Towards mapping emotive gait patterns from human to robot

Integration of emotions enhances naturalness of human-robot interaction (HRI). This requires that the robot is equipped with hardware to express emotions. Believability and recognition of expressions is increased if the same emotional state is expressed in all modalities which the robot is capable of. Within this aspect, our work analyzes if a walking robot can express emotions in the way it walks and if these expressions are recognizable. The emotive gait patterns are derived from human characteristics for emotive gait. The parameters step length, height and time for a single step vary depending on the emotion. Mapping these changes to the kinematics of the robot and exaggeration of the walking styles leads to distinguishable expressions for the dimensions pleasure, arousal and dominance. Experimental results on a hexapod show that differences in arousal are best expressed and thus recognized. Comparing an animation of the hexapod with the real robot indicates that the robot is perceived as slightly more pleasant and active. This study shows that by changing its walking style the hexapod expresses emotions, in particular differences in arousal, which can be used to increase expressiveness in HRI.