Real-time balancing strategy

This has been said before, but teams need to put more thought into their “real-time” balancing strategy with their teammates. Several times this week, I’ve seen alliances with large leads attempt to do a double balance and fail. This almost always results in at least one robot taking a hard crash on the floor. Many times, it results in neither robot balancing, either because both teams fell off or because a robot that fell off is still touching the bridge.

So teams, if you’re winning the match by more than 10 points and expect it to stay that way, back off and let one robot balance. I know you planned to double balance at the beginning of the match, but if it won’t help you win, why take the risk? I know you want to show off, but please don’t, for the sake of strategy and your robot’s health.

On the other hand, if you and your teammates not afraid to take a fall, maybe it’s good practice for elims…

Finally, how do you actually coordinate this on an alliance? I’m curious to hear from some “people on the ground” about how they’ve handled this.

It is important to do 2 things when preparing a balance strategy. First, plan ahead and stick with the plan. We had a couple situations during the qualifying rounds at Waterford were alliance partners changed there mind on balancing in the middle of the match, leading to a loss. Second, decide who will adjust to create balance. One strategy is to have the robot on the side highest in the air adjust. What you don’t want is 2 (or 3 in the case of a triple balance) adjusting at the same time. As the season continues balancing will improve. Our elimination alliance at Waterford has the distinction of being the only alliance to pull off a triple balance and still lose the match. I predict that “double triples” will be common by the Championship.

We always had someone park on the bridge and let go of the controls and we pushed the other bot up. (we cant do a triple) On that note, I’ve noticed at Waterford if you get good at driving its not hard to defend against a triple balance if your there before the other robots. 3601…beat us by two points, it was a great semi-final match. We need to get good at the bridge defense. :slight_smile:

This is a perfect. It’s our exact focus this weekend, first figure out which team best first the Co-op balance with us and make sure we stick to it. For with-in alliance balances, a lot of it is good communication between driving coaches.

If you’ve got a strong drive train and a good bit of traction on the bridge, the best way to balance is have only one team do the pushing. When we were doing our triple balance at FLR, we advised our alliance to drive against us, at a relatively fast rate, so we would all stay stable and no one would roll. It’s almost as good as having a bridge appendage. However, that only works if you have really good traction on the bridge, and carpet, and have a strong drive train (we did–rubber treads and supershifters).

On the subject of in-match strategy, it’s important to make it clear to your partners before the match that in a case that you will win with a single balance, which robot should be the one that stays on the bridge.

Every time I see someone fail a double when they would have won with a single, I cringe.

I’ve been working my keester off trying to perfect balancing over my team’s competitions. My teams and teams we work with have had a total of two robots, one at each event, fall off the bridge, but each time it was for forces outside our control.

Here is what I look for from my teammates as well as whoever I am coopertitioning with:
-If a team can and does shoot, how accurrate is it?
-Can they lower the bridge, and if so how effective/quick/controllable is that operation?
-How effectively can teams communicate with each other?

Those three are the absolute most important pieces, and really the third one is BY FAR the ABSOLUTE, MOST CRUCIAL ASPECT!!! I cannot emphasize enough how much it helps to talk it out with alliance mates.

I ask about shooting because those points are still important in winning matches, also to get a better idea of what kind of timing is going to be necessary. Most of the time, if a team can shoot very well, I have them spend about half of the match shooting and then focus on the balancing. That has been working extremely well so far.

Bridge manipulation is obviously imperative in this game. Teams that can effectively lower the bridge and get on it have tended to focus on this aspect even if they are good shooters. Once the bridge is lowered, it becomes a matter of how to get (hopefully) two robots on without causing damage/flips/etc. What has been beyond helpful here is having one robot lower the bridge, and then have one of the alliance bots just push the first one up the bridge SLOWLY. Slow and steady definitely wins this race.

