Precision landing control based on direct force for flying-wing carrier-based aircraft

The unique advantages of the flying-wing aircraft make it one of the future directions for advanced fighter development. However, in the landing control process, flying-wing aircraft with novel rudder configurations faces such challenges as the nonlinearity, redundancy and coupling of control surfaces, and interference from ship wakes of. To address these issues, this paper establishes a six-degree-of-freedom nonlinear mathematical model of tailless aircraft with multiple control surfaces and proposes a direct force control law based on the Incremental Nonlinear Dynamic Inversion (INDI) control framework. This proposed method designs a direct force trajectory control law, an attitude angle control law, and a speed maintenance control law using the nonlinear incremental dynamic inversion approach. Additionally, a Fixed-Time Disturbance Observer (FTDO) is designed to estimate and compensate for the coupling between the direct force control loop and the attitude control loop, achieving dynamic decoupling between the two loops. Considering various control surface characteristics and the execution capability of thrust vectoring, an integrated direct force control method combining aerodynamic control surfaces and thrust vectoring is designed. The nonlinear control allocation problem is transformed into an incremental linear control allocation problem using the aerodynamic coefficient Jacobian matrix, allowing for rapid online calculation of actual control surface deflection increments. Simulation verification shows that introducing direct force control based on incremental nonlinear dynamic inversion into the landing control law of flying-wing carrier-based aircraft can enhance the ability of such aircraft to quickly correct trajectories and suppress airwake, which ultimately, significantly improves the precision of aircraft landing and provides a solution for the deployment of flying-wing carrier-based aircraft.