How to guide robots with IR beacons?

[zootsuitman]

I have a robotics project where I need to guide a few robots to specific circles that are at a random distances. On the day it is due I will be given the distance to the middle of the circle and can adjust what ever guidance system I have. There is a budget cap on the project so i would like to use just one or two controlling things for every robot. Now what I was thinking was to set up some sort of IR beacon in the starting square (as none of the controlling factors can leave the square). If I placed two beacons, one at each corner or the square (each circle is a certain distance from each side of the square) I could have an arduino to remotely control them. I hope that makes sense so if you have any ideas or questions that would welcome both. Thanks in advance,
Zootsuitman

[jwatte]

How would you turn the two emitters into a position? Even if you could sense the angles very accurately (high-resolution narrow angle camera, say) you will have a hard time telling two sensors at an angle from two sensor far away unless you can include significant parallax in the set-up.

I would use motors with encoders tied directly to wheels. Like the pololu d25 or d37 motors. Add an Arduino or Axon to count the ticks and calculate distance traveled. You can make sure you travel straight by keeping both (left/right) counts in sync. Then turn a known amount and go straight again. Motors + wheels + controller should be about $100, plus some amount for batteries and chassis and stuff.