Robot vacuum: rules and touch sensors

What the experiment shows

A robot vacuum can’t see the whole room: it drives, bumps into an obstacle and turns away. Sensors and simple “if — then” rules let it clean most of the room.

How to run it

1. Press “Run” and watch the crumbs disappear.
2. Open the “Logic” tab: find the timed turn rules and the crumb sensors.
3. Add another turn rule at the 36 second mark.

Questions to discuss

• Which spots does the robot clean worst? Why?
• How could it avoid getting stuck behind the sofa?

The science

A simple robot has no map: it drives straight and bounces elastically on contact. Random bounces and occasional timed turns cover the room, though not perfectly. The longer it runs, the more it covers — an example of a random walk.

Try it at home

Put a few boxes on the floor and push a toy car around: it never covers everything, but touches a lot.

What to change in the editor

• Make the robot faster.
• Rearrange the furniture to create dead ends.