Ph.D Dissertation Defense: Crystal Chao

Title: Timing Multimodal Turn-Taking in Human-Robot Cooperative Activity

Date: Thursday, March 12, 2015
Time: 10:00 am - 12:00 pm
Location: Marcus Nanotechnology Bldg., Room 1117-1118

Dr. Andrea L. Thomaz (Advisor), School of Interactive Computing
Dr. Ronald C. Arkin, School of Interactive Computing
Dr. Henrik I. Christensen, School of Interactive Computing
Dr. Karen M. Feigh, School of Aerospace Engineering
Dr. Candace L. Sidner, Department of Computer Science, Worcester Polytechnic Institute


Turn-taking is a fundamental process that governs social interaction. When humans interact, they naturally take initiative and relinquish control to each other using verbal and nonverbal behavior in a coordinated manner. In contrast, existing approaches for controlling a robot's social behavior do not explicitly model turn-taking, resulting in interaction breakdowns in which the human is uncertain about when to act. They also lack generality, relying on scripted behavior control that must be designed for each new domain.

This thesis seeks to enable robots to cooperate fluently with humans by automatically controlling the timing of multimodal turn-taking. Based on our empirical studies of interaction phenomena, we develop a computational turn-taking model that accounts for multimodal information flow and resource usage in interaction. This model is implemented within a novel behavior generation architecture called CADENCE, the Control Architecture for the Dynamics of Embodied Natural Coordination and Engagement, that controls a robot's speech, gesture, gaze, and manipulation. CADENCE controls turn-taking using a timed Petri net (TPN) representation that integrates resource exchange, interruptible modality execution, and modeling of the human user. We demonstrate progressive developments of CADENCE through multiple domains of autonomous interaction encompassing situated dialogue and collaborative manipulation. We also iteratively evaluate improvements in the system using quantitative metrics of task success, fluency, and balance of control.