Machine learning can be a most valuable tool for improving the flexibi
lity and efficiency of robot applications. Many approaches to applying
machine learning to robotics are known. Some approaches enhance the r
obot's high-level processing, the planning capabilities, Other approac
hes enhance the low-level processing, the control of basic actions. In
contrast, the approach presented in this paper uses machine learning
for enhancing the link between the low-level representations of sensin
g and action and the high-level representation of planning. The aim is
to facilitate the communication between the robot and the human user.
A hierarchy of concepts is learned from route records of a mobile rob
ot. Perception and action are combined at every level, i.e., the conce
pts are perceptually anchored. The relational learning algorithm GRDT
has been developed which completely searches in a hypothesis space, th
at is restricted by rule schemata, which the user defines in terms of
grammars.