Flying Wing UAV Research Articles

Attitude Control of Flying Wing UAV Based on Active Disturbance Rejection Control and Multi-Object Nonlinear Control Allocation

For the attitude control of flying wing UAV, need to consider the problems of model parameters perturbation and external disturbances, and resolve the special problems of redundant control surfaces and nonlinear control efficiency. The control problem of attitude tracking is investigated based on active disturbance rejection control (ADRC) and multi-object nonlinear control allocation. ESO are designed to estimate and compensate for disturbance. It can improve both the robustness and control performance of the control system. Control allocation make full use of the redundant control effectors to realize the integrated tradeoff multi-object control allocation under varying flight conditions and missions.

Flight Stability and Control of Tailless Lambda Unmanned Aircraft

Marques P. (2013). Flight stability and control of tailless lambda unmanned aircraft. International Journal of Unmanned Systems Engineering. 1(S2): 1-4. This paper illustrates the unique challenges with which Aerospace Engineers are presented in achieving dynamic stability and autonomous flight control in tailless lambda unmanned aircraft. The static margin in lambda configurations is short, making the aircraft unstable. To compensate for the short static margin, a priority in lambda UAV design is to obtain a small linear pitching moment. Negligible pitching moment is implemented using reflex camber airfoils that complement the longitudinal dihedral provided by combined wing sweep back and washout. The reflex airfoil permits a wider choice of wing planform and enhances control authority with minimum elevon deflection. Stability analysis shows that a lambda UCAV is longitudinally unstable in ground effect, in both the flaps extended and flaps retracted configurations. Vortical flow and asymmetrical vortex bursting unsteadiness in a rapidly maneuvering next generation near-lambda 1303 UCAV are responsible for unexpected changes in pitch, roll and yaw coefficients and illustrate the difficulty in maneuvering the UCAV beyond certain critical angles of attack. The primary mechanism of lateral-directional control in a W–shaped flying wing UAV is provided by drag rudders, however lateral-directional control in such aircraft requires a sophisticated on-board flight control system. © Marques Aviation Ltd – Press.