过调制技术在光纤陀螺寻北中的应用

Application of over modulation technique in fiber optic gyroscope north-seeking

针对光纤陀螺的寻北精度受测量噪声限制的问题,提出采用过调制技术提高光纤陀螺寻北精度的方案.以4位置寻北方法为例进行的理论和数值仿真分析表明:光纤陀螺的寻北误差与随机游走系数成正比.降低光纤陀螺的随机游走系数(RWC)可以等比例提升其寻北精度.过调制技术通过选择最佳调制相位对光纤陀螺的信噪比进行优化,可以有效降低光纤陀螺的随机游走系数.进行过调制前、后光纤陀螺的寻北实验,结果表明:过调制后光纤陀螺的随机游走系数降低程度与寻北精度提升程度相当,均约为30%,符合理论分析和计算结果,说明采用过调制技术可以有效提高光纤陀螺的寻北精度.

The scheme of improving the north-seeking precision of fiber optic gyroscope（FOG）by over modulation technique was proposed in view of the problem that the north-seeking precision of FOG is limited by measurement noise.Take 4-position north-seeking method for example,the results of theoretical and numerical simulation analysis show that the FOG＇s north-seeking deviation is proportional to the random walking coefficient（RWC）.When the RWC decreases,the north-seeking precision of FOG can be promoted by equal proportion.The over modulation technique can optimize the signal-to-noise ratio of FOG by choosing the optimum modulation phase and can reduce the FOG＇s RWC effectively.North-seeking tests were carried out before and after over modulation,the results showed that after the over modulate,the reduction of RWC was about 30%and corresponded to the promotion of north-seeking precision.The results of tests conform to the theoretical analysis and calculation results,which illustrates that north-seeking precision of FOG can be effectively improved by the over modulation technique.