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Identifier

000457008

Title

A dialogue system for human-robot interaction

Alternative Title

Ένα διαλογικό σύστημα ανθρώπου-ρομπότ

Author

Πρασατζάκης, Χριστόφορος Ζ.

Thesis advisor

Πλεξουσάκης, Δημήτριος

Reviewer

Αργυρός, Αντώνιος
Patkos, Theodore

Abstract

Human-machine interaction and communication is one of the “hottest” topics in Computer Science. As technological advancements are getting closer to the non-expert human, the need for implementing free-form verbal communication between a user and an intelligent system is becoming more important, due to its simplicity and naturalness of interaction. One method of human-computer communication appropriate for non-expert users is “robotic conversation agents”, the job of which is to engage in conversation with the human: the user asks questions in a natural language (e.g., English), and the chatbot answers the user’s question in the same natural language as the question itself. In this thesis, we designed a chatbot architecture (which we will call P-Chat), which uses the Event Calculus, a formal action language, in order to represent the chatbot’s knowledge. It relies on the Clingo reasoner, which implements ASP (Answer Set Programming) rules, in order to infer new knowledge about the robot’s world and about the agents inhabiting it, exploiting causal, temporal and epistemic reasoning. Our architecture is adaptable to diverse domains that require chatbots for human interaction with machines. It enables users to ask questions not only about the chatbot’s environment, but also about other agents’ beliefs (epistemic questions) or about retrospective events, thus enabling users to form a more complete picture about the world and the events that occur and modify it. Finally, when it comes to training our system, we present a rigorous training method, so that a question can be reused with different agents/objects/domains, reducing the cost of retraining from scratch for each individual query. We present the implementation of a dialogue system for the interactions between two agents – a human and a robot – which interact with other objects in the environment. All participating agents have partial observability of the world, therefore may possess incomplete or erroneous beliefs about the current world state or about the events that took place. The implemented system supports a wide variety of query types, ranging from polar to wh- questions, being either non-epistemic (i.e., about the state of the world), 1st order epistemic (i.e., about what the robot believes the state of the world may be), or 2nd order epistemic (i.e., about what the robot believes that other agents believe the state of the world is).

Language

English

Subject

Answer set programming

Chatbots

Clingo

Epistemic questions

Event calculus

Human-machine interaction

Knowledge reasoning

Επικοινωνία ανθρώπου-μηχανής

Επιστημική λογική