Parsing natural language sentences into robot actions

In this paper we propose a Natural Language Processing engine that allows the NAO humanoid robot to execute natural language actions spoken by the user. To this aim we created an ontology that describes body parts, actions, and incompatibilities between actions. The system can work in two modes: stateless and stateful. In stateless mode, the robot returns to its default position after each action. In stateful mode, it performs the actions sequentially and may refuse a command if incompatible with the robot current state. Our system handles compound and multiple expressions that the robot understands and performs.