Crazy robot idea for this year 2

[staplemonx]

the first idea was not circulated much but it was a 3 ball shooter on segway like chassis that could fit on the bridge with any two other robots and would flop over once power is cut.

how ever the second idea is

if you made a flying ball that had about an 18" diameter with bumpers on it that could do to things; fly to opponents end and sit in oppomnents 3 point basket, fly to bridge and hover while touching an alliance robot for 30 seconds and then fall and roll to the ground at the end of the match. http://www.atomicrobotics.com/2011/10/flying-ball/

would this be legal?
would this be a game changer?

I am looking at rules now. can't find rule that says you aren't allowed to be above the opponents fender or touching rims. they assumed this would not be possible with the 14" arm and 60" height limit.

Plus I haven't seen anything about what is considered a balance if after game play your robot falls off bridge.

‎1 battery (or super capcitor if allowed to replace) 1 CIM, 3 small control motors froma quad copter rig, 1 victor, 1 quad copter control board (unless CRIO has to be used), 1 wirless controller, 1 circuit breaker, 1 light, 1 wireless adpter and walla you have a single rotor helicopter self contained that just has to fly for 1 minute with that weight

If CRIO has to be used does the crio have to be on the robot? can it be on the control board and connect to a secondary wireless RC like control system?

Specifically i would be looking for anyway to offload weight from the required "large FRC" components.

Just a thought. Good night

[Tristan Lall]

Fun ideas...however, they're fraught with peril.

For the first one, if it falls over while on the bridge, doesn't that risk unbalancing it due to the centre of gravity shifting? Check out the 5 second rule, [G37].

For the second, among many other potential issues, you will need to deal with having the battery, the cRIO and other heavy things onboard to be considered a robot. Also, how will you avoid unsafe operation?

[staplemonx]

Originally Posted by Tristan Lall

Fun ideas...however, they're fraught with peril.

For the first one, if it falls over while on the bridge, doesn't that risk unbalancing it due to the center of gravity shifting? Check out the 5 second rule, [G37].

For the second, among many other potential issues, you will need to deal with having the battery, the cRIO and other heavy things onboard to be considered a robot. Also, how will you avoid unsafe operation?

Check out flying ball, no unsafe operation unless their is a control issue, in some ways no different than a ground based bot.

the 5 second rule. Doh.... then it would nee to land. as long as partner has flat spot with whole in it to land on we are good.

[Tristan Lall]

Originally Posted by staplemonx

Check out flying ball, no unsafe operation unless their is a control issue, in some ways no different than a ground based bot.

In some ways no different, but different in one crucial respect: it's a lot harder to protect the scorer's table and the front row of spectators. A control issue on a regular robot rarely leads to a departure from the playing field; that's hard to guarantee on a flying robot. And because it's above the field barrier, disablement doesn't mitigate the threat nearly as well. (Plus, as determined by the required parts, it would have to weigh a minimum of around 20 lb—that's a lot of momentum to arrest.)

[remulasce]

This has been discussed. Flying is illegal because it is impossible to keep your bumpers in the bumper zone. Bumpers must be in the zone during normal operation, and if flying is normal, you need them there while flying.

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.

EDIT: I stand corrected. The bumpers need only be in the Bumpers Zone while the robot is standing on a flat floor. See post below.

[bduddy]

Originally Posted by remulasce

This has been discussed. Flying is illegal because it is impossible to keep your bumpers in the bumper zone. Bumpers must be in the zone during normal operation, and if flying is normal, you need them there while flying.

That's not what the rule says...

[R29]

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

So it seems that a flying robot is completely legal, as long as it is deemed to be safe... good luck with that!

[remulasce]

I stand corrected. The required battery + crio, combined with the limited set of motors, are more than enough to make this impossible in my view, but if you can do it, I think the "safety" rule is the only thing standing in your way. Which would also be near-impossible to satisfy, but you may try as you like.

[PAR_WIG1350]

Originally Posted by remulasce

I stand corrected. The required battery + crio, combined with the limited set of motors, are more than enough to make this impossible in my view, but if you can do it, I think the "safety" rule is the only thing standing in your way. Which would also be near-impossible to satisfy, but you may try as you like.

???
This years set of motors has one of the highest power densities I have seen in FIRST. If you ran all of the 550s (all 8) into a single gearbox (low reduction, high speed), and put a large prop on it, you could get some substantial lift.

