The Articulated Head pays attention

摘要

The Articulated Head (AH) is an artistic installation that consists of a LCD monitor mounted on an industrial robot arm (Fanuc LR Mate 200iC) displaying the head of a virtual human. It was conceived as the next step in the evolution of Embodied Conversational Agents (ECAs) transcending virtual reality into the physical space shared with the human interlocutor. Recently an attention module has been added as part of a behavioural control system for non-verbal interaction between robot/ECA and human. Unstructured incoming perceptual information (currently originating from a custom acoustic localisation algorithm and a commercial people tracking software) is narrowed down to the most salient aspects allowing the generation of a single motor response. The requirements of the current task determine what salient means at any point in time, that is, the rules and associated thresholds and weights of the attention system are modified by the requirements of the current task while the task itself is specified by the central control system depending on the overall state of the AH with respect to the ongoing interaction. The attention system determines a single attended event using a winner-takes-all strategy and relays it to the central control system. It also directly generates a motor goal and forwards it to the motor system. The video shows how the robot's attention system drives its behaviour, (1) when there is no stimulus over an extended period of time, (2) when a person moves within its visual field, and (3) when a sudden loud auditory event attracts attention during an ongoing visually-based interaction (auditory-visual attention conflict). The subtitles are direct mappings from numeric descriptions of the central control system's internal states to slightly more entertaining English sentences.