Kicking System Design Considerations

[NOV8R]

A kicking system can be described as a mechanical manipulator used to accelerate a ball to a desired velocity to a desired trajectory. This can be achieved in many different ways with various actuators. Check out this research paper Segway CMBalance Robot Soccer Player. http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf
The paper presents information necessary to design and implement a soccer ball manipulation system for a mobile robot such as ours. We used to concepts in this paper to design the pneumatic kicking system we are going to use.

[kamus1000]

Originally Posted by NOV8R

A kicking system can be described as a mechanical manipulator used to accelerate a ball to a desired velocity to a desired trajectory. This can be achieved in many different ways with various actuators. Check out this research paper Segway CMBalance Robot Soccer Player. http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf
The paper presents information necessary to design and implement a soccer ball manipulation system for a mobile robot such as ours. We used to concepts in this paper to design the pneumatic kicking system we are going to use.

Don't you think that the maximum pressure is not enough to use the pneumatic system the times we need?

[MrForbes]

That probably depends on how far you think you need to kick the ball.

[kamus1000]

Originally Posted by squirrel

That probably depends on how far you think you need to kick the ball.

We are testing the pneumatic and see if we can use it to throw the ball into the goal or make the ball cross the bumper, but I think that we are going to lose so much pressure in only one shoot trying to cross the ball.

[kwotremb]

We had a mechanism last night going with pnuematics that was kicking the ball just fine over a bump. Not enough for the field, but a bump just fine. Going to try tonight to see if we can make it kick any further, but at least gettting the ball from zone to zone or pushing a ball into a goal should not be a problem. Im sure some teams will be launching it the length of the field with pnuematics. (remember levers are your friend)

[DMetalKong]

Originally Posted by kwotremb

We had a mechanism last night going with pnuematics that was kicking the ball just fine over a bump. Not enough for the field, but a bump just fine. Going to try tonight to see if we can make it kick any further, but at least gettting the ball from zone to zone or pushing a ball into a goal should not be a problem. Im sure some teams will be launching it the length of the field with pnuematics. (remember levers are your friend)

If I may ask, how did you have the pneumatics set up?
We had compressor -> two tanks -> regulator -> two tanks -> switch -> piston and the hit was rather wimpy. The piston was a 1.5" OD x 2" stroke. Thanks.

[MrForbes]

Originally Posted by DMetalKong

The piston was a 1.5" OD x 2" stroke. Thanks.

842 is using a 2" bore by 12" stroke piston....

http://www.youtube.com/watch?v=QLH-XqNyQ-0

takes a lot of power to move that ball fast, so you need a pretty big cylinder

[NOV8R]

1583's design uses several 1 1/2 inch x 2 inch stroke cylinders and yes they are levered to the kicking plate. We are building a full size prototype now. Don't forget you need some type of ball control mechanism to hold the ball against the kicking plate. We're prototyping one of those now also.

[IndySam]

Originally Posted by squirrel

842 is using a 2" bore by 12" stroke piston....

http://www.youtube.com/watch?v=QLH-XqNyQ-0

takes a lot of power to move that ball fast, so you need a pretty big cylinder

and the key to getting a 2" cylinder to fire quickly is to pre-load it. If you watch the video you will see them manually releasing the mechanism, not just cycling the valve.

[=Martin=Taylor=]

The problem with pneumatics is that the bigger you go the slower the piston fires.

There are many ticks to speed up pistons. Preloading is a good option.

One idea I had was to use a mechanism like the pedal on a base drum to "gear up" the piston, allowing it to swing quickly.

We were able to get about 14' of range and about 18" of height with a simple 1.5" bore piston.

[ricky finethy]

i dont like a kicking design my self i look at the desing like a rotary vs a piston engin the rotary spins with no starting and stoping while the pistion engin has to start and stop all the time

[kwotremb]

Originally Posted by DMetalKong

If I may ask, how did you have the pneumatics set up?
We had compressor -> two tanks -> regulator -> two tanks -> switch -> piston and the hit was rather wimpy. The piston was a 1.5" OD x 2" stroke. Thanks.

That is what our basic design will be when we full start building things. Right now we are using a 1.5 bore 8 inch stroke that has been in the KOP before. We are going right from the schools shop 120 psi tanks to a regulator to 60 psi, then the 2 small tanks we can use, then the valve and piston. Right now we just have some wood rigged up to get a prototype going. We are going to get some smaller diameter pistons to see if kick faster/further or not, hopefully get them in next week, or else we know the 1.5 bore works fine.

Right now we have the piston attached a little over half way up a 13 or so inch bar, then a 'foot' at the end of that bar that kicks the ball. We had the ball consistently going over 14 or so feet in the air, enough to get from one section to the next. I think our max was over 17 feet with one of the configurations we tried. We even put a ball about 2-3 feet in front of our kicker to simulate starting positions of the balls and it went right up and over.

Just out of curiosity, what are other teams doing to return their piston to the starting point. Right now are are planning on using some surgical tubing, because if you keep the exit valve open when you kick you can get more speed from the piston.

[Enigma's puzzle]

If you need to increase the force coming from your piston, and/or speed it up you could always consider adding a spring or tying some surgical tubing in a way that it will assist the firing mechanism(up to doubling the power of a single piston stroke), however if you lose too much pressure, you may not be able to retract the pneumatics quick enough to abide by the rules.

I though id throw this power and thought generating idea out for you to kick around.

[PortugazD.Ace]

My team has been trying to figure out how to do it our selfs. We tried 3 or 4 tanks with a 1.5 inch bore with an approximate 5 inch stroke. We managed to get the ball about half way up the bump when we were about 5 feet away. BTW, does anyone know how many balls we're allowed to kick at once?

[JB987]

Originally Posted by PortugazD.Ace

My team has been trying to figure out how to do it our selfs. We tried 3 or 4 tanks with a 1.5 inch bore with an approximate 5 inch stroke. We managed to get the ball about half way up the bump when we were about 5 feet away. BTW, does anyone know how many balls we're allowed to kick at once?

Only one that is in your possession...