I got the idea to make a wearable GPS logger wich logs the routes you walk.
This logged data will be uploaded to a server. A robot could now get a position to go, search the database on the server for any logged point in the area wich connects to a point wich is near the target area. Because a human beeing already walked there (and was outside and nothing was above him ;) ) there should be almost no obstacles..
Of course, the robots course will be logged, too but my intention is to create data from more than one source to control another source.