Integrated Guidance and Control for Autonomous Rendezvous of Unmanned Aerial Vehicle during Aerial Refueling

The guidance law and the flight control system design problem for the unmanned aerial vehicle (UAV) in the autonomous rendezvous phase of aerial refueling have been studied in this paper. Firstly, according to the relative relationship between virtual tanker aircraft and UAV, the guidance law of UAV is designed by dividing terminal angle restriction and speed restriction. With respect to the terminal angle restriction guidance law, global fast terminal sliding mode control strategy is introduced to ensure that UAV can quickly track the virtual tanker aircraft in finite time. Then, the tracking angle obtained by the guidance law is converted to the desired attitude angle signal. Moreover, a double integration-based sliding mode control method is applied to design the UAV flight control scheme, and the radial basis function (RBF) neural network is used to estimate the uncertain terms of UAV. The designed double integral sliding mode method is capable of meticulous control for the UAV attitude, and make the attitude of the UAV reach the desired command signal in a limited time. Finally, the effectiveness of the designed control system is demonstrated by numerical simulations.