Playmate robots that can act according to a child´s mental state

We propose a playmate robot system that can play with a child. Unlike many therapeutic service robots, our proposed playmate system is implemented as a functionality of the domestic service robot with a high degree of freedom. This implies that the robot can play high-level games with children, i.e., beyond therapeutic play, using its physical features. The proposed system currently consists of ten play modules, including a chatbot with eye contact, card playing, and drawing. The algorithms of these modules are briefly discussed in this paper. To sustain the player´s interest in the system, we also propose an action-selection strategy based on a transition model of the child´s mental state. The robot can estimate the child´s state and select an appropriate action in the course of play. A portion of the proposed algorithms was implemented on a real robot platform, and experiments were carried out to design and evaluate the proposed system.