Eur. Phys. J. B 63, 329-339 (2008)
DOI: 10.1140/epjb/e2008-00175-0
Predictive information and explorative behavior of autonomous robots
N. Ay1, 2, N. Bertschinger1, R. Der1, F. Güttler3 and E. Olbrich11 Max-Planck Institute for Mathematics in the Sciences Leipzig, P.O.B. 100920, 04009 Leipzig, Germany
2 Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501 USA
3 University Leipzig, Informatics, PF100920, 04009 Leipzig, Germany
der@informatik.uni-leipzig.de
Received 31 August 2007 / Received in final form 5 March 2008 / Published online 24 April 2008
Abstract
Measures of complexity are of immediate interest for the field of autonomous
robots both as a means to classify the behavior and as an objective function
for the autonomous development of robot behavior. In the present paper we
consider predictive information in sensor space as a measure for the
behavioral complexity of a two-wheel embodied robot moving in a rectangular
arena with several obstacles. The mutual information (MI) between past and
future sensor values is found empirically to have a maximum for a behavior
which is both explorative and sensitive to the environment. This makes
predictive information a prospective candidate as an objective function for
the autonomous development of such behaviors. We derive theoretical
expressions for the MI in order to obtain an explicit update rule for the
gradient ascent dynamics. Interestingly, in the case of a linear or
linearized model of the sensorimotor dynamics the structure of the learning
rule derived depends only on the dynamical properties while the value of the
MI influences only the learning rate. In this way the problem of the
prohibitively large sampling times for information theoretic measures can be
circumvented. This result can be generalized and may help to derive explicit
learning rules from complexity theoretic measures.
89.70.Cf - Entropy and other measures of information.
87.19.lo - Information theory.
87.85.St - Robotics.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2008



Document 