A 'companion' ECA with planning and activity modelling

In this paper, we describe the development of an Embodied Conversational Agent (ECA) implementing the concept of a companion, i.e. an agent supporting the persistent representation of user activities and dialogue-based communication with the user. This first experiment implements a Health and Fitness companion aimed at promoting a healthier lifestyle. The system operates by generating an 'ideal' plan of daily activities from background knowledge and dialogue interaction with the user. This plan then becomes an activity model, which will later be instantiated by reports from the user and analysed by the agent from the perspective of initial objectives. At various stages of the day, the plan can still be adapted through further dialogue. The agent is embodied using a wireless rabbit (Nabaztag™) device situated in the user's home. After describing the planning component, based on Hierarchical Task Networks (HTN) and the spoken dialogue system, we present a working example from the system illustrating its behaviour through various phases of user activity generation, updating and re-planning.