LFT Modeling and Robust Stability Analysis of Missiles with Uncertain Parameters
HOU Zhen-qian and LIANG Xiao-geng / WANG Wen-zheng / LI Rui
International Journal of Aeronautical and Space Sicences, vol. 15, no. 2, pp.173-182, 2014
Abstract : The structured singular value (¥ì) analysis based method has many advantages for the robust stability analysis of missiles with uncertain parameters. Nevertheless, the present linear fractional transformation (LFT) modeling process, which is the basis of ¥ì analysis, is complex, and not suitable for automatic implementation; on the other hand, ¥ì analysis requires a large amount of computation, which is a burden for large-scale application. A constructive procedure, which is computationally more efficient, and which may lead to a lower order realization than existing algorithms, is proposed for LFT modeling. To reduce the calculation burden, an analysis method is developed, based on skew ¥ì. On this basis, calculation of the supremum of ¥ì over a fixed frequency range converts into a single skew ¥ì value calculation. Two algorithms are given, to calculate the upper and lower bounds of skew ¥ì, respectively. The validity of the proposed method is verified through robust stability analysis of a missile with real uncertain parameters.
Keyword : LFT, skew-¥ì, real-uncertain-parameters, robust-stability, missile |