  We present an approach for visualizing mobile robots through an Augmented
Reality headset when there is no line-of-sight visibility between the robot and
the human. Three elements are visualized in Augmented Reality: 1) Robot's 3D
model to indicate its position, 2) An arrow emanating from the robot to
indicate its planned movement direction, and 3) A 2D grid to represent the
ground plane. We conduct a user study with 18 participants, in which each
participant are asked to retrieve objects, one at a time, from stations at the
two sides of a T-junction at the end of a hallway where a mobile robot is
roaming. The results show that visualizations improved the perceived safety and
efficiency of the task and led to participants being more comfortable with the
robot within their personal spaces. Furthermore, visualizing the motion intent
in addition to the robot model was found to be more effective than visualizing
the robot model alone. The proposed system can improve the safety of automated
warehouses by increasing the visibility and predictability of robots.
