PDA

View Full Version : FINA Relay Take-Off Rule w/ Automated Equip?



wiredknight
March 5th, 2010, 12:26 AM
Beer bet.

Does anyone have a link to the FINA rule that explains how automated equipment is used to judge relay take offs?

The FINA rules I've been able to find on-line first point you to section SW 13.1, which then points you to FR 4. But FR 4 doesn't address it.

I need the link to the explict FINA paragraph to win my beer.

I already have the undocumented statement from the Washington Post April 1, 2007.

"Officials ruled Crocker left 0.01 of a second earlier than the allowable start time. Crocker got off the blocks with a reaction time of -0.04 of a second. The most allowed is -0.03."

Thanks

knelson
March 5th, 2010, 12:39 AM
Good question. I can't find an explicit rule in the FINA rules and I doubt there is one. Here's the obvious rule about relay starts:

SW 10.11 In relay events, the team of a swimmer whose feet lose touch with the starting platform before the preceding team-mate touches the wall shall be disqualified.

I'm wondering if they use a tolerance value stated by the timing manufacturer to set the allowable negative reaction time. So, in Crocker's case maybe Omega published that the reaction times for this system were accurate to +/- 0.03 seconds, thus Crocker's -0.04 was an automatic DQ.

osterber
March 5th, 2010, 10:55 AM
In the patent application for the Daktronics relay exchange platform (patent 7403135), in the background for the patent, it says


In current practice, it is difficult for an electronic timing system to detect the actual instant the second swimmer loses all contact with the relay takeoff swimming platform. Currently available relay takeoff sensors rely on measuring the force exerted by the second swimmer on the relay takeoff swimming platform, some using a mechanical switch mechanism in the relay takeoff swimming platform top, others using a pressure sensitive piezo device. Experiments have been conducted with this latter method using load cells and accelerometers. It has been demonstrated that the accuracy of force measurement methods is limited by the fact that the swimmer may have one toe in contact with the relay takeoff swimming platform, but exert an immeasurable force against it. This results in the start being signaled before it has actually occurred. Because of this, FINA allows a tolerance of 0.03 second in relay exchange timing. In other words, a swimmer will not be disqualified unless the timing system shows a departure more than 0.03 second before the swimmer in the water touches the touchpad sensor. The “0.03 second” figure was established in tests using an Omega Sports Timing starting block, which showed that the signal from the relay takeoff swimming platform was consistently between 0.024 and 0.027 seconds before the actual departure.

This is the Daktronics patent for their "contact based" relay exchange pad, which detects contact, and not pressure. Their (Daktronics) documentation says that they are accurate to 0.01 second. So -0.01 second is a DQ.

-Rick

wiredknight
March 5th, 2010, 11:09 PM
Thanks for the replies and the time and research that went into them !

It is frustrating (to me, anyhow) that we can't seem to locate FINA documentation of this procedure. Even if it is vendor specific (i.e. Omega or Daktronics, etc.), I would think FINA would have to publish guidelines.

I may have to thirsty :)

osterber
March 8th, 2010, 10:51 AM
Does anyone have a reference for an online copy of the current FINA rules? The FINA web site has information about ordering the printed rulebook, but it requires a bank transfer of funds (no checks or credit cards!). I found a couple copies of the 2005-2009 rulebook online. But I can't find the current 2010+ rulebook online anywhere.

-Rick

ande
March 8th, 2010, 12:25 PM
big meets have
1) pressure pads on the blocks &
2) touch pads on the wall

the timing system records the moment when the swimmer touches the wall on his final lap for his part of the relay.

When the next relay member dives, the pressure pad on the block records the final moment the next swimmer touched the block.

The timing system compares the moment when
the incoming swimmer touches the wall to the moment when the leaving swimmer leaves the pad.

The leaving swimmer attempts to anticipate the incoming swimmers' touch.
Her feet just need to be touching the starting block after the incoming touches the wall. The leaving swimmer can be stretched out over the water about to leave the block.

remember there's 2 responsibilities
1) the incoming swimmer needs to make a predictable touch
2) the leaving swimmer needs to properly anticipate the incoming swimmers touch

Here's a little guideline on relay reaction time ranges:
if you left

-0.01 or less
you jumped but -0.03 to -0.01 is acceptable

0.00 to 0.09
you're cutting it too close

0.10 to 0.25
a good range for good exchanges, keep closer to 0.10

0.25 to 0.40
is slow but a good range to do safe starts for prelim swims to not get DQed for finals (usually the marching orders for prelims is
safe starts / swim fast

0.40 or more
is slow, you probably wanted to congratulate your team mate or help them out of the water before you left

osterber
March 8th, 2010, 02:03 PM
Ande - That's not correct.

The rules say that if you leave early, then you are disqualified. Period.

The manufacturers publish different standards for what "early" means on their equipment.

For Omega, their system apparently has difficulty detecting the departure from the starting block down to about 0.027 seconds. So on an Omega system, -0.03 seconds on an exchange is legal. This is because their system will sense "departure" about 0.03 seconds before contact is actually lost.

