Possible Discrepency - G17

[AlexD744]

If you look in section 7.3.4.3 (Handling Balls) at G17, there is a formula for how long you have to put a ball back in play after it has passed through the ball counter. In the blue box below, it explains that you get an additional 4 seconds for each ball in the alliance station before it is returned, but with the formula they have given, you would get four seconds less for each ball. Also, with this formula, you could possibly have a negative amount of time to put a ball back into play. We thought maybe there was a subtraction where there needed to be an addition, but this would give unlimited time. Any explanations or help would be awesome. (especially because we were not able to download the extended explanation) Thanks!

[engunneer]

I had issues with the DOGMA pdf too. was it not accepting your password?

[jacobhurwitz]

Originally Posted by AlexD744

but with the formula they have given, you would get four seconds less for each ball

I also can't open the DOGMA pdf, but I had a different interpretation of the formula. The key to understanding the formula is that T_expire and T_score represent times on the countdown clock.

Pretend you score a ball with 1 minute (60 seconds) left on the clock. If there are zero balls waiting to be returned to the field, then this ball must be returned before the clock reads 49 seconds left, because 60 - [11 + (4*0)] = 60 - 11 = 49. If there is already one ball waiting to be returned to the field, then the just-scored ball (now the second ball waiting to be returned to the field) must be returned before the clock reads 45 seconds left, because 60 - [11 + (4*1)] = 60 - 15 = 45. Thus, you have an extra 4 seconds to return this second ball because there's a backlog of balls waiting to be returned.

[samepstein]

Originally Posted by engunneer

I had issues with the DOGMA pdf too. was it not accepting your password?

Yes, I believe there is an error with the password set for the DOGMA pdf.

[Ekaru]

As said, the formula gives you 4 more seconds for each ball, no error, due to how the formula works.

[GBIT]

Originally Posted by jacobhurwitz

I also can't open the DOGMA pdf, but I had a different interpretation of the formula. The key to understanding the formula is that T_expire and T_score represent times on the countdown clock.

Pretend you score a ball with 1 minute (60 seconds) left on the clock. If there are zero balls waiting to be returned to the field, then this ball must be returned before the clock reads 49 seconds left, because 60 - [11 + (4*0)] = 60 - 11 = 49. If there is already one ball waiting to be returned to the field, then the just-scored ball (now the second ball waiting to be returned to the field) must be returned before the clock reads 45 seconds left, because 60 - [11 + (4*1)] = 60 - 15 = 45. Thus, you have an extra 4 seconds to return this second ball because there's a backlog of balls waiting to be returned.

this was my understanding as well and i feel that it will be a discussion for the Q&A soon... I also could not get into the DOGMA pdf..

[BRAVESaj25bd8]

I don't think there is much discrepency at all. jacobhurwitz explained it pretty well. The key is that t_exp and T-score are the number of seconds left. Therefore, the expected time can be negative because if you get a ball for example with less than 11 seconds remaining, it does not ever need to be put back on the field. Negative times actually do make sense here because they represent the "never" possibility for the time at which a ball must re-enter the field. Hope that helps.

[AlexD744]

Thank you, I understand now, I was interpreting it as that t-exp as the amount of time you had to return the ball, not the time by which the ball was returned. Thank you again.

[Scott358]

I see the times provided by the formula in rule G17 are the clock times, not the ball return times, but I'm still not clear on how long we have to return the first ball....

When the first ball enters, would n=1?

If so, according to the formula, wouldn't we have 15 seconds to return the ball (not 11 as described in the blue box below the rule)?

Obviously with the penalties associted with holding balls too long, they should be returned to the field ASAP, but just wondering about the math.

[EricH]

Originally Posted by Scott358

I see the times provided by the formula in rule G17 are the clock times, not the ball return times, but I'm still not clear on how long we have to return the first ball....

When the first ball enters, would n=1?

If so, according to the formula, wouldn't we have 15 seconds to return the ball (not 11 as described in the blue box below the rule)?

Obviously with the penalties associted with holding balls too long, they should be returned to the field ASAP, but just wondering about the math.

Nope, it's 11 seconds. n = 0. The second one (if the first one hasn't made it out) would get 15 seconds.

Oh, and if you haven't found this out already, the DOGMA document isn't locked anymore. It's got a really good explanation.

[Scott358]

Thanks for the re-confirming n=0 when the first balls passes.

From the way I read it, it would be that n=1 when the first ball is scored, as that is now the "# unexpired balls currently in station" (per DOGMA definition, since I thought "currently" is triggred when it is scored) or per rule G17 that n=1 since that ball has "passed through the ball counter".

I think I've been reading way too many contracts as work lately!!!

In the end, I can see the intent is n=0 for the first ball, so it is what it is.

[MiniNerd24]

Depending on which side your team is on (the current leader or minor) you may or may not need to remember the code, just each ball in play within 2.5 s. of receiving should be a good set point for a minor alliance or you could remember the formula in case you have the lead and delay the time the balls go in, thus giving the opposition time to score, but again you could just have the formula on your dashboard and multiply adjust it to the amount of balls you're receiving.
I was probably rambling that probably wasn't help but I just want everyone to know there are more options.

EDIT: Tell me in the demonstration the little tunnel over the return rail looked like it had a yellow sensor on top, is that an IR sensor to tell whether the ball is returned? If so I guess the time the ball needs to be returned must be from the time received to the time it takes to go through that tunnel.

[vg674]

Originally Posted by MiniNerd24

EDIT: Tell me in the demonstration the little tunnel over the return rail looked like it had a yellow sensor on top, is that an IR sensor to tell whether the ball is returned? If so I guess the time the ball needs to be returned must be from the time received to the time it takes to go through that tunnel.

If I understand correctly, the time starts with the counter in the goal, whatever mechanism it may be, and ends with the counter on the ball return.

[EricH]

You are correct. There is a sensor in the chute from the goal and another over the player station. When a ball comes in, a flag is set for a certain time (based on the formula). When a ball goes out, the next flag is cleared.

And the sensor in the chute (and probably in the return) is a quadrature-encoded photoelectric sensor. (Forget whether that's in Section 6, the field drawings, or the DOGMA document, but it's there.)

[Abrakadabra]

Here's a few shots from the Kickoff showing the two counting devices: