In this paper we propose and experimentally validate a bilateral teleoperation framework where a group of UAVs are controlled over an unreliable network with typical intercontinental time delays and packet losses. This setting is meant to represent a realistic and challenging situation for the stability the bilateral closed-loop system.
In order to increase human telepresence, the system provides the operator with both a video stream coming from the onboard cameras mounted on the UAVs, and with a suitable haptic cue, generated by a force-feedback device, informative of the UAV tracking performance and presence of impediments on the remote site.

In addition to the theoretical background, we describe the hardware and software implementation of this intercontinental teleoperation: this is composed of a semi-autonomous group of multiple quadrotor UAVs, a 3-DOF haptic interface, and a network connection based on a VPN tunnel between Germany and South Korea. The whole software framework is based upon the Robotic Operating System (ROS) communication standard.