The Robonauts 118 - 2012 Video

[Justin Ridley]

FIRST Community, we, the Robonauts, went out on a ledge this year by designing a feature on Endeavour that some thought might not be doable and even more thought might not be legal. As for the engineering of the problem, for us, it has been very exciting and VERY challenging ... the students and mentors have all become better designers by creating the "Robot On The Ledge". As for the legality, we posed many of the same questions as you have concerning whether hanging is covered under G10 and waited for weeks for clarification. Although it would take volumes to document our discussions, please allow us to explain why we feel this design, and others like it, falls within the intent of the rules.

The FIRST manual opens asking something of the teams; " When reading these rules, please use technical common sense (engineering thinking) rather than “lawyering” the interpretation and splitting hairs over the precise wording in an attempt to find loopholes." We have used this as a guideline, and to the best of our ability followed this model. We feel FIRST could have been more clear with their intentions, but alas we have happily worked with what we've been given. We began this season striving to find an innovative solution that fit within the realm of options presented within this year's game challenge. The intent of the challenge is for a robot to be fully supported by a balanced bridge in a way that does not damage the field components.

From the manual there are two game rules and a dictation in the arena section that govern a successful balance.

[G10]
Robots may not grab, grasp, grapple, or attach to any Arena structure. Robots may not push or react against the top of the Fender. (Robots may push or react against any element of the Arena that is not protected by another rule.)

[G12]
Robots may not damage any part of the Arena, including Basketballs.
Violation: Potential Disablement if the Head Referee determines that further damage is likely to occur.

A Bridge will count as Balanced if it is within 5° of horizontal and all Robots touching it are fully supported by it.

Our design uses a fixed downward facing C-shaped appendage on the end of an arm. The appendage is driven down with the gap of the C-shape coming to rest over the angled rail of the bridge. When the arm continues to travel down the robot angles slightly as it is lifted to become supported by the bridge. When slightly angled, the two inner walls of the C-shaped appendage merely react the load of the robot against the inside of the angled bridge rail and the outside features of the bridge. We believe this two point reaction of a fixed mechanism to support our robot weight falls within the intent of the rules because it is clearly written that robots may push or react against any element of the Arena. This simple reaction of forces is demonstrated by the robot being removed from the bridge simply by lifting it straight up. Our intention was actually to drive along the rail while maintaining this two point reaction... an engineering challenge we have not yet been successful at achieving with a fully weighted robot.

We would venture to say that the rule prohibiting the actions of grab, grasp, and grapple are of peoples primary concern, so let us elaborate on how our team understands the rules. To grab, grasp, or grapple you need actuation. Any reasonably astute thinker would agree that to grab or grasp a pencil off of a desk you would need to actuate or squeeze your fingers together. Grapple is a less commonly used verb and we believe inherently brings in some discrepancies because of this. When we use grapple, we often describing someone grabbing another person with their arms in a fight. We tried to look up grapple in the engineering bible (AKA the Machinist Handbook) but it was a dead end. So we turned to our home dictionary where grapple as a verb is defined with phrases "to hold", "to seize in a firm grip", "to clinch", "to engage in a struggle", and "to try to overcome". Like grab and grasp, these phrases bring to mind thoughts of actuation to accomplish the action. Our design is fixed and does not allow us to take "firm grip" of the bridge. We would venture to say that a fair amount of confusion arises from trying to relate the verb "grapple" to the mechanism known as a "grappling hook". We believe these are different parts of language used to describe different things and the latter should remain irrelevant and out of the discussion when attempting to clarify the verb grapple.

Briefly we will mention that adequate measures have been taken to prevent any damage to the field, including hang calculations for bending, analysis for localized deformation, and extensive testing on our bridge for scarring. There is a zip tie near the center of the bridge that to the best of our testing knowledge, we do not cut when a loaded weight crosses it. There are LEDs within the bridge c-channel structure that we do not interact with.

Questions have been raised throughout the season to FIRST alluding to this strategy. With each question we eagerly awaited an answer that would give us better direction one way or another. The opportunities were presented in the Q&A system for FIRST to make a clear and concise ruling on what they intended to be illegal actions and what they didn’t. They did not take this opportunity, which we feel is a move (albeit a frustrating one) to leave the challenge open and create opportunities for innovation.

We have no intention of cheating the system, gaining an unfair advantage, or exploiting the rules (we're not even sure how well our strategy will work in this game). We also understand others may disagree with our interpretations. Regardless of the ruling, the Robonauts will be better because of our efforts.

Thanks for your input,
The Robonauts

[jwfoss]

Justin,

Thank you for taking the time to type out and explain your teams discussion and point of view in relation to your mechanism and how it applies to the rules. It is clear that you took a path less travelled and went for a unique design. I commend you on your efforts in building what looks to be a highly effective machine. We will be watching the ruling on this closely. Good luck this season, and see you in CT.

