Expressing Emotions with the Social Robot Probo

Probo is a huggable animal-like robot, designed to act as a social interface. It will be used as a platform to study human robot interaction (HRI) while employing human-like social cues and communication modalities. The robot has a fully actuated head, with 20 degrees of freedom, capable of showing facial expressions and making eyecontact. The basic facial expressions are represented as a vector in the 2-dimensional emotion space based on Russel’s circomplex model of affect (Posner et al. in Dev. Psychopathol. 17(03):715–734, 2005). The recognition of the underlying emotions based on the robot’s facial expressions were tested in different user studies and compared with similar robotic projects. This paper describes the concepts of the robot Probo and the ability to express emotional states.