采用数字相位跟踪的光纤陀螺解调方案设计

干涉型光纤陀螺仪是一种基于Sagnac效应测量物体相对于惯性空间旋转角速度的光纤传感器。提出了一种采用数字相位跟踪的方式对光纤陀螺进行信号解调的方案,通过产生一个相位来跟踪旋转产生的Sagnac相移,从而解调出旋转角速度。数字相位跟踪采用坐标旋转数字计算机(CORDIC)算法实现,占用逻辑资源少且运算速度快。经过在光纤陀螺的数字信号处理系统中进行实验验证,设计的解调方案可以对200°/s以下的转速进行有效解调,标度因数非线性度为1200 ppm,零偏稳定性为0.027°/h。

Demodulation scheme for fiber-optic gyroscope based on digital phase tracking

Interferometric fiber-optic gyroscope (IFOG) is a kind of fiber-optic sensor which measures the rotational angular rate relative to the inertial frame based on Sagnac effect. A demodulation method based on digital phase tracking (DPT) is proposed for IFOG. The rotation-induced Sagnac phase shift is tracked by a generated phase to demodulate the rotational angular rate. The digital phase tracking is accomplished by coordinate rotation digital computer (CORDIC) algorithm that has less logical resource consumption and faster computing speed. After evaluation in the digital signal processing system of a fiber-optic gyroscope,this scheme is able to demodulate rotational angular rate less than 200 °/s and demonstrates a scale factor nonlinearity of 1200 ppm with bias stability of 0.027 °/h.