What are other teams doing about static discharge due to the foam tiles?
If you’re in a relatively small area (a classroom, etc.), you might consider a humidifier to keep the humidity up during the dry winter months. Otherwise, I’ve seen people spray the fields with stuff like Static Guard, but I’m not sure that’s legal or if it can cause long-term damage to the tiles, the robot wheels, (or your lungs).
I’m not sure, but maybe I’ve seen people use plain water to mist over a field, too.
Too bad the tiles aren’t ever so slightly conductive so the field can be electrostatically grounded.
At world’s last year im pretty sure they sprayed some sort of anti static so if anything, you should spray your practice field to get use to driving on it.
The worlds’s fields have always (at least since I’ve been there) been sprayed with an anti static spray. Here’s some info from the Words FAQ:
Q: Will the competition officials use anti-static spray on the fields this year? What
is the spray that will be used?
A: Yes, it is normal practice to use an anti-static spray at a competition of this size. This
spray or something similar may/will be used to spray the tiles during the World
Championship: http://www.mouser.com/ProductDetail/Techspray/1726-
QT/?qs=sGAEpiMZZMvJqaFk9BIivz97Mkiy9G9ySotD3j1hkLM%3d.
In our experience, the best things we have done to reduce static(Primarily dealing with IME’S) is spraying the prongs and then reinserting them into the VEX cortex. Also, another tip that I would recommend would be not be dragging your robot across and making the motors rotate manually while everything is connected. The reasoning behind is that we learned this builds up static that will make the robot crap out in competition and make connection issues. So if you need to transport your robot short distances, make sure your motors aren’t moving. This is why our team has fabricated a neutral gear in our transmission system.
I don’t understand how spraying the prongs might reduce static charge. Static charge can build up on the robot even when the wheels are rotating atop the field mats (and not just when the wheels are dragging across the mats).
If you backdrive a motor, you can generate some electrical power, and there are times when this is enough to light up the indicator lights on the Cortex, but this is not the same thing as generating electrostatic charge which can turn the entire robot into a spark generator. I don’t know if backdriving the motors can generate enough electricity to do something weird to the Cortex - I think I asked the forum about that last year but I don’t recall the answers I got.
My team originally integrated an IME into each of the 4 motors so we could program correction etc. Since, we have only been able to ever get one or two of them to work at a time. It’s quite frustrating as our robot will sometimes strafe drive a little when all of the motors are set to 127. We are pretty sure it is static and we really wish we could fix it for autonomous.
You can spray the fields with anti-static spray. If you don’t want to other solutions are to reset your IMEs by unplugging and replugging them every time before you turn on your cortex or to wipe down your motors and wires with dryer sheets before you go use the motors.
Our teams generally don’t use IMEs unless we really can’t fit quads on the robot. We go to ginormous lengths to get a quad on instead of an IME 
We will probably try some of your suggestions to see if they help. The problem with quads on our robot is we don’t have enough sensor ports or room in the drive to fit them, so either we get the IME’s to work, or only run one at a time.