Abstract:With a good time-frequency resolution, wavelet transforms have received a great consideration in the structural dynamic analysis. This work takes a wavelet-based approach to identifying the modal parameters of a certain type helicopter. An auto regression (AR) model in the wavelet domain is established by applying a continuous wavelet transform to the time-history responses of the fuselage. And Coiflets function is used as the mother wavelet. The coefficient matrices of the AR model, which parameterize the dynamic characteristics of the system, are calculated through the pseudo-inverse method. Modal parameters are further obtained by solving the eigenvalue matrix. The effects of wavelet transform scaling coefficient, shifting parameter and noise on the ability to accurately evaluate the modal parameters are investigated. Results comparison are carried out with finite element analysis and other methods, to show that the applied wavelet method is with high resolution and insensitive to noise, suitable for modal parameters identification of helicopters.
何绪飞;邓忠民;武晓东. 基于小波域AR 模型的直升机结构模态参数辨识[J]. , 2010, 29(9): 201-205.
HE Xufei;DENG Zhongmin;WU Xiaodong. Modal parameters identification of a helicopter based on AR modelsin the wavelet domain. , 2010, 29(9): 201-205.