Two Questions Regarding Hurdling

[thefro526]

So I was thinking of a strategy with a mentor, and we were thinking about blocking a ball being hurdled with a launcher. Assuming that we make no contact with the robot hurdling is this legal?

I was thinking something along the lines of having our elevator all the way up braced against an opponents overpass. When the opponent would go to launch their ball it would hit our elevator and bounce off. I'm assuming that this is a legal move because we would have made no contact with the opposing robot and if we were bumped our robot would be moved.



Now for question 2. According to the manual a Hurdle is defined as: HURDLE: When a TRACKBALL CROSSES a FINISH LINE while passing above the OVERPASS
and then contacts either the floor or another ROBOT before re-contacting the originating ROBOT.

Does this mean that theoretically passing the trackball over is considered a hurdle?


I would Post in Q/A but I have no clue who has the Username and password

[GaryVoshol]

First question, legal yes. But wise? Some of those trackballs will be coming with a good velocity on them.

Second question, I don't understand what you're asking.

[thefro526]

In the second question I meant to ask is one robot passing the trackball to another robot a hurdle?

And I think If we braced our elevator right it could take the hit from a trackball

[EricH]

In the second question I meant to as is one robot passing the trackball to another robot a hurdle?For the second question, I think it would be a hurdle.

[thefro526]

That is what I though the rule mean too.

[Scott Carpman]

I think for q2, you need to be more specific. I interpret your question to be this situation:

Blueabot Alpha is has just hurdled a blue trackball over the Blue Overpass. The ball lands in the Red homestretch and is picked up by Blueabot Beta. At this point Blueabot Alpha has passed under the Blue Overpass and completed a lap. Blueabot Beta decides to pass the blue trackball to Blueabot Alpha.

At this point, Blueabot Beta passes the ball from the opponents side of the field, over the Blue Overpass, and into the arms of Blueabot Alpha.

This does NOT count as a hurdle.
To complete a proper hurdle, the robot must be in it's own homestretch.

That is, if I interpreted your question correctly.

[EricH]

This does NOT count as a hurdle.
To complete a proper hurdle, the robot must be in it's own homestretch.

That is, if I interpreted your question correctly.That is incorrect (http://forums.usfirst.org/showthread.php?t=8571). To have the hurdling protection, a robot must be in it's own homestretch. Still a legal hurdle.

[Alex_Miller]

Also the ball has to hit the ground or a robot from the other alliance before anything else otherwise it doesn't count as a hurdle.

[Taylor]

From the GDC:

Rule <G42> protects a Robot and any Trackball that may be in its possession during the Hurdling attempt. The Trackball is only protected while it is in the possession of the Robot. If a Robot launches or throws a Trackball, then that protection is no longer in effect once the Trackball breaks contact with the Robot. So, an opposing Robot may attempt to block a launched Trackball. But any team building a Robot that will attempt to do so should be very aware of the effects of momentum, inertia, impulse loads on long moment arms, dynamic stability, and what happens when an unstoppable force strikes an immovable object.

[ALIBI]

Question One: Probably OK, however, most of the launchers that I have seen would not have any trouble pointing a little left or right to shoot around you unless your elevator is really wide (80").

Question Two: Yes. It looks like it will be OK to pass to another robot on your alliance as long as no part of that robot is in or above the home stretch and it must be clear to the refs that for at least a split second the trackball is not in contact with the catching robot after the trackball has completely passed the finish line. There are several Q&A's that get close to answering this question but none that specifically talk about the catching robot.

MasterAlex: I searched the rules and Q&A, I am sorry if I missed it, but I did not find anything that says it must be a robot from the other alliance. This could impact several strategies we are working on. Could you please point me in the right direction to find that ruling, I could have missed something. Thank you in advance.

[Wayne Doenges]

Unless you can reach over 11' high, our robot (Phoenix) will have no problem shooting over you :ahh:

however, most of the launchers that I have seen would not have any trouble pointing a little left or right to shoot around you unless your elevator is really wide (80").
I would think most (if not all) can do this.

[dpc131]

Another thing to consider if this strategy is employed is the moment arm that is created by bracing against the overpass. I believe that if you are blocking and not attempting to hurdle a bump from another robot is allowed to signal a pass. Even a small bump to signal a pass may have devastating consequences.

[cwood]

as for blocking it is legal but you will have a hard time at it even if you do some how manage to be in the way at the right time most shooters that i have seen could simply back up a few feet, taking advantage of their considerable range, and throw the ball well over your arm unless it is 10 to 11 feet high so legal but not nessecarily practical

[Ryan O]

Also, you mentioned "bracing" the arm of your bot. The rules forbid attaching to any of the field elements, so it depends also on what you meant by that

[GBilletdeaux930]

here check out this video. http://robotics.arc.nasa.gov/events/2008_frcwebcasts.php#webcasts two in a row by 537 at about 1:15 to 1:20 they wobble a bit but it was amazing. I was in que for the next match so i saw that and i was just like :yikes: :ahh: the whole crowd was like on their feet yelling because it was so amazing to watch

[Rick TYler]

I can't remember which team it was, but at Seattle a robot blocked the launchers to great effect. They had a tall robot designed to knock balls off the overpass. They would position themselves in the homestretch of the other alliance and just sit. If bumped, they would move off, but the launcher would then be too close to shoot. If the launcher fired from its optimum range, they would either hit the blocking bot, or have to maneuver into a clear position to fire. In either event, the defender either blocked the shot, forced the shooter into a bad location to launch, or simply wasted some of the shooter's precious time. It was a nice strategy, and one that I am surprised not to have seen on Webcasts of other Regionals.

[dtengineering]

Since most launchers don't shoot straight up, the ball remains in contact with the robot as it projects upwards and forwards. This means that a launcher could pull up right behind a blocking robot, fire the ball into the robot, and draw a penalty on the blocking robot as the blocker would be contacting the ball while the launcher was attempting a hurdle. Minus ten for the blocker if the ref catches it, and the ball is still "live" for a hurdling attempt without needing to do another lap.

The refs in Seattle were on top of this... in fact they were on top of pretty much everything... and in fact our final game of qualifying in Seattle was decided in the last few seconds when an opponent was penalized for blocking our shot.

Now it might work better if you positioned the blocking robot on the counter-clockwise side of the overpass. Since the ball needs to completely pass over the finish line to complete a hurdle, the ball would not have scored, and there is no way that the blocking robot would be contacting either the ball or the launching robot in the home stretch.

However I know from our launching experience that our drivers were able to hurdle (and even place the ball on the overpass) when there were two balls already on the overpass... so while the blockers do slow launchers down, they aren't likely to stop them.

Jason

[The Lucas]

In the semis at FLR, 272 did their best Patriot Missile impression by shooting down Sparx's hurdle right over the overpass :yikes: . No hurdle, and both balls bounced back near their launching robot. Craziest thing I've seen so far this year.

[Rick TYler]

The refs in Seattle were on top of this... in fact they were on top of pretty much everything... and in fact our final game of qualifying in Seattle was decided in the last few seconds when an opponent was penalized for blocking our shot.

I certainly saw that shot and block -- it's probably the one to which I referred in the last post -- I didn't realize they called a G42 on it. (You'd think as the scorekeeper I would know, wouldn't you?) That same bot used the interfere-subtly-with-the-hurdlers technique throughout the later matches of qualifying. It worked pretty well, and I don't think it drew many penalties.