Increasing Acceptance of Haptic Feedback on UAV Teleoperations by Visualizing Force Fields

In tele-operating an UAV human operators fully rely on cameras to control the vehicle from a distance. To increase operator situation awareness and reduce workload, a haptic feedback on the control stick has been developed which acts as an automatic collision avoidance system. A virtual force field surrounding the moving vehicle interacts with obstacles surrounding it, yielding repulsive forces on the stick that lead the vehicle away from them. Albeit successful in significantly reducing the number of collisions, the haptic interface received low user acceptance ratings. Operators do not always fully understand the collision avoidance automation intentions, and they experience the haptic forces as intrusive. This paper discusses the development and testing of several visualizations of the underlying automation intentions, primarily the artificial force field. Results of a human-in-the-loop experiment show that these visualizations indeed led to higher user acceptance ratings, without affecting the operator’s safety, performance and workload.