I'd fight for the legality. If a ref says otherwise, direct them to your post up there. Makes perfect sense to me, and my job on the team is to read the rules.

[JaneYoung]

Originally Posted by SuperNerd256

Mostly? How can there be more???

They have to add the competition salsa mix: focus, fun, and cheering fans. For additional spice, the fear factor will be added as they go.



Congrats, Robonauts! Can't wait to see Endeavour at the Alamo.

Jane

[Brandon Holley]

Justin-

Great description of your thought process. We too went down a similar path of thinking, but we do differ slightly in one area. As I'm sure you guys did based on the description of your thought process, one word caught us up on this design, "grapple".

The first thing many people think of when you use the word "grapple" besides wrestling, is grappling hook. In my interpretation, essentially the c channel guide that reacts with the side rail of the ramp is accomplishing the same thing a grappling hook would. I am also in total agreeance with you that this is only one interpretation. I commend your team on "going for it" and I look forward to seeing what the final call on the field is when you lift that thing off the ground for the first time. Job very well done.

-Brando

[rachelholladay]

God thats beautiful. The robot, the video, the workspace. It's shame you guys can't drop by the Bayou...

[BrendanB]

Originally Posted by O'Sancheski

I am now more frightened than I thought I was going to be.

I agree Connecticut can't come fast enough now!

[Elizabeth Waters]

REALLY looking forward to seeing it in action at Lone Star. That hang excites us.

[Chris]

Awesome robot.

The legality rulings of this will be interesting to follow

The following Q&A seem to apply.

Q. Are the definitions for "Arena structure" and "element of the Arena" the same? If so, are there instances in which a robot "reacting against" an Arena structure might be construed as an instance of a robot grabbing, grasping, grappling, or reacting with an Arena structure of the Arena? FRC0188 2012-02-02
A. Yes. Yes.

Q. Per this rule, would a device that utilizes a passive "appendage" deployed over the center line barrier (bump) to prevent your machine from being moved or twisted when hit (by applying forces to opposing sides of the barrier be considered a violation of this rule? Please elaborate on rule intent. FRC1730 2012-01-11
A. The intent of Rule [G10] is stated in its opening sentence, "Robots may not grab, grasp, grapple, or attach to any Arena structure." While, we cannot comment on the legality of a specific design, holding on to a field element is considered grappling and a violation of Rule [G10]
(Realize this is about bump but the bolded section seems applicable)

Q. Is it permissable for a robot on the bridge to extend a device that can also react off the bottom surface of the bridge provided that device does not grasp the bridge firmly? FRC0180 2012-01-15
A. Rule [G10] does not put a qualifier on how a Robot may legally grasp the Bridge. It simply says it cannot do it.
Again the answer seems applicable.

I just figured i'd post the Q&A to save people the time of looking them up.

Great robot regardless and I Look forward to welcoming you to CT!

[tzjin]

Beautiful video for a beautiful robot!

I'm also curious about that shooter, especially with the huge flywheel and the apparent direct drive? I thought I saw a gearbox within the white u-channel, but it spun with the shaft so I'm a tad confused.

Best of look with your balancer! I hope I can see you guys live at Champs!

PS. Gorgeous cheeseholing

[BrendanB]

Guys, you can go back and forth all day with definitions, rules, and the Q&A but it won't matter until you get to an event and the LRI/Head Ref get involved. Obviously the Robonauts have put a lot of thought and work to get there robot into all the rules required to play and I see it as legal and many members see it as legal but again, the GDC hasn't explicitly said if it was legal/illegal and they haven't competed.

Only time will tell but until then stop beating the dead horse of 179/118 and just say it is awesome already!

[eedoga]

I've been waiting for this. You guys do amazing work. We'll be looking out for you in all of the video streams.

Best of luck this year.

Edoga

[Madison]

I'm looking forward to seeing this up close next weekend and very interested in how things work out with respect to hanging from the side of the bridge.

Out of curiousity -- does that mechanism require that bridge is already level (or near level) to work properly? Can it accommodate a tipped bridge?

[Brandon Holley]

Originally Posted by BrendanB

Only time will tell but until then stop beating the dead horse of 179/118 and just say it is awesome already!

Whoa whoa whoa now. I dont see a reason we cant have a mature discussion about this. As someone who spent a significant amount of time researching rules and designing an almost identical system and coming to a different conclusion I think my comments are worthwhile. If I was 118, I would certainly like to hear how other veteran teams view the issue.

I also believe 179 is completely different than 118.
-Brando

[Astrokid248]

Originally Posted by Jeff Rodriguez

Youtube version?

Vimeo blocked here.

Sorry, the shuttle footage used in the video violates YouTube's copyright policy. Vimeo's policy is more lenient.