Robot Navigation by Light 1

The ability to return to a base location is crucial for moving animals; so it is for mobile robots. Insects like bees and ants achieve this task by a combination of di erent mechanisms: coarsegrained dead-reckoning, using a global reference frame such as the sun, takes them back close to their nest. Once near the desired location, either a search behaviour (ants) or a navigation by local landmarks (bees) is initiated and takes the animal home. We present a navigation system for a mobile robot that shows similarities to this solution. Using a distant light source (the sun, for example), the robot is able to return back to base within about 10% of the total distance travelled. The robot then switches to a negrained local navigation, exploiting the structure of its environment and returns to its base by means of local landmarks. Presented at the European Conference on Arti cial Life, ECAL 1993, Brussels 24.26.5.1993.