stevez said:
A good friend of mine (fellow engineer) works part time on a large, modern farm. He was telling me about planting crops then cultivating or treating with the aid of a system that incorporates GPS and some local benchmarks for the precision needed. I understood that the system would automatically steer the equipment based on info on where seeds were planted. I'm sure that's way beyond what you want but researching agricutural uses of GPS may help with your project.
I was thinking that lasers could triangulate position and follow the mower but that seems rather complicated. You have at least two, maybe three stationary laser units that would scan for the mower and the mower would have a receiver that could differentiate between each stationary unit. The stationary units would report direction only - then a computer would have to calculate the position.
John Deere sells GPS systems for there tractors, basically put in the route and it'll do whatever to the field, no driver needed. So... there GPS systems must be pretty accurate.
for the lawnmower, maybe it could just sense the height of the grass... if it's over 3 inches, mow that part, under 2 inches, it's already been mowed, or something? I guess that would be a little complex though.