Motor power breakdown:
-AndyMark motors (AM- 0912)> 180.83W * 2 = 361.66W (current is below limit)
-Banebots RS-550-120-------> 253.52W * 4 = 1014.08W **(slightly less due to current limits, at this power level, they draw 43.2 amps each)
-Fisher Price 00801-0673-----> 291.59W * 2 = 583.18W **(prob. not quite this high, this would require 54.76 amps per motor)
----> this comes out to 1958.92 Watts, theoretically. So, How much would that be able to lift? (more specifically, how much would that be able to lift using a propeller?)

[EricH]

Originally Posted by PAR_WIG1350

So, How much would that be able to lift? (more specifically, how much would that be able to lift using a propeller?)

It depends on the prop, and the air density. Quite possibly even the specific prop. The one overarching question which won't be answered by motor power is prop thrust--motor power is good for getting that thrust, but can't be precisely correlated without some testing. A 27x13 is quite a hefty prop, even for a hefty motor like an FP.

And I've seen a case where the same prop tested at two different thrust levels in two different locations. Not fun trying to figure out why...I suspect it had something to do with either the air density or a mounting change, or both.

[PAR_WIG1350]

Originally Posted by EricH

It depends on the prop, and the air density. Quite possibly even the specific prop. The one overarching question which won't be answered by motor power is prop thrust--motor power is good for getting that thrust, but can't be precisely correlated without some testing. A 27x13 is quite a hefty prop, even for a hefty motor like an FP.

And I've seen a case where the same prop tested at two different thrust levels in two different locations. Not fun trying to figure out why...I suspect it had something to do with either the air density or a mounting change, or both.

Well, air density at FIRST venues, which are often climate controlled and at fixed altitudes, shouldn't be too hard to calculate, plus the mounting won't change as long as it is on the robot. Additionally, the same website also sells 26, 24, 22, 21, 20.5, and 20 inch props in varying pitches.

Does anyone have performance data from 2009 for similarly sized propellers?

[JamesCH95]

Don't get caught up in the details with props and their inefficiencies, sizes, etc. Do the broadest, most basic calculation possible to check and see if it is within the realm of feasibility.

If we take a minimum robot mass (25lbs) and use the entire cross sectional area of the robot envelop, 28inX38in we find that we will need to generate approximately 0.0235psi (162Pa) of dynamic pressure just to 'hover' in free air, ignoring ground effects.

Pdynamic = ( fluid density * fluid velocity^2)/2

fluid density = 1.18kg/m^2 (~STP)
Pdynamic = 162Pa

Fluid Velocity => 16.9m/s

Total air flow rate is 28in*38in*16.9m/s = 11.6m^3/s

In a basic sense we need enough power to accelerate 11.6m^3 of air to 16.9m/s in 1s. This can be simplified to a basic energy problem:

Air mass = 11.6m^3*1.18kg/m^3 = 13.7kg

air velocity = 16.9m/s

Air's kinetic energy = 1/2*mass*velocity^2 = 1950Joules

Time available to apply this energy = 1s

Total power required by this method = 1950J/1s = 1950W to maintain hover, including no inefficiencies.

This is about what PAR_WIG1350 figured that eight motors, drawing well over 280A, could produce.

It is technically unfeasible with our legal battery. It is technically unfeasible with our required main breaker. Even if these barriers were removed, the motors would not last long at peak power.

[CalTran]

Originally Posted by bduddy

That's not what the rule says...

So it seems that a flying robot is completely legal, as long as it is deemed to be safe... good luck with that!

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

[R01-2]
The Frame Perimeter of a Robot is defined by the outer-most set of exterior vertices on the Robot that are within the Bumper Zone, which is between 2 and 10 in. from the floor.

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

[R08]
Robot parts shall not be made from hazardous materials, be unsafe, cause an unsafe condition, or interfere with the operation of other Robots.

Read it as you will.

[pandamonium]

A giant Helium balloon would off set the weight. Is that legal?

[Tristan Lall]

Originally Posted by pandamonium

A giant Helium balloon would off set the weight. Is that legal?

No it wouldn't. It would add both weight and buoyancy. The specification restricts robots on the basis of weight only.

The helium itself would be legal, unless in a hazardous state.

[EricH]

Originally Posted by pandamonium

A giant Helium balloon would off set the weight. Is that legal?

Can you fit it in the maximum size?

For something as heavy as a typical FRC robot, the required helium-carrying device will most likely have a hard time fitting in the field, if not the venue. Trust me on this. For something like a 18" sphere, with bumpers and battery, you could probably fit said helium-carrying device into the field if you didn't max-weight the robot. However, maneuverability would be highly limited due to rules about leaving the field boundary.