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View Full Version : pic: Team 857 Prototype Killough 2002

CD47-Bot
09-10-2003, 00:54
[cdm-description=photo]16411[/cdm-description]
sanddrag
09-10-2003, 00:54
Are those FP motors? What kind of reduction system do you have?
Cory
09-10-2003, 01:01
Those are drills. We only had two FP's in 2002, and three drills.

Cory
Ken Leung
09-10-2003, 01:01
They should be the Drill motors. Back at 02', there were 3 drill motors in the kit of parts.
Wetzel
09-10-2003, 01:08
Mmm....preeetty....
I bet the code is really ugly though, and with the languge shift to C I wonder how much rewritting will have to be done.


Wetzel
FotoPlasma
09-10-2003, 01:13
Originally posted by Wetzel
Mmm....preeetty....
I bet the code is really ugly though, and with the languge shift to C I wonder how much rewritting will have to be done.


Wetzel
Well, logically, with the language change, it'd be 100% rewritten. Concepts may stay the same, but that's probably all.

I would very much like to see the code to control this kind of drivetrain, for either the BS2SX based control system, or, when we get it, the PIC based control system.
James114
09-10-2003, 01:14
i want to know what the design of each individual wheel is, i have tried designing wheels like those and it can be difficult.:ahh:
Wetzel
09-10-2003, 01:25
Originally posted by FotoPlasma
Well, logically, with the language change, it'd be 100% rewritten. Concepts may stay the same, but that's probably all.

I would very much like to see the code to control this kind of drivetrain, for either the BS2SX based control system, or, when we get it, the PIC based control system.

I was wondering how much the mathwork in particular would have to change.

Lots of designwork over the summer, and its back to the drawing board.

Hurray for the real world. :)


Wetzel
sanddrag
09-10-2003, 02:01
My bad. I knew we only got 2 FP's. I don't know what I was thinking. Of course they are drills. But someone please tell me or give a photo of the reduction between the motor and the wheel...
Kris Verdeyen
09-10-2003, 11:36
Instead of complicated math, they got cute with some mechanical hardware - they could be up and running in C in ten minutes:

http://www.chiefdelphi.com/pics/bin/1065667277stick.jpg
Matt Krass
09-10-2003, 20:32
Quaint...

Cheesy, but Quaint.

J/k that's actually pretty cool (and amusing). But, was it hard to drive?
EStokely
09-10-2003, 20:34
<<Instead of complicated math, they got cute with some mechanical hardware - they could be up and running in C in ten minutes>>

Hey thats not bad!!!

At first I thought it was just a joke but it makes sense to me.

I may just file that away for future explotation. :-)

thanks for the pic
ajlapp
11-10-2003, 14:15
i explained some of these controls and stuff in another thread, but i'll throw it up here for you guys also.

those are drills for the record, and i could show you how to make those omni-wheels, with the right tools they're very simple to build.

check out this video for a look at it in action.

http://stuweb.ee.mtu.edu/~alkrajew/FIRST/kiwi.mpg

CONTROL STUFF

we used three normal joysticks, connected together with a "y"-shaped yoke, and ball joints. the x-axis of each stick was unwired, and the threey-axis of each stick were wired into one coupler.......just to save space on a cramped IO.

so each y-axis of the joystick represents the velocity vector of one wheel. the joystick does the complex task of converting cartesian coordinates to polar coordinats inherently.

the robot goes in the direction the stick is pushed, or spins if the stick is rotated in the center.

the attached pictures show how the joystick is a vector based model of the real robot......instead of a motor and gear set, you have a potentiometer. you manually input the velocity of each motor and the robot responds. (both pictures were prototypes)


problems!
our drivers created what they called slip. this was their method for driving. it was based on a general direction rather than a finite point in space. they kind of glided the robot to its position. the joystick doesn't make it super easy to go in straight lines, but straight is irrelevant when you can go anywhere instantly.

we worked around this by making multiple faces for our robot to operate on......front didn't really matter.
Madison
11-10-2003, 14:56
Originally posted by Kris Verdeyen
Instead of complicated math, they got cute with some mechanical hardware - they could be up and running in C in ten minutes:



Unfortunately, there's now a precedent that makes it illegal to modify the joysticks in any way. So, fun with math, anyone?
JVN
11-10-2003, 15:45
Originally posted by M. Krass
Unfortunately, there's now a precedent that makes it illegal to modify the joysticks in any way. So, fun with math, anyone?

As a Mech-E, I'd like to think we could find some way of coupling 3 joystick together in a similar way to the one shown above.

Duct tape anyone?

Programming math is for ninnies!
Jmoo
11-10-2003, 22:42
Really simple to drive, soooo easy to program, I just got on this team last year. This summer, I took our 2002 robot to my house. Added a brain, programmed it up in like 1 minute, and just went nutz. Only problem is that it's only good on flat carpet....
ajlapp
12-10-2003, 18:21
making a new stick without modifying the originals is no problem.........in fact some of this testing has been done. but who knows if we'll ever use the drivetrain again.

i really love it, but i'm not convinced that its a game winner, and since we haven't had three matched motors again, its made me more skeptical.
Rickertsen2
12-10-2003, 18:54
Is the thing hard to stop?
ajlapp
12-10-2003, 19:03
is this a traction question? or something else?
Gadget470
13-10-2003, 08:12
Team 857's old website had a great 8mb video of this thing in action.

(Link from another thread: http://stuweb.ee.mtu.edu/~alkrajew/FIRST/ Video includes Dope's cover of Right Round = woo!)