Laser reflector

I've solved the problem of sloping floors by adding a simple reflector to the robot, so that the laser-beam is guided toward the light-sensitive resistors. I used double-sided tape to attach pieces of aluminum foil to a couple of smooth pieces to Lego, which was then angled to create a simple reflector:

The robot now looks like it has a beak:


With this reflector, the robot was able to follow the laser-beam across my livingroom with no human intervention.

I've now tried the laser-idea, and it works well enough. As usual though, the real world is presenting me with problems. In this case the fact that my living-room floor is sagging in the middle by at least one centimeter:-). Since the light-sensitive resistors are fairy small, this causes them to loose sight of the laser in the middle of the room. For now, the plan is to manually adjust aim the laser as needed.