The possible positions of the vision tetras are well defined in the field drawing. How closely will the actual position of the vision tetras match their specified positions? There are no markings on the field to position them by. Will the people setting up the field have some sort of template or will they be placed by eye?
Well, they’re placed in one of the 8 positions randomly, so you’ll need a camera to find them anyway. I suppose you could try to guess which place the tetra will be in, but you might not be too lucky 
The people from FIRST setting up the field will place to the inch, because that is specifically marked on the fields digram with measurements included.
Where exactly does it say that? I can’t seem to find anything like that.
Check the field layout on FIRST’s website. Here is a link that takes you directly there. http://www2.usfirst.org/2005comp/Drawings/2005_Field_layout.pdf
Folks,
Haldir is correct. The EXACT location of the vision tetras is indeed a “known” position and is accurate to one inch. The official field layout is HERE.
I also created a larg-scale paper “tabletop” playing field HERE as well as a printable 11’x17" playing field with no dimension lines HERE which does indeed show the floor markings of where the randomly-placed vision tetras can possible go.
The referees will place the vision tetras onto the field on the pre-difined spaces at the beginning of a match “very shortly” before autonomous period starts.
So…You could pre-program your robot to “know” all eight possible locations and send a signal just before the match that the vision tetras are in locations #2 and #7 as an example. Or…read on
There is a separate discussion about enabling the on-board cameras to watch the field and to seek-out the location of the vision tetras as they are being placed, even before the gun goes off…very advanced…and scary!
Is it legal/possible to communicate with your robot between placing it on the field and the end of autonomous mode? Can you have power to your camera and/or robot controller before the start of the match?
-Mr. Van
Coach, 599
Where have you guys found specifically that the vision tetras will be aligned to within an inch? The stationary field elements (goals and field borders) should be +/- 1". In the past, moveable field objects have not been placed with nearly that accuracy as it delays the matches too much.
No, you can’t. The robots are placed on the field before the vision tetras are placed. Once the robots have been placed, you will not be able to communicate with them until the end of the autonomous period. So there is no (legal) way to send a signal to the robot after the vision tetras are placed and before the start of the match to tell the robot the locations of the vision tetras.
-dave
Dave,
I fully agree with you…but, there is a lot of chatter elsewhere HERE in this forum about how the camera module is “enabled” all by itself and that the on-board system can be running in “stealth” mode before the autonomous mode starts. I think you’ve peeked at that thread as well.
There are teams that are advanced enough to be contemplating a field scan while the visual tetras are being placed; and then “memorizing” the actual two locations out of the eight possible placements. Namely, can the on-board system be “computing” and “hunting” the locations of the vision tetras before the start even if the DRIVE is disabled. Correct; no signal is “sent” fromt he driver, but the on-board controller can do it’s own closed-loop process with the camera???
It goes back to the fundamental definition of “disabled”. The entire robot sub-system power is not disabled.
Maybe the judges can put “hoods” over the vision tetras until the starting gun goes off…
To Joe Ross,
The offical field diagram shows dotted lines for the eight randomly-placed vision tetra marks. So…that means that those eight locations are “known” coordinates.
What is NOT known is whether or not the humans that place the vision tetras will actually put them on the pre-defined locations or not…