My team is at the St. Louis regional. We have already completed inspection and have been running practice matches today. A short time ago an inspector/referee (not sure which) told our team that our robot might be out of compliance with the 2 to 10 inch bumper zone. What happens is our drive train will raise up when we accelerate. This is an side effect of having a freely articulating drive train to converse the bump.

The question is how is this 2 to 10 inch window measured. Is it during inspection? Is it during play? Is the robot supposed to be moving?

I could see this call going either way. The total max height the bumpers get to is 13 inches, before the articulating drive hits a mechanical stop. One part of me sees the issue being a referee issue, but then again how r they going to judge it. You can’t take a ruler out during a match and check. The other part of me says it should be an inspector issue since its a rule in the “robot” rules. We have been basically given the clear by the inspectors, but now they are discussing it with the field crew.

We did compete at Knoxville regional with no issue. No questions at all. Actually we got some, that’s really cool. I know this doesn’t mean anything, but just thought I would add that.

I know I won’t get an official answer from you all, but would just like to see what the general consensus would be.

I personally, am not there yet. So all this information is coming second hand from phone calls. Any comments would be appreciated.

Bumpers must be located entirely within the Bumper Zone when the Robot is standing normally on a flat floor.

Emphasis mine.

Not sure about your situation. I just wanted to post the relevant rule. Hope it helps some. Try searching the Q&A

The bumper zone is measured on a flat floor, while the robot is standing normally.

If you passed inspection, you’re fine. If that inspector/ref keeps bringing that up, send him to the Lead Robot Inspector to get the official ruling/the rulebook.

You should have a manual on hand so you can discuss the issue with the referees and clarify just which rules they think you’re breaking and how. In my opinion, you’re not breaking the rules (unless you’re articulating the bumpers/bumper mounts themselves, in which case you are).

The relevant rules are as follows:

We competed with over an inch of suspension travel and didn’t have an issue. Leaving the bumper zone should only be a problem if the robot is designed to, say, tilt backwards, to the point if it were set on a flat floor the bumpers would be outside the bumper zone. Tilting during the match is alright as long as the robot will stand upright flat on the floor.

At least, that’s the consensus my team came to after a very lengthy discussion. We ended up with “paradiagonal” bumpers, sloping upward from the bow to the stern as a result :slight_smile:

We got a ruling from the officials (still again I don’t know if it was inspectors or referees).

We are allowed to compete but if at any time the refs believe that we are using the “raised” bumpers to our advantage they will give us a technical foul. (basically to do damage to other robots, field, sabotage etc)

Reading between the lines, I think they probably have doubt with the ruling but in the spirit of FIRST are letting us compete. Something to get clarified by Q&A if we get to Championships.

Thanks for the quick responses.

I think this is the same thing as we have. sometimes its even slopes from starboard to port side.

There is no rule that says you can’t use your bumpers to your advantage. If you want to use them to get on top of the barrier, you can. Of course, anything used to damage the field is illegal, so don’t use them for that. If they try to tech foul you for ‘gaining advantage’ from your bumpers, ask them under what rule they are giving it to you under. If they have any doubt in the legality of the bumpers, they should make you comply, not modify the rules to allow potentially illegal bumpers.

The Blue Box Under R01-2 might help.

Though, that doesn’t cover you during acceleration. You could argue that your robot is in a transitory state but it’s a little iffy.

Do you have a picture of your robot’s drive train? You might be able to do something simple like add a piece of surgical tubing to one of the free floating members to make it less likely to move during stopping and starting. Done right, it shouldn’t/wouldn’t make a difference in your barrier crossing ability but this is design dependent.

To avoid any confusion, I believe that the robot in question has a drivetrain such that it can actively change its “ride height” and thus its bumper height; it’s not just suspension travel. If indeed this allows the robot to place its bumpers outside the Bumper Zone, I don’t think it should be competing, but that’s just me…

EDIT: I saw one or two such drivetrains at the St. Louis Regional, and I saw this team, but I’m not sure if they went together. It’d be great if the OP could describe their robot a little more completely…

You might be right, but I interpreted this post a bit differently than you.

If the drivetrain were actively articulated, a solution would be as easy as some programming to prevent unwanted articulation. But since the OP said it was freely floating, I believe that the motion is unpowered which would cause the drive to rock during starting/stopping/changing direction. If they added a slight bit of resistance to this motion (Think a simple spring to dampen it) it might be all they need to keep the bumpers legal while also retaining what sounds to be a nifty mechanism.

I’m glad someone finally tried this, because I’ve long wondered whether FIRST meant to disallow this kind of mechanism with the articulating bumper rule.

If part of your robot follows the bumper, and part of your robot follows the floor, with respect to which reference point(s) on the robot is the articulation supposed to be measured?

