How does descoring work?

[jgannon]

I must not be understanding this correctly... can someone help shed some light?
<G36> HOME STRETCH Height Restriction – ROBOTS in the HOME STRETCH of the opposing ALLIANCE can not be more than 6 feet tall. A PENALTY will be assigned for each infraction.
<G22> Direction Of Traffic – ROBOTS must proceed around the TRACK in a counter-clockwise direction. Once a ROBOT has CROSSED a LANE MARKER or FINISH LINE, it shall not break the plane of the line by moving in the clockwise direction. A PENALTY will be assigned for each infraction.
How do you ever get your ball down from the overpass overlooking your opponent's finish line? You can't even reach the overpass when you're in the opponent's home stretch, and because the edge of the overpass is aligned with the finish line, you aren't allowed to reach to the overpass once you're out of the home stretch. Do you just have to hope that your opponents don't wait until the end to knock your ball down? In the end game, can you not score on your opponent's side? Can you not descore on your opponent's side?

[LordTalps]

Seems you drive past the home stretch, turn around, and either grab it or knock it off from there. Sucks...

edit: thinking. I'll prob come back to this thread.

[jgannon]

Seems you drive past the home stretch, turn around, and either grab it or knock it off from there. Sucks...
Based on <G22>, I'm pretty sure that that's not a legal alternative.

[jacobhurwitz]

You could knock the ball down with a blast of air. If your robot is six feet tall, it's only six inches to the overpass.

[LordTalps]

Based on <G22>, I'm pretty sure that that's not a legal alternative.
You can go in any direction in a given quadrant, you just can't cross the lines going the wrong direction. Otherwise if a ball rolled into a corner, you're in extremely hot water.

edit: And you can be on the finish line in the wrong direction, just not CROSS it, from how <G22> reads to me.

[Scott358]

The ball weighs about 10 lbs, so a blast of air from six inches away is going to be tough.

I assume the ball is nested in the bridge, therefore the bottom might be below the 6' limit. This might allow you to punch the ball off. Thoughts?

[Ragnarokae]

So you could go past the overpass, then turn around and knock the ball off...

Besides, G22 says "by moving", not by turning.

<G22> Direction Of Traffic – ROBOTS must proceed around the TRACK in a counter-clockwise direction. Once a ROBOT has CROSSED a LANE MARKER or FINISH LINE, it shall not break the plane of the line by moving in the clockwise direction. A PENALTY will be assigned for each infraction.

[Ragnarokae]

I agree w/ the ball hanging idea, any way to calculate how low it hangs?

[LordTalps]

The ball weighs about 10 lbs, so a blast of air from six inches away is going to be tough.

I assume the ball is nested in the bridge, therefore the bottom might be below the 6' limit. This might allow you to punch the ball off. Thoughts?
Getting my math out, brb.

But to jgannon, you can turn around and knock it down.
7.2 Definition of crossing

You're considered crossing when ALL PARTS have crossed the line. GO past, turn around, don't fully cross the line, you're fine and dandy.

[jgannon]

GO past, turn around, don't fully cross the line, you're fine and dandy.
No! What you describe would not be considered crossing, but it would certainly be breaking the plane. Remember, "Once a ROBOT has CROSSED a LANE MARKER or FINISH LINE, it shall not break the plane of the line by moving in the clockwise direction." Any motion that caused you to break the plane of that line from there would have to be clockwise in nature.

[Ragnarokae]

No! What you describe would not be considered crossing, but it would certainly be breaking the plane. Remember, "Once a ROBOT has CROSSED a LANE MARKER or FINISH LINE, it shall not break the plane of the line by moving in the clockwise direction." Any motion that caused you to break the plane of that line from there would have to be clockwise in nature.

The key word here is "moving." Wouldn't pivoting be allowed? You could at lest pivot counter-clockwise if that is where the problem lies.

[dbell]

I agree w/ the ball hanging idea, any way to calculate how low it hangs?

We measured about 70 inches from the bottom of the ball the floor, at the kickoff.