COMMUNICATIONS!!! I CANNOT STRESS THIS ENOUGH!!! ALLIANCES MUST CONTACT ONE ANOTHER IN GAME!!! Here I give a huge advantage to my pardners because I happen to be very, very, very good at yelling effectively. When getting on the alliance bridge, it is sooo soooo sooo helpful to have the two teams working on balancing communicating or at the very least working towards some plan. What I’ve noticed is that as long as the two teams know what they need from each other, things work out better. For example, the first team up the alliance bridge (most of the time/in my experience) needs to let the second team get right up on them, to the point that the second team should be pushing the first one up the bridge. Once the two of them are on, a lot of success was had by just stopping and allowing the bridge to fall as it may. Throughout this process, there needs to be as much meaningful back-and-forth communication as possible. Like, the first team up needs to be telling the second team to push and keep pushing or whatever. With regards to plans, having them is fantastic, and remembering them is nigh on impossible. I always, always, always, try to have a rock-solid plan within the three teams on my alliance. Then, during the match, I always try to remind my teammates of the plan we agreed on so that everything works.

With regards to coopertition, this part of the game has become astonishingly important. Here plans become vital. With the coopertitioning teams, I always stress the importance of deciding on a single, firm time in the match to start working on the balancing. Anything less gets to be messy, unless the two teams doing it are so good at the process that they can do it in no time flat. During today’s matches, my team focused on coopertition, so I have gotten a ton of fresh insight. Our best results came from having a set-in-stone time that we went for the coopertition bridge balancing act. At that time, it takes a certain amount of pre-determined choreography to make things work. Today, when it worked, which was about 5 times for us, the key was getting the two teams coopertitioning to drive together (i.e. both touching, one pushing the other, however it makes sense). Once both were solidly on the middle bridge, it was perfect. I am not kidding when I say that we were able to balance in a matter of 15 seconds at the most, and there was essentially no worry of multiple bots balancing at once.

Speaking of active balancing…I admit I stole this from another team, but it’s fantastic advice anyway: only ONE robot can be the active balancer at a time! This revelation has been saving teams lives in competition. Most of the time, what I’ve been advising my alliance pardners to do is get the robots solidly on the bridge and then stop moving. Let it fall where it may, and whichever robot is in the air is the only one that should move, and it should move very, very slowly and carefully.

We allocate 30-45 seconds to balancing (what a handy warning sound they play at 30 seconds to remind you that you better hurry!), take another (hopefully) predetermined robot with us, and get up there. We ask the bottom robot to push us, and when they usually can’t, we drive slowly enough forward that we never lose bumper contact. If we overshoot, we try to do the same thing going upwards. Nothing scares me more than when the other driver starts to drive up fast enough that they break contact. I really don’t want anybody to flip my robot.

But when things happen in the elimination rounds and you suddenly have to go into an unplanned double balance with another team, it’s good to follow that strategy. If you both can and have balanced before, stick to that, don’t move fast, and don’t do anything drastic. You should be talking, quite possibly yelling, to your coaches about what you see, how you feel about what’s happening, and what you want. Just let it all out there and leave it to your coach to decide what to tell the other coach/driver.

We only flipped one robot at our event, and they got flipped next time they played the exact same way. They only drove halfway onto the bridge before stopping. We tried to push them off the bridge, but they came back, and they wouldn’t listen to our coach telling them we would do it alone.

You either need to know what you’re doing, listen to someone who knows what they’re doing, or get away from the bridge.

My team’s strategy that we implemented at the Sacramento/Davis regional was to start balancing with 2 robots at about the 50 sec left mark. This usually was enough time, but what we would do is at the 20 sec mark, if it didn’t look like it was going to happen, whoever was on the lower side of the bridge would bail out, and the other robot would balance by itself. 20 seconds was usually just enough time for 1 robot to balance by itself, so it probably wouldn’t have been enough for 2.

This strategy worked out pretty well for us, and by the end of the qualification matches on friday our team was tied for the most bridge points of anyone at the regional.

