动态Allan方差的理论改进及其应用研究

Research on Theoretical Improvement of Dynamic Allan Variance and Its Application

动态Allan方差(DAVAR)法是一种分析非平稳性信号的有效工具,但在辨识噪声时存在功率泄漏和定量表示单一的缺陷。为此,提出窗函数组合法和噪声量值的二维表示法对其加以改进,用于分析和定量描述光纤陀螺动态误差中的各种噪声项。窗函数组合法在光纤陀螺动态误差分解的基础上采用矩形窗和汉宁窗分别对其中的中低频噪声和高频噪声进行分析。噪声量值的二维表示法即根据DAVAR原理得到噪声量值随采样点数目增加的变化规律。实验结果证明窗函数组合法可以满足不同频段噪声的辨识要求,减小功率泄漏;噪声量值的二维表示法可以准确地反映出动态误差中各噪声项的变化特征。

The dynamic Allan variance （DAVAR） is an effective method for analyzing non-stationary sxgnal. However, it has defects such as power leakage and single quantification in noise identification. Therefore, window function combination method and two-dimensional expression of noise value are introduced for their improvements. They are used for analysis and quantitative measurement of various noise terms in the fiber optic gyroscope dynamic error. Based on the dynamic error resolution of fiber optic gyroscope, rectangular window and Harming window are applied to analyze low and intermediate frequency noise and high-frequency noise, respectively. According to the principle of DAVAR, the noise variation laws with the numbers of sampling point are obtained, namely, the two- dimensional expression of noise value. The experimental results indicate that window function combination method satisfies the identification requirements of noise in different frequency ranges and reduces power leakages moreover, the changing characteristics of every noise item in the dynamic error are accurately reflected by the two-dimensional expression of noise value.