Ball deflectors.....don't

[Gary Dillard]

1st week regional and lots of field com problems as usual. However, the biggest problem we've seen on the real field is that the ball deflectors do a terrible job of keeping the balls out from under the bridge, and if it's on the far side you can't even see it's there. Lots of teams unable to drop the bridge because there is a ball stuck under it.

[alectronic]

i was noticing that too from what i could see online. it seems like the actual balancing isnt too bad if you have don't try too last second. but if the balls are stuck there, then it doesn't even matter. it will be interesting to see if there is a design update for week 2.

[its da PAT!!!]

i was noticing that too from what i could see online. it seems like the actual balancing isnt too bad if you have don't try too last second. but if the balls are stuck there, then it doesn't even matter. it will be interesting to see if there is a design update for week 2.
Im glad we add a second camera. I hope the figure out a way to fix this.

[Steven Donow]

This was noted during many pre-ship date scrimmages. FIRST's response, IIRC, was that this was intended and is an added challenge.

[Austin2046]

further proof as to why going over the bump is necessary :P

but seriously, i would advise teams to cross the barrier and approach the bridges from the side closer to their alliance stations. You can see if there are balls under that side and your tipping the bridge down should dislodge any balls on the far side of the bridge. If there are balls under your side of the bridge then approach from the far side... if there are balls under both... then i'm not sure what you do :/

rock the bridge?

[Bob Steele]

I wonder what is going to happen when an alliance rolls balls under both sides of the opposing alliance bridge..so they cannot balance it.

I wonder if this will be a G25 violation? It should count as an interference with the act of balancing... if that is the case... it will be a difficult call for a referee to make if it is done ... it is a huge penalty... technical foul AND the balance score...

It would be easy to call if it were done obviously but I can see balls being chased and getting stuck... who is to say it was intentional?

I wish the deflectors worked better..

[Andrew Lawrence]

I know it's supposed to be part of the "challenge", but I don't think it'd be fair to see any teams loose a match only because their bridge was blocked by two of balls.

[RyanCahoon]

if there are balls under both... then i'm not sure what you do :/

rock the bridge?

you make a collector that can fit under the bridge to pull them out

[avanboekel]

you make a collector that can fit under the bridge to pull them out

But we were told from the start that this wasn't going to be a problem in this year's game.

[kjohnson]

I wonder what is going to happen when an alliance rolls balls under both sides of the opposing alliance bridge..so they cannot balance it.

I wonder if this will be a G25 violation?


Its a G14 violation:


Strategies that use Basketballs to either aid or inhibit Balancing of any Bridge are not allowed.
Violation: Technical-Foul, and counting or discounting the affected Bridge as Balanced, as appropriate.

[Grim Tuesday]

Its a G14 violation:

I think the question was if the balls were placed there inadvertently, but by the actions of an alliance.

I find it somewhat disturbing that this problem is being considered part of the challenge, when they went to specific lengths to assure us it wouldn't. (http://youtu.be/-AMaqqmoLgQ?t=49s)

[kjohnson]

I think the question was if the balls were placed there inadvertently, but by the actions of an alliance.

I find it somewhat disturbing that this problem is being considered part of the challenge, when they went to specific lengths to assure us it wouldn't. (http://youtu.be/-AMaqqmoLgQ?t=49s)

From the video: "Its there to help balls roll out from under the bridge."

I haven't seen or heard anywhere where FIRST has specifically said that balls wouldn't get stuck under the bridge. As seen in the video, the polycarb sheet lifts on one side when the other side of the bridge is pushed down. The weight of the bridge has to be removed from the top of the ball before it will roll out. From the field demo video that you linked, it looks to me like the bridge and polycarb sheet are behaving just as FIRST expected.

[AllenGregoryIV]

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

[BigJ]

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

I think the "it wasn't on the low cost field!" argument was covered last week with 118's hanger.

I dunno. I feel like the issue would come up in design when discussing bridge interactions. "Would I ever want to pick the bridge up? What are the reasons?" etc.

[Nuttyman54]

The field is working as designed, from my point of view that design was not clearly stated. Since the ball ramps aren't part of the low cost field there was a slim chance a team would discover this challenge on their own with out some hints from FIRST. They could have worded it "that the ball ramps allow balls to be removed when the bridge is tipped to the other side" and I think a lot more teams would have understood the challenge as FIRST intended it.

The problem here is that, even if that was clear, a scenario still exists where a ball can get stuck under either side, making it impossible to lift up and clear*.

