Comparison of three aeroelastic state-space modeling methods

Three methods used for aeroelastic state-space modeling are discussed in this paper. They are least square (LS) method, minimum-state (MS) method and fit state-space approximation (MA) method. The modeling characters of these methods are analyzed and summarized through two models, according to flutter and response of frequency respectively. In the research of rational function approximation methods (LS and MS methods) on aerodynamic forces, the effects of lag root are highly analyzed. The character of MA method is also discussed. Finally, the modeling effects and utilizing principles are compared integrally, which then could be considered as assistance to engineering applications. The simulation results indicate that the MS method, used conveniently, is the preferable one which can generate models with low order and appropriate accuracy. The model founded on MA method gives the best accuracy of response of frequency, as compared with that of the standard result.