I have been searching for info about the most suitable (and cheap) sensor for measuring distance indoors in bright light up to 15 m. So far I haven't found anything that really seems to fit my needs. So I ask you for help.
I'm constructing a robot that is going to move around in a room with slightly sloping walls, of the size of 60 m x 20 m. The robot has to pass every inch of the floor as fast as possible (much like a vacuumcleaner robot), so I was thinking that it should go along the long sides of the walls checking the distance to the walls on both sides and at each end of the wall move a bit further from wall X closer to wall Y. So the distance that needs to be measured is never more the 10 m but I would like to have a margin of 5 m just in case. As I have understood it a common ultrasonic sensor probably wont do it well since it only can handle up to 10 m (and I can't have that it fails now and then). The best thing I can imagine would be if there was a solution that could keep track of the exakt position of the robot in the room, like a distance sensor in all four directions. In that case I also could maneuver it to it's "home" without a beacon. The most important thing though is to keep track of the long walls.
Any bright ideas?