Design and wind tunnel test of an advanced controller for aerial refueling docking

A sensitive and robust controller is one of the core technologies for efficient and safe aerial docking. This study focuses on the rapid and precise docking control of a refueling system under complex airflow disturbances. A high-fidelity model of the system with gimbal composite hinge pairs is established. Building upon a controller composed of backstepping control and a sliding mode observer, the design incorporates considerations for embedded hardware transplantation factors, such as onboard models and filter design, thus realizing the design of an advanced aerial docking controller that is hardware-implementable. Finally, through ground simulation tests and wind tunnel flight tests, the dynamic response characteristics of the controller with onboard model dynamic feedback under the two types of test environments were comparatively analyzed. The results provide effective design references for the verification and development of similar advanced controllers. Furthermore, a comparative analysis of the response differences in docking characteristics between a Proportional-Integral (PI) controller and the advanced disturbance-rejection controller under wind tunnel test conditions was conducted. This analysis indicates the significant advantages of the advanced disturbance-rejection controller in accomplishing the aerial docking mission of the refueling system.