Bumpers and the Frame Perimeter

[EricH]

Originally Posted by Steve W

[R02]
The Robot must satisfy the following size constraints:
[...]
E. no other part of the Robot may extend beyond the vertical projection of the Frame Perimeter (with the
exception of minor protrusions permitted per 0).
[...]
If a Robot is designed as intended and pushed up against a vertical wall (with Bumpers
removed and appendages retracted), only the Frame Perimeter (or its minor protrusions)
will be in contact with the wall.

As an LRI it seems clear to me. The bumpers are to be fastened to the frame so how do wheels fit in?

I would like to remind the LRI of the definition of Frame Perimeter found in [R01-2]. This definition allows wheels to extend beyond the frame, provided that they do not cross the Frame Perimeter ([R02-E] as quoted) and the gaps are under the size allowed by [R33] for adequate bumper support (and the bumpers are attached as per [R28-E]).

However, the OP's attached design shows a rather octagonal frame perimeter. This may make compliance with multiple portions of the bumper rules rather difficult. The question in the drawing is which frame perimeter is the real one; the answer is that without something structural (per the attachment rules for the bumpers) out in front of the front wheels and behind the back wheels, neither is the actual one. There's a diagonal portion from the corner of the frame to either the wheel or the standoff, most likely the standoff because the frame perimeter cannot have articulating elements (and this diagonal could easily cause a violation of [R02-E] and [R27]'s 8" coverage requirement from a vertex). Structural elements other than the standoffs would probably not be necessary on the sides due to the gap allowance and the definition of frame perimeter; however, all gaps should be checked for compliance with [R33] and extra structure planned for accordingly.

To answer the OP shortly: No, the wheels would not define the frame perimeter due to being articulated/moving; they would exceed it instead. You'll need something to extend the frame perimeter (as defined by the rules) beyond the wheels.

[Al Skierkiewicz]

Gentlemen,
Without ruling on the bumper design we have to first establish a Frame Perimeter. That is determined by wrapping the virtual string around the frame in the critical zone of 2" to 10" above a flat floor. In the above example, I see nothing that would support the string such that the Frame Perimeter encloses the wheels as shown in the drawing. Bumpers aside, this design does not meet the Frame Perimeter rules.