Bump or bridge?
 

I think people are overestimating the traffic at the bridge.

Let's put a vote here

Re: Bump or bridge?
 

Is the question which one i prefer to go over?

Re: Bump or bridge?
 

Yes

Re: Bump or bridge?
 

Your most valuable resource in game during a match is time. If it takes you 5 seconds to cross a bridge and 2 seconds to go over the barrier (and neither damages/tips your robot), it is best to traverse the barrier. This extra 3 seconds per zone change is an extra 3 seconds that could be used to get that balance done just right as the clock strikes 0, or hit that buzzer beating 3 pointer! Always keep time in mind when evaluating your options.

Re: Bump or bridge?
 

Bump. The bridges will be like the Breakaway tunnels. Even without traffic, they will take too much time to traverse.

Re: Bump or bridge?
 

Optimistically, the bridge. Most likely, we will go to the bridge during autonomous and get on. We will then stay on the other side feeding the whole time.

Re: Bump or bridge?
 

The tunnels didn't take longer to go through. In fact you can argue that going over the bump took longer. Only when you include traffic did it become a hinderence. That being said there are 3 bridges in this years game so traffic shouldn't be as big of an issue.

Re: Bump or bridge?
 

psst....kinda captained an alliance to einstein in 2010 with a robot that never went over bumps.

Re: Bump or bridge?
 

Remember, you need to push the ramp down every time you have to get on. Depending on the mechanism, this can add a whole lot of time to traverse the same distance over the bump. Getting on the bridges is really only helpful in the end game.

Re: Bump or bridge?
 

The bridge ramp angle is about 17 deg.
With long config and 10" wheels, the bump causes the robot to tilt about 9 deg.

I vote for the bump during game play

Re: Bump or bridge?
 

Reliable ways to quickly crawl up the bump seem to be more feasible if done in the long configuration. If a wide wheelbase is chosen to more easily enable floor-loading, it might be very difficult to cross the bump with a wide but short robot.

Re: Bump or bridge?
 

Our team has almost finished constructing the bridge and its big.

While I do agree most of the team it would be faster to traverse the bump, it may not be always be faster, nor safer.

1. Why it might not be faster.
U have to slow down to cross said bump, if u full throttle the bump, u could flip or damage ur robot. Thus it may not be faster.

2. Robot safety.
Like I stated above, flipping or internal damge is not good.

3. Why bridge.
Practice is perfect. If u can traverse the bridge in qual games, u will get better at balancing because while the bridge is large it is still a challenge.

Personally I would rather traverse the bridge, unless u design the robot to absorb the shock that it will take hitting that bump.

While this is my own personally opinion, I warn caution to any team who tries to traverse the bump.

Re: Bump or bridge?
 

You sure?

having been on a team that went over the bumps in 2010 full speed with little slow down, i know going over these "curbs" is nothing if you use the right drivetrain.

Re: Bump or bridge?
 

Well it went over once...

Re: Bump or bridge?
 

If your design can cross the bump, then you will never be forced to cross the bridge.

As a competitor in the 2001 competition with a similar bridge, I can tell you going over that WILL take you longer than you think, and WILL tip more robots than you think it will. Also, tipping the bridge down so that you can initially get onto it will not be a trivial task for most teams, and will take a significant amount of time. Do not forget that the bridge does not stay down and must be lowered before you can begin to traverse it.

If you doubt me, look up some game video from 2001 and see how bad it can be, that year there were no apposing alliance, everyone was working together as one time and still some robots never traversed the bridge.

Re: Bump or bridge?
 

I think the bridge is a viable option because of the damage that going over the barrier could cause to components, as well as the problems of tippy-ness and designing a frame and manipulator around a bump. Here is more video of the bridge (built by my team today) :http://www.youtube.com/watch?v=zG01r...KrS8tzFvtklp1w

Re: Bump or bridge?
 

That's true, but I think that the 2010 game had a much different dynamic than this game. Zone game play was preferred, and strategies centered on teams staying and controlling a specified zone.

Here, one might have to take multiple trips back and forth in order to retrieve balls. That is, of course, if long range feeder/shooter bots don't become a norm.

But I suppose it's only speculation at the moment. I'll say better to be safe and be able to do both.

- Sunny G.

Re: Bump or bridge?
 

The bridge is a safe-haven from defending/opposing robots. As long as you are traversing the bridge of your color, your robot is "completely protected" from any defensive or opposing robots. One side of the bridge leads to your alley, which is also "safe" from opposing robot interaction (unless the opposing robot wants to get fouled). These are guaranteed by rules G28 and G25.

I could not say the same for the bump. A good defensive robot could theoretically pin you anywhere near or on the bump, which causes problems.

Re: Bump or bridge?
 

Simply put, if your only option is the bridge, you are stuck with the bridge. But, if our system can do both, you don't have to worry about it, and can surprise the competitors. Most systems to cross the bump can also be made to cross the bridge. Just do both.

Re: Bump or bridge?
 

Both. Even if you can get over the bridge swiftly and smoothly every time, another robot can fall off and block it or take half the match to negotiate it.

Wetzel

Re: Bump or bridge?
 

we didnt either

Re: Bump or bridge?
 

I want to do both why isn't that a poll question.

Re: Bump or bridge?
 

Go run game simulations and remember the lesson of Breakaway. You are maximally efficient at scoring when you reduce time spent traveling to a minimum. It seems to me like many people on CD are vastly overestimating the number of times a given robot will need to cross the field to be effective. Go look at the name of the game...

