Flipped Trailer

[aRm]

Would a robot be disabled if their trailer was somehow flipped on its side during a competion? I was thinking that with the low friction there would be a lot of "power-slide" type turns with the trailer flailing out behind the robot. And if such a turn is done fast enough or another robot hits the trailer just the rightvway in the middle of a "power-slide" turn there is a chance that the trailer might flip.

I have not personally seen one of the trailers in person and I do not how the how heavy the trailer is or how the weight is distributed, so what I am talking about might never happen.

Also I do not remember reading about rules covering this issue in the 2009 Handbook, but I just might not have looked hard enough.

Thanks :confused:

[EricH]

It probably won't be disabled by the referees, unless <G30> Arena Damage is occurring. However, I personally would strongly advise that if a trailer tips over, the team towing the trailer should hit the E-stop just to make sure. <G31> allows this, and the reason I say that is because a 150 lb robot towing a 30+ lb trailer that probably has a much higher coefficient of friction than the robot does is pretty close to incapacitated.

[ScottOliveira]

I think it is unlikely (although possible) that a trailer will flip. The low friction allows for very easy slipping, so the trailer is far more likely to slide than flip (the trailer rolling over is in the simplest sense a wheel, in order for it to turn there has to be enough friction that it doesn't slip). The trailer also has a fairly wide wheel base, which also makes it harder for it to turn.

Our team has done some practice with a basic trailer, that never came close to flipping even when it was whipped back and forth, but I'm not sure if they had the swivel hitch installed (which is necessary for the trailer to flip without the entire robot going over as well).

[wendymom]

Bacon played Human Lunacy last week along with 665 and 2757. Trailers flip much easier than you would think. Granted ours were trash cans attatched to the kids belt loops by carabiners...but still. When you tried to turn fast or to sharply...flip!

[ScottOliveira]

Bacon played Human Lunacy last week along with 665 and 2757. Trailers flip much easier than you would think. Granted ours were trash cans attatched to the kids belt loops by carabiners...but still. When you tried to turn fast or to sharply...flip!

I don't feel that Human Lunacy would be very comparable to the real game. First, a trash can (presumably wheeled in some way) would have a significantly higher center of gravity (unless the bottom was additionally weighted in some way), which would make it significantly easier to flip. Also, attaching the tongue higher up also makes it easier to flip, as any applied force is translated in part into an upward force on the base. There are many other things that could affect your results, but I am not sure of the details of how you played your game.

[Vikesrock]

From my unscientific building and playing around with our team version of the trailer it will be MUCH harder to flip than a garbage can.

We had similar issues with trash cans with our human lunacy on the school's linoleum floor, but no such issues whipping the trailer around behind last year's robot.

The CoG of the trailer appears to be pretty low to the ground and the wheelbase is pretty wide. Coupled with the low friction I think these things will be near impossible to tip ( <1 per regional)

[Black Claw]

From the way the trailers design is, i think it will be heard for the trailer to be flipped. But if it finds a way to be flipped, I think your would be disabled since the trailer connection is connected to the trailer.

[writchie]

.... but I'm not sure if they had the swivel hitch installed (which is necessary for the trailer to flip without the entire robot going over as well).

If you examine the latest drawings closely you will find that the swivel hitch is pinned so the trailer and robot share the same fate as far as tipping is concerned.

[Ryan Caldwell]

it is far more likely the trailer will just slide rather than flip perk to having no friction.

[ScottOliveira]

If you examine the latest drawings closely you will find that the swivel hitch is pinned so the trailer and robot share the same fate as far as tipping is concerned.

I hadn't looked at the drawing enough, apparently. Upon further examination it seems you are quite correct. This means that the likelihood of the trailer flipping depends on the likelihood of your entire robot going. Any robot with a high center of gravity will be more likely to have their entire robot and trailer combo go.

I think this also raises an interesting question - in the event of an accidental trailer flip, how are balls that fall out scored? Rule G25.1 states:

<G25.1> De-scoring GAME PIECES – Once a GAME PIECE has been SCORED, it may not be intentionally de-scored (e.g. removed from the TRAILER). De-scoring a GAME PIECE will cause a PENALTY to be assigned. At the end of the match, any intentionally de-scored GAME PIECES will be considered SCORED as originally placed. GAME PIECES that are knocked free from tenuous placements as a result of normal game interactions (e.g. a GAME PIECE on top of a pile of MOON ROCKS that completely fill a TRAILER falls off when the TRAILER is bumped) will not be penalized.Emphasis mine.

If the trailer flip were accidental, would any balls that roll out of the trailer not count? The trailer could be scored by the balls in it when it flipped, but that would prevent further scoring by the other team. If balls that roll out still count, there would be the possibility that a team scores with the same ball twice, by pushing an already scored ball back into the overturned trailer. Any ideas on this?

[EricH]

I do believe this has already been asked, at least partially, in various forms on Q&A.

http://forums.usfirst.org/showthread.php?t=11243

In case of trailer tips, the score in that trailer is preserved for the rest of the match. Should game pieces come out, they're anybody's to score again.

The question is, can you score in a tipped trailer? Physically, I think it would be possible, based on the definition of scoring. However, I'm not quite sure if a tipped trailer can legally be scored on.