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View Full Version : 2012 Bumper rule gray area

ratdude747
07-01-2012, 13:33
after looking at the bumper rules, Bumper height seems to be not mentioned anywhere...

either I am missing something, they missed something, or they intentionally left it ambiguous (perhaps to allow robots to cross the center bump and why lift kits appeared in first choice).
GaryVoshol
07-01-2012, 13:36
Bumper Zone is defined in the Blue Box under [R01], 2 to 10 inches from the floor.
ratdude747
07-01-2012, 13:40
Bumper Zone is defined in the Blue Box under [R01], 2 to 10 inches from the floor.

ah. Brain fart.
GaryVoshol
07-01-2012, 13:41
No, not a brain fart. Perhaps the lack of a search, but nothing more.

But - does anyone remember Blue Boxes specifically mentioned as not being part of the rules in previous years? I can't find any such definition this year.
Al Skierkiewicz
07-01-2012, 15:18
look for corrections in future team updates.
Steve Ketron
09-01-2012, 12:43
so is that 2 to 10 inches measured from the bottom of the bumper correct?????
SteveGPage
09-01-2012, 12:49
so is that 2 to 10 inches measured from the bottom of the bumper correct?????

No, from the floor, as mentioned in [R01] "... within the Bumper Zone, which is between 2 and 10 in. from the floor."

The bumpers need to be totally contained inside of that zone, meaning the bottom can not be any lower than 2 inches from the floor, or the top any higher than 10 inches from the floor.
DarrinMunter
09-01-2012, 13:00
With the bumpers that low, driving over the center bump (not using ramps) is going to take a bit more thinking.....
Japper
09-01-2012, 13:18
[R01] states, "The robot must have a Frame Perimeter that is comprised of fixed, non-articulated structural elements of the robot. The frame perimeter of a robot is defined by the outer-most set of external verticies on the robot that are within the bumper zone which is between 2 and 10 in. from the floor."


To me this reads like it is only covering the side perimeter of the robot and not the bottom as I am trying to see if we can incorporate an extra set of wheels on a swing arm under the robot to allow us to lift our (2" from the floor) bumpers over that metal curb in the middle of the field.

Any thoughts on that?
SteveGPage
09-01-2012, 13:22
With the bumpers that low, driving over the center bump (not using ramps) is going to take a bit more thinking.....

Notice, if you place the bumpers in the higher part of the zone, the bottom of the bumpers would be about 4.5 inches off the floor. The barrier is only 4 inches tall.
Jon Stratis
09-01-2012, 13:23
It definitely seemed like the rules were missing the whole "definitions" section that they've had in the past, where things like frame perimeter and bumper zone were defined.
SteveGPage
09-01-2012, 13:24
To me this reads like it is only covering the side perimeter of the robot and not the bottom as I am trying to see if we can incorporate an extra set of wheels on a swing arm under the robot to allow us to lift our (2" from the floor) bumpers over that metal curb in the middle of the field.

Any thoughts on that?

How the bumper zone is calculated with a swing arm changing the height from the floor sounds like a question to submit to the GDC.
Alan Anderson
09-01-2012, 13:57
It definitely seemed like the rules were missing the whole "definitions" section that they've had in the past, where things like frame perimeter and bumper zone were defined.

Yep, I spent a good half hour searching for it Saturday afternoon. The unobvious definitions seem to be scattered throughout the blue boxes.
the man
09-01-2012, 14:29
Notice, if you place the bumpers in the higher part of the zone, the bottom of the bumpers would be about 4.5 inches off the floor. The barrier is only 4 inches tall.

Wouldn't it be closer to 5", slightly less for bumper covering material?
Bryce Paputa
09-01-2012, 15:13
Another thing with the bumpers, is that one of the images seems to be incorrect, figure 4-2

http://i.imgur.com/o0BbJ.jpg
(http://imgur.com/o0BbJ)

Although there is some unnecessary bumper, I don't see an issue with the circled edge.
Chris is me
09-01-2012, 15:20
Another thing with the bumpers, is that one of the images seems to be incorrect, figure 4-2

http://i.imgur.com/o0BbJ.jpg
(http://imgur.com/o0BbJ)

Although there is some unnecessary bumper, I don't see an issue with the circled edge.

A frame perimeter is contained inside a convex polygon.
ToddF
09-01-2012, 15:23
We decided a better caption for that arrow would have been "not required". Have to see if they change it.
Alan Anderson
09-01-2012, 16:35
The Bumper must be against the Frame Perimeter. On that particular corner, there's a bunch of bumper material inside the perimeter.

If you want to make a separate piece of bumper-ish assembly along that inside edge, and count its weight as part of the Robot, then I don't think there are any rules against it, but you can't make it part of the Bumper.
EricH
09-01-2012, 17:08
The Bumper must be against the Frame Perimeter. On that particular corner, there's a bunch of bumper material inside the perimeter.

If you want to make a separate piece of bumper-ish assembly along that inside edge, and count its weight as part of the Robot, then I don't think there are any rules against it, but you can't make it part of the Bumper.
Exactly.

Over the past few years, a number of teams have asked questions about configurations exactly like the one shown. The response has been, almost universally, "No, it's not part of the bumper. No, that's not the frame perimeter."

Could you do it? Yep. Does it get counted as a bumper? Nope. Does it therefore count against size and weight? Yep. At least, that's my interpretation. (And no, I'm not on the GDC or remotely affiliated with them. So this is not an official interpretation.)
GaryVoshol
09-01-2012, 20:39
Notice that a portion of the "interior bumper-like structure" extends beyond the Frame Perimeter - that's the primary reason it's not OK. The section of the actual Bumper that extends partially across the cutout is also troublesome; I don't know if the rules address it as "unsupported" or not.

And as noted above, any bumper-like structures that do not qualify as Bumpers must be counted in size and weight.
rich2202
13-01-2012, 01:06
Bumper Zone is defined in the Blue Box under [R01], 2 to 10 inches from the floor.

Seems clear on the face of it. Even traversing the bridge, the bridge floor is the "floor", and the 2-10" zone can be maintained at all times.

Times when the 2-10" zone is exceeded:

1) While balancing (especially with 3 bots), when a bot "overhangs" the bridge, is the plane of the bridge floor considered the floor, or is the part that overhangs counted from the arena floor?

2) When traversing the barrier, the barrier can be considered the "floor". But, once you overhang the barrier, is the arena floor now the floor? If you have big wheels, it will lift the front of your bot way above the the zone. It might be in the zone with reference to the barrier, but once the front of the bot clears the barrier, the wheels may still be on the barrier, and the bumper is way out of the zone.

If the barrier is considered the "floor", then it causes a problem when the frame goes over the barrier before the wheels lift the bot. The bumper could have 0" clearance of the top of the barrier.
Al Skierkiewicz
13-01-2012, 07:53
Rich,
Bumpers are inspected when the robot is on the floor. That is the only logical way to look at them. If a robot turns over, the bumpers do not become illegal simply because they exited the bumper zone.

[R29]
Bumpers must be located entirely within the Bumper Zone when the Robot is standing normally on a flat floor.