To add to the fray, I actually saw this happen at the Oregon Regional. Team 2046 was in the process of balancing, and they were a few points ahead of the other alliance. The other team was attempting to balance one robot, and you could tell that the original intention of 2046’s alliance was to double balance, but at the last minute, they let up and single balance. Some people were like “wait, what just happened?” but it actually was a very strategic move: They knew that if the other team balanced and they themselves didn’t, they would lose the match, but if both single balanced, they would still win. They won.

I agree that it’s important to try to stick with a plan, but if the opportunity presents itself, in RTB (Real Time Balancing), from what I saw, making quick decisions may win you the match. It was a REALLY exciting match.

422 has a lower OPR than it could have gotten simply because we played to win. We would scout out an alliance, and most of the time we could take our hybrid score, single balance the bridge, and win. The only times it didn’t work was the first match, where I didn’t give my driver enough time, and in two matches where we were left stranded on the co-op bridge while the other team took their bridge for the win.

We won a lot of matches because teams got greedy, or weren’t paying attention. Two of our wins came from unnecessary double balances on the opponents’ bridge that ultimately failed to score a single balance.

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This happened to us a couple of times. Our team was on the bridge in the process of letting our partners on and I (the coach) realized that we had enough of a lead that a double was unnecessary. Step one, I tell my drivers to balance the bridge which will stop our partners from getting on. And then I run across the alliance station, tap our alliance’s coach on the back, and tell the to back away. Works well.

Great stuff on here. At our first regional, it seemed to us that many robots would experience unwanted rolling down the bridge while trying to balance with a partner. This seems to often result in some kind of toppling, either us or our partner. We’ve been working (with our practice 'bot) on a braking system to lock 2 wheels until the bridge has a chance to come to rest, and then make any final adjustments. Has anyone seen a braking system used, or have thoughts on it’s usefulness?

I know the Space Cookies had a system in Davis where they could basically stick a pneumatic piston through one of the gears in their gearbox to act as a break. To my knowledge, they never really used it balancing the bridge, because of the necessity of making both coarse and fine adjustments to their position up until the last moment.

We used pneumatic cylinders with an aluminum “pad” against one wheel on each side of our robot for brakes (shamelessly copied from 1477 after seeing how well theirs worked in Thursday’s practice sessions). Being able to lock your robot in place on the bridge makes a HUGE difference in how easily and how fast you can balance it whether it’s a single balance or multiple robots trying to balance.

I haven’t seen anything out there that worked better at locking a robot onto the bridge.

Thanks for the feedback. This is exactly the approach we’re pursuing. We’ve never seen 1477’s robot but props for being first with the idea. Good luck to all in week 4. :smiley:

I wasn’t that we weren’t the only team at Alamo with brakes on the robot. It’s cool to learn that we and 1477 went down the same path there.

Our software guys developed an “e-brake”, which (as best as I understand it, being a non-engineer) basically holds the robot in position on the bridge, using microadjustments in force generated by the motors based on gyro input as to whether the bot is moving. Or something like that. Anyway, with the e-brake on, the robot doesn’t move, it just sits on the bridge whether it is flat or tipped.

I would think a physical brake would be helpful if you can do it, for example, on the coopertition bridge. There is 1 point for being fully supported but unbalanced, so if you can hold yourself and the other robot on at the end of a match (by tipping the bridge your way and engaging the brake) you can still get a point, whereas a robot with an “electronic brake” system would simply roll off at the end of a match.

On a slightly related note, it seems that getting 1 coopertition point this year is quite a bit more difficult than getting 2. Maybe the GDC will come up with a more intuitive “consolation point” system for Championships. They did reserve the right to alter bridge scoring, after all.

Yeah, I realized that the other day - that it will still roll down when power goes off. Oh, well, can’t have everything. (Or maybe you can, but we don’t.)

Our electrical team was able to wire the brake/coast jumper pins on our drive victors to the Digital Sidecar, this allows us to control brake/coast in code. Our driver can enable “Bridge Mode” in order to switch to the breaking setup, as well as some other driver interface tweaks.

We also found that a low gear is incredibly useful this year, as it makes balancing many times easier.