[Dave]

Line tracking is hard. 3 out of 10 grad students at Carnegie-Mellon had trouble with it. It 'aint easy. However, apparently there's a lot of "backlash" in the gears, so dead-reckoning won't be quite accurate. possibly counting shaft revolutions and/or time can give semi-accurate location and speen input.
Line-following with a slowish (but still good) processor aint to good either... it would take 4/60ths of a second for the signal to get to the first processor anyway... and that's a long time. So, what are some ideas out there?