No Arm for Blocking Shots!

Competition Rules/Strategy
#1

I’ve seen both on our team and discussion here on ChiefDelphi teams considering multi-functional arm units. I’d just like to remind teams of rule <G45> this year:

<G45> Active BALL control - ROBOTS may not control BALL direction with active MECHANISMS above the BUMPER ZONE. Violation: PENALTY.

This means any arm, hanging device, self-righting mechanism, monkey, etc. that is above the bumper zone may not be able to be used to block an opposing robot’s shots (something that needs to be checked with the Q&A). This might constitute changing BALL direction and could incur a penalty. Feel free to park in front of an opposing goal with your robot though and already cover enough with your frame to prevent any shots from going above you.

By the way, this could give teams that can actually pop a ball in the air a major advantage, since teams can only passively block if their robot is tall enough (and the taller they are, the harder they fall…).

#2

I completely disagree with your interpretation of that rule. The key word in that rule is “active”. If your arm isn’t moving and happens to be struck by a ball I don’t see how it violates that rule. Again, my interpretation also could be wrong, but my point is make sure your interpretation is correct before advertising it as so.

-Brando

#3

If you can block with a taller robot, you can block with something sitting still above the bumper zone. It’s just like having the taller robot. It’s not an ACTIVE mechanism, so it should be legal.

#4

I think that this is definitely something that needs to be posed to the Q&A when it opens up. My team had the same debate about this, which lasted maybe 10 or 15 minutes, and nobody could agree on an interpretation. When there are several interpretations of a rule, it’s best to ask and get the official one.

#5

Is an arm that is not moving an active MECHANISM? I would tend to think it is not, but a succinctly worded Q&A question would remove all uncertainty.

Also, remember <G13> - opposing robots cannot cause you to take a penalty through their actions. If the rule is interpreted in the way you suggest, then shooting a ball at my arm would cause YOU to take the penalty. I am almost certain that this is not the GDC’s intent (but I’ve been wrong before).

Either way, I think to declare that this is the correct interpretation of the rule is a bit premature.

#6

Sorry if my original post sounded rather decisive on the issue, I mainly wanted to bring this to team’s attentions since I can see it potentially being interpreted to ban blocking devices.

The issue really is what is an active MECHANISM? The manual says:

MECHANISM – A COTS or custom assembly of COMPONENTS that provide specific functionality on the ROBOT. A MECHANISM can be disassembled (and then reassembled) into individual COMPONENTS without damage to the parts.

Unfortunately the only mention of an active MECHANISM is in rule <G45>, so it’s not really clear what the word “active” means preceding MECHANISM. Does it imply that the MECHANISM is moving? Or only that it can be moved? Perhaps that it is being used for its intended purpose, and movement is irrelevant?

As usual, don’t finalize any designs or strategies until we get our first round of Q&A questions and updates.

#7

Would air be counted as a active mechanism? ie: can your robot have a high powered blower that can change the direction of a launched ball if the blower is below the bumper zone facing upwards at an angle?

#8

Common senes would direct me to think that moving fan blades or other devices to direct air would certainly be an active mechanism, and would definitely violate this rule.

#9

Think about it this way. Would you tell alliance-mates/opponents/judges/your grandmother that:

  1. We have a fan on our robot that deflects balls.
    OR
  2. We have a fan on our robot that blows air. And the air happens to deflect balls.

Although, that still leaves the question of a fan that’s below your bumper zone. Of course, this is a moot point, as soccer balls are a LOT heavier than poof-balls or moon rocks.

#10

So does that mean we can not shoot the balls from the top of our robot?

#11

You can, if you don’t mind getting 3 or 4 or 5 penalties in the process. Please read the manual to see just how many rules are violated by this concept.