(Incidentally, if a connection allows motion, it’s “articulated”—preventing the motion doesn’t overcome that condition, at least if “articulated” is meant to be adjectival. The other interpretation of “articulated” is in the sense of the past tense of a verb. I don’t know which interpretations FIRST had in mind.)

The issue isn’t the field; it’s what might happen to another robot if they hit it when the bumpers are high. Since I’m one of the inspectors that was involved in the conversation with the refs, I think I can explain.

The bumper rules call for 2-10 inches on a flat floor; this includes sitting on the ramps. During transition (over the bumps, onto the ramp) we’re allowed to have the bumpers not be totally within that zone, per a Q&A. The question is what happens when they are travelling on the flat floor (not in transition).

We started trying to figure out if that would be a violation. It’s not; there appears to be no penalty for a robot with bumpers out of the zone while on the field. However, there is the damage to other robots rule (G27). This is what they could get called on. There was some discussion about since they know their bumpers could hit another robot to high, any contact would be willful. I don’t believe that’s where we ended up.

Bottom line: you passed inspection, and we warned you about possible penalties. If you want further explanation you need to talk to the head ref; it’s now out of the inspectors’ hands.

btw, the “ruling” you got was from inspectors. We were all wearing the yellow hats, and not striped shirts… :slight_smile:

I didn’t look in detail at their robot (I didn’t inspect it), but I don’t believe their frame is articulated. That would be a violation of R01-2. Their bumpers aren’t articulated; that’s R30. If their drive train changes position with respect to itself is not any kind of issue; there’s no rule against it.

Just so everyone’s on the same page:

Deliberate or damaging contact with an opponent Robot on or inside its Frame Perimeter is not allowed.
Violation: Technical-Foul and potential Yellow Card
(The damage rule is also found in [G26], strategies aimed at damage.)

I read that as, if it’s a high hit, no penalty unless it’s either deliberate or damaging, and it makes it to or into the Frame Perimeter. You hit the bumpers at all, especially on the outside, all bets are off as to whether deliberate can be called; it’s very possible to make the case that you didn’t intend to, especially with the wide bumper zone this year and the potential ramifications of hitting a high bumper with a low bumper or vice versa. That just leaves damaging–and I hope that people actually build their robots to take a hit these days (back in my day… well, let’s just say that bumpers were optional or non-existent until after I graduated high school, and leave it at that). That’s the ref’s nightmare right there–you have to be reasonably certain that it’s deliberate contact to or inside the frame perimeter before you call that foul.

But, if an opposing robot decides to try to force the issue by hitting while this design is in acceleration, then that robot now has to deal with the risks of [G27], not because of the robot design currently under discussion, but because they’re trying to force a foul and possibly committing one in the process…

It’s only the frame perimeter that can’t be articulated. If the bumper is rigidly attached to that part of the robot, and it always satisfies the definition of a frame perimeter, I don’t think there’s a violation of [R01-2].

Thanks for clarifying, I didn’t understand the issue fully. Highlighterheads are the best!

You are correct; I was imprecise. I’m not sure how to rigidly attach a bumper (which by rule must be non-articulated) to a frame perimeter (which also, by rule, must be non-articulated) in such a way that any articulation could take place. But then, I’m not very clever.

A potential issue is that since their bumpers are so high in this configuration it’d be way to easy for them to go over the top of the other robot’s bumpers, even if there’s a bit of contact between the bumpers. So I don’t think “…hit at all…” necessarily would prevent a penalty. And since it’s deliberate OR damaging, deliberate isn’t necessary. How much breakage is necessary to get to “damage” isn’t something I know anything about; no zebra training for me.

Hopefully there won’t be any issues; they won’t run into someone with raised bumpers and the whole discussion will be moot. The inspectors were concerned that we didn’t let them go through without full knowledge of what could happen, so if they choose to make some change to help mitigate the situation they can. We did that; I hope everyone concerned thinks we did it right. We certainly tried; we had a bunch of discussion before we ever talked to the refs. This wasn’t something that we just kind of breezed into.

But again, the bottom line – you guys should probably go stand in the question box & get a clear understanding, from the head ref, of the refs’ position on this. They’re the ones who’s position matters at this point.

The point I was trying to make was that even when the bumper and the structure comprising the frame perimeter are rigidly attached to each other (as the rules require), that frame-bumper assembly can be articulated with respect to some other parts of the robot. That’s non-controversial when we’re talking about articulation of the frame-bumper assembly relative to arms and shooters (or perhaps we would ordinarily call it articulation of arms and shooters relative to the frame-bumper assembly—technically, they’re the same thing). But when we talk about articulation relative to drivetrains, the perception is frequently different. I that difference in perception is, strictly speaking, unfounded.