Articulation

Are robots with articulated frames allowed under the rules? Any thoughts and suggestions?

Nope.

<R11> The FRAME PERIMETER must be comprised of fixed, non-articulated structural elements of the ROBOT. The FRAME PERIMETER must remain a fixed, unchanging polygon throughout the MATCH.

I would like a more official declaration on this subject, too. An articulated vehicle, just like the big earth movers, would make lots of sense. If you make two rigid frames, shaped like the home plate in baseball, with bumpers covering all 5 sides of each half, it would seem to still meet the rules. At the pivot point, the rules allow for a short section of compressible bumper that the pivot mechanism would squish on one side.

This type of vehicle construction would greatly improve the steering and traction at the same time. It would, however, greatly limit the room for a ball handling/kicking mechanism.

That type of construction would make compliance with <R07> impossible.

Let’s say that you built that frame type rigidly. You would not be able to put bumpers on that met <R07-I> or <R07-A>, attaching to the frame perimeter, under the definition of a frame perimeter, without violating <R07-M>. Now, you make it articulate, as described. Not only are you violating the aforementioned <R07-A> and <R07-I>, you are violating <R11> and, at the same time, <R07-M>.

However, there is a way to do this legally. Build a solid exterior frame in the bumper zone that covers the largest perimeter allowed, and have the articulating drive underneath or inside. (Or just use a crab drive.)

I can understand wanting a more official declaration. I’m just saying that you should prepare for that articulation type, without the above suggestion incorporated, to be officially declared illegal.