[Ragnarokae]

We measured about 70 inches from the bottom of the ball the floor, at the kickoff.

Is that measurement, or were you able to calculate that? If it was calculation, I would really like to know how for future reference.

[LordTalps]

No! What you describe would not be considered crossing, but it would certainly be breaking the plane. Remember, "Once a ROBOT has CROSSED a LANE MARKER or FINISH LINE, it shall not break the plane of the line by moving in the clockwise direction." Any motion that caused you to break the plane of that line from there would have to be clockwise in nature.
Hope you're not getting too worked up, just thinking in a lot of directions and not spent a lot of time arond the rules. You're definitely right there. We might be limited to the bottom of the ball, going to figure out how low it hangs in a second.

Another thought though -- what if they intended for it to be a penalized process? If you want to get your second ball into play, you have to gamble the points?

[Ragnarokae]

Another thought though -- what if they intended for it to be a penalized process? If you want to get your second ball into play, you have to gamble the points?

If so, the human demonstration didn't show it.

[Gertlex]

Use another ball to descore a ball?;)

Edit: As seen in the Arena rules, the Home stretches are only a quarter of the field each. Go past your opponents finish line and you're free to return to >6' height. You can stop and drive around in a given quarter of the field, as long as you don't go back across a line.

[Bongle]

Is that measurement, or were you able to calculate that? If it was calculation, I would really like to know how for future reference.

Posted this in a couple other threads today.

given a trackball center at (0,0)
given a trackball contact point with a rail at (16,y) (the rails are 32" apart)
given the trackball is 20" and assuming it remains approximately spherical, then...

x^2 + y^2 = r^2
16^2 + y^2 = 400
y^2 = 400 - 256
y = 12

So the contact point for the rails will be 12" below the center of the ball. This means that between the rails, the bottom of the ball should be 8" below them, and thus 2" below the maximum allowed height of a robot in the opponent zone. However, this is in an ideal world where the rails are infinitely thin and the ball is perfectly sperical. Since the rails are 1.5" wide and the ball will deform some, the ball may be slightly higher than where I computed it to be, and the contact space for a robot will be very, very small.


Glad to hear someone did the actual measurement and it was close :)

Here's a diagram:
http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5914&d=1199558995

[dbell]

Is that measurement, or were you able to calculate that? If it was calculation, I would really like to know how for future reference.

We measured that at the kickoff.

But it is possible to figure it out. The overpass bars are 32 inches apart.(the arena 6.2.2) The balls are 40" in diameter.(the game piece 6.3) And the overpass is 78 inches high.
I'll let you do the math.

[LordTalps]

Is that measurement, or were you able to calculate that? If it was calculation, I would really like to know how for future reference.

Circular relationship, err, function for a circle. X^2 + Y^2 = R^2

Radius of ball -- 20"
length of overpass -- 32", believedly.

16^2 + y^2 = 20^2
y = 12. 12 is the height from the center of the sphere to the overpass.

20 - 12 = 8" the ball dips down at maximum, giving us only 2" of impact room to play with.

edit: b10. bleh.

[Ragnarokae]

Here is a link to another thread with a math proof regarding the height of the ball on the overpass. http://www.chiefdelphi.com/forums/showthread.php?t=60666&page=4

We have approx. 2 in or less to work with...

[Ragnarokae]

Sorry everyone, I forgot to hit refresh, and thus missed LordTalps' post.

[Ty Tremblay]

You cannot be over 6' high in your opponent's home stretch, so you must go under the overpass in order to reach high enough to descore the ball. BUT, when you go under the overpass, you cannot touch the ball because you would then break the plane of the opponent's finishline, causing you to recieve a penalty.

This seems like a vicious circle to me.

[Ragnarokae]

You cannot be over 6' high in your opponent's home stretch, so you must go under the overpass in order to reach high enough to descore the ball. BUT, when you go under the overpass, you cannot touch the ball because you would then break the plane of the opponent's finishline, causing you to recieve a penalty.

