[JesseK]

I'm pretty sure '08 bots who could run around the field multiple times used more than just gyros and encoders (...like human IR control...).

That said, in the quadrotor world there's only 1 way to go: Butterworth-filtered accelerometers and redundant gyros that failover. The filters help to reduce noise at the circuit level. The gyros are on a reset circuit that resets their power every N seconds to reduce slop (and there's another issue...can't remember the name...where over time their readings become more offset). While one is resetting, the other has valid data. I'm not the circuit genius behind this ... I'm the one who integrated the architecture together to make everything work together as 1 system

In the FRC world, we've used encoders and gyros with success (2007) and failure (2008). Encoders give a # of ticks per rotation, and that can translate into inches per tick. If you poll the gyro every N milliseconds, you can use some trig (using lookup tables on those systems) to calculate your position with pretty good accuracy. Accelerometers have generally been too noisy to be accurate for planar field positioning in our experience. This year we will probably use filters with them for angular arm positioning (shh, don't tell my team that ... ).