Week 1 lessons learned: balancing strategy

[ToddF]

I've been watching the KC and Alamo regionals streaming today and have seen many attempts to balance a bridge with two robots, and some successes. Many of those attempts end up with a flipped robot. I hope other teams are watching as well, and will think hard about their balancing strategy.

What works: Drive onto the bridge. Tip it towards the other robot. Allow the other robot to push you onto the bridge and do the backwards scoot to do the final balance.

How to flip over the other robot: Drive onto the bridge. Tip it towards the other robot. Allow the other robot to drive partially onto the bridge, and back away from it. Attempt to balance the bridge yourself.

This second method nearly always results in both robots fighting each other for control of the balancing. Sooner or later one of them ends up partially off the bridge when the other is on the far end, flipping the one on the downhill side.

DON'T be the team that flips anyone who tries to balance with them. Please.

[wilhitern1]

Our problem at the moment is that we have questionable traction (we're working to improve it). Pushing another robot up the bridge seems unlikely for the time being... We expect to be able to get on the bridge without help however.

[GCentola]

Another thing I've noticed is that teams arent allowing enough time. The bridges seem to be last-second thoughts, and often dont turn out successfully.

On the cooportition bridge, it doesn't appear that there is any logical plan for approaching it. Are alliances discussing it pre-match? It would seem as if some sort of pre-planned process would help balance (as you said, two robots trying to adjust for each other just makes it wobble back and forth)

[pandamonium]

Why are some robots spending the entire match trying to pick up balls or shoot and miss a hand full of times but then never have time for the bridge? They could spend the majority of the match focusing on the bridge. I think it is important to be realistic with the strengths and weaknesses of your robot. 20 points seems to be enough to win the majority of qualification matches...

P.S. I would love to see 1126 and 1511 on a cooportition bridge together next weekend.

[GCentola]

Originally Posted by pandamonium

P.S. I would love to see 1126 and 1511 on a cooportition bridge together next weekend.

Same! We are looking forward to FLR! You guys definitely have a cool robot! If this happens, i'm sure we will know what to do after reading this thread.

[Grim Tuesday]

Right now I'm feeling really good about making our robot have a very high traction drive system. There seem to be a lot of teams who are slipping all around the bridge and are completely unable to pull off a balance. I would be surprised to see many of these teams in eliminations.

[GCentola]

Speaking of low traction, that seems to be the death of 1 Co-op point. If both alliances are on the C-Bridge, but it isnt balanced, you still get one CP each, but it looks like right after the match ends, the bridge tips to one side and the one on top pushes the other one off accidentally when it slides down.

[who716]

Originally Posted by GCentola

Speaking of low traction, that seems to be the death of 1 Co-op point. If both alliances are on the C-Bridge, but it isnt balanced, you still get one CP each, but it looks like right after the match ends, the bridge tips to one side and the one on top pushes the other one off accidentally when it slides down.

Yes we thought of this during build session and ended up using a two speed transmission this helps a ton on the bridge because it allows us to make very slow movements while on the bridge and it allows us to stay on the bridge if its tilted or not. the only bad thing is getting it of the bridge after we balanced as its hard to roll.

[Alpha Beta]

Originally Posted by who716

Yes we thought of this during build session and ended up using a two speed transmission this helps a ton on the bridge because it allows us to make very slow movements while on the bridge and it allows us to stay on the bridge if its tilted or not. the only bad thing is getting it of the bridge after we balanced as its hard to roll.

Your post reminded me to go back and watch our 2nd match. It looks like our low gear keeps everyone on the co-op bridge for 5 seconds after the match ends, even though we are not at rest. According to G37, and G41 this should have been worth 1 co-op point to both alliances. It was not awarded, we did not even think to challenge for it at the time, and it does not appear as if the refs are even looking for the 5 second count.

