28-03-2003 22:27

$aravind.k$

NICE!

WOW! THAT IS ALL I HAVE TO SAY!

28-03-2003 22:33

DougHogg

"Yoda" making 1st contact with the bins

Above is our robot, "Yoda", making 1st contact with the stack in our 1st match and 1st regional for 2003 in Arizona.

In the background, you can see the big screen which also shows our arm and the official clock at 1:58. (Interestingly, the arm on the big screen is lagging a little behind our actual arm.)

It took 59 frames on our video (which is 1.97 seconds at 30 frames per sec.) for our arm to hit a bin in the stack and start it tipping over.

28-03-2003 23:24

Solace

touching boxes is ok I guess, but how long does it actually take you to knock them down?

28-03-2003 23:28

Collin Fultz

don't forget how bin placement during hp mode affects your auton

29-03-2003 00:50

David.Cook

If you didn't get to watch the Philly Regional web-cast, check out the Brazilian team (383). They have a pretty fast bar action. One thing they did differently is to deploy the bar, and drive towards midfield to knock the bins down. They pretty repeatably get the nearest four stacks.
Great job guys!

29-03-2003 02:01

tonyargote

WOW
You acutally touched the boxes in 2 seconds!!!!


Note: Our autonomous mode was evil for the first 3 matches.

29-03-2003 02:28

Kristina

I've seen this in action at the Chatsworth scrimmage and it's extremeley effective and super fast (and a little scary when you're a ref and it swings above your head but I'm guessing you fixed that all). Great idea, keep it up and good luck at your other comps!!!

29-03-2003 14:38

DougHogg

In Arizona, we were "scissoring" the stack (knocking it over starting at one end). Below is a picture of our robot "Yoda" and the stack at 3.5 seconds into autonomous:


The "arm" robot on the left is our opponent, Cyber Blue 234's "Flailer". Here "Yoda" beat "Flailer" to the punch, but I know Team 234 had enhanced Flailer's speed by the end of the Arizona Regional.

I am going to create a thread with pictures from this match of "arm against arm".

29-03-2003 15:56

DougHogg

We can't forget. I recall how you successfully messed up our autonomous in our second match against you, and beat us.

By the way, I consider our 1st match against your "Flailer" to be a real classic because both arms swung on the stack.

Anyway, we are tied with you guys in matches, 1 to 1.

As to our autonomous, we made some changes in Arizona, as did you I noticed. Also we have been reviewing video tapes of all our matches, and on Thursday, at the S. Calif. Regional, we will be doing some extensive work on our robot and our autonomous.

Maybe we will meet again on the playing field in Houston for another "shoot-out".

Regardless, good luck to your team. I am hoping to see an "arm" robot in the playoffs at the nationals--if not "Yoda", then your "Flailer" or one of the other "arm" robots. (I am still trying to get the video feed to watch Team 71's "Beast".)

29-03-2003 16:09

DougHogg

It was kinda' scary at Chatsworth. We had to post someone on the side to make sure no one was in range.

We did some major changes after that, including limit switches to prevent the arm from going out of bounds or rotating the wrong way, and it was handled by the Arizona Regional where we were 4th seed and semi-finalists.

As an aside, one day the rotating motor for our arm had a loose connection and the arm came up but didn't rotate. The engineer who designed the arm stepped forward to see what the problem was, when wouldn't you know it, the arm suddenly swung and hit him right between the eyes. He is fine, but he was definitely sore for a few days. I guess there is a lesson to be learned there: loose connections don't always stay loose.

29-03-2003 16:38

Christina47

wows. thats fast. good JOB. =P

29-03-2003 22:05

Collin Fultz

cool. good luck.

sounds good to me. we'll look for ya there.




COME TO THE IRI

30-03-2003 18:25

Pin Man

Which regional was that? Arent you top heavy with that arm?

30-03-2003 18:49

Gope

Wow, thats fast, faster than Beatty even, but you might be careful with it, our auto mode hits the boxes in 2.75 seconds and Beatty was around 2.5..In the quarter finals at the Mid-West regional we caught their arm on our way over the ramp and flipped them over in auto mode rendering them useless for the rest of the game, be carefull you also don't become the victim of a very fast very low CG robot.

30-03-2003 20:10

DougHogg

That was the Arizona Regional.

We are definitely heavier up top than most of the robots this year, but we never tipped in our 15 matches in Arizona, or in any of our practice matches.

30-03-2003 20:36

Pin Man

I see...

31-03-2003 03:28

DougHogg

We were just watching SOAP108's video's of Beatty (Team Hammond #71). (Finally got Windows Media Player working on my Mac but had to reload the movies every time until just now when I finally found a way to download the movies.)

The "Beast" looks very fast. In fact in the videos, it looks just as fast as our arm, and their swing is concluded faster. It would be another interesting match if we wind up competing with them. Of course, one of these days we will be allied with another arm and that would be interesting as well.

We watched videos of Team 16 also. Amazing how you scream around that corner! If it isn't a trade secret, how do you do that? I would love to see your matches in the elimination rounds, but I couldn't find them. If the elimination rounds for the MidWest are online somewhere, I would love to hear about it.

Anyway, thanks for the forewarning. We haven't tipped yet and it would be nice to continue that trend. Hopefully our arm would glance off you and bounce up, since we hit higher on the stack than Beatty.

See you in Houston. I think it's going to be very interesting this year.

01-04-2003 01:51

Matt Brinza

Doug:

Soap108.com has updated their site, and have uploaded the elimination matches. I suggest you watch QF4.1! You'll notice that 71 positioned their robot opposite ours for QF4.2 (their auton worked nicely that time).

Look forward to seeing you again at Nationals!

