Horizontal Bar: Vertical Velocity

[Greg]

Does anyone know how we are supposed to measure the "vertical velocity" of the rope that was used in the kick-off demonstration for the "robot" to hang from the horizontal bar? What happens if it exceeds 10 ft/sec due to discrepancies in the measurement method used by the team and the judges?

[Aaron Lussier]

I belive what Woody and Dean said is that taking Gravity in to account, The (hook, teather, grabber,rope) can not move more than a foot and a half straight up with out exceding 10 ft/s. Therefore You must design a (hook, teather, grabber,rope) that does not have to travel more that a foot and a half to get over the bar. If this is wrong please correct me, as this is what I got out of the given explanitation.

-Aaron

[Jeremy L]

i believe that the distance it travels going up doesn't matter, its how far down it goes...because it's when the device comes down that it would be hitting something.

at least that's what i think...

hmmm...

[Trinora]

I think they don't want kids getting skewered in the pits, or breaking other people's robots ingame.

[Mike Rush]

Use the energy equations

mgh = 1/2 (mv^2)
gh=(v^2)/2
h=v^2/2g
h=100/64.4
h=1.55 ft

if the object goes up over 1.55 feet it is travelingmore than 10 ft/s

(I hope this is right... It's been a long time )

[GregTheGreat]

Originally Posted by Mike Rush

Use the energy equations

mgh = 1/2 (mv^2)
gh=(v^2)/2
h=v^2/2g
h=100/64.4
h=1.55 ft

if the object goes up over 1.55 feet it is travelingmore than 10 ft/s

(I hope this is right... It's been a long time )

I can see this being correct... I believe that for safety sake this rule was made... and knowing FIRST they will enforce this very heavily. (Since Dean and the gang put so much emphisis on it in the kickoff)

-Greg The Great

P.S. Scroll Throught the comp docs on usfirst.org they will probabally demonstrate what can and can't be done.... although I am sure you will see many clarifications to this rule in updates... (I would guess in the first 3)

[Aaron Lussier]

1.55 Ft Instead of 1.50 ft, </Mr Burns Voice> Excellent </Mr.Burns Voice> That extra half a foot could be useful.

[tkwetzel]

This is interesting, because this maximum velocity is relative to the robot. They did not think this through, because technically, whatever is being sent over the bar is part of the robot. This means that relative to itself, it isn't moving. They need to mention something about this, because I believe that they mean that the mechanisms cannot exceed 10 f/s. Or if it is in reference to the base of the robot, will someone make a jumping robot so the mechanism relative to the robot is not traveling more than 10 f/s, but is traveling faster relative to the field?

And 10.55 f/s is not an extra half a foot more than 10.5 f/s. 0.05 feet is approximately half an inch.

[GregTheGreat]

Originally Posted by Aaron Lussier

1.55 Ft Instead of 1.50 ft, </Mr Burns Voice> Excellent </Mr.Burns Voice> That extra half a foot could be useful.

I believe it is an extra 1/20th of a foot.... or maybe I am just blinded by my excitement.

-Greg The Great

[KevinB]

Originally Posted by Aaron Lussier

1.55 Ft Instead of 1.50 ft, </Mr Burns Voice> Excellent </Mr.Burns Voice> That extra half a foot could be useful.

Thats not a half a foot, thats 1/20 of a foot! (~half an inch)

[Aaron Lussier]

Originally Posted by GregTheGreat

I believe it is an extra 1/20th of a foot.... or maybe I am just blinded by my excitement.

-Greg The Great

Oops, my Bad, I didn't even think when I wrote that, I was just excited.

[GregTheGreat]

Originally Posted by tkwetzel

This is interesting, because this maximum velocity is relative to the robot. They did not think this through, because technically, whatever is being sent over the bar is part of the robot. This means that relative to itself, it isn't moving. They need to mention something about this, because I believe that they mean that the mechanisms cannot exceed 10 f/s. Or if it is in reference to the base of the robot, will someone make a jumping robot so the mechanism relative to the robot is not traveling more than 10 f/s, but is traveling faster relative to the field?

And The Controversy Begins....

I understand how everyone is trying to figure this out.... since the bar appears to be one of the major aspects of the game... remember this is the first day.... let FIRST figure out the exact rules... don't go crazy trying to figure out the ruling of this... I know all to easy how going crazy over a early misunderstood/non-defined rule goes. (Human Player 2K3)

-Greg The Great

[Paul Marshall]

As far as the velocity being relative to the robot. I would take it to mean the base of the robot (intention of the rule). Or you would probably consider the "robot" the CM or the Robot Controller, one of the two, in either case, they probably won't be flying upwards very fast. Also in the rules, it states that for inspection you need to be able to prove that it doenst' exceed 10ft/s. The way they suggest that you do this is to video it with a known frame rate and a marked background. Ref. 5.4 <R82>

[Joe Johnson]

My interpretation is that Vmax rule was intended to be a safety measure -- especially from with regard to tethered projectiles shot at the bar by springs (think grapling hooks & crossbows ;-) and with regard to largish longish arms hitting the bar after a long wind up (think executioners axe ;-)

Given this, I really think that it is the veritical component of the "exit velocity" of anything shot at the bar and the vertical component of any windmill arm swinging at the bar.

That is how I'd call it anyway.

Joe J.

[Mike Betts]

Originally Posted by Joe Johnson

I really think that it is the veritical component of the "exit velocity" of anything shot at the bar and the vertical component of any windmill arm swinging at the bar.

I agree and would extend this to the "jumping robot" scenario... 1.5 ft maximum jump.