Basically, we think that there will be next to no bridge traffic among alliances that are good at playing Rebound Rumble. Designing a robot to cross the bump adds additional design constraints for both your intake and your drive, and saves you... not that much time. The decision you have to make is whether or not the fairly small amount of extra time is worth designing an intake and drive to cross the bump.

Re: Bump or bridge?
 

My team has currently determined that it shouldn't be overly hard to get over the barrier with kitbot West Coast Drive (without any testing mind you), and if we find that we can't do it with the kitbot drive, we will create a mechanism to get over. Designing the intake to deal with that is going to be a challenge, especially going into this planning to not use pneumatics.

5 Weeks and 4 Days 'till Stop Work Day. Good luck Ladies and Gentlebots.

Re: Bump or bridge?
 

I think it comes down to how many times you plan on crossing the the middle of the field in a match. I am currently thinking that this game will become more like 2010 where many robots had no reason to cross the bumps many times during a match. Some have said that you might as well make your robot able to cross the bump and bridge, but I think there are designs out there that could make the bump a reasonable sacrifice in order to make other parts of your bot better.

But, like I said, it will depend mainly on how many times you think you will need to cross the midfield. If crossing the midfiled is going to be a main part of your strategy, then I think the robot will need to be able to do both.

I created a pole for the number of times expect to cross mid-court to get an idea of what others are expecting. See:
http://www.chiefdelphi.com/forums/sh...ad.php?t=99676

Re: Bump or bridge?
 

I believe the balls are so different from 2010 that you will have to be relatively close (my guess would be the farthest most teams can get it in from is the key). Soccer Balls are designed to bounce, and were meant to be used in a field about 2-4 times larger than the FIRST field. The balls this year are foam filled; it's going to be interesting to see how many teams can get them to travel halfway across the court.

Re: Bump or bridge?
 

This may have been mentioned earlier, but our team is thinking that one robot in each alliance will most likely want to be a guard and pass balls to their alliance's scoring side. This means that the guard bot would only have to cross over once. Using the bridge once per game does not seem like a good enough reason give your robot the ability to jump the bump.


Also anyone planning on just going over the bump is forgetting a very important thing. You will have to have a way to get onto the bridges for end game. For these reasons the people who are planning on doing both seem like their doing the right thing. Personally I feel that it's unnecessary to jump the bump, and that doing so could cause you more problem (ex. tipping, router getting jostled and loosing connection, and potential for damaging the robot just from impact.)

Re: Bump or bridge?
 

Good points. A counter question I would have for you is what do you think your estimated time for crossing the bridge will be? Meaning, approach the bridge, tilt it, cross it.

Even if you save 4 or 5 seconds, and you only cross 2 or 3 times in a match, thats saves you around 12 seconds. That could be over 10% of the entire match.

The tradeoff everyone will need to make a decision on, is that time worth saving by complicating other aspects of your design?

-Brando

Re: Bump or bridge?
 

After a long meeting on sunday and running the 2012 Catalyst; we have decide to go over the bridge but still be able to go over the bump if the bridges are being used.

Re: Bump or bridge?
 

to be honest both would be good for flexablity

Re: Bump or bridge?
 

My guess right about now is three to four seconds added per crossing of bridge rather than bump. We plan to cross once at most; two crossings in a match would surprise me. We are perennially strapped for time given our limited number of full-time mentors, so complicating other aspects of the design is a big tradeoff for us. Basically, we knew during our discussion that if we made the wrong decision, our season would effectively be over... if we didn't build for the bump and it wound up necessary, we'd fail at the tournament, but if we did build for the bump and it wasn't necessary, we'd have wasted valuable time and probably have an inferior scorer.

Suffice to say it was a difficult decision.

Re: Bump or bridge?
 

I like this kind of optimization approach to thinking in FRC. With any game with a small count, recycling game piece, the goal ultimately will become at the very top level an efficiency challenge.

Remember 469? Try your hardest. It's still week 1, anything is possible.

Re: Bump or bridge?
 

True. But F.I.R.S.T. stands for something. So it just shows that efficiency is becoming an important concept in modern technology, increasingly so.

Re: Bump or bridge?
 

Totally agree. This end game is interesting because for the first time in my FIRST career (unless you count Lunacy, which I really don't), that building for the end game actually was advantageous for the majority of the match. Unless you have the capacity to both balance on the bridge and cross the barrier REALLY REALLY WELL, the bridge just seems the way to go.
-$0.02

Re: Bump or bridge?
 

Where is the "both" option?

Re: Bump or bridge?
 

The poll results are making me even more happy with my team's decision to go over the bridge.:D

Re: Bump or bridge?
 

FWIW, we're designing a robot to be good at either scoring from our key or clearing (i.e. launching) balls from the alley to our side. We decided NOT to build a robot that would often traverse the field. It seems like the ability to control the balls will be a dominate factor for the main game.

KC

Re: Bump or bridge?
 

I think it's going to be less important in elims to be able to cross the bump. The strategy that I envision being played out doesn't involve any crossing of the sides more than once, though that requires coordinated and fully functional alliances.

That said, it's not too hard to make a frame capable of crossing the bump anyway without sacrificing much, if anything.

One of our ideas was two powered wheels on two supports connected at an angle. The idea is that you have a sensor rotate the wheels, and if done perfectly, you would barely even notice the bump. Switch them fast enough and you might even be able to drive full speed right through it, as if nothing even happened.

Just an idea.

http://gyazo.com/3bc93bbb13c500e9f7b...png?1326347340

Re: Bump or bridge?
 

We are doing the bump