Development of a wireless pilot arm–wearable haptic interface for unmanned aerial vehicle wing deflection sensing

When the flight of an unmanned aerial vehicle is controlled by a ground pilot, a wing deflection monitoring is required to avoid overload wing structural failures. Therefore, integrated structural health monitoring technologies are being developed to transfer such information to the pilot. In general, this information can be monitored visually by the ground pilot. In this study, a haptic interface enables human–machine communication through tactile sense and provides synchronized information exchange between a pilot and an unmanned aerial vehicle. In other words, we propose not a vision interface but a haptic interface to transfer the wing deflection information to the ground pilot; this interface is named “Fly-by-haptic,” which is beneficial because the vision of the ground pilot is already performing multiple tasks. For a proof of concept, four integrated fiber Bragg grating sensors were installed on a half wing specimen to measure dynamic strains. The wing deflection information was estimated by the displacement–strain transformation matrix. The wing deflection information was wirelessly transferred to actuate vibro-haptic motors installed in a pilot arm–wearable haptic interface. Finally, a human test was performed using the developed haptic interface; the test results determined that the 15 participants, who are novices, showed 100% accuracy for wing deflection.