Research Of Unpowered Emergency Landing Control Technologies For Flying Wing UAV

UAV may encounter unexpected accidents caused by engine failure during the flight, designing the navigation and control strategy for the unpowered UAV, to ensure that the UAV can land safely back on the airport, is a critical technology in UAV flight control field. This paper takes a flying wing UAV as the research object, made a study on this issue which includes the judgement standard of whether to return to the airport when the UAV encountered engine failure, the navigation strategy and the landing route on returning back, and the control law for unpowered UAV. On the ground of the study, a set of navigation and control strategy for UAV’s unpowered landing is put forward, and the flight control law of unpowered landing on which RSLQR control method is applied is designed.First of all, the mathematical model of the object is established based on Newton’s classical mechanics theory, and the aircraft body characteristics are analyzed, including the aerodynamic performance, operational performance, maneuverability and modal characteristics, providing the basis of the control design for the object.Next, the trajectory of unpowered landing was researched, the process of unpowered landing is divided into four stages, and key points of each stage is described in detail, the navigation strategy and landing route are designed. The influence of altitude and heading of unpowered UAV to its ability of returning is analyzed based on its performance, and summed up a judgement standard to determine whether the aircraft has the ability of returning back and landing at the airport. The flight control law is designed,considering the the robustness requirements of unpowered flying wing UAV, on which RSLQR control method is applied.Finally, in order to validate the navigation strategy, landing route and the flight control law, simulation platform is constructed using MATLAB,and unpowered landing under typical condition, the model uncertainty condition, the initial state of uncertainty condition, and the wind disturbance condition are simulated. Results show that, the navigation and guidance strategy, the route of unpowered landing and the flight control law designed in this paper meet the unpowered landing requirements of the flying wing UAV.