Three-axis coupled flight control law design forflying wing aircraft using eigenstructure assignment method  

作　　者：Lixin WANG Ning ZHANG Ting YUE Hailiang LIU Jianghui ZHU Xiaopeng JIA 

机构地区：[1]School of Aeronautics Science and Engineering,Beihang University,Beijing 100083,China [2]Chinese Flight Test Establishment,Xi’an 710089,China

出　　处：《Chinese Journal of Aeronautics》2020年第10期2510-2526,共17页中国航空学报（英文版）

基　　金：supported by the Fundamental Research Funds for the Central Universities of China(No.:YWF-19-BJ-J-322)。

摘　　要：Due to elimination of horizontal and vertical tails,flying wing aircraft has poor longitudinal and directional dynamic characteristics.In addition,flying wing aircraft uses drag rudders for yaw control,which tends to generate strong three-axis control coupling.To overcome these problems,a flight control law design method that couples the longitudinal axis with the lateraldirectional axes is proposed.First,the three-axis coupled control augmentation structure is specified.In the structure,a‘‘soft/hard"cross-connection method is developed for three-axis dynamic decoupling and longitudinal control response decoupling from the drag rudders;maneuvering turn angular rate estimation and subtraction are used in the yaw axis to improve the directional damping.Besides,feedforward control is adopted to improve the maneuverability and control decoupling performance.Then,detailed design methods for feedback and feedforward control parameters are established using eigenstructure assignment and model following technique.Finally,the proposed design method is evaluated and compared with conventional method by numeric simulations.The influences of control derivatives variation of drag rudders on the method are also analyzed.It is demonstrated that the method can effectively improve the dynamic characteristics of flying wing aircraft,especially the directional damping characteristics,and decouple the longitudinal responses from the drag rudders.

关 键 词：Drag rudder Eigenstructure assignment Flight control law Flying wing Three-axis coupled 

分 类 号：V249.1[航空宇航科学与技术—飞行器设计]