Uncertainty modeling and robust flight control of unmanned combat aerial vehicle

This paper focuses on the robust analysis of stability and performance of an unmanned combat aerial vehicle (UCAV) which suffers from aerodynamic parameter variation. Firstly, the Linear Fraction Transformation (LFT) based model is established by physical modeling method, upon this the sensitivities of uncertain parameters are investigated and the original model is appropriately simplified. After that, H_∞ and μ methods are used for synthesis of different output-based control laws. Finally, μ analysis is utilized to conduct robust analysis of stability and performance of the close-loop system. Time domain simulations demonstrate: 1) aerodynamic parameter variation is mainly responsible for the degradation of steady performance; 2) the system with μ controller is more robust than H_∞ controller and the requirements are well met even in the worst case.