When a robot needs to guard a region of space within a building, it's faced with solving geometric problems known as the Watchman Problem and the Art Gallery Problem. A new paper titled Online Searching by an Autonomous Robot (PDF format) describes the use of a KURT3D robot with a low cost 3D laser scanner to find realistic solutions to these problems. They test their work by putting the Linux-based robot through its paces in the great hall of Schloss Birlinghoven at Fraunhofer Institute for Autonomous Intelligent Systems. Video of the robot in action and 3D scans are available on the website.