Generating artificial smile variations based on a psychological system-theoretic approach

Emotional expressions are considered to be important for robotic and virtual agents to improve nonverbal communication in human-machine-interaction. In this paper we focus on a subset of emotional expressions, namely the smile and it´s variations. The proposed concept for generating artificial smile sequences is based on the system-theoretic psychological model of smiling, which is based on the Zurich Model of Social Motivation. The model and seven different types of smiles are introduced and it is presented how to integrate this model in a virtual agent. The evaluation of the generated facial expressions shows that the seven types of smiles are distinguishable from each other and can be classified according to given categories.