Whether it's intentional or not, the fact of the matter is that it was represented to teams that a system was in place to keep balls from getting stuck under the bridges, and balls are still getting stuck under the bridges. I have yet to see any robots which can get on the bridge without lowering it or without the assistance of another robot**.

When you have something as basic to the game as a Coopertition bridge, which counts as a win, it should be doable by almost every team...but if balls get jammed, nobody's getting on that Coopertition bridge.

There are some things the GDC can rightfully say are "part of the challenge", such as the chains sometimes deflecting goals in 2006 and 2010, or popped tubes in 2007 and 2011. This should not be one of those, as it is a situation which prevents teams from being able to complete a major part of the game, by no fault of their own, and is happening it a large number of the matches.

*I have not played with a real bridge with balls stuck under it. It's possible that they will move enough that rocking the bridge will clear them, even though it can't be pushed down far enough to climb on to

**With the exception of 118's hanger mechanism, pending legality rulings. It's worth noting that 179 can hang from the bridge without climbing on it, but someone needs to get on it first for them to be able to balance by hanging, thus they would require the assistance of another robot (and another robot requires theirs).

[savage]

Its a G14 violation:

Yes it is a T foul and we will be on the look out for this.

[nikeairmancurry]

I have seen a robot get on the bridge with balls trapt under it. Tonight at Kettering's practice 33 did it a few times, but I do not believe they knew the balls were there due to the fact the were driving towards themselves.

[mathking]

From looking at a bunch of videos, it looks like lifting the bridge only a little bit will allow a trapped ball to roll free. So if your bridge manipulating device can both push up and pull down you should be able to wiggle trapped balls out if they are on both sides. Push the side you are on up to get that ball out. Then push it down and drive up, freeing the ball on the other side.

[pfreivald]

Many of the past eight years we have made a critical mistake of one kind or another, usually in terms of assuming some kind of nominal value wasn't nominal. Thus, we paid a lot of attention to the bridge "help"ing keep the balls from jamming underneath... ...which doesn't mean they won't.

With the 14" extension restriction, they do appear for the most part to make the balls accessible to robots with the appropriate mechanism to knock them out (and/or suck 'em in).

Instead of railing against the unfairness of it all, teams should be considering what they can do between now and their own events (or now and tomorrow's first match) to be able to clear balls from underneath the bridge.

------------

And on that note, from what I can tell watching Alamo and KC today, lifting the bridge doesn't seem to work more than maybe 50% of the time (or less), so another method might be desirable.

[Josh Goodman]

Pat's post is exactly how I interpreted it as well. The ball deflectors do keep the balls from jamming up near the pivot base of the bridge (where all the balls would go without them). The definition said it would help keep the balls from jamming....which it does. It never said anything about rolling them with grace out from under the bridge so your robot can sweep them up with ease.

With the right manipulator, the balls under the bridge are accessible to all teams. It might not have been as readable as "a mechanism to put balls into hoops", but it's clear many teams thought of this problem and built devices to compensate. In my mind, it's all part of the game.

[jlindquist74]

*hikes pants up a few inches above his waist*

Suggestion: Consider this a part of your engineering education.

If I had a nickel for every time a vendor's product didn't *quite* perform according to spec, or some library or application fell short of the claims in its documentation, or behaved in some odd way that got in the way of my efficiently-planned project or solution, I'd be long retired.

Sometimes you can get a vendor to fix what ails you. But often, there isn't enough time, enough money, enough material, or enough staffing to do it. (You may also not be a big enough customer/client to accommodate.) You will usually work around it as best you can, and move forward. Maybe you and the vendor can fix it for release 2, but business or market pressures say you gotta ship release 1 without that fix.

If you choose this for a profession, you will run into this a lot.

You might study other teams' designs--even if their robot design is radically different from yours, there may be an element you can adapt this weekend, or carry in to the next competition. Or maybe it will help you design workarounds next year, if you're an underclassman. Learning from others' work is half the fun, anyways...

[Ivan Helmrich]

In KC today, several matches saw balls under both sides of bridges. It turns out if the ball is near the end of the bridge, the thing has to be tipped all the way to the floor on the other side or the ball won't move.

I wouldn't complain about it as an impediment, it plays the same for all. If FIRST's goal is to make coopertition a cool thing for the crowd to see though, they missed the boat. The ball under the bridge seems to have a randomizing effect on how successful teams are. It is a very specific type of mechanism that can deal with it the way it is currently playing out.

