Low-order equivalent matching methods for aircraft with flying wings

The low-order equivalent methods are aimed at conventional aircraft. They are not suitable for aircraft with flying wings as a result of flying wings' new handing and stability characteristics. To improve the accuracy and success rate of low-order equivalent matching for aircraft with flying wings, the differences between aircraft with flying wings and conventional aircraft in aerodynamic characteristics, manipulation characteristics, and control system design, are analyzed, and then the research on low-order equivalent methods for aircraft with flying wings is undertaken. The influence of matching frequency range on matching result is obtained via frequency domain characteristic analysis. Square wave signal, 3211 signal, and chirp signal are widely used as input signals for low-order equivalent matching. Their applicability is tested in time domain responses and matching results, and the results show that the square wave signal is most suitable for aircraft with flying wings. The influence of signal strength on matching results is investigated via simulation and analysis. A joint-design method is proposed, in which both directional motions and lateral motions are included in lateral-directional motivating command design. The new method can improve success rate for lateral-directional low-order matching.