  Humans are highly skilled in communicating their intent for when and where a
handover would occur. However, even the state-of-the-art robotic
implementations for handovers typically lack of such communication skills. This
study investigates visualization of the robot's internal state and intent for
Human-to-Robot Handovers using Augmented Reality. Specifically, we explore the
use of visualized 3D models of the object and the robotic gripper to
communicate the robot's estimation of where the object is and the pose in which
the robot intends to grasp the object. We tested this design via a user study
with 16 participants, in which each participant handed over a cube-shaped
object to the robot 12 times. Results show communicating robot intent via
augmented reality substantially improves the perceived experience of the users
for handovers. Results also indicate that the effectiveness of augmented
reality is even more pronounced for the perceived safety and fluency of the
interaction when the robot makes errors in localizing the object.
