Vision-based hardware-in-the loop simulation test of vision-based net-recovery for fixed-wing unmanned aerial vehicles

For the operation of the small UAVs(Unmanned Aerial Vehicles), convenient landing system is required especially in a restricted environment. Since a net-recovery system does not require large area for landing, a vision-based net-recovery system is suitable for the autonomous landing of the small fixed-wing UAVs. In this study, HSV (Hue, Saturation, Value) colour model is used to detect a red recovery net for the improvement of the colour detection performance. Pure pursuit guidance law is used for a longitudinal guidance system, and the longitudinal guidance is provided by pitch angle commands. HILS (Hardware-In-the Loop Simulation) system has been developed for the vision-based net-recovery system. The visionbased HILS consists of a Flight Control Computer (FCC), vision system including camera and screen, and other equipments. Finally, vision-based HILS test is performed to verify the performance of the proposed UAV guidance law and the target acquisition of the camera.