Ivan

[Akash Rastogi]

Relevant- https://www.facebook.com/photo.php?fbid=121786804617817&set=a.109011835895314.7218.107270772736087&type=1&theater

[Travis Hoffman]

With the right manipulator

Tape measure grappling hooks. :cool:

[Kevin Sevcik]

Tape measure grappling hooks. :cool:
Stacked on top of other robots to start the match.

[PAR_WIG1350]

Tape measure grappling hooks. :cool:

Another RI team used one of these to hang in 2010 quite successfully. Didn't even need an arm to lift it up to the bar, they just extended it up and lifted themselves up by retracting the tape.

[Brandon_L]

Tape measure grappling hooks. :cool:

http://www.youtube.com/watch?v=y63OV_E7M-4 - nuff said

[Gary Dillard]

Head ref announced new rule today: teams are allowed to have a fifth team member on the side of the field giving hand signals so they can tell if there is a ball there, or anything else they want to signal apparently. Interesting.

[Billfred]

Head ref announced new rule today: teams are allowed to have a fifth team member on the side of the field giving hand signals so they can tell if there is a ball there, or anything else they want to signal apparently. Interesting.
Well, that's a new development... (Okay, so there were two coaches in 2001...but it's practically new.)

Can any of the other Week 1 events confirm this change?

[Steven Donow]

Well, that's a new development... (Okay, so there were two coaches in 2001...but it's practically new.)

Can any of the other Week 1 events confirm this change?

Watching the streams of the Hatboro-Horsham MAR District and Smoky Mountain Regional, this doesn't seem to be the case (of course the camera angle at HH doesn't show the middle, but Smoky Mountain shows the whole field). Though that would be an interesting change...

[DampRobot]

To me, from the matches I watched, it seems like the problem really is teams don't try to ballance soon enough, and that they don't use bridge pushers build for "the rigor of the game." This seems less like a failure of FIRST, but rather a failure of teams to design durrable and functional mechanisims. Not that I think our team's will be any beter, though.

[JackS]

I saw a bridge balance not count because balls were under the bridge and were supporting it...

[Andrew Lawrence]

I saw a bridge balance not count because balls were under the bridge and were supporting it...

Really? Did the teams put the balls there, or even somewhat allow them to go there? If not it should have counted.

[AllenGregoryIV]

Well, that's a new development... (Okay, so there were two coaches in 2001...but it's practically new.)

Can any of the other Week 1 events confirm this change?

Alamo did not have this change as far as I am aware and I was an inspector on the field for a lot of the competition.

[johnmaguire2013]

We were not allowed a fifth member at Kettering. Instead we tried to use crowd members to tilt a sign we had (we have four signs - 3, 3, 2, 2.) if a ball was stuck under a bridge (which confused our driver the very first match.)

However when we moved on the second day, even us in the crowd couldn't see the bridge from the other side.

[Andy A.]

Whether it's part of the design challenge or not, it's frustrating.

It's possible for the balls to get pinched between the polycarb 'deflector', and the field boarder on the alliance color bridge. Even with our ball pickup device, designed to lift the bridge and suck balls out, we couldn't clear them when they got like that. It's rare, but they're just plain stuck, and in a manner I don't think anyone expected.

Balls trapped under the bridge decided many matches. It's a bummer, and short of a change to the deflector that FIRST is likely unwilling to make, it's going to be a common one.

[slijin]

Head ref announced new rule today: teams are allowed to have a fifth team member on the side of the field giving hand signals so they can tell if there is a ball there, or anything else they want to signal apparently. Interesting.

How did you find this out? Was there any particular regional that this was announced at?

[wolfeman]

Whether it's part of the design challenge or not, it's frustrating...

Balls trapped under the bridge decided many matches. It's a bummer, and short of a change to the deflector that FIRST is likely unwilling to make, it's going to be a common one.

It's water under the bridge at this point [pun intended] but having
just losing in the semis in Hatboro-Horsham due to this issue,
I have to agree. If you look at the original bride video here:

http://www.youtube.com/watch?v=-AMaqqmoLgQ&feature=related

the big difference between the video and the actual field was the polycarb sheet sagged badly. It not even close to a flat sheet as shown in the
video and was ineffective in having balls roll back out.

It would be an egregious violation of the rules and gracious professionalism,
but an effective strategy would be for inbounders to 'accidentally'
send balls under an opponents bridge...

[Gary Dillard]

How did you find this out? Was there any particular regional that this was announced at?

The head referee at Smoky Mountains came to our team and the team next to us in the pits first thing Friday morning and asked to speak with the drive teams; he specifically told us we were allowed to have a fifth person that did not count toward our 4 on the drive team that could stand on the side of the court and give hand signals. I assume he did the same to all the teams there.

