Lifting

Do you have design control over the box ? If so, you could attach some feet
to it - or make sure it rests on a pallet of some sort, and use a fork lift
type mechanism. You would then only need to slide the forks underneath and
tilt it a bit to move it from place to place - assuming origin & destination
are about the same height.

That's just one idea !
JCD

Suction?

The robot has to start off and end up fitting in the 30cm box. So it
can expand after the competition starts, but at the beginning it has
to fit and at the end it has to return to that fitting size. (just as
some background info) Someone mentioned suction, but I don't believe
we're allowed to use any hydraulics, pneumatics, etc. And I don't have
design control over the box. Its 30cm plexiglass and probably held
together by some metal L-piece. No top or bottom on the box.

Just a thought - you might be misreading the rules slightly. In mini-sumo,
for instance, the robot has to start off fitting inside a 10cm x 10cm box
of the same variety, but that is done manually by having a person lower and
lift the box.

Later,
Jon

--------------------------------------------------------------
   Jon Hylands      Jon@huv.com      http://www.huv.com/jon

  Project: Micro Raptor (Small Biped Velociraptor Robot)
           http://www.huv.com/blog

Sorry, I'm not misreading it. I just explained it badly. The box is
put over the robot and a cover is put on and it must fit inside. The
box is then removed to its default position and the robot is placed in
its starting position. The robot doesn't actually start the
competition inside the box. But at the end it will be tested again to
make sure it still fits inside the box though it may expand during the
actual competition.

Here is the playing field: http://soinc.org/events/robotram/RRplayfield08.pdf
Basically the idea is that you need to get all of those items (tennis
balls, index cards, batteries) in the box. I believe two of the
balloons have to be popped and their pieces need to remain in the box.
And two need to be completely removed from the box (in any condition).
Time plays a role. So it should be quickest to push the tennis balls
into the same area as the batteries and index cards and  then lift the
box and put it over all of those items with the balloons still inside
and then find some other way of dealing with the balloons.

Not necessarily, since the box is much heavier than the other pieces,
it will have to be moved more slowly for a given robot power,
and it is an "all or nothing" strategy.
  Have you completely your brainstorming and decision matrices,
and decided this is the best path for you,  or are you still exploring
values for the decision matrices in the engineering development process?
The edp usually leads to better robots than
the "just build something" method.

If you choose to, One way to move the box is to push a thin blade down
against the carpet and under the front bottom edge of box, then
extend a grip-hook over the top edge and pull back to lift.  This
can possibly be done with one motor and some linkage.  google for
"3bar.cdy" for a 4bar linkage simulator.

jgraber@ti.com writes:


That looks like a Vex kit, and appears to grip from the top edge only.
The driver needs more practice or a slower wheel speed.
I like the dropped balloon pop plate,  but does the robot need
to drive back on top of it to meet the ending guidelines?
Possibly the robot wouldn't have to drop it,  
it could merely start parked on it, which is a cool out-of-the-box idea.
  It doesn't seem like there was any problem with power to lift the box
or drive around with it.
  It doesn't meet the requirement of keeping balloon parts in the box,
and not much possibility of selecting which balloons to pop.

It is still an all or nothing strategy.
If there are walls to push against to load a scoop,
and if there are partial points for some objects only,
a scooper may be more likely to score partial points on each round.

I haven't seen the rules, but the video bot seems reasonably
capable/viable, and not hard to copy given a Vex starter kits with
a total of 3-8 motor drive units.
 2 wheel drive or 4 wd
 1-2 for gripper
 1-2 for tipper

Potential Improvements:  
  park on plate instead of drop it.
  practice driving or smaller drive speed
  bumper/herder extentions to make it easier to push/herd objects into position,
   possibly reuse tipper as hoop-ball capture bumper, rather than just push
  Possibly top hook extentions to steerably pop balloons from the top
  better weight distribution to be able to pick up box without tipping over


--
Joel

Another problem is that if the items leave the rectangle they're no
longer counted. (Though the robot can leave).

Do the rules say it has to go back into the *same* box?
If not, have you thought about pyros?
;-)

It doesn't have to go into the box at any point. Basically the rules
just say that to qualify, the robot has to fit into a 30cm cube at the
beginning and end of the competition. At no point does it actually
have to be in the box, it just has to be able to fit. Pyros?

    The robot doesn't have to go into the box at all,
although it can.   It just has to take stuff out of
the open-top box and put other stuff in.  Here are the rules:

http://www.soinc.org/events/robotram/RobotRamb-C-07.pdf

                John Nagle

Yeah, I believe I said that, if cryptically I apologize. Those are
last year's rules. The objects are somewhat different this year and
the balloon goals are different. But the basic goal is the same.