  This paper develops a methodology for collaborative human-robot exploration
that leverages implicit coordination. Most autonomous single- and multi-robot
exploration systems require a remote operator to provide explicit guidance to
the robotic team. Few works consider how to embed the human partner alongside
robots to provide guidance in the field. A remaining challenge for
collaborative human-robot exploration is efficient communication of goals from
the human to the robot. In this paper we develop a methodology that implicitly
communicates a region of interest from a helmet-mounted depth camera on the
human's head to the robot and an information gain-based exploration objective
that biases motion planning within the viewpoint provided by the human. The
result is an aerial system that safely accesses regions of interest that may
not be immediately viewable or reachable by the human. The approach is
evaluated in simulation and with hardware experiments in a motion capture
arena. Videos of the simulation and hardware experiments are available at:
https://youtu.be/7jgkBpVFIoE.
