Kiryu Completed! (1132, RAPTAR)

[Sachiel7]

OK everybody, Kiryu (pronounced key-eww), our 2005 bot from Team 1132, RAPTAR Robotics, is finally complete and has shipped away!
Luckily, I grabbed a few snapshots of Kiryu a few hours before we shipped, so I thought I'd share them with you! Please post comments.
For those of you who saw us at the DC Scrimmage, much progress has developed since!
More on this after some pictures!!!

Kiryu in its starting pose:
http://www.raptar.net/MultiMedia/200.../Acquired2.jpg

Kiryu with its *new* manipulator locked into position (more details on this in a minute!)
http://www.raptar.net/MultiMedia/200.../Acquired3.jpg

Kiryu blocking a standard goal:
http://www.raptar.net/MultiMedia/200.../Acquired4.jpg

Kiryu with arm fully extended:
http://www.raptar.net/MultiMedia/200.../Acquired5.jpg
http://www.raptar.net/MultiMedia/200.../Acquired6.jpg

Kiryu's Controls (You cant quite see how clean they are)
http://www.raptar.net/MultiMedia/200.../Acquired7.jpg

"The Piston" (Note the reed switches...)
http://www.raptar.net/MultiMedia/200.../Acquired8.jpg

And finally, a closeup of Kiryu's manipulator:
http://www.raptar.net/MultiMedia/200.../Acquired9.jpg

So, here's the "story of our manipulator".
After DC, it was evident that a bar would not be efficent enough for the task we were trying to complete. We needed something that would align the tetra with itself, give us more distance from the goal, and maintain the tetra alot better. Within One Day, we fabricated our "tri-rocket launcher" manipulator out of PVC, Lexan, McMaster tread, and three plastic baseballs. FIRST is probably the only cause for WalMart to have customers buying platic baseball bats and balls at 11 at night for building a robot! Anyway, we tested the system today and it worked great!

With that said, I thought I'd give a nice thourough explination of our robot, our strategy, design, controls, etc.

After we went through the phases of analyzing the game and formulating our strategy, we came to the conclusion that we needed a bot that was fast and accurate, worked with one tetra at a time, and could cap on all goals. We also wanted the design to be able to function defensively without any change in hardware or mechanisms.

Once we had our strategy, it was obvious that we were going to need a good lift. We analyzed several different types of lifts, but we liked the 4-bar style lift the most. Both for its simplicity, and for its easy integration with pneumatics.

Enter CAD. For our First year, we've finally been able to fully utilize CAD to design all our assemblies and the final result after construction was amazing. it proved to be one of our most powerful tools this year.

So, here's some info about how Kiryu's lift works. Kiryu's lift functions on a multi-positional piston that extends the manipulator from around 25" for ground level tetras to about 10' 2". We used a 24x2" piston running at about 40 Psi. After evaluating our multi position setup, we came up with a solution that would both double our air supply, and increase our positioning accuracy. The solution is to "single power" the arm. In other words, the piston extends by adding pressure into the end of the piston, and exausts by venting that pressure. the forces of the arm on the piston are more than enough to retract it.

Now if that positioning setup wasn't enough, it gets even better. All 6 of the reed switches from the 3 pistons we ordered are positioned along Kiryu's main piston at preset heights. Basically, they're setup so that (for example) "switch 2 will trigger when the arm is at loading zone height", or, "switch 3 will trigger when were at standard goal height". This allows our drivers to simply tap a button for the position they are seeking and the piston will align the arm accordingly. One more nice thing about the positioning system is this: Our manipulator has been lined with sensors to detect when it has a tetra within its "grasp". This tells the positioning system to seek a different reed switch for proper positioning. For example, if the robot does not detect a tetra on it, and the human presses "standard goal height", it will seek to switch 3, which will put the manipulator at a height just above the standard goal. However, if it sees that it has a tetra, it will seek to switch 4 instead, which will put the arm at a height such that the base of the tetra hangs just above the goal.
(I hope the controls awards guys get a good look at what we're doing! Has anyone done anything this level with pneumatics before? I've heard of other teams using multipositioning, but none with such a setup...)

Kiryu also has a series of autonomous modes (some still in progress )
But they include:
-Capping a vision tetra (our camera code is working )
-Working with the hanging tetras....in some way...
-Capping the starting tetra quickly onto a goal

Well, I dont have time to explain much more, but please, post comments and questions.
Thanks all, and good luck!
See you at VCU! (and hopefully Champ! )

[Joe Matt]

I hope you fixed the "run into Sparky at the beginning of the match" code.

[Sachiel7]

Heh, sorry bout that!
That actually was my sis driving (for about the 2nd time), not our auto code
I dont think she plans on driving our base though at competition
I hope Sparky 6 is ok! Our new manipulator shouldnt do as much damage as our old one could have, thankfully.
(PS - Feel free to poke us back anytime soon )

[Joe Matt]

Originally Posted by Sachiel7

Heh, sorry bout that!
That actually was my sis driving (for about the 2nd time), not our auto code
I dont think she plans on driving our base though at competition
I hope Sparky 6 is ok! Our new manipulator shouldnt do as much damage as our old one could have, thankfully.
(PS - Feel free to poke us back anytime soon )

Come to our pits, I'll show you the wound...

[bombadier337]

How did you all manage to maintain pressure in your pneumatics with that ~24 inch actuator? We use a 12 inch, 2 inch bore bimba actuator, and we still occasionally run out of pressure and have to wait on the compressor, and thats with our allotted 2 tanks.

[Sachiel7]

We single power our arm. Basically, to lift the piston up, we put air into the back of the piston. To lower the arm, we simply vent that air and the force of our arm on the piston (mainly weight) retracts it very well. The top pressure intake on the piston is open to airflow.
BTW, I saw your bot! It looks great (if not a bit similar thats ok )
I can show you our pneumatics setup at VCU if youd like to try it! It should be pretty easy to incorporate with your multiposition setup

[bombadier337]

I posted a final pic of our bot, you should check it out. We had the entire base for the arm welded finally (it was bolted into lexan so we could get it running on Saturday, but it was too bendy), and we tweaked our claw design to pick up tetras better. Did you guys fix whatever autonomous you had running, because it looked like you were stalling your motors out bad. I'm glad to see you fixed your claw design, it seemed to be a little bendy when I saw it running.

[Sachiel7]

Heh, actually we werent stalling them out, we were having issues with our camera tracking code. It wasnt arcing out into the field like it shouldve been when it didnt see the tetras
Anyway, we've fixed that (I think )
I'm glad to hear you guys got that assembly welded! I had another question about your pneumatics too. What pressure level is your main regulator set to? Ours is set to 40psi, which is a bit more than we need (you always want more, usually twice the power it takes) and if yours is just set to 60, your probably using alot more power than you need to to complete the task. I know it took me 2 years to get that through to my team
Anyways, I hope everything works out ok!