This seems like a vicious circle to me.

Well, we have about 2 inches of space that the ball will hang down below the plane. Still, two inches is not a lot of space...

[jgannon]

It's good to see that there is potentially a way to legally descore. In any case, I'm really hoping that this isn't the intent of these rules. As a referee, it's going to be insanely difficult to tell if a robot was at 72" or 73" when it knocked out the ball.

[LordTalps]

It's good to see that there is potentially a way to legally descore. In any case, I'm really hoping that this isn't the intent of these rules. As a referee, it's going to be insanely difficult to tell if a robot was at 72" or 73" when it knocked out the ball.
Yep. There's some guesswork in the case, and you'd have to be very hopeful the ref didn't decide to penalize you just for coming close to the height limit. That or have some very good evidence that you didn't/can't.

[skrew-ball]

ok, my team is here discussing this. would the risk of a penalty at end game be worth it? a 10 point penalty and a 12 or 24 point denial. The height penalty is also done by the break of the height plane, not the time out of it. So you could extend out, knock off the 2 balls and drive around in the opposing lane, preventing any future occurance. -10 on you, -?? on them minimum of -12 on them. Thus giving you a minimum of a 2 point advantage, increasing in 12 point increments.

Also, couldn't you score more than 10 points to offset the penalty?

[jgannon]

ok, my team is here discussing this. would the risk of a penalty at end game be worth it? a 10 point penalty and a 12 or 24 point denial. The height penalty is also done by the break of the height plane, not the time out of it. So you could extend out, knock off the 2 balls and drive around in the opposing lane, preventing any future occurance. -10 on you, -?? on them minimum of -12 on them. Thus giving you a minimum of a 2 point advantage, increasing in 12 point increments.

Also, couldn't you score more than 10 points to offset the penalty?
There was some discussion about this idea last year... if it was worth it to interfere in the opponent's home zone, take a couple penalties, but keep the opponent from lifting. The general consensus was that intentionally taking penalties would be a yellow-cardable offense. I don't necessarily agree with this (I like the idea of fouling to stop the clock in basketball, or taking a delay-of-game in football to give your punter more room to kick), but that seems to be the prevailing opinion. However, this year there is only one instance of a yellow card being mentioned in the manual, and no explanation of how the card system works, so it's hard to say if there will actually be yellow cards. Maybe intentional penalties will be acceptable this year?

[skrew-ball]

So at this point I assume it is ok

p.s. others, the yellow card is for not moving when bumped
after 6 seconds

[LordTalps]

It's a lot of point counting, unless the rules somehow get changed or opened up for more interpretation.

[Ragnarokae]

It's a lot of point counting, unless the rules somehow get changed or opened up for more interpretation.

Yeah, one of the speakers on the Kickoff broadcast said the the refs were in for a rough time. The refs have to go through an actual course and tests before they can actually referee.

[LordTalps]

Yeah, one of the speakers on the Kickoff broadcast said the the refs were in for a rough time. The refs have to go through an actual course and tests before they can actually referee.
I was more thinking on a strategic side but yes, the refs are in for trouble XP

[MarySheridan]

So the rules state that

<G36> HOME STRETCH Height Restriction – ROBOTS in the HOME STRETCH of the opposing ALLIANCE can not be more than 6 feet tall. A PENALTY will be assigned for each infraction.

In the video of the HUMAN PLAYERS, the blue alliance was passing a ball over the lane divider. Though the lane divider is 6ft tall, stretching to get the ball over the top seems to be pushing it. Is that okay to do? Just sit there and wait for a ball to come your way?
On that note, I know there have been six zillion threads on this, but it has been decided that pushing a Trackball off of the other side of the overhand during any mode would be considered illegal, correct?

[LordTalps]

So the rules state that

<G36> HOME STRETCH Height Restriction – ROBOTS in the HOME STRETCH of the opposing ALLIANCE can not be more than 6 feet tall. A PENALTY will be assigned for each infraction.