01-04-2003 02:36

DougHogg

Thanks Matt,

I received an email from shawny963 of Team 930, one of your alliance partners from the MidWest, letting me know about the videos, and I just watched SF2m2. I sure do like your robot! Awesome!

I haven't seen QF 4.1 yet. It is hereby moved to the top of my list.

Hey, we are looking forward to seeing you. I hope that we are in the same division. In fact, Team 16 is our number one choice for a running partner, if the fates are so kind to us. Of course the odds are against us being in the same division and everyone will have to see how various robots will work together. We understand that. But we are making some very interesting enhancements on Thursday at the S. Calif. Regional, and we plan on being very much in the running in the Nationals. Time will tell, but being partnered with you guys would be amazing.

See you in 10 days. (Wow, we are going to be busy for the next while.)

01-04-2003 12:25

T967

slr

I was at the ST. Louis reg. and can tell you that baxter's bot is A L I V E. The thing knows what it's doing were it is and can really mess yah up in auto. It hits the stack and then procedes to do crazy things like back up and go at another stack, flail around after hitting the stack, hit the stack and keep going at that insane speed of theirs. One match somethan' broke though and it went nuts about half way up the ramp. It's scary how it always seems to do the correct thing though.

01-04-2003 12:40

Kojib

How we do it.

Basically, very strong drive-train and dead reckoning. We are 3-WD, with Bosch drill motors locked into highest setting on front wheels with 4:1. Our Rear wheel is powered with both Chiaphuas. They drop into a helical gear set which sends a shaft through the center of the wheel (on bearings) into a planetary set (the sun, more specifically). We then simply bolt the planets to an aluminum hub we fabricated for the wheel, giving us 15.66:1. The entire rear assembly rotates 180' using a globe motor and a cable (it rests on 102 lycra ball bearings). As the rear assembly rotates, we slow down one of the front wheels to keep it from binding through turns. This gives us approx. 12 fps with enough torque to drag me (160 lbs, 5'8") lying down across carpet (also up the mesh and the HDPE, but I don't like repeating those experiments). All three wheels are 8" Skyway pneumatics inflated to approx. 17 psi.

01-04-2003 17:33

Pin Man

It's hard to believe that 2 seconds... thats fast... i'd have to see it to believe it...

01-04-2003 17:59

DougHogg

Re: How we do it.

Are you shifting gears to get that kind of speed as well as torque?

I gotta see the two Chiaphuas hooked up to one wheel. Very cool.

See you in Houston.

01-04-2003 20:37

Jnadke

Re: Re: How we do it.

Nope... They're pure speed from the moment they move.

You gotta see it to believe it, 16 is definately THE fastest robot at MR... pretty much twice as fast as the fastest bot there.

It's pretty interesting how they did that... used 4 motors but differently. I suppose it works really great looking at it...


Beatty isn't really that great, they had major problems even making it up the ramp. I suppose that will be solved by nationals with higher traction wheels. Their arm can get the stack, but it's a telescoping PVC arm. Any bot like 16 can easily overpower it and tip ther robot, it's just a matter of getting there before they do. It also tends not to fully telescope outward, so they usually get anywhere from 1/4 to 3/4 of the wall.

01-04-2003 20:49

DougHogg

Re: Re: Re: How we do it.

With that much speed, I would have thought their torque would be limited. How can they drag someone up the ramp?

(Hm...very interesting, Dr. Watson. The mystery will be solved in Houston.)

01-04-2003 20:50

Gope

We put both chips on the same wheel with a 15.66:1 gear ratio, it gives us plenty of tourque and insane speed! No shifting involved at all.

Not to mention the fact that we're making radial movements while everyone else is making linear movements, which makes us turn a whole lot faster than anyone else.

01-04-2003 21:03

Jnadke

Re: Re: Re: Re: How we do it.

Torque and Speed are directly related if you look at a Torque-Speed curve of a motor. As one goes up, the other goes down. Torque is the pushing power of the robot. It is also what causes the acceleration of the robot.

With that said, using 4 motors, a lot more torque can go to the wheels, causing the robot to accelerate much faster. Even though they have the wheels geared rather high, they get up to speed rather quickly. Once they get up to speed, torque isn't a factor, so speed takes over, which allows them to go rather fast.

It's more complex that that, but that's the gist of it.


As for hooking up two motors in unison, it's not unheard of. We (269) have 2 chiaphua motors connected in unison on our transmission for the differential. It's needed for our car-style steering, which allows us to move in radial and linear movements much like 16. Although we are not as fast as 16, our radial motion allows us to get to the wall faster than ordinary robots.

01-04-2003 21:28

Kojib

Actually, when we were designing our drive train, we had made the same mistake twice which really helped us. We misinterpreted the charts for the drill and chip' motors. We planned on them putting out about 2/3 the power they actually do. When we ran it for the first time, we were all stunned as we had been planning on about 7-8 fps. It took a few days to figure out what happened, but we weren't too hard on ourselves. *grin*
If you like, I can give you a full run-down of our robot at nat's. Just go to our pit and ask for either Garrett (me) or Jesse (Gope). Actually, anyone could give u the robot run down, but Jesse and I know it forwards and backwards. Also, Jesse is on our compliance team, so he could probably get CAD drawings if you like.

01-04-2003 21:48

DougHogg

I want to see both those robots (16 and 269) at the Nationals.

We have a neat shift on the fly arrangement with 8 full-time wheels powered by the 2 chiaphua's. We set 4 wheels down at a time, and with our 4 inch wheels, we can push really well.

We are making a few changes on Thursay, which will allow us to spend more time in high gear (using 8 inch wheels), so we will be faster than we were in Phoenix, but we aren't going to try to drag race with Teams 16 or 269.

Anyway, thanks for the info.