Mecanum on the bridge?!

[bearbot]

Well done and congrat on the FIRST team to post video

[578robotsrock]

A robot that could do this would be a welcome to any alliance, assuming the shooter/scoring function works.

[the man]

Good. Now how does it fair against the steel bump?

[redlau]

How are they planing to tilt the bridge? or are they planning to have an alliance member tip it down for them?

[mr.roboto2826]

I believe this is a test with there 2011 bot to see if mecanum would work for the bridge. Nothing more.

[578robotsrock]

This is withing no doubt a 2011 robot they are using for proof of concept. I'd like to see a video of them against barrier next.

[Djur]

Originally Posted by mr.roboto2826

I believe this is a test with there 2011 bot to see if mecanum would work for the bridge. Nothing more.

Exactly. We should have a video of automatic balancing out in a few days.

[Soxman04]

Good find Xenozero!

I'm team captain of RobotsByTheC, and I filmed that video. That is in fact our robot from last year. I was kind of surprised the robot was able to do it. Its incredibly top heavy with its center of mass far in the front. The material on the bridge actually has about half the friction of lexan, the material used on the actual bridge. We used fiberboad, because lexan is expensive. I'de be happy to take any other questions.

[J93Wagner]

While I can't say anything about the legitimacy of the video, I can say that what you saw is possible as we tested for that on Monday and got results saying that it can be done.

[dtengineering]

Check out the 1:00 minute mark on this video for confirmation that mecanums can climb.

http://www.youtube.com/watch?v=gyn9e...eature=related

With Jaguars and the cRio, building a feeback system to ensure that it climbs straight should be much easier than driving with the open loop controls we had on the robot when we climbed this ramp.

Jason

[richy0101]

Our team tested our mecanum wheels from last year on the bridge and it was able to go over it perfectly. As for the bump, I think that would be only be possible with shocks.

[J93Wagner]

Originally Posted by richy0101

Our team tested our mecanum wheels from last year on the bridge and it was able to go over it perfectly. As for the bump, I think that would be only be possible with shocks.

Nope, that was another thing we tested on Monday besides balancing the bridge. A robot can go over with 8" wheels. Granted, I have no idea how it would react to slamming straight into it full speed ahead, but then again, I have no idea how any other drive train would do in comparison as well.

[Duke461]

Originally Posted by J93Wagner

Granted, I have no idea how it would react to slamming straight into it full speed ahead, but then again, I have no idea how any other drive train would do in comparison as well.

Much better, for the most part.

[Duke461]

Not to rain on people's parades here, but.....
***Before I go on, I feel I need to point out that I do have experience with Mecanums. 2 years. 1.5 years driving***

• In that first video, some on the other side is holding the ramp up (or down, however you look at it). Now, I can't prove it, but I'm pretty darn sure that that helps the robot get up.
• It took a long time to get up that ramp. Too long.
• 1 out of 5 times that drivetrain will probably fall off, unless you go super slow, which in that case see Bullet point #2
• What happens if for some reason you can't go over the bridge that round? Mecanum's will have an extremely hard time maneuvering the ridge.
• The material on that bridge was different than that of in the real game
• In the second video, the Mecanum's were having a very hard time getting up the bridge (not too sure how it helped Mecanum's case). If anything, it shows that carefully done programming will be required just for your drivetrain.
• The more top heavy these robots become, the harder it will get.
• A preponderance of team's this year will have a strong hard pushing robot. Good luck scoring on one. It's not fun.

Please take my criticism in a constructive manner, as I will do the same.
-Duke

[Djur]

Originally Posted by Duke461

Not to rain on people's parades here, but.....
***Before I go on, I feel I need to point out that I do have experience with Mecanums. 2 years. 1.5 years driving***

• In that first video, some on the other side is holding the ramp up (or down, however you look at it). Now, I can't prove it, but I'm pretty darn sure that that helps the robot get up.
• It took a long time to get up that ramp. Too long.
• 1 out of 5 times that drivetrain will probably fall off, unless you go super slow, which in that case see Bullet point #2
• What happens if for some reason you can't go over the bridge that round? Mecanum's will have an extremely hard time maneuvering the ridge.
• The material on that bridge was different than that of in the real game
• In the second video, the Mecanum's were having a very hard time getting up the bridge (not too sure how it helped Mecanum's case). If anything, it shows that carefully done programming will be required just for your drivetrain.
• The more top heavy these robots become, the harder it will get.
• A preponderance of team's this year will have a strong hard pushing robot. Good luck scoring on one. It's not fun.

Please take my criticism in a constructive manner, as I will do the same.
-Duke

• I was holding the opposite end of the bridge up to allow the robot on because it doesn't have a lowering mechanism (last year's bot). The robot moved under its own power the entire time.
• There's uneven friction on the mecanums and the fiberboard is ~3x more slippery than the actual Lexan surface, so it takes longer to drive up.
• The drivetrain will not fall off the robot (if that's what you meant), nor will the robot drive off the edge if there's a careful driver.
• Not really. Mecanums still have good grip on the surface of the bridge.
• Not my robot, so I don't know what's up in that video.
• That applies for every robot, too.
• I can't see how that's applicable specifically to mecanums.

Hope this helps.