Intermittent Gliding Flight Control Design and Verification of a Morphing Unmanned Aerial Vehicle

The intermittent gliding flight method takes advantage of the updraft is adopted to increase the flight endurance time of a type of multifunctional morphing unmanned aerial vehicle (UAV). This type of UAV is able to be folded before launch, launch from a cylindrical launch tube, and adjust the wing span and sweep angle during flight. It has the advantages of convenient storage and transportation and can use the energy of the updraft. In order to effectively utilize the updraft, the mathematical model of updraft is established, and an updraft judging method is proposed. In order to complete the intermittent gliding flight, the flight progress is divided into two stages and a segmentation control law is proposed. During the intermittent gliding stage switching, the wing sweep angle and wing span length are varied to accommodate requirements of different stages. H-infinity robust control design method for gain scheduling based on linear parameter varying model is used to ensure the stability of the morphing UAV during the wings change. The mathematical simulation verifies the effectiveness of the morphing control algorithm. After that, a semi-physical simulation verification involving a mathematical UAV model with a physical wing changing mechanism, a physical embedded flight control module, the real flight attitude, and the virtual route are implemented. It has been verified that the morphing UAV can remain stable throughout the entire cycle of the intermittent gliding. Moreover, the intermittent gliding flight with updraft can reduce the fuel consumption of the morphing UAV and increase its flight endurance time.