Bionic Visual Control for Probe-and-Drogue Autonomous Aerial Refueling

Abstract

The probe-and-drogue autonomous aerial refueling (AAR) docking suffers the multiwind disturbances leading to the low accuracy of receiver position control and drogue relative position estimation. This article proposes a bionic visual navigation control system in a hardware-in-loop simulation environment and further develops an AAR outfield experiment platform for promoting the success of probe-and-drogue AAR docking. The drogue region and markers are detected by the biological method imitating the eagle-eye color vision mechanism. The different visual navigation methods based on the ellipse fitting, marker matching, and marker prediction are, respectively, applied to the three possible situations in AAR docking for precise pose estimation. Moreover, a relative position control scheme of the receiver, which is constructed by back-stepping design technique and gain-adaptive equivalent sliding mode control, is proposed to compensate multi-wind disturbances and model uncertainties. Fuzzy logic position strategy is designed to compensate swing of the drogue caused by the multiwind disturbances. The AAR outfield experiment platform contains two unmanned aerial vehicles to verify a part of the proposed navigation control method. Extensive experimental results are presented to demonstrate the effectiveness of the bionic visual navigation control system for the high accuracy of the visual navigation and antidisturbance position control.