Crazy robot idea for this year 2

[Jared Russell]

Under normal atmospheric conditions, helium has a lifting ability of 1 gram per liter*. The maximum volume of your robot is 28x38x60. Let's pretend you fill that entire volume with helium (impossible, since you would need to lose some volume for the electronics, battery, bumpers, etc.)

28" x 38" x 60" x 1 gram/liter = 2.3 pounds of lifting capability. Not even enough for the cRIO itself.

* http://science.howstuffworks.com/helium2.htm

[EricH]

Originally Posted by Jared341

Under normal atmospheric conditions, helium has a lifting ability of 1 gram per liter*. The maximum volume of your robot is 28x38x60. Let's pretend you fill that entire volume with helium (impossible, since you would need to lose some volume for the electronics, battery, bumpers, etc.)

28" x 38" x 60" x 1 gram/liter = 2.3 pounds of lifting capability. Not even enough for the cRIO itself.

It gets better. You also have to have something to hold the helium. However, you could possibly get better lift by pressurizing the helium, allowing more liters to be added... which opens up its own set of problems, including the fact that helium escapes from containers very easily if there are any holes at all.

[JamesCH95]

A perfect battery can support around 60A draw for the whole match, at around 11.5 volts. Lets be generous and say you only want a few moments of flying and the battery can support 150A at around 10.5V. This is 1575 Watts, which should be able to lift around 16-17lbs.

I do not believe that it is possible to lift all of the required hardware (battery (13lbs), cRIO (1.4-2lbs), cRIO modules, power board (1.6lbs), digital sidecar (0.25lbs), main breaker, bumpers, motors, radio (0.5lbs) etc) with the battery's available power. This is even without accounting for losses such as resistance in wiring and motor inefficiencies. In fact, that 1575W of theoretically available electrical power is probably around 1200W if you use RS775-18s at peak efficiency (78%). Voltage at the motors will be lower than 10.5V, so ding some more power...

I think it's safe to say that the battery cannot output enough power to lift the absolute minimum FRC legal robot.

[Siri]

Originally Posted by CalTran

Well, I think that the things that make this illegal to be:


^Even if you were able to get flying, you're still restricted to an air ceiling ~10" above the ground.

That's where the bumper zone is located, but it only matters with regard to R29 (in fact, it's only ever mentioned in these two rules).

[R29] Bumpers must be located entirely within the Bumper Zone when the Robot is standing normally on a flat floor.

Otherwise no one would be able to wheelie onto the bridge, lift themselves across the barrier, etc.

It seems the GDC also has chosen not to answer the question of whether a circular (or spherical) robot has no exterior vertices or infinite ones, so you might not need bumpers at all! ([R27]: "Robots are required to use Bumpers to protect all exterior vertices of the Frame Perimeter".)

Originally Posted by remulasce

In addition, no part of your robot may extend more than 60" off the ground- wait. Only when in contact with the other alliance's carpet. So you're good on that front.

True, all robots are limited to 60" while in contact with the "carpet and/or Key on their Alliance Station end of the Court" [G20].
...However, "Otherwise, Robots are limited to 84 in tall" [also G20].
...However, "The vertical measurement is always in relation to the Robot." [Q&A, G20]. Those tricky GDCers

So as long as your flying robot is not over 84" tall and not over 60" tall when placed on the Court before the match [G01]--with respect to itself--it should pass G20 and G01. (G01 is not clear about cases in which the robot is never actually placed on the Court, i.e. it floats.)


Now the safety thing, that's an issue. Field personnel have enough problems without a flying ball of helium filled with a battery+cRio*+router+/-bumpers flying at their heads. Yikes!


*[R52] Robots must be controlled via one programmable National Instruments cRIO (part # cRIO-FRC or cRIO-FRCII), with image version FRC_2012_v43. Other controllers shall not be used.

[Clayton Yocom]

Originally Posted by PAR_WIG1350

they were legal in 2009, nobody used one, but the legality was confirmed in Q&A.

New offseason project, convert Jake, our 2009 'bot, into a hovercraft.