pic: Team 857 Prototype Killough 2002
 

Are those FP motors? What kind of reduction system do you have?

Those are drills. We only had two FP's in 2002, and three drills.

Cory

They should be the Drill motors. Back at 02', there were 3 drill motors in the kit of parts.

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.

wheel design
 

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:

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

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...

Complex digital control system
 

Instead of complicated math, they got cute with some mechanical hardware - they could be up and running in C in ten minutes:

Quaint...

Cheesy, but Quaint.

J/k that's actually pretty cool (and amusing). But, was it hard to drive?

<<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

stuff i explained in other threads
 

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.

Re: Complex digital control system
 

Unfortunately, there's now a precedent that makes it illegal to modify the joysticks in any way. So, fun with math, anyone?

Re: Re: Complex digital control system
 

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!