Flight Flutter Modal Parameters Identification with Atmospheric Turbulence Excitation Based on Wavelet Transformation
In view of the feature of flight flutter test data with atmospheric turbulence excitation, a method which combines wavelet transformation with random decrement technique for identifying flight flutter modal parameters is presented. This approach firstly uses random decrement technique to gain free decays corresponding to the acceleration response of the structure to some non-zero initial conditions. Then the continuous Morlet wavelet transformation of the free decays is performed; and the Parseval formula and residue theorem are used to simplify the transformation. The maximal wavelet transformation coefficients in different scales are searched out by means of band-filtering characteristic of Morlet wavelet, and then the modal parameters are identified according to the relationships with maximal modulus and angle of the wavelet transform. In addition, the condition of modal uncoupling is discussed according to variation trend of flight flutter modal parameters in the flight flutter state. The analysis results of simulation and flight flutter test data show that this approach is not only simple, effective and feasible, but also having good noise immunity.
作 者： Zhang Bo Shi Zhongke Li Jianjun 作者单位： Zhang Bo,Shi Zhongke(Department of Automatic Control, Northwestern Polytechnical University, Xi'an 710072, China)Li Jianjun(The Engineering Institute, Air Force Engineering University, Xi'an 710038, China)
刊 名： 中国航空学报（英文版） ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS 年，卷(期)： 2007 20(5) 分类号： V2 关键词： flight flutter modal parameters identification atmospheric turbulence excitation wavelet transformation random decrement technique acceleration response