Designing For Robust Movement In A Child-Friendly Robot

Motion is a critical aspect of communication, required to create natural interactions between humans and robots. Robots for the classroom pose several constraints on motion, which make them challenging to design, including maintaining the safety of the child and the robot, responding in a timely fashion, and creating motions that are expressive and not scary. In this paper we present the mechanical design of a social robot and demonstrate that it is capable of safe motion within the proximity of children through analysis and empirical testing of the arms. The robot has a novel mechanical design for its two arms, which include torso-mounted, back-drivable, torque-limited stepper motors. The results suggest that our design succeeds at increasing safety levels while enabling the use of socially acceptable speeds of motion during the interaction. This study implies that the design of robotic agents for social interaction with children should consider the design of mechanical features that enable safe contact between the human and the robot while not limiting the robot to slow motions that would impair the timing of the interaction.