高精度光纤陀螺过采样技术分析与应用

数字闭环光纤陀螺中，采用AD转换器将模拟信号转换为数字信号，AD转换中的量化噪声将直接影响光纤陀螺的零漂指标。过采样是一种降低量化噪声的技术，过采样过程将噪声功率平均分布到以采样频率为截止频率的频带内，有效降低了直流到奈氏频率中的噪声功率。本文对高精度光纤陀螺中的噪声特征进行分析，针对高精度光纤陀螺中噪声低的特点，设计了适用于高精度光纤陀螺的过采样方案，为解决由于噪声低带来的均值误差，该方案在被测信号中叠加了正态分布的噪声。通过在陀螺中进行实验，证明设计的采样方案对于降低陀螺的零漂性能是有效的。

Theory Analysis and Application of Oversampling in FOG

In digital closed-loop fiber optic gyroscope, AD converter is used to translate analog input into digital signal. Quantization noise in AD conversion will influence bias stability of FOG. Oversampling is a kind of technology to reduce quantization noise. In this procedure noise power is distributed equably in the whole scale of direct current to sampling frequency, so the part of direct current to Nyquist frequency is reduced. In this paper, character of noise in high precision FOG is analyzed. According to the character of low noise in high precision FOG, oversampling method fit for high precision FOG is used. To solve average error come from low noise, white noise is add into the input signal. Through experiment in FOG, it is proved that this method of oversampling is effect to improve bias stability.