[artdutra04]

Or you can build a small accelerometer into the Robot Controller itself...

If anyone's ever voided their warranty on their controller and opened it up to peek inside, there seems to be enough space in there for at least a small breakout board sized accelerometer.

While an accelerometer may help to determine high-speed ramming calls, it won't help for things like pinning or egregious/overly-aggressive driving. While comparing the spikes in the gee forces from one robot to another might help determine which robots did in fact make serious contact, it would still be up to the referees to determine which was the offending bot.

If none of the referees saw the incident take place, there is no way for them to know which was the offending robot based off the accelerometer data alone. Having on-board accelerometers would only help the referees to decide if some "borderline" hits were considered fair play or egregious behavior.