基于小波域AR 模型的直升机结构模态参数辨识

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振动与冲击 ›› 2010, Vol. 29 ›› Issue (9) : 201-205.

论文

基于小波域AR 模型的直升机结构模态参数辨识

何绪飞;邓忠民;武晓东

作者信息 +

Modal parameters identification of a helicopter based on AR modelsin the wavelet domain

HE Xufei; DENG Zhongmin;WU Xiaodong

Author information +

文章历史 +

摘要

小波变换具有良好的时频分辨率，在结构动特性参数辨识领域引起了广泛的关注。利用连续小波变换，
给出一种小波域的模态参数识别算法。对某型号直升机机身的时序响应进行分析，使用Coiflets小波基函数建立小波域的
自回归(AR)模型。模型系数决定了系统的动力学特性，利用伪逆法求解模型的特征矩阵，系统模态参数的辨识问题就转
化为求解特征矩阵的特征值和特征向量。讨论了小波变换尺度、时移参数及噪声对模态参数辨识精度的影响。将模态识
别结果分别与有限元分析及其它方法所得结果进行比较，表明文中所用小波变换方法分辨率高、抗干扰能力强，适用于
直升机结构的模态参数辨识。

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.

导出引用

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]. 振动与冲击, 2010, 29(9): 201-205

HE Xufei;DENG Zhongmin;WU Xiaodong. Modal parameters identification of a helicopter based on AR modelsin the wavelet domain[J]. Journal of Vibration and Shock, 2010, 29(9): 201-205