Autonomous Landing Control of Fixed-wing UAVs: from Theory to Field Experiment

Abstract

This paper describes our work on autonomous landing control of fixed-wing unmanned aerial vehicles (UAVs). A hierarchical control structure is developed for autonomous landing of fixed-wing UAVs. In the hierarchical control structure, active disturbance rejection controllers are designed for attitude control. A proportional guidance law is proposed for height tracking. Other controllers, such as flight path angle controller, heading angle controller and taxiing controller, are designed using proportion integration differentiation technique. A test system is developed to validate the hierarchical structure and narrow the gap between the theory and practice. The test system includes an X-Plane based hardware-in-the-loop(HIL) simulation subsystem and a flight test subsystem. The interface and protocol between the autopilot and X-plane are designed same with that of the flight test platform. Consequently, the autopilot passed the validation in the HIL simulation can be directly moved on to the flight test platform. Finally, results of the HIL simulation and field experiment are presented to demonstrate the performance of the proposed approach and the entire test system.