[MrJohnston]

We first decided what our primary function would be. We then decided how fast we thought we'd need to be able to accomplish that primary function in order to be a top robot.

Our goal was to be able gather and stack 5/6 totes and one recycling container (all off the ground) and stack them in under 30 seconds. Recognizing that some of that time would be used simply driving the robot from spot-to-spot, we knew we needed an "aggressive" intake system and lifter. So, we told our engineering team that we needed the acquiring and lifting mechanisms to accomplish the following in about one second:
* Grab totes and bins (even if not perfectly lined-up)
* Bring them in to the stack (we have an internal-bottom stacker).
* Lift the item just over 12 inches, to prepare for the next tote.

We found several ways to accomplish this, but they all had one commonality: They had some sort of active "grabbing" mechanism on the intake. Every possibility that we studied that did not have such a mechanism was not going to be able to gain control of the totes fast enough to satisfy our speed goals.
Could it be done? I dunno. We are always looking for super-simple ways to accomplish things. We just didn't find it this time.

No, the robot is not finished yet, so we really don't know if we have accomplished the goals... However, so far it is on track to do so. Hopefully we'll know by next weekend.....