Vision-Based and Differential Global Positioning System to Ensure Precise Autonomous Landing of UAVs

This paper presents a precision landing system for unmanned aerial vehicles (UAVs). When designing the solution, we paid special attention to the required accuracy of the various sensors. The system comprises a highly accurate flight controller and a visual sensor for object detection or Real Time Kinematic (RTK) positioning module. The platform is constructed to integrate into various types of unmanned aerial vehicles. The method for the visual tracking of the landing platform via an optical camera enables us to increase the landing reliability. The precise position of the unmanned aerial vehicle at landing is provided by an image analysis where the specially designed landing platform is detected. All calculations for precision landing guidance are performed directly on board. An infrared (IR) camera is used as the main sensor for monitoring the IR light beam. This aircraft guidance technique does not necessitate data transfer to and from the landing station. More complex but expensive systems is RTK GPS (Real Time Kinematic Global Positioning System) which can be suitable solution to replace visual sensor. A hexacopter drone was used for the test flights, and the results obtained were then subjected to comparison. The navigation to the location was first tested by a GPS sensor only, subsequent tests flights, however, already relied on a visual sensor and RTK GPS module.