Daktronics and Colorado Time Systems both publish a 0.00 margin. I.e., -0.01 is a disqualification on those systems.

There is no rule that says that you're allowed to jump "a little bit".

-Rick

osterber
March 8th, 2010, 02:24 PM
Let me also clarify that there is a difference between the timing system detecting an early take-off, and actually being DQed. It all depends on your rule book.

Under the NCAA rule book, if your exchange (subject to manufacturer's margin publications) is +0.09 (safe) through -0.09 (early), then the timing system wins always. I.e., if a Daktronics or Colorado relay exchange detects -0.01 in a NCAA meet, it is an automatic disqualification. Presumably, with an Omega system, -0.04 is an automatic disqualification.

The USA Swimming and USMS rule books don't have anything nearly so clear. Use of relay exchange pads is subject to a little more interpretation. The guidance that we have used in New England, which we are told has become the defacto standard across the country, is that it requires a dual confirm still to DQ. The relay pad can be one half of a dual confirm. I.e., if automated equipment says "early", then it requires a human to dual confirm it. Generally, we have practiced the standard that the relay pad can also save you. For example, if two human officials call an early take-off, but the automated equipment says +0.01, then that overrules the officials.

The FINA rule book doesn't get into specifics, but it appears that for things like the Olympics, that the automated equipment wins. I have not observed human officials doing visual relay exchange judging at the Olympics in some time. It appears that in a dispute, they would go to video replay.

-Rick

mattson
March 8th, 2010, 03:09 PM
In the patent application for the Daktronics relay exchange platform (patent 7403135), in the background for the patent, it says



... It has been demonstrated that the accuracy of force measurement methods is limited by the fact that the swimmer may have one toe in contact with the relay takeoff swimming platform, but exert an immeasurable force against it.
...



The starting block measures the time when you stop applying force to the pad. That is not the same as the time when you actually no longer contact the top of the starting block.

Whether -0.03 is the best safety margin, dunno. But a negative time does not necessarily mean the person left early.

osterber
March 8th, 2010, 04:51 PM
The starting block measures the time when you stop applying force to the pad. That is not the same as the time when you actually no longer contact the top of the starting block.

Whether -0.03 is the best safety margin, dunno. But a negative time does not necessarily mean the person left early.

You should read the rest of the Daktronics patent application. Their patent is for a relay take-off pad that measures contact, not force. The quoted section is part of the support for why they wanted to come up with a way to measure contact, and _not_ measure force, because force is subject to those problems.

-Rick

osterber
March 8th, 2010, 05:00 PM
What I'll point out as an example... we have a set of Daktronics relay pads. In my experience, while testing... if there is an empty paper cup on the relay pad, and I pick up that cup... the pad will usually register that as a "departure".

-Rick

knelson
March 8th, 2010, 05:07 PM
Yeah, I guess the problem with a force transducer is that as soon as you have a positive acceleration in the vertical direction the pad will say you left the block even though this probably happens a few hundredths of a second before your feet actually leave the block.

orca1946
March 9th, 2010, 12:44 PM
WOW ! I was not aware of such tight equiptment being used ! That is cool that we have caught up to track !

lefty
March 9th, 2010, 08:47 PM
I wonder, if one does a little hop a second before take off will the mechanism malfunction?

knelson
March 10th, 2010, 12:01 AM
I wonder, if one does a little hop a second before take off will the mechanism malfunction?

I think it would and I think this is why the NCAA rulebook specifies that the automatic system is only used to -0.09 seconds. They figure if it's more than that it should be a judge's call. Did the swimmer just leave really early, or was it something like you describe?

osterber
March 10th, 2010, 09:35 AM
I wonder, if one does a little hop a second before take off will the mechanism malfunction?

At least in the Daktronics system I am familiar with, no. The relay pad sends a signal to the timing console for every "departure" that it detects. So if there's a hop before the take-off, the relay pad will send two "departure" signals. The timing console is looking for the last departure signal, and compares it to the earliest time registered on the touchpad. Basically, the timing console keeps a moving window of opportunity... it's looking for touchpad and relay pad activity that are within a couple seconds (I don't know the exact time window), so that it gives every benefit of the doubt to the swimmer(s).

This is why it's important, when using relay pads, not to touch them. For example, if someone is leaning on the relay pad during an exchange, the pad may not properly detect the departure of the swimmer. (Yes, it's a way to cheat.)

-Rick

osterber
March 10th, 2010, 09:39 AM
I think it would and I think this is why the NCAA rulebook specifies that the automatic system is only used to -0.09 seconds. They figure if it's more than that it should be a judge's call. Did the swimmer just leave really early, or was it something like you describe?

Clarification -- The NCAA rule is only "exclusive" to -0.09 seconds. If the automatic system detects -0.10, and it is observed by one human official, it is a DQ.

But yes, the theory is that any good official should be able to observe a departure that is -0.10 early or worse. Similarly, if they are +0.10 safe or better, there is little to no chance any human would accidentally call a false start.

(We have had a few cases where an official made a call for false start when the timing system detected +0.00, +0.01, +0.02.)

-Rick