[nathan_hui]

Not necessarily. The frame perimeter in the contact zone needs to be covered in bumpers. The rules never specify bumpers above the contact zone. In fact, the robot cannot exceed the frame perimeter (at the contact zone, thus the bumper perimeter) in starting configuration, so a spherical robot is impossible.

A circular robot on the other hand would be confounding. However, let's assume for a moment that the robot is perfectly circular (practically, it never could be). Thus, there would exist either no corners, or an infinite number of corners. Now, a strict interpretation of the rules indicates that each corner must have at least 8" of bumper on either side not that each side be at least 8 inches. Thus, if a circle were to consist of all corners, then the entire frame perimeter would need to be covered with bumpers. If it were not, then no bumpers!

However, we know we can't make a perfect circle. We'll have to make it an infinitesimal n-gon, or as near that as possible. Thus, we define it to be infinite corners, thus the robot needs bumpers on all sides. Practically, though, it'd probably be a single U-channel bent and welded or bolted at one spot to itself to close the circle. So if you could bend it nicely, then it'd actually be a teardrop, so you'd only need a 16" bumper near the weld!

To be honest, the rules, especially in previous years, have had disclaimers stating that the intent of the rule, not the word of the rule, will be enforced. I believe the intent of the rule here is to prevent injury and damage to a robot or human should a corner come in contact with something. A 90 degree corner will normally rip stuff, if there's no covering on it. A round bot won't run corners into anything, it'll just rub. I don't think bumpers were intended to protect much against head-on collisions - it wouldn't help with holes in the bumpers (as the rules currently allow), so I think that the inspectors wouldn't consider that. Likewise, the GDC probably wouldn't have thought this discussion possible, or if they did, they probably (and rightly so) guessed it to be purely theoretical.

Sorry about the rant. I think I got my point through though.