Abstract
This paper discusses the feasibility of a longitudinal and lateral direction integrated flight control system for UAV (Unmanned Aerial Vehicle). From the numerical simulation results, the UAV with the flight control system designed based on a longitudinal and lateral directions decoupled linearized model indicates strong cross-coupling effect between the motions in longitudinal and lateral directions as the angle of attack increases in rolling phase. Therefore it is desirable to design a flight control system considering the cross-coupling effect between the motions in longitudinal and lateral directions. In order to cross the coupling effect, a longitudinal and lateral direction integrated linearized model is designed and a robust control technique based on H_∞. control method is employed to design the longitudinal and lateral direction integrated flight control system. The designed flight control system is applied to the UAV and the performance is verified through the six-degree-of-freedom nonlinear simulation at high angle-of-attack in rolling phase. The designed flight control system demonstrates satisfactory performance that cannot be achieved by the controller designed in a decoupled manner.
