摘要
To reduce the drift error existing in the output signal of fiber optic gyroscopes （FOG）, a mathematical model of the FOG output signal is set up; the error characteristics of the FOG output signal are analyzed, and semi-soft threshold filtering is chosen based on the comparison of hard threshold and soft threshold filtering. The semi-soft threshold wavelet package filtering method is applied in the filtering of the FOG output signal. Experiments of the stationary and dynamic FOG output signals filtered with the wavelet package analysis are carried out in a lab environment, respectively. Experiments done with the real-time measured FOG signal show that the method of semi-soft threshold wavelet package filtering reduces the mean square error from 5 （°）/h to 1 （°）/h, so it is effective in eliminating the white noises and the fractal noises existing in the FOG. The novel method proposed here is proved valid in reducing the FOG drift error, satisfying the technical demands of high precision and realtime processing.
为了减小光纤陀螺仪输出信号中的漂移误差,对小波变换和小波包变换进行了理论分析和比较,建立了光纤陀螺仪输出信号的数学模型,分析了其输出信号的误差特性,在详细分析比较硬阈值和软阈值小波滤波的基础上,提出了采用半软阈值作为滤波阈值.并在实验室环境下分别对光纤陀螺静态和动态输出数据进行了半软阈值小波包滤波实验.对光纤陀螺实时测量信号的实验结果表明:采用半软阈值小波包滤波方法对光纤陀螺仪输出数据进行处理,静态和动态输出信号误差均方差可以从5(°) /h减少到1(°) /h,有效地消除了光纤陀螺仪中白噪声和分形噪声的影响.该方法比小波滤波方法更加有效地消除了光纤陀螺漂移误差的影响,且能够满足光纤陀螺仪输出高精度和实时处理的要求.
基金
Pre-Research Program of General Armament Departmentduring the11th Five-Year Plan Period(No.51309020503)
the National De-fense Basic Research Program of China(973 Program)(No.973-61334)
the National Natural Science Foundation of China(No.50575042)
Specialized Research Fund for the Doctoral Program of Higher Education ( No.20050286026).
