How can you pick up a hula hoop?

[pakrat]

Hey all,

I was sitting at my house thinking about different field objects and good grabbers, and i was wondering, how would YOU pick up a hula hoop if it was part of a game challenge? i guess that what you would need to pick up the hoop and place it on top a tall platform (the hoop would have to be placed so that it is parallel to the ground)

[Eugenia Gabrielov]

This is a really interesting concept. I have a few considerations.

Are we looking at a normal light plastic hula hoop? Those break easily. A robot would have to manipulate it with some kind of small arm structure in this case. If the hula hoop is in the ground, the arm would have to be able to reach down and grab it as such. If it's hanging, that's a lot more like this year's system and just grabbing it and locking it. I think a robot arm like 234 (for those who saw their efficient lock system) would be excellent if the hula hoop was hanging. Such an arm could be manipulated to reach down and clasp the hoop off the ground if it fell.

If the hula hoop is more sturdy, that gives a bit more leeway as to the power of the arm and the manipulation of the hoop. Also, what is the size parameter? Hula hoops are actually kinda big, and while light, a robot lifting many of them would have to plan out how to not let them get caught on things.

Just some thoughts, sorry for the lack of mechanical technicalities.

[Ryan M.]

Hm... a hook. If the hula hoop was standing up, a hook would definetly work. Laying down, you'd have to make sure it can slip under the hula, but pretty much the same.

If the hook can extend far enough to get the end of the hula hoop over to the far edge of the platform, you're good.

[pakrat]

for my idea, the hoop would be on the ground. maybe even picking up a hoop from a stack of hoops...

And the hoops would be prolly aluminum and not all cicular shapes...

[Mike]

What about some kind of wedge system? Insert something into the middle of the hoop, expand it and then wedge the hoop with it.

[pakrat]

That could work, but it might have to expand to get pretty large. And remember, this would have to be raised such that the hoop could be placed somewhere, say 8 feet in the air. Maybe more...

[Jaine Perotti]

Originally Posted by pakrat

That could work, but it might have to expand to get pretty large.

The distance that the gripper would have to expand would not necessarily be very large.

In this paint sketch, the gripper configuration resembles a peace sign, with the shorter of the two arms expanding inward and outward - only a minimal distance. The actual expansion distance would not be very large - the only large thing about this arm is its height, which is not very restricted considering that the height limit for the robot (this year anyways) is a generous 60".

Here's an idea of how this gripper would look like on a robot, when the robot was picking up the hula hoop from the ground:

In the above picture, the "peace sign" gripper would center itself inside the hula hoop on the ground. Then, the two extending arms of the gripper (the short arms of the peace sign) would expand outwards (using pneumatics perhaps?), and the hula hoop would become "wedged" on to the arm.


Here's what it might look like in its upright position:

This is what the robot might look like after the hula hoop has been "wedged" between the two expanding arms and the one non-expanding arm. After being "wedged", it can be lifted up and placed anywheres. There are a whole slew of possible arm mechanisms to go along with this gripper - in the picture, I drew in two rotating joints that would be used to position the hula hoop (of course, the configuration of the arm mechanisms would depend on the game task).

If any of these ideas don't make sense to you, let me know and I will try to make it clearer. The idea behind this gripper is that there is minimal expansion required to "wedge" the hoop. Because the two extending arms of the gripper are angled, they don't have to stretch the entire diameter of the hula hoop. The third (non expanding) arm provides enough resistance for the two expanding arms to create an effective wedging mechanism.

Nice idea Mike - I really like it! Expanding off of other peoples ideas is fun.

-- Jaine

[tiffany34990]

nice job jaine..

my mind right now says wedge it up and have a small grabber..

back to packing though...

nice brain teaser for all of us though

[pakrat]

seems like an okay way to pick the thing up, but inefficient for putting on top of the platform, especially at 8 feet in the air. What about some sort of clamp that grabs it like a person would wiht their hands, and just put that on a telescoping lift?? i feel that might be a little harder to grab with, but more efficient as far as the height of the arm goes...

[sanddrag]

Originally Posted by pakrat

What about some sort of clamp that grabs it like a person would wiht their hands, and just put that on a telescoping lift??

Good idea. If you could grab it tight enough, you could even make the clamp rotate so you could bring the hoop to horizontal, or even further up to vertical so you are then holding at the bottom rather than the top.

[pakrat]

thank all of you for the ideas and proving that there are several ways to do it. Keep the good ideas coming...

[c-squared_2006]

I may sound like an idiot but here goes... I'm horrible at explaining my thoughs...

We can take a combo of ideas, primairly the wedge idea and the clamp/gripper idea. We can come up with a gripping system that some how uses the wedges to 'lift' the hoop so the grippers could "tighten" and obtain better control of the hoops. I have a design in my head, it's just that I can't describe it. Don't worry if you don't understand my ramblings... sorry

[mechanicalbrain]

I found the best answer to these type of question is to do it yourself and observe. From watching myself do it a couple times you need a gripper that comes from both sides (so as not to push it away) gets under (thin "fingers") and lifts the hoola hoop off the ground as it picks it up. Something like the claws in those stuffed animal game boxs would be perfect though don't give it that third finger that makes it so hard to use!

[Cory]

I'd do something along the lines of 175's 2005 gripper.

you have a wedge shaped piece to get under the hoop, and then a piece that rotates down and clamps onto it, allowing you to pick it up and keep it parallel to the ground

[Al Skierkiewicz]

Ya know, back when I was a kid and hula hoops were new on the block...A quick way to pick it up from the ground was to step on it, slide your foot back and the friction rotates it right into your hand. And you thought that was a hacky sack trick.