指数窗对阻尼识别的影响

Effect of Exponential Window on Damping Estimation

采用理论分析和数值模拟相结合的方法 ,考察了指数窗对阻尼估计的影响 ,探讨了脉冲响应加窗后的傅里叶变换特性 ,研究了窗截断对变换的影响 ,导出了阻尼比校正公式。研究结果表明 ,加指数窗对半功率点法估计的阻尼有显著影响 ,但对频率识别影响较小 ,所提出的阻尼比校正公式 ,能明显改善阻尼的估计精度。

Sampling truncation and adding exponent window to pulse resp on se(PR) are two important factors interfering the repeatability of damping measur ement. They were investigated by theoretical analysis and numerical simulation. The characteristics of Fourier transform of PR with exponent window were also di scussed, and rectification equation of damping estimation was deduced. The study results show that firstly, the precision of damping estimation is influenced by the exponent window significantly, but not of natural frequency, secondly, the damping rectification equation can improve precision of damping measurement high ly.