[slijin]

The head referee at Smoky Mountains came to our team and the team next to us in the pits first thing Friday morning and asked to speak with the drive teams; he specifically told us we were allowed to have a fifth person that did not count toward our 4 on the drive team that could stand on the side of the court and give hand signals. I assume he did the same to all the teams there.

Interesting. Thanks for the info; I wonder if refs at later regionals will also allow it, considering forum consensus seems to be that this wasn't allowed at Kettering or Alamo.

[GaryVoshol]

Interesting. Thanks for the info; I wonder if refs at later regionals will also allow it, considering forum consensus seems to be that this wasn't allowed at Kettering or Alamo.

Nor at Gull Lake.

[Grim Tuesday]

That's frankly quite bizarre. It would seem that the head ref overstepped his boundaries, and changed the rules quite dramatically. I hope that they had a chat with FIRST before this rule change.

[Kevin Selavko]

**With the exception of 118's hanger mechanism, pending legality rulings. It's worth noting that 179 can hang from the bridge without climbing on it, but someone needs to get on it first for them to be able to balance by hanging, thus they would require the assistance of another robot (and another robot requires theirs).[/SIZE]

As we posted yesterday in the Alamo thread, the GDC made a decision regarding our bridge balancing mechanism. We wanted to provide a little more of the details that were provided to us. A picture of us using this mechanism to balance the co-op bridge with 488 was posted in the Alamo thread. This was a very exciting moment and the Robonauts are proud of achieving this on Thursday of our first regional.

The head ref at Alamo approached our team prior to opening ceremonies on Friday. He told us that a telecon was held last night amongst the GDC and they determined our robot’s mechanism fell under their definition of the word “grapple” when interacting with the bridge. It would therefore be a violation of [G10] when used, and be penalized accordingly. We were told it was not the GDC’s intention that teams utilize the features at the edge of the bridge to hang or lift off of during a balance.

During a break in matches at the beginning of the day, the head ref explained this ruling to the crowd. During this he read the following definition for Grapple: “The use of a tool to catch, hold, or rake to gain a physical/mechanical advantage”.

In our conversations with the head ref he expanded on this definition, talking about devices which react against multiple surfaces to create a moment or torque.

We understand that we took a risk in this design. Nonetheless, we are disappointed in the ruling the GDC has made. Even more, we are disappointed that the risk we took was created only because FIRST refused to answer direct Q&A questions related to it. Answering the following question could have clarified this situation very simply and early in the build season. At the time, it was our honest belief that if FIRST intended for this to be illegal, they would have stated so here.
located here. (http://www.chiefdelphi.com/forums/showthread.php?t=104118&highlight=118)

[Retired Starman]

The head referee at Smoky Mountains came to our team and the team next to us in the pits first thing Friday morning and asked to speak with the drive teams; he specifically told us we were allowed to have a fifth person that did not count toward our 4 on the drive team that could stand on the side of the court and give hand signals. I assume he did the same to all the teams there.

As I understand it, this is not an official FIRST rule change, but within the discretion of the local Head Ref. The ruling essentially said that teams could have someone outside the court perimeter (past the curtains) making hand signals to indicate a ball under the bridge. This person could be anyone and was NOT an official drive team member.

Essentially, the teams were being allowed to formalize an otherwise unofficial signaling system which has always been available.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

[Andy A.]

The head referee at Smoky Mountains came to our team and the team next to us in the pits first thing Friday morning and asked to speak with the drive teams; he specifically told us we were allowed to have a fifth person that did not count toward our 4 on the drive team that could stand on the side of the court and give hand signals. I assume he did the same to all the teams there.

At GSR we were told that we could have the Safety Captain handle the robot cart, and stand on the sidelines with the carts. We were not told that he/she could give hand signals, though I suppose you could.

The 'solution' is for drivers to recognize how a bridge behaves when a ball is trapped in a place they can't see. If it's not working, stop trying to drop the bridge and figure out a way to either tip it up to clear the ball or pursue something else.

It is possible for a robot to get on the bridge from the other side and 'crush' the ball enough in most cases for a second robot to get on the bridge on the ball side. It depends on where the ball is under the bridge and how much of a lip the robot can climb over.

[RogerR]

The head referee at Smoky Mountains came to our team and the team next to us in the pits first thing Friday morning and asked to speak with the drive teams; he specifically told us we were allowed to have a fifth person that did not count toward our 4 on the drive team that could stand on the side of the court and give hand signals. I assume he did the same to all the teams there.

