Analysis of Asymmetric Control Efficiency for Folding Wing Morphing Aircraft

The purpose of this paper is studying the asymmetric morphing control efficiency of a folding wing morphing aircraft. Firstly, the nonlinear dynamic equations and aerodynamic model that can depict the full morphing process are derived. Then, an asymmetric morphing control model is proposed based on the asymmetric morphing control method. Finally, by comparing with the efficiency of conventional control and the dynamic response of simulation, we find the maximum effective interval of the asymmetric morphing control. The results show that the efficiency of asymmetric morphing control is higher at lower flight speeds, and the asymmetric morphing control can provide the highest roll handling efficiency near the reference folding angle of 90°. Introduction Morphing aircraft can initiatively change the aerodynamic configuration to expand the flight envelope and according to the different flight missions. The investigation shows that the asymmetric sweep is beneficial to maintaining sensor pointing the target despite crosswinds and be able to complete the mission planning more effectively.[1] Morphing wing aircraft can be more propitious to enhance the maneuverability and the agility than conventional aircraft through asymmetric morphing. In recent years, some investigations have been carried out on asymmetric morphing of various variant aircraft. Beaverstock C S et al investigated the influence on flight dynamics when the aircraft in the process of symmetric and asymmetric span morphing.[2] Yang G T studied the mechanism of asymmetric morphing to achieve roll control for low roll efficiency problem in lateral control of morphing aircraft with variable sweep and variable span.[3] Tong L studied the multi-body dynamic modeling and flight control of asymmetric variable sweep aircrafts.[4] Folding wing morphing aircraft have larger variants. Thus it is essential to carry out the investigation of the feasibility of improving the maneuverability and the agility by asymmetric morphing. Most investigations in recent years on dynamic modeling and control methods of this type variant aircraft are based on the symmetric morphing process.[5, 6] Obradovic B et al studied the aerodynamic load distribution in the asymmetric morphing process.[7] This paper studies asymmetric morphing control scheme and efficiency of asymmetric morphing control, defines and simplifies the asymmetric morphing control. By comparing asymmetric morphing control with conventional control surface and numerical simulation, the maximum effective range of asymmetric control is obtained. State Representations Geometry Configurations Taking a micro folding wing morphing aircraft as an example, two separate actuators allow the inner wings to rotate related to the axes which are parallel to the fuselage axis, modifying the dihedral angles up to 120° while the outer wings keep level (see Fig 1).