Video (Match 17): http://www.more.net/content/2012-qualification-matches
Match ends at 3:43 on the video, and wheels don't touch carpet until 3:52. At that point the ref gives the all clear signal. Head ref is clearly watching the robot roll off the bridge, but has no reference to the 5 second stipulation from G37.

Lesson Learned: If you have a low enough gear to put yourself in this situation you may want to ask the Head ref how they will determine when 5 seconds has elapsed during the drivers meeting on the Thursday practice day.

PS. What difference would this have made? In hind sight, none. At the time it could have been huge.

[GilaMonsterAlex]

I was really surprised to see that so many teams didn't get the strategy of balancing the bridges (not to say it's easy). I was expecting more team work.

Since the kick off, I was harping to my students about how we should "choo-choo" onto the bridge with another team. It was a major reason why we withheld our bridge manipulator. We weren't sure we needed it.

Now I'm going to make sure to harp about communication with the alliances about our balancing strategy. It will make for a much better competition.

The one thing I'm going to predict is that more and more teams will abandon ball scoring and line up on the bridge balancing. This to me makes the game a bit more boring and takes away the challenge. I wouldn't be surprised to see a rule change where you have to wait til the 30 second mark before you make an attempt to balance the bride (not crossing).

Also, just so I understand this correctly. 148 uses a piston or shaft down to the ground to level out the bridge correct? Do they lift the piston right before the end?

[wireties]

Originally Posted by GilaMonsterAlex

Also, just so I understand this correctly. 148 uses a piston or shaft down to the ground to level out the bridge correct? Do they lift the piston right before the end?

Looked like that to me...

[dj bauch]

Originally Posted by GilaMonsterAlex

Also, just so I understand this correctly. 148 uses a piston or shaft down to the ground to level out the bridge correct? Do they lift the piston right before the end?

Yes, they had a little "foot" they could use to stabilize the bridge. Very clever design. Once the bridge was stable, they would lift the foot back into the robot.

[Kimmeh]

Originally Posted by GCentola

On the cooportition bridge, it doesn't appear that there is any logical plan for approaching it. Are alliances discussing it pre-match? It would seem as if some sort of pre-planned process would help balance (as you said, two robots trying to adjust for each other just makes it wobble back and forth)

At Kettering there seems to be a fairly consistent planned attempt for the cooperation bridge. (Whether is works is a different story however...)

And yes, the second robot pushing the first robot on the bridge works better than each team trying to balance individually. Warning: Less is more. Small baby steps will get you further than plowing straight through.

[Tetraman]

I was the driving mentor/instructor for 174 this year, and I can say we have practiced the art of balancing every chance we could. Mastering such a thing is always difficult for anyone as a slight movement alters everything. But the number one thing we discussed was allowing time to score on the bridge and being ready for a team that makes a last second mad dash. If we get on the bridge with 30 seconds, or even a whole minute left on the clock, as long as it will end up with +10, +20 or +40 to our score (or +2 qualifying points) it will be worth it.

[dellagd]

Originally Posted by GCentola

Another thing I've noticed is that teams arent allowing enough time. The bridges seem to be last-second thoughts, and often dont turn out successfully.

On the cooportition bridge, it doesn't appear that there is any logical plan for approaching it. Are alliances discussing it pre-match? It would seem as if some sort of pre-planned process would help balance (as you said, two robots trying to adjust for each other just makes it wobble back and forth)

Definitely discuss pre-match. I usually go out and find our alliance members 3 matches in advance to discuss these things.

Originally Posted by Tetraman

I was the driving mentor/instructor for 174 this year, and I can say we have practiced the art of balancing every chance we could. Mastering such a thing is always difficult for anyone as a slight movement alters everything. But the number one thing we discussed was allowing time to score on the bridge and being ready for a team that makes a last second mad dash. If we get on the bridge with 30 seconds, or even a whole minute left on the clock, as long as it will end up with +10, +20 or +40 to our score (or +2 qualifying points) it will be worth it.

My thoughts exactly. Our team was struggling but once I realized this, it was a good thing.