  The increasing number of robots in home environments leads to an emerging
coexistence between humans and robots. Robots undertake common tasks and
support the residents in their everyday life. People appreciate the presence of
robots in their environment as long as they keep the control over them. One
important aspect is the control of a robot's workspace. Therefore, we introduce
virtual borders to precisely and flexibly define the workspace of mobile
robots. First, we propose a novel framework that allows a person to
interactively restrict a mobile robot's workspace. To show the validity of this
framework, a concrete implementation based on visual markers is implemented.
Afterwards, the mobile robot is capable of performing its tasks while
respecting the new virtual borders. The approach is accurate, flexible and less
time consuming than explicit robot programming. Hence, even non-experts are
able to teach virtual borders to their robots which is especially interesting
in domains like vacuuming or service robots in home environments.
