A ground-based multi-sensor system for autonomous landing of a fixed wing UAV

This paper presents a novel ground-based multi-sensor system for guidance and safe landing of a fixed-wing Unmanned Aerial Vehicle (UAV). Unlike with our previous works, this newly developed system is based on one Pan/Tilt Unit (PTU) with visible light camera laser pointer and Ultra-wideband (UWB) radar. To simplify the calibration process in the wide area, a DGPS-based calibration method was designed. As a compensation for camera, we integrated UWB radar module to achieve higher accuracy of localization and implemented laser pointer with retroreflector to enhance the target feature in the distance, which extends the detection range. Then, we used Canny edge detector and Hough transform to track the UAV in the air. Finally, several field experiments with small- and middle-size platforms demonstrate that our system has the ability to acquire the target from a long range and meet the requirements of robustness and real-time capability. Therefore, the proposed system is suitable to complement or replace the GNSS-based position estimation in situations where GNSS information is unavailable or inaccurate.