Let's Talk About The Bridge:

[vamfun]

Originally Posted by Marc S.

See the rule updates, all robots must be touching the ramp to be supported by the ramp. So now you just have to build a robot that can lift itself high enough to allow a robot to fit underneath. Maybe some team collaboration is needed.

.......any Robots touching it are fully supported by it.”
I am not sure that the new update precludes robot on robot. The bottom robot is touching the ramp and it is supported by the ramp. It doesn't matter that there is another robot on top of it.

However, one could also argue that the upper robot must be supported by the ramp by default since it is on a robot completely supported by the ramp.

Hmmmm seems more clarification is needed here for sure.

[Gray Adams]

Originally Posted by vamfun

.......any Robots touching it are fully supported by it.”
I am not sure that the new update precludes robot on robot. The bottom robot is touching the ramp and it is supported by the ramp. It doesn't matter that there is another robot on top of it.

However, one could also argue that the upper robot must be supported by the ramp by default since it is on a robot completely supported by the ramp.

Hmmmm seems more clarification is needed here for sure.

I would say the intent of the rules doesn't preclude robot on robots, but that's just my interpretation. It's hard to believe the GDC wouldn't want you to get points for balancing robots like that, unless you're trying to use it as a loophole of sorts so you could touch the ground or something.

[Jim Wilks]

Originally Posted by Djur

There actually is a metal bracket on the edge to prevent robots from driving off; it's about 1 inch high if I remember right.

2" angle stock as per the drawings

[Ernst]

Completely unrelated to all of the posts in this thread so far, but I have a new question:

Do these measurements seem accurate?
If not, are they close enough that it doesn't really matter?

[Chinoman27]

OUr team was mulling over an idea like this. Two non driven wheels with no interaction with the drive train are on the end of a rotating arm of sorts. THis arm is left horizontal at the base of the robot within all wheels and bumpers while drivng. When robot is approaching the bridge the arm is pushed down, pushing the wheels onto the ground lifting the front end of the robot off the ground high enough to place front wheels on bridge. Back wheels can still drive robot forward to get front wheels over bridge edge. Then the arm is pulled back and the robots weight pulls the bridge down with the front wheels already on and alternate wheels stowed back below.

[Siri]

Originally Posted by Ninja_Bait

Interesting question. G27 prevents you from doing it on the coopertition bridge:



But not with your own alliance partners. Hmmm....

Hmm...<G27> prevents contacting opposing robots within their frame perimeter. Any rule about the bumpers?

[LinuxArchitect]

Originally Posted by davidthefat

Personally, I want to take all the human aspects out of the balancing. The operators are facing them head on, not to the side of the board. So my plan is to get all the alliance members up and tell them to drop all controls so the software can do its work.

I don't follow... you're expecting each alliance partner to have such software and that it is compatible? That would be taking coopertition to a new level.

[LinuxArchitect]

Originally Posted by Siri

Hmm...<G27> prevents contacting opposing robots within their frame perimeter. Any rule about the bumpers?

You're expected to make contact within the bumper zone. Normally to push an opponent, but pulling/pushing a partner even with the aid of a mechanism would seem ok to me.

IMHO, each robot should have a bumper grabber to aid in bridge balancing by latching on to their neighbor. You have a pretty good (but not perfect) idea where your partner's bumper will be so it shouldn't be too difficult. Perhaps not a top priority though.

[PayneTrain]

Originally Posted by Chinoman27

OUr team was mulling over an idea like this. Two non driven wheels with no interaction with the drive train are on the end of a rotating arm of sorts. THis arm is left horizontal at the base of the robot within all wheels and bumpers while drivng. When robot is approaching the bridge the arm is pushed down, pushing the wheels onto the ground lifting the front end of the robot off the ground high enough to place front wheels on bridge. Back wheels can still drive robot forward to get front wheels over bridge edge. Then the arm is pulled back and the robots weight pulls the bridge down with the front wheels already on and alternate wheels stowed back below.

Why not save your arm idea the stress of lifting a 140 pound fully loaded robot and just push the bridge down in the front?

[noceradave]

the center of gravity of your own robots's a counterweight

[Joe Johnson]

Based on the calcs that I have done (from the info the video provides plus the other data from the rules, etc.),

• at level, it takes about 15lbs at the edge to tip to an empty bridge
• the bridge must weigh about 200lbs and it's CG must below 9" above the barrier top or else their would be zero restoration torque when down - I estimate it is at 7" FWIW
• If two robots with their combined CG on the centerline of the bridge (and they weigh 143 lbs each), it takes 35lbs to push the edge of the bridge down and their combined CG can move +/-5” without tipping the bridge. If one robot is stationary, the other robot can move +/-10”!
• Further, assuming each has a CG 20” above the plane of the top of the bridge and they are in their nominal balance position, if the bridge is tipped to the ground, it will take 39lbs at the edge of the ramp to lift them back up.
• Continuing… if they move from their together from their nominal position, they will have to move more than 6” up the ramp to make the bridge neutrally balanced (+ a bit more to get it to move). Note that this is beyond the 5" they have from nominal (see above) and they then have to stop the bridge so they will have to move maybe 3" back once they start tipping.
• If only one robot does the rebalancing, they will have to move 12" up the ramp ...

I could go on, but this is all physics guys…



There's a lot to think about... ...fun fun fun...


Joe J.

[vamfun]

Thanks for the analysis Joe....

Do we know exactly how far the Bridge edge is from the wall. We have it at around 1 inch. Can anyone confirm this from taking measurements from the actual demo field?

[rscheer]

Does anyone have the wieght of a battery handy?

[plnyyanks]

IIRC, they're ~15 lbs

Edit: looking it up, they're 6.2 kilograms = 13.6686603 pounds (from the datasheet)

[RRLedford]

[Semi-teaser] Once you realize that getting FOUR full size robots on the bridge is quite possible without them overlapping, then the ways for easily getting three on and balanced start to look a lot easier to accomplish.

-RRLedford