Wow.

Not that I would change anything at this point, but we were never told that, and none of the teams we worked with ever mentioned it. This could have been a game changer for us. I don't recall 772 or 234 having a spotter either. I just ran back and forth behind the driver station trying to get a clear angle on the other side of the bridge. After we tipped twice because of balls, we installed a back up camera to look for them, but never got it to work properly.

I feel like this might've been something to call a drivers meeting for; maybe they told someone in our pit, and it didn't make it to me or my drive team, but that's unlikely.

[Siri]

Interesting. Thanks for the info; I wonder if refs at later regionals will also allow it, considering forum consensus seems to be that this wasn't allowed at Kettering or Alamo.Nor Hatboro-Horsham. This would have made a huge difference to a lot of teams. We did coordinate about the Co-Op bridge in quals, though. We couldn't have a separate spotter; it was just up to the coaches.

[Gary Dillard]

That's frankly quite bizarre. It would seem that the head ref overstepped his boundaries, and changed the rules quite dramatically. I hope that they had a chat with FIRST before this rule change.

Since it happened first thing Friday, naturally I assumed there was some kind of telecon after first practice day of first regionals and this was the result; sounds like it wasn't the case. I will mention that Dr. Aidan Browne, the "head head referee", was one of the judges at this regional and maybe there was a consult.

[45Auto]

I was personally planning to have a kid in the stands with a big sign they waved if there was a ball under the bridge. That was a pretty common practice in Breakaway (2010) to let the drive teams know that there were balls available up against the driver station wall right in front of them that they were unable to see.

If they formalize it, fine, if not, there'll be lots of teams with someone on the sideline or in the stands giving hand signals.

[kjohnson]

Teams,

Make sure to ask the question about having an extra team member beside the field for the purpose of signaling in your driver's meeting. Until an official Team Update is released, no one knows whether this will be allowed or not. Better to be safe than sorry.

Please do NOT utilize your Safety Captain or Media Pass team member to signal from the side of the field unless explicitly told you can do so. I have seen teams receive a yellow card for gaining an unfair advantage by doing that. Signaling from the stands is fine because everyone has the same opportunity.

[JB987]

At GSR we were told that we could have the Safety Captain handle the robot cart, and stand on the sidelines with the carts. We were not told that he/she could give hand signals, though I suppose you could.

The 'solution' is for drivers to recognize how a bridge behaves when a ball is trapped in a place they can't see. If it's not working, stop trying to drop the bridge and figure out a way to either tip it up to clear the ball or pursue something else.

It is possible for a robot to get on the bridge from the other side and 'crush' the ball enough in most cases for a second robot to get on the bridge on the ball side. It depends on where the ball is under the bridge and how much of a lip the robot can climb over.

I agree. A rule change isn't really needed. Careful observation (and) second camera could make a huge difference...ignorance is not bliss in this case.:)

[Josh Fox]

Signaling from the stands is fine because everyone has the same opportunity.

I would be careful about that. I'll admit I haven't gone over the manual with a fine-toothed comb this year since I'm not really involved with FIRST that much this season, but I'm fairly confident signaling from the stands has been just as illegal as signaling from the sideline in years past.

I know that in 2010 there were some people who signalled which direction 469's deflector was facing from the stands, and that was just in poor taste in my opinion.

[kjohnson]

I would be careful about that.
...
that was just in poor taste in my opinion.

I completely agree. Although using the crowd isn't exactly outlawed, the teams with seats close to the field have an advantage. Ultimately that decisions is left to the Head Ref:

The Head Referee may assign a Yellow Card as a warning of egregious Robot or team member behavior at the Arena.

I've seen that call against a team using their Media Pass member beside the field to signal the drivers, but I'm not aware of any calls against teams in the stands.

[billbo911]

Based on a few practice rounds that I watched today, I believe the modifications to the ball deflector actually works quite well. I saw only one ball under a bridge. It came out as soon as the bridge was lifted a couple inches.

[Ty Tremblay]

Based on a few practice rounds that I watched today, I believe the modifications to the ball deflector actually works quite well. I saw only one ball under a bridge. It came out as soon as the bridge was lifted a couple inches.

I'll second this. I did field reset during the practice matches at the WPI Regional. Balls that roll under the bridge immediately roll back out unless they're pinched by the bridge and the deflector (which happens rarely). From what I've seen, the only time balls prevent a team from tipping the bridge is when they're prevented from rolling out by the robot that's trying to tip it.