Ramp bot vs. Arm bot

Technical Technical Discussion
1

Ramp - bot vs. Arm bot
For those who are not familiar with this year’s FIRST Robotics Competition’s game this year (Rack and Roll), please go to this link before reading this post. This will bring you to the animation that every team in the FIRST Robotics Competition watched on Kickoff on January 6, 2007.
mms://sargasso-3.arc.nasa.gov/2007/first/010607kickoff.wmv

For a more detailed description of the rules, please visit this link

http://www2.usfirst.org/2007comp/Manual/2007_FRC_Manual.zip

Now back to my original question:

What is better for the FIRST Robotics 2007 Competition, a ramp - bot or a robot that has an arm with no ramp? This is the question that was discussed at our team’s meetings during the first week after kickoff.

An arm may be able to score on the Spider Rack but if the ringers are spoiled it will not help the team a lot. Also if the Spider Rack is shaking, it will be much harder for the robots to put the keepers, ringers, and spoilers on the spider racks. Of course if your robot excels in using an arm or some way to score on the Spider racks, then that will not affect you too much.

Conversely, a Ramp - bot will not be able to score well (if at all) on the Spider Rack. So I would guess that each Ramp - - bot would play defense on the opposing alliance for most of the game. The key attribute of the Ramp - - bot is that is that it can elevate its two alliance partners 4 or 12 inches off the ground at the end of the match. This is extremely important because for each robot that is elevated 4-11.9 inches off of the ground, the alliance is awarded 15 bonus points. For each robot that is elevated 12 inches or more off of the ground, the alliance is awarded 30 bonus points. That is a lot of points if the alliances have trouble scoring on the spider racks, then the alliance with the ramp - - bot will have 30- 60 points (if the robots are able to get up the ramp).

I personally think that the ramp - bot is a better robot, because if you can guarantee 60 points for each game, then you have a pretty good chance of winning the match. This is just my opinion but I would love to hear what everyone else’s opinion and/or criticism. As a Team that will be competing at a Regional and the National Competition, we would like to know what the consensus of other teams or just people interested in FIRST Robotics.

To all Teams that will be competing in the FIRST Robotics 2007 Competition, good luck!

P.S. I am a proud member of Team 250 from Upstate New York. I encourage you to visit our website (http://team250.org/2006/index.php) or e-mail me at m.rossi@team250.org

2

The best bots will be able to do both.

As I see it in the finals there are 16 spots for arm bots and 8 for ramp/ lift bots. The teams That will seed highest will have very effective manipulators and will score most of their points on the rack.

3

The problem I see with only Ramp/Defensive bots is that you are at the mercy of your alliance. The more robots that can lift other robots, the more interesting the Rack becomes. Think about it, if both sides can lift then everything depends on the Rack.

5 in a row gets you 32 pts negating one lifted robot. One more negates the second lifted robot(both over 12 inches). So should you try to get a row of 6 or try to lift 2 bots up 12 inches?

One thing is certain this game requires very dynamic strategies that can change in at any second.

4

That is very true but if you have an arm bot you are also at the mercy of your alliance partners. If they have bad ramps or no ramps at all then your team is in trouble.
Also I don’t think that many alliances are going to be able to get a row of 5 or 6 with out it being screwed up by a spoiler. So I don’t think that a long rows will be a big problem

5

A ramp bot does not guarantee an alliance any points during a match. You must rely on your alliance to score any points. This is why I believe an arm bot is better, because you can score points as an individual robot.

6

Its all a matter of population.

Why would you want multiple ramp-bots on the same alliance?

Ring-bots will always be in greater demand then ramp-bots.

(Of course if everyone follows this logic, we will be in trouble ;))

7

eh?

i think you have forgotten that a ramp bot can play defense the entire game. i think the ramp bot could even pin a robot (not sure about the rules on this one). so, that negates AT LEAST one opposing robot. likely a good defense robot can entirely shut out one robot (the best one on opposing team) and do some interference on one other…

so an opposing team with effectively 1.5 bots get 6 in a row? on a moving target that has little clearance for a tube? in 2 minutes or so? wow… that is tough. i hope you have good autonomous mode… oh wait, never mind, the defense bot will just run over there and get in the way…

when you look at it from a whole, i think the best TEAM is to have 2 arms and 1 ramp bot. you won’t win every match, but on the average you’ll likely do well.

