Question on 3 inch perimeter rule

[Leav]

Originally Posted by GaryVoshol

All of this is really academic. It doesn't matter. The FRAME PERIMETER is defined at the BUMPER ZONE height, 10 to 16 inches off the ground. That's above the ball. If you want an indent below the BUMPER ZONE to channel the ball, it's perfectly legal. The ball will fit under your bumper.

If I understand you correctly I think you are mistaken.
step 1) define frame perimeter (e.g. using the string method)
step 2) ball may not enter more than 3" into frame perimeter, when viewed from the top. (i.e. may not enter more than 3" into the projection of the frame perimeter to any surface parallel to the floor)

[GaryVoshol]

Originally Posted by Leav

step 2) ball may not enter more than 3" into frame perimeter, when viewed from the top. (i.e. may not enter more than 3" into the projection of the frame perimeter to any surface parallel to the floor)

<R19> ROBOTS must be designed so that in normal operation BALLS cannot extend more than 3 inches inside the FRAME PERIMETER below the level of the BUMPER ZONE.

(emphasis mine)

But

<G46> BALL Penetration Restriction – The BALL must not extend more than 3 inches inside the FRAME PERIMETER as defined in Rule <R19>. Violation: PENALTY for a basic infraction, plus a YELLOW CARD if no immediate attempt to remedy.

They really should have repeated "below the BUMPER ZONE" here, instead of just referencing <R19>.

Nevertheless, this is the way it has to be interpreted. Else, whenever an airborne ball went above your robot, you'd be in violation.

[Leav]

Yup. thanks for the correction!