A speech-driven embodied group entrainment system with the model of lecturer´s eyeball movement

We have already developed a speech-driven embodied group entrained communication system called “SAKURA” for activating group interaction and communication. In this system, a speech-driven computer graphics (CG) characters called InterActors with functions of both speaker and listener are entrained to one another as a teacher and some students in a virtual classroom by generating communicative actions and movements. In this study, for the basic research of realizing smooth communication during embodied interaction between human and robot, we analyzed the eyeball movements of a lecturer communicating in a virtual group by using an embodied communication system with a line-of-sight measurement device. On the basis of the analysis results, we propose an eyeball movement model that consists of a saccade model and a model of a lecturer´s gaze at an audience, called “group gaze model.” Then, we developed an advanced communication system in which the proposed model was used with SAKURA for enhancing group interaction and communication. This advanced system generates a lecturer´s eyeball movement on the basis of the proposed model by using only speech input. We used sensory evaluation in the experiments to determine the effects of the proposed model. The results showed that the system with the proposed model is effective in group interaction and communication.