In the video of the HUMAN PLAYERS, the blue alliance was passing a ball over the lane divider. Though the lane divider is 6ft tall, stretching to get the ball over the top seems to be pushing it. Is that okay to do? Just sit there and wait for a ball to come your way?
On that note, I know there have been six zillion threads on this, but it has been decided that pushing a Trackball off of the other side of the overhand during any mode would be considered illegal, correct?
It's not illegal, just very hard to do without breaking either G22 or G36 as posted above.

[Kingsmen]

The definition of crossing the line is that all the parts of the object have to cross the line. So a manipulator crossing into the homestrech but not the rest of the robot would not count for the height rule.

[legotech25]

You cannot be over 6' high in your opponent's home stretch, so you must go under the overpass in order to reach high enough to descore the ball. BUT, when you go under the overpass, you cannot touch the ball because you would then break the plane of the opponent's finishline, causing you to recieve a penalty.

This seems like a vicious circle to me.

But does the finish line tape count as the home stretch or not? chances are it does, but then our only access point is the two or so inches that extend past the pvc...

[Nick Moroz]

It is my understanding that the "Home Stretch" (in which your robot has to be 6' or under) is only 1/4 of the field. As shown in the picture below, taken from the manual, the "Home Stretch" is defined as the area from your finish line to the middle of the field. Therefore, you can go past the opposing alliance's "Home Stretch" and knock the ball from the roost towards the opposing alliance's "Home Stretch". This allows the opposing alliance to easily push their ball past their finish line: a seperate strategy.

Bottom line: go past their "Home Stretch" and knock their ball from its roost.

http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5920&stc=1&d=1199578149

Nick Moroz
Volunteer Engineer
Team 548 Robostangs

[Nathans]

It is my understanding that the "Home Stretch" (in which your robot has to be 6' or under) is only 1/4 of the field. As shown in the picture below, taken from the manual, the "Home Stretch" is defined as the area from your finish line to the middle of the field. Therefore, you can go past the opposing alliance's "Home Stretch" and knock the ball from the roost towards the opposing alliance's "Home Stretch". This allows the opposing alliance to easily push their ball past their finish line: a seperate strategy.

Bottom line: go past their "Home Stretch" and knock their ball from its roost.

http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5920&stc=1&d=1199578149

Nick Moroz
Volunteer Engineer
Team 548 Robostangs

That doesn't work, since G22 says you can't break the plane of a lane marker or finish line once you've crossed it.

[Kevin Sevcik]

It is my understanding that the "Home Stretch" (in which your robot has to be 6' or under) is only 1/4 of the field. As shown in the picture below, taken from the manual, the "Home Stretch" is defined as the area from your finish line to the middle of the field. Therefore, you can go past the opposing alliance's "Home Stretch" and knock the ball from the roost towards the opposing alliance's "Home Stretch". This allows the opposing alliance to easily push their ball past their finish line: a seperate strategy.

Bottom line: go past their "Home Stretch" and knock their ball from its roost.

http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5920&stc=1&d=1199578149

Nick Moroz
Volunteer Engineer
Team 548 Robostangs

Nick, the concern is the interaction with this plan and G22. G22 states that a robot will be penalized if it breaks the plane of a finish line or lane marker that it has CROSSED. So if you cross the opponent's line to get out of their home stretch and extend above 6', then you can't have any part of your robot break the plane of the finish line while you're bumping the ball back and away from you.

[Brandon Holley]

Heres something interesting..

If you look at the game animation, a red robot OBVIOUSLY exceeds the 6 foot mark in the blue alliances homestretch. Its at 1:52 in the animation. This contradicts the rule.

[gam3fr3ak1]

The definition of crossing the line is that all the parts of the object have to cross the line. So a manipulator crossing into the homestrech but not the rest of the robot would not count for the height rule.