2centz
slloyd

8

If you hold the row of 6 till the end(fight the spoilers) then you have a net gain of 4 pts over 2 lifted robots of the opposing alliance!

eh?

i think you have forgotten that a ramp bot can play defense the entire game. i think the ramp bot could even pin a robot (not sure about the rules on this one). so, that negates AT LEAST one opposing robot. likely a good defense robot can entirely shut out one robot (the best one on opposing team) and do some interference on one other…

so an opposing team with effectively 1.5 bots get 6 in a row? on a moving target that has little clearance for a tube? in 2 minutes or so? wow… that is tough. i hope you have good autonomous mode… oh wait, never mind, the defense bot will just run over there and get in the way…

when you look at it from a whole, i think the best TEAM is to have 2 arms and 1 ramp bot. you won’t win every match, but on the average you’ll likely do well.

2centz
slloyd
Reply With Quote

You can only pin for 10 sec, and this year I believe they are going to be very aggressive on pushing an shoving penalties.

In the beginning I also believed that the clearance is going to a challenge but when you consider that fact that the ringer is flexible 30 degrees offset hanging is not going to be terribly difficult…

9

that is the problem. unless you go team by team asking what are you guys doing, then you just have to bring whatever you have to regionals and do what you say you were going to do.

10

What about a both bot ??:rolleyes:

11

If it can do both reliably, all the better.

12

We thought about that too. But we came to the conclusion that it would be better to focus on one attribute and make that work perfectly. If there is time later then maybe we will try to use the attribute we left out (the arm or ramp). But honestly that is very unlikely so I personally think that we should just go with our idea and hope that our alliance partners will be complimentry to our robot. Like Dominicano0519 said, unless you plan on asking every team, then there is no way of knowing who will be building what kind of robot.
By the way, I noticed that some of the replies cam from people who are going to the Finger Lakes Regional. Team 250 will also be competing at RIT, so I will see you there! Good Luck!

13

That is our goal. You know how that goes. Weight might be a problem.

14

Just something that I forgot to ask: For those of you that voted “Something else” on the poll, what did you mean? I would love to know…just to see what what you thought up.
Thanks!

15

Being able to lift two robots 12 inches every round definitely does not guarantee 60 points every round. There are many instances when one of your alliance partners may tip over, become immobile, or just might not be able to get back to the end zone in time.

16

The three teams I have/am working with are all making both bots, ramp and arm, it is quite feasible.

I am a huge supporter of playing defense, check out the elimination matches in Boston, defense was the strategy that worked best for us last year. However the fact that we won Boston it was because we were picked by the two most dominate bots, if we could shut down 1 bot on the other team they could out score the other two. The problem with playing defense is that you won’t seed well; you need to be paired with high scoring bots to win. You are much better off building a bot with a good scoring mechanism (arm) and a powerful drive train. You are not guaranteed to get picked if you are just a ramp bot. The 60 points are not guarunteed, the last two years there were pretty easy ways to score at the end of the round (in 2005 there wasn’t even a ramp) and allot of matches alliances just couldn’t do it. If there are 8 bots at Rochester that can score even 2 or 3 tubes and can be an effective ramp, you can almost guarantee that a pure ramp bot won’t be picked.

If your team could use some help especially with the strategy portion of the game PM me, I am over at RPI, I don’t have a car but I could get over there a couple of nights to meet with you. I talked to your mentors at the RPI/GE FLL competition

17

Well, our conclusion to this was to build a bot with an arm. To have a bot with an operable arm guarantees points for your alliance. To build a ramp bot you really are dependent on your alliance to get up on you, not fall down on their side, not be ramp bots too, and have the ability to score points without you helping offensively. SO, in my opinion it is a good idea to build an arm with as few degrees of freedom as possible and can place a tube on the spider leg in one swoop. Then, if you get your arm working smoothly with time left in the building season, build your ramp. The only pro for a ramp bot is that it can be an effective defense player

18

In my oppion the best way to look at this is to build the robot so that it can place the ringers on the “Spider” and then after that is done and perfected you can move onto the ramp.

also building a ramp-bot make the assumptiont that your other 2 teammates will be able to score the ringers on the “Spider”

If your allience is made up of 3 robots that can score the ringers is better than a team that has 2 ramp-bots and one scorer.

perfect alliance 2 scrore-bots, 1 ramp-bot that can lift two other bots

19

how about: perfect alliance 3 score-bots, one of which can lift the other two

20

the upper echelon teams will be able to score effectively on the racks, the ramp bots, though trivial in terms of strategy to get 60 points, is only true if your two random partners can fit on your ramp. A wide bot wouldnt fit on a bot that was built with a ramp that was narrow. We cant just assume that all bots will fit on everyone else’s ramps and vice versa. The only guarantee is that if you built an effective ringer scorer, you have a great chance to score a lot of points.
Last year, I assumed everyone was building a robot that would go on the ramp since that was a guarantee 25 points. That was not true. At the end of a match, if your alliance is losing, your quick decision might be to move spoilers or add on more ringers to empty positions.
I’m just saying, it all depends.
Just my .02 cents.