I have this idea for a positioning system based on IR+ultrasound beacons. It is very simple, and I'm surprised that I can't find anything like that already in use. I guess there are some problems that I can't see, so I wanted to ask you to point the flaws in my idea before I invest time and materials into chasing a pipe dream.
The goal is to get an accurate position of a robot inside a room that is decorated with some additional beacons. The positions of the beacons are known to the robot, so that it can position itself relative to them.