But the rule for going backwards is different, you cant "break the plane" so no part of your robot can go back to a previous quadrant w/o incurring a penalty

[d.courtney]

Just do it from your side. Reach over the wall and hit the ball off. No height restriction there :D

[Nick Moroz]

I think you may be right. However; there should be part of the ball that sticks over the plane of the "Home Stretch". It will most likely be a judgment call by the referee.

If it is the case that you cannot knock the other alliance's ball from their side of the field, then at least you can knock down their ball if they put it on the roost of your alliance's side. I do believe that any ball of your alliance that is suspended by the arena and not a robot will score you 12 pts. <G14>

[Daniel_LaFleur]

Hmmm.... am I missing something here???

If we break the 6' height restriction in the "home strech" we incur a 10 point penalty but we may be able to remove 12 (or 24) of the opponents points in doing so?

Does this mean that they are encouraging us to break that restriction?

[Nick Moroz]

Also, the rails of the overpass are 32" wide, allowing roughly 4" of ball on either side that would not be in the "Home Stretch". 4" should be plenty to knock it down.

[lukevanoort]

Just do it from your side. Reach over the wall and hit the ball off. No height restriction there :D
Because of the 80" operating size restriction, I don't think that'll work either.

[Boothy180]

Because of the 80" operating size restriction, I don't think that'll work either.

Yet, in the animation, a blue bot does this at around 2:57

[lukevanoort]

Yet, in the animation, a blue bot does this at around 2:57
The game animation is not an official rulebook and infractions have already been noted in it.

[GearsOfFury]

Heres something interesting..

If you look at the game animation, a red robot OBVIOUSLY exceeds the 6 foot mark in the blue alliances homestretch. Its at 1:52 in the animation. This contradicts the rule.

Reading all of these posts, and seeing the clear violation in the video, makes me wonder if the rules are meant to be different in Hybrid mode? Otherwise, you'd be the only one who could knock off the opposing team's ball from the start, and there'd be no reason to ever knock it down...!

Of course, later in the video, the blue robot reaches around in *front and over* where it's going, before it gets to the home stretch... seems like an easy way around this all if you're willing to build an arm that can reach that far!

[keenanmolner]

Heres something interesting..

If you look at the game animation, a red robot OBVIOUSLY exceeds the 6 foot mark in the blue alliances homestretch. Its at 1:52 in the animation. This contradicts the rule.


So, Is it that you can only get your trackball down during Hybrid mode? because if you try to get it down in the main time period, you have to reach up 6'6" to get it down. that breaks rule <G36>. Also, during the final period of time, you are "encouraged" to knock down opposing teams trackoballs. can you only do that if they put their trackball on their side?

[GBIT]

given a trackball center at (0,0)
given a trackball contact point with a rail at (16,y) (the rails are 32" apart)
given the trackball is 20" and assuming it remains approximately spherical, then...

x^2 + y^2 = r^2
16^2 + y^2 = 400
y^2 = 400 - 256
y = 12

So the contact point for the rails will be 12" below the center of the ball. This means that between the rails, the bottom of the ball should be 8" below them, and thus 2" below the maximum allowed height of a robot in the opponent zone. However, this is in an ideal world where the rails are infinitely thin and the ball is perfectly sperical. Since the rails are 1.5" wide and the ball will deform some, the ball may be slightly higher than where I computed it to be, and the contact space for a robot will be very, very small.

Posted this in a couple other threads today.


Glad to hear someone did the actual measurement and it was close :)

Here's a diagram:
http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5914&d=1199558995



Umm. Hope not too many people used this number because our team found it to be wrong. We noticed the the equation above used numbers assuming the ball was on center with the pipes. this is not true seeing that the ball rests on the top of the pipes. We found the hang to be (assuming the the 6.5' overpass is on center with the pipes) it would hang only 1.5 inches below the 6' legal limit. If the 6.5' is at the bottom of the pipes it would hang only .67 inches from the 6' limit. this is assuming the the ball in of 40" diameter.



here is the diagram:
http://www.chiefdelphi.com/forums/attachment.php?attachmentid=5926&d=1199655203