edge of the robot.

By this interpretation, only if the fork tines stayed connected (or at least touching) at their tips until the fork's base broke the perimeter, and only at that point they separated to desired positions, would "contiguousness" be maintained OUTSIDE the perimeter at all stages of appendage deployment.

If the contiguous test allows tracing "contiguity" back inward past the outside perimeter of the bot, that would not make much sense, since EVERY SINGLE component of the robot will ALWAYS be contiguous with every other piece, assuming that parts merely being in contact satisfies the contiguous test.

Since the entire robot is always 100% contiguous with itself, the mere use of the term "contiguous" for appendage testing TOTALLY IMPLIES that that it is meant to be applied ONLY to the portion(s) of the appendage that protrudes from the bot, and applied ONLY to what is occuping the SPACE BEYOND the perimeter.

It is only by delimiting the SPACE that the bot occupies, into an inside of and an outside of the perimeter, that any portion of the robot can ever be considered as "dis-contiguous," based on its relation to the "CUTTING PLANE" of the perimeter.

Imagine a Star Wars lightsabres cutting arcs to match the vertical edge perimeter of your bot. If an appendage starts to deploy, and at any time throughout its maximum of 14" horizontal motion the lightsaber can cut it off, such that TWO OR MORE PIECES fall on the floor, then the appendage probably fails the contiguous-outside-the perimeter test.

-RRLedford

[Tuba4]

The following has been posted to the Q & A system:

In a prior answer it was stated that an appendage can fork outside the frame perimeter yielding a Y shaped appendage. Can an appendage be attached to the frame at 2 points and terminate in 2 points as long as they are joined by a cross member, yielding an H shaped appendage?

[MrForbes]

Originally Posted by Squillo

BTW, I just have to get this out there. I know it is the GDC's language, and I should take it up with them, but as a lawyer (and mentor/'rulesmeister') I really resent the negative connotation that has been placed on the term "lawyering". It just so happens that a large part of proper legal reasoning, argument and decision-making is focused on discerning the INTENT behind the rule, statute, or contract, and explaining how/why our interpretation is in accord with that INTENT

I think we're aware that that is what a large part of proper legal reasoning is. The thing that gives lawyers a bad reputation is the occasional improper use of the technique to find loopholes.

Some of us have learned over the years to look right away for the most conservative interpretation of the rules, it saves a lot of redesign.

[RRLedford]

At what point does an appendage become an appendage?

Is it at its attachment point inside the bot, or at the point where it crosses outward beyond the perimeter? Along what paths are we supposed to trace out contiguity tests. If all bots are 100% contiguous then what establishes dis-contiguousness as relating to appendages?

What exact application of appendageness and contiguity determine whether we have just one, or more than one appendage protruding?

What if our whole robot just expanded in all directions (above the bumpers of course) for 14" beyond its initial size, and we consider this our "frame appendage"? If it is contiguous are we in violation? What if we deploy diagonally at a corner? Can the appendage still only be 14" diagonally from the corner, or (14") X (1.414) -- still within a rectangle going 14" further outward than the frame?

-RRledford

[RRLedford]

Originally Posted by Tuba4

The following has been posted to the Q & A system:

In a prior answer it was stated that an appendage can fork outside the frame perimeter yielding a Y shaped appendage. Can an appendage be attached to the frame at 2 points and terminate in 2 points as long as they are joined by a cross member, yielding an H shaped appendage?

Why do we need a bar to make the H - shape? The robot it self is the cross bar of the H, at least as far as the contiguity test goes, that could pass.
If the robot itself CAN'T be the H-bar, then where beyond the two pivot points must the H-bar fall? Must it swing out past the perimeter to make it a legal forked arm? What if the deploy fails in the muddle and the H-bar stays inside the robot perimeter while the two tops of the H break the perimeter? Is this a double appendage deploy or can we trace contiguity back inside the perimeter and around between the two sides of the H?

We really need some better clarification on the same level as the way the bumper mounts are detailed with good example diagrams.

-RRLedford