基于脉冲响应相关函数的模态辨识算法

Modal Identification Algorithm Based on Cross-correlation of Impulse Response

利用不同时刻系统测量噪声具有独立同分布的特点,对脉冲响应进行相关处理,可以提高信噪比。为解决传统的基于脉冲响应的模态辨识算法的辨识精度问题,用某点脉冲响应同参考点响应之间的相关函数代替该点的脉冲响应以形成基于脉冲响应相关函数的模态辨识算法,并从理论上证明脉冲响应相关函数算法的辨识精度优于传统的脉冲响应算法。通过对一个四自由度系统模态频率和阻尼比的仿真辨识,验证了脉冲响应相关函数辨识算法的有效性。

The signal-noise-ratio can be greatly improved after corresponding computations of impulse response performed. The cross-correlation related to a reference point was proposed to identify the structural modal parameters. Theoretical analysis and numerical examples indicate that the identification precision is significantly increased under the same noise condition by the use of the improved algorithm based on cross-correlation.