一种衰减信号加窗频域插值算法  

Interpolation Algorithm for Discrete Fourier Transforms of Weighted Damped Sinusoidal Signals

作　　者：刁瑞朋[1] 孟庆丰[1] 

机构地区：[1]西安交通大学机械工程学院,西安710049

出　　处：《西安交通大学学报》2013年第7期85-90,共6页Journal of Xi'an Jiaotong University

基　　金：国家重点基础研究发展规划资助项目(2009CB724304);国家自然科学基金资助项目(51275380;51175049)

摘　　要：为了提高多频衰减正弦信号参数估计的精度,提出了一种加窗频域插值算法。先利用信号加窗技术对时域信号施加Hanning窗,然后利用频域插值方法计算出频率和衰减因子等参数值。结合Hanning窗和频域插值的方法,不仅可减小远程泄漏的影响,而且也消除了短程泄漏的影响,从而提高了对多频衰减正弦信号参数估计的精度。通过对算法的参数变化、噪声干扰和谱线分辨率的敏感性分析表明,即使在较强的噪声干扰和频谱泄漏下,算法依然具有较高的估计精度和稳定性,且计算效率高,内存占用低,因此较适合于对计算资源要求苛刻的信号特征提取场合,为机械冲击故障特征的提取提供了一种可选方法。An algorithm for improving the estimation accuracy of parameters that characterize a multi-frequency damped sinusoidal signals is presented,where the signals are weighted by Hanning window before the fast Fourier transform and the frequencies,amplitudes,phases and damped factors are obtained by frequency domain interpolation.The long-range and short-range leakages are thus reduced to improve the estimation accuracy.The sensitivity analysis for the varying signal parameters,noise and spectral resolution verifies the higher reliability and accuracy for both stronger noise and spectral interference cases.The higher computational efficiency and lower memory demand are suggested especially for poor computing resource situations.Extracting the impact signals of the rotor test bed using this method is illustrated.The result shows that the method can be used as an optional method for the fault features extraction of the mechanical impact.

关 键 词：衰减信号 频域插值 参数估计 频谱泄漏 

分 类 号：TN911.72[电子电信—通信与信息系统]