| 振动信号谱估计的低频畸变 |
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| 引用本文： | 吴家驹.振动信号谱估计的低频畸变[J].宇航学报,1988(4). |
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| 作者姓名： | 吴家驹 |
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| 作者单位： | 北京强度与环境研究所 |
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| 摘 要： | 本文以航天运载器为例,分析了实测振动信号功率谱的低频畸变现象。指出用基于FFT的周期图方法对长度很短的样本作谱估计时,分辨率太低和数据窗不合适是低频畸变的主要原因。文中讨论了纠正低频畸变的方法,给出了消除低频畸变的实例,结果是令人满意的。 本文还提出了谱分析中“可信分析频带”的概念。认为一次(帧)分析中的上下限频率之比必须小于某个值;凡不满足上述条件的处理结果,低频段的功率谱密度值都是值得怀疑的。
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| 关 键 词： | 信号处理 谱分析 |
THE LOW FREQUENCY DISTORTION OF THE SPECTRAL ESTIMATION FOR VIBRATION SIGNAL |
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| Wu Jiaju.THE LOW FREQUENCY DISTORTION OF THE SPECTRAL ESTIMATION FOR VIBRATION SIGNAL[J].Journal of Astronautics,1988(4). |
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| Authors: | Wu Jiaju |
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| Institution: | Beijing Institute of Strength and Environmental Engineering |
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| Abstract: | Taking the aerospace vehicle for example, the low frequency distortion phenomenon of the spectral estimation for the measured vibration signal is analyzed. It is pointed that the low frequency distrotion is mainly factor from low resolution, short sample and inadequate window, when the spectral estimation is based on the periodgram of FFT algorithm. The method and example for correcting the low frequency distortion are presented. The result is satisfactory.A new concept related to spactral estimation, desired frequency band, is first presented. It is considered that the ratio of upper and lower limit frequency at one frame estimation must be less than a certain value. If not, the power spectral density is questionable. |
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| Keywords: | Signal processing spectral analysis |
| 本文献已被 CNKI 等数据库收录！ |
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