Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filt...Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filtering methodology is proposed. Firstly, fractional differencing （FD） method is introduced to trans-form fractal noise into fractional white noise based on the estima-tion of Hurst exponent for long-term dependent fractal process, which together with the existing white noise make up of a gener-alized white noise. Further, an improved denoising algorithm of wavelet maxima is developed to suppress the generalized white noise. Experimental results show that the basic noise terms of FOG greatly decrease, and especially the slow drift is restrained effectively. The proposed methodology provides a promising ap-proach for filtering long-term dependent fractal noise.展开更多
A novel all-digital scheme for open-loop fiber-optic gyroscope (POG), where only two key points of output wave were digitized directly, has been proposed. A control equation, with which the modulation depth of PZT mod...A novel all-digital scheme for open-loop fiber-optic gyroscope (POG), where only two key points of output wave were digitized directly, has been proposed. A control equation, with which the modulation depth of PZT modulator is stable when setting the modulation depth as 4.35 and a calculation equation, with which the Sagnac phase can be worked out, are derived. A modulation depth control and an automatic correlation sampling and a gain control technology were induced. A photo-type FOG was made and tested. The good performance was achieved.展开更多
针对光纤陀螺热致漂移补偿问题,提出一种整体式三轴耦合线性多变量光纤陀螺捷联惯组系统热致漂移补偿模型,该模型由温度梯度、温度和温度二次方多项式组成。根据模型线性特性,采用最小二乘法确定模型参数。进行实验采集漂移数据进行模...针对光纤陀螺热致漂移补偿问题,提出一种整体式三轴耦合线性多变量光纤陀螺捷联惯组系统热致漂移补偿模型,该模型由温度梯度、温度和温度二次方多项式组成。根据模型线性特性,采用最小二乘法确定模型参数。进行实验采集漂移数据进行模型验证,为提高参数辨识精度,提出了一种滑窗MAD(sliding window median absolute deviation,SWMAD)法以剔除野值点,引入梯度倒数加权滤波器(gradient inverse weighted,GIW)对数据进行预处理,处理后的数据通过奇异值分解(singular value decomposi-tion,SVD)进行降噪。补偿结果表明,提出的三轴耦合线性多变量模型能有效补偿系统的热致漂移,并能提高系统精度。展开更多
基金supported by Aviation Science Foundation(20070851011).
文摘Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filtering methodology is proposed. Firstly, fractional differencing （FD） method is introduced to trans-form fractal noise into fractional white noise based on the estima-tion of Hurst exponent for long-term dependent fractal process, which together with the existing white noise make up of a gener-alized white noise. Further, an improved denoising algorithm of wavelet maxima is developed to suppress the generalized white noise. Experimental results show that the basic noise terms of FOG greatly decrease, and especially the slow drift is restrained effectively. The proposed methodology provides a promising ap-proach for filtering long-term dependent fractal noise.
文摘A novel all-digital scheme for open-loop fiber-optic gyroscope (POG), where only two key points of output wave were digitized directly, has been proposed. A control equation, with which the modulation depth of PZT modulator is stable when setting the modulation depth as 4.35 and a calculation equation, with which the Sagnac phase can be worked out, are derived. A modulation depth control and an automatic correlation sampling and a gain control technology were induced. A photo-type FOG was made and tested. The good performance was achieved.
文摘针对光纤陀螺热致漂移补偿问题,提出一种整体式三轴耦合线性多变量光纤陀螺捷联惯组系统热致漂移补偿模型,该模型由温度梯度、温度和温度二次方多项式组成。根据模型线性特性,采用最小二乘法确定模型参数。进行实验采集漂移数据进行模型验证,为提高参数辨识精度,提出了一种滑窗MAD(sliding window median absolute deviation,SWMAD)法以剔除野值点,引入梯度倒数加权滤波器(gradient inverse weighted,GIW)对数据进行预处理,处理后的数据通过奇异值分解(singular value decomposi-tion,SVD)进行降噪。补偿结果表明,提出的三轴耦合线性多变量模型能有效补偿系统的热致漂移,并能提高系统精度。
