作者：李彦，王鹏跃
单位：北京航空航天大学仪器科学与光电工程学院，北京 100191
中图分类号：V19                
文献标识码：A                
文章编号：1006-883X(2020)11-0033-05
收稿日期：2020-10-09

摘要：随着卫星指向精度和分辨率水平的提高，卫星微小角振动受到了更多的重视。应用EMD和Hilbert谱分析结合的方法虽然可以得到微小角振动信号在任意时刻的时间-频率-能量的特征信息，但传统EMD方法存在端点效应与模态混叠问题，制约了算法的精度和应用范围。针对此问题，采用多项式拟合延拓与基于Hilbert特性的频谱搬移方法对EMD算法进行改进，减小了端点效应带来的误差，消除了信号包含相近频率分量时的模态混叠现象。利用单轴转台的微小转动模拟卫星上微振动状态，用光纤陀螺测量微小角振动信号，使用改进算法处理所得信号，验证了改进算法的优越性。
关键词：卫星微小角振动；改进经验模态分解算法；模态混叠；光纤陀螺

Analysis Method of Satellites Micro-angular Vibration Based on Improved EMD
LI Yan, WANG Peng-yue
School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China
Abstract: With the improvement of satellites pointing accuracy and resolution level, the satellites micro-angular vibration has received more attention. Although the combined method of EMD and Hilbert spectrum analysis can obtain the characteristic information of the time-frequency-energy of the micro-angular vibration signal at any time, the traditional EMD method has the problem of end effect and modal aliasing, which restricts the accuracy and application range of this algorithm. In order to solve this problem, the EMD algorithm is improved by polynomial fitting continuation and the spectrum shift method based on Hilbert characteristics, which reduces the error caused by the end effect  and eliminates the modal aliasing phenomenon when the signal contains similar frequency components. The micro-rotation of the single-axis turntable is used to simulate the micro-vibration state on the satellite, and the micro-angular vibration signal is measured by the fiber optic gyroscope. The improved algorithm is used to process the obtained angular vibration signal, which verified the superiority of the improved algorithm.
Key words: satellites micro-angular vibration; improved EMD; modal aliasing; fiber optic gyroscope

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